The porosity, pore size distribution, and continuity dictate the  interaction of the biomaterials and transplanted cells with the host  tissue. Fibrovascular tissue will invade a device if the pores are  larger than approx 10 um, and the rate of invasion will increase with  the pore size and total porosity of a device (25,26). This process  results in the formation of a capillary network in the developing  tissue (26). Vascularization of the engineered tissue may be required  to meet the metabolic requirements of the tissue and to integrate it  with the surrounding host. In urologic applications, it may also be  desirable to have a nonporous luminal surface (e.g., to prevent leak-  age of urine from the tissue).   The direction that we have followed to engineer urologic tissue  involves the use of both synthetic (polyglycolic and/or poly-lactic acid  and alginate) and natural (bladder submucosa, intestinal submucosa,  peritoneum, and reconstituted collagen) biodegradable materials with  and without cells.    Urothelial and muscle cells can be expanded in vitro, seeded onto the  matrix, and allowed to attach and form sheets of cells. The cell-matrix  scaffold can then be implanted in vivo. We have performed a series of  in vivo urologic associated cell-matrix experiments. Histologic analysis  of human urothelial, bladder muscle, and composite urothelial and blad-  der muscle-matrix scaffolds, implanted in athymic mice and retrieved  at different time-points, indicated that viable cells were evident in all  three experimental groups (27,28).   Implanted cells oriented themselves spatially along the matrix sur-  faces. The cell populations appeared to expand from one layer to several  layers of thickness with progressive cell organization with extended  implantation times. The matrix alone evoked an angiogenic response by  5 d, which increased with time. Matrix degradation was evident after  20 d. An inflammatory response was also evident at 5 d, and its resolu-  tion correlated with the biodegradation sequence. Cell-matrix compos-  ite implants of urothelial and muscle cells retrieved at extended times  (50 d) showed extensive formation of multilayered sheet-like structures  and well-defined muscle layers. Matrices seeded with cells and manipu-  lated into a tubular configuration showed layers of muscle cells lining  the multilayered epithelial sheets. Cellular debris appeared reproduc-  ibly in the luminal spaces, suggesting that epithelial cells lining the  lumina are sloughed into the luminal space. Cell matrices implanted  with human bladder muscle cells alone showed almost complete replace-  ment of the polymer with sheets of smooth muscle at 50 d. This experiment  demonstrated, for the first time, that composite tissue engineered structures  could be created de novo. Prior to this study, only single-cell-type tissue  engineered structures had been created. The malleability of the synthetic  matrix allowed for the creation of cell-matrix implants manipulated into  preformed tubular configurations. The combination of both smooth muscle  and urothelial cell-matrix scaffolds is able to provide a template wherein a  functional ureter or urethra may be created de novo.   In the studies performed for tubularized structures, such as ureters  and urethras, if an entire segment was replaced, cells were needed in  order to prevent contracture. However, if the area replaced was small in  at least one of its dimensions, i.e., an onlay graft for urethral replace-  ment, the cells were not essential for adequate healing (29-31). A col-  lagen-based matrix has been used successfully for urethroplasty in  patients requiring re-do hypospadias repair (see Fig. 1) (31).    Fig. 1. Radiographic urethrogram of a patient with a reconstructed urethra  using a collagen matrix shows maintenance of a wide caliber without any  evidence of stricture.    In other sets of experiments, bladder tissue was engineered and used  for augmentation using similar techniques as aforementioned (32).  Partial cystectomies were performed in beagles. Both urothelial and  smooth muscle cells were harvested and expanded separately. Allo-  genic bladder submucosa obtained from sacrificed animals was seeded  with muscle cells on one side and urothelial cells on the opposite side.  All beagles underwent cruciate cystotomies on the bladder dome. Augmen-  tation cystoplasty was performed with the allogenic bladder submucosa  seeded with cells, and with the allogenic bladder submucosa without  cells. Bladders augmented with the allogenic bladder submucosa seeded  with cells showed a 99% increase in capacity compared to bladders  augmented with the cell-free allogenic bladder submucosa, which  showed only a 30% increase in capacity.    In all of the studies performed at our laboratory, whenever entire  segments of tissue were replaced, there was a difference evident between  matrices used with autologous cells and those used only as a regenerat-  ing scaffold. Matrix-cell composites retained most of their implanted  diameter, as opposed to matrix only, wherein graft contraction and  shrinkage occurred (33).   The results of all our prior studies showed that the creation of artifi-  cial bladders may be achieved in vivo, however, much work remained  to be done in terms of the functional parameters of these implants. In  order to address the functional parameters of tissue-engineered blad-  ders, an animal model was designed that required a subtotal cystectomy  with subsequent replacement with a tissue-engineered organ (34).   A total of 18 beagle dogs underwent a trigone-sparing cystectomy. The  animals were randomly assigned to one of three groups. Group A (n=6)  underwent closure of the trigone without a reconstructive procedure.  Group B (n=6) underwent reconstruction with a cell-free bladder-shaped  biodegradable polymer. Group C (n=6) underwent reconstruction using  a bladder shaped biodegradable polymer that delivered autologous  urothelial cells and smooth muscle cells. The cell populations had been  separately expanded from a previously harvested autologous bladder  biopsy. Preoperative and postoperative urodynamic and radiographic  studies were performed serially. Animals were sacrificed at 1, 2, 3, 4, 6,  and 11 mo postoperatively. Gross, histological, and immunocytochemi-  cal analyses were performed (34).   The cystectomy-only controls and polymer-only grafts maintained  average capacities of 24% and 46% of preoperative values, respectively.  An average bladder capacity of 95% of the original precystectomy vol-  ume was achieved in the tissue-engineered bladder replacements. The  subtotal cystectomy reservoirs that were not reconstructed and polymer-  only reconstructed bladders showed a marked decrease in bladder com-  pliance (10% and 42%). The compliance of the tissue engineered bladders  showed almost no difference from preoperative values that were mea-  sured when the native bladder was present (106%). Histologically, the  polymer-only bladders presented a pattern of normal urothelial cells with  a thickened fibrotic submucosa and a thin layer of muscle fibers. The  retrieved tissue-engineered bladders showed a normal cellular organiza-  tion, consisting of a trilayer of urothelium, submucosa, and muscle (Fig. 2).  Immunocytochemical analyses for desmin, a-actin, cytokeratin 7,  pancytokeratins AE1/AE3 and uroplakin III confirmed the muscle and  urothelial phenotype. S-100 staining indicated the presence of neural  structures. The results from this study showed that it is possible to tissue  engineer bladders that are anatomically and functionally normal.    Fig. 2. Histological analysis of canine bladders 6 mo after surgery. Hematoxy-  lin and eosin histological results (orig. magnif. X100) are shown for (A) blad-  der control; (B) the bladder dome of the cell-free polymer reconstructed bladder  showing extensive fibrosis, and (C) the bladder dome of the cell-seeded poly-  mer reconstructed bladder showing a normal architecture.    A large number of congenital and acquired abnormalities of the geni-  tourinary system, including ambiguous external genitalia, the extrophy-  epispadias complex and impotence, would benefit from the availability  of transplantable, autologous corpus cavernosum tissue for use in recon-  structive procedures. Given the major structural and functional impor-  tance of corpora cavernosal tissue, it is clear that the availability of  autologous corporal smooth muscle tissue for use in reconstructive pro-  cedures would be of great clinical utility, facilitating enhanced cosmetic  result, while providing the possibility of de novo, functional erectile  tissue.   Experiments performed in our laboratory were designed to determine the  feasibility of using cultured human corporal smooth muscle cells seeded  onto biodegradable matrix scaffolds for the formation of corpus cavernosum  muscle in vivo. Primary cultures of human corpus cavernosum smooth  muscle cells were derived from operative biopsies obtained during penile  prosthesis implantation and vaginal resection. Cells were maintained in  continuous multilayered cultures, seeded onto polymers of nonwoven  polyglycolic acid, and implanted subcutaneously in athymic mice. Ani-  mals were sacrificed at various time-points after surgery and the implants  were examined via histology, immunocytochemistry, and Western blot  analyses (35).    Corporal smooth muscle tissue was identified grossly and histologi-  cally at the time of sacrifice. Intact smooth muscle cell multilayers were  observed growing along the surface of the polymers throughout all  retrieved time-points. There was evidence of early vascular in-growth  at the periphery of the implants by 7 d. By 24 d, there was evidence of  polymer degradation. Smooth muscle phenotype was confirmed  immunocytochemically and by Western blot analyses with antibodies  to a-smooth muscle actin.   Further studies were performed wherein corpora cavernosal muscle  cells were co-cultured with endothelial cells. The co-cultured cells were  seeded on polymers and implanted in vivo. At retrieval, by 42 d, there was  tissue organization similar to normal corpora (36). These studies provided  the first evidence that cultured human corporal smooth muscle cells could  be used in conjunction with biodegradable polymer scaffolds to create  corpus cavernosum tissue de novo.   In the future, it could be foreseen that corpora cavernosal tissue could  be safely and easily obtained under local anesthesia in a percutaneous,  office-based procedure. Once harvested, this tissue could be used to estab-  lish explant cultures of autologous human corporal smooth muscle cells,  fibroblasts, and endothelial cells. These cells, after expansion in vitro,  could be seeded onto biodegradable polyglycolic acid polymer scaffolds  where they would attach and multiply. Once delivered to the in vivo  environment as an autograft in a reconstructive procedure, they might  reorganize and resume their highly specialized physiologic function.    Currently, the principal method of reconstructing a phallus when  insufficient tissue is present, is to utilize silicone rigid prostheses.  Although silicone penile prostheses has been an accepted treatment  modality since the 1970s, issues with biocompatibility remain (37).  Creation of a natural penile prostheses composed of vascularized auto-  logous tissue may be advantageous. We had previously demonstrated  that autologous chondrocytes suspended in biodegradable polymers  would form cartilage structures when implanted in vivo (38,39). We  recently investigated the possibility of creating a natural phallic pros-  thesis consisting of autologous chondrocytes, which, if biocompatible  and elastic, could be used in patients who require genital reconstruction.   Cartilage was harvested from the articular surface of calf shoulders.  Chondrocytes were isolated, grown, and expanded in vitro. The cells  were seeded onto preformed cylindrical polyglycolic acid polymer  rodsat a concentration of 50 x 106 chondrocytes/cm?. Cell-polymer  scaffolds were implanted in vivo. Each mouse had two implantation    sites consisting of a polymer scaffold seeded with chondrocytes and a  control (polymer alone). The engineered rods were retrieved at 1, 2, 4,  and 6 mo after implantation. Stress-relaxation studies to measure bio-  mechanical properties, including compression, tension, and bending,  were performed on the retrieved structures. Histological analyses were  performed with hematoxylin and eosin, aldehyde fuschin-alcian blue,  and toluidine blue staining (40).   Gross examination showed the presence of well-formed milky-white  rod-shaped solid cartilage structures which were approximately the same  size as the initial implant (see Fig. 3). A series of stress-relaxation tests  were performed in order to determine whether the engineered cartilage  rods possessed the mechanical properties required to maintain penile  rigidity. Biomechanical analyses of all specimens demonstrated similar  patterns. The compression studies showed that the retrieved cartilage  rods were able to withstand high degrees of pressure. A ramp compres-  sion speed of 200 um/s, applied to each cartilage rod up to 2000 um in  distance, resulted in 3.8 kg of resistance. The tension relaxation studies  demonstrated that the retrieved cartilage rods were able to withstand  stress and were able to return to their initial state while maintaining their  biomechanical properties. A ramp-tension speed of 200 um/s applied to  each cartilage rod created a tensile strength of 2.2 kg, which physically  lengthened the rods an average of 0.48 cm. Relaxation of tension at the  same speed resulted in retraction of the cartilage rods to their initial state.  The five cycles of bending studies performed at two different speeds  showed that the engineered cartilage rods were durable, malleable, and  were able to retain their mechanical properties. None of the rods was  ruptured during the biomechanical stress relaxation studies, which    showed that the cartilage structures were readily elastic and could with-  stand high degrees of pressure. Histochemical analyses with hematoxy-  lin and eosin, aldehyde fuschin-alcian blue, and toluidine blue staining  demonstrated the presence of mature and well-formed chondrocytes in  all the implants. There was no evidence of cartilage formation in the  controls.   Inasubsequent study, autologous cartilage seeded rods were implanted  into rabbit corporas. The scaffolds were able to form cartilage rods in  vivo, in the corpora. The engineered penile prostheses were stable, with-  out any evidence of infection or erosion (4/).   These preliminary studies indicate that creation of a penile prosthesis  composed of chondrocytes can be achieved using biodegradable poly-  mer scaffolds as a cell-delivery vehicle. The engineered tissue forms a  cartilaginous structure that resists high pressures. The use of an autolo-  gous system would preclude an immunologic reaction. This technology  could be useful in the future for the creation of a biocompatible mal-  leable prosthesis for patients undergoing penile reconstruction.    End-stage renal failure is a devastating disease that involves multiple  organs in affected individuals. Although dialysis can prolong survival  for many patients with end-stage renal disease, only renal transplanta-  tion can currently restore normal function. Renal transplantation is  severely limited by a critical donor shortage. Augmentation of either  isolated or total renal function with kidney cell expansion in vitro and  subsequent autologous transplantation may be a feasible solution. How-  ever, kidney reconstitution using tissue-engineering techniques is a  challenging task. The kidney is responsible not only for urine excretion,  but for several other important metabolic functions in which critical  kidney byproducts, such as renin, erythropoietin, and vitamin D, play a  large role. We explored the possibility of harvesting and expanding  renal cells in vitro and implanting them in vivo in a three-dimensional  organization in order to achieve a functional artificial renal unit wherein  urine production could be achieved (42,43). Studies demonstrated that  renal cells can be successfully harvested, expanded in culture, and trans-  planted in vivo where the single suspended cells form and organize into  functional renal structures that are able to excrete high levels of uric acid  and creatinine through a yellow urine-like fluid. These findings suggest  that this system may be able to replace transplantation in patients with  end-stage failure.   Other approaches have also been pursued for renal functional replace-  ment. Polysulphone hollow fibers have been prelined with various extra-    cellular matrix (ECM) components and seeded with mammalian renal  tubular and endothelial cells (44). Permselective convective fluid trans-  fer and active transport of salt and water were demonstrated. Using this  approach, prototypic biohybrid constructs have been developed that are  able to replicate the renal excretory functions. In addition, this system  is able to facilitate gene and cell therapies by modifying the cells prior  to seeding.    Both urinary incontinence and vesicoureteral reflux are common  conditions affecting the genitourinary system, wherein injectable bulk-  ing agents can be used for treatment. There are definite advantages in  treating urinary incontinence and vesicoureteral reflux endoscopically.  The method is simple and can be completed in less than 15 min, has a  low morbidity, and can be performed in an outpatient basis.   The goal of several investigators has been to find an ideal implant  material for the endoscopic treatment of reflux and incontinence. The  ideal substance should be injectable, nonantigenic, nonmigratory, vol-  ume stable, and safe for human use. Toward this goal, we had previously  conducted long-term studies to determine the effect of injectable  chondrocytes in vivo (38). We initially determined that alginate, a liquid  solution of gluronic and mannuronic acid, embedded with chondrocytes,  could serve as a synthetic substrate for the injectable delivery and main-  tenance of cartilage architecture in vivo. Alginate undergoes hydrolytic  biodegradation and its degradation time can be varied depending on the  concentration of each of the polysaccharides. The use of autologous  cartilage for the treatment of vesicoureteral reflux in humans would  satisfy all the requirements for an ideal injectable substance. A biopsy  of the ear could be easily and quickly performed, followed by chondro-  cyte processing, and endoscopic injection of the autologous chondro-  cyte suspension for the treatment reflux.   Chondrocytes can be readily grown and expanded in culture.  Neocartilage formation can be achieved in vitro and in vivo using  chondrocytes cultured on synthetic biodegradable polymers (38). In our  experiments, the cartilage matrix replaced the alginate as the polysac-  charide polymer underwent biodegradation. We then adapted the sys-  tem for the treatment of vesicoureteral reflux in a porcine model (39).   Six miniswine underwent bilateral creation of reflux. All six were  found to have bilateral reflux without evidence of obstruction at 3 mo  following the procedure. Chondrocytes were harvested from the left  auricular surface of each miniswine and expanded with a final concen-    tration of 50-150 x 10° viable cells/animal. The animals then underwent  endoscopic repair of reflux with the injectable autologous chondrocyte  solution on the right side only.   Cystoscopic and radiographic examinations were performed at 2, 4,  and 6 mo after treatment. Cystoscopic examinations showed a smooth  bladder wall. Cystograms showed no evidence of reflux on the treated  side and persistent reflux in the uncorrected control ureter in all animals.  All animals had a successful cure of reflux in the repaired ureter without  evidence of hydronephrosis on excretory urography. The harvested ears  had evidence of cartilage regrowth within one month of chondrocyte  retrieval.   At the time of sacrifice, gross examination of the bladder injection  site showed a well-defined rubbery-to-hard cartilage structure in the  subureteral region. Histologic examination of these specimens using  hematoxylin and eosin stains showed evidence of normal cartilage for-  mation The polymer gels were progressively replaced by cartilage with  increasing time. Aldehyde fuschin-alcian blue staining suggested the  presence of chondroitin sulfate. Microscopic analyses of the tissues  surrounding the injection site showed no inflammation. Tissue sections  from the bladder, ureters, lymph nodes, kidneys, lungs, liver, and spleen  showed no evidence of chondrocyte or alginate migration, or granuloma  formation.   Our studies showed that chondrocytes can be easily harvested and  combined with alginate in vitro, the suspension can be easily injected  cystoscopically and the elastic cartilage tissue formed is able to correct  vesicoureteral reflux without any evidence of obstruction (39).   Using the same line of reasoning as with the chondrocyte technology,  our group investigated the possibility of using autologous muscle cells  (45). In vivo experiments were conducted in minipigs and reflux was  successfully corrected.   The chondrocyte technology is currently being used in FDA-sanc-  tioned studies for in-patients with reflux and incontinence (see Fig. 4)  (46). In addition to its use for the endoscopic treatment of reflux and  urinary incontinence, the system of injectable autologous cells may also  be applicable for the treatment of other medical conditions, such as  rectal incontinence, dysphonia, plastic reconstruction, and wherever an  injectable permanent biocompatible material is needed.    Leydig cells are the major source of testosterone production in males.  Patients with testicular dysfunction require androgen replacement for  somatic development. Conventional treatment for testicular dysfunction    Fig. 4. (Top) Preoperative VCUG in a patient shows bilateral vesicoureteral  reflux. (Bottom) Postoperative radionuclide cystogram after endoscopic treat-    consists of periodic intramuscular (im) injections of chemically modified  testosterone, or more recently, of skin patch applications. However,  long-term nonpulsatile testosterone therapy is not optimal and can cause  multiple problems, including erythropoiesis and bone density changes.  The possibility of using leydig cell microencapsulation for controlled  testosterone replacement was evaluated (47). Microencapsulated leydig  cells may offer several advantages, such as serving as a semipermeable  barrier between the transplanted cells and the host’s immune system, as  well as allowing for the long-term physiological release of testosterone.   Purified leydig cells from rat testes were prepared on a Percoll gra-  dient. Cell viability and identification was performed by Trypan blue  and 3b-hydroxysteroid dehydrogenase (3b-HSD), respectively. Leydig  cells were suspended in 1.2% sodium alginate solution and extruded  through an air-jet nozzle into a 1.5% CaCl, solution were they gelled, and  were further coated with 0.1% poly-L-lysine. The encapsulated cells were  pulsed with human chorionic gonadotropin (hCG) every 24h. The medium  was sampled at different time-points after hCG stimulation and analyzed  for testosterone production. MTT assay was performed every day toensure  cell viability. Control experiments were performed using nonencapsulated  purified leydig cells under the same conditions (47).   More then 90% of the cells recovered from the Percoll gradient stained  positively for 3b-HSD. Both Trypan blue exclusion and MTT assays  showed that 95% of the cells were viable. Biochemical measurements,  which were performed every 4 h, showed that the microencapsulated  leydig cells produced testosterone. Testosterone levels in the presence  of hCG ranged between 35-60 ng/dL/10(6)/24 h. Testosterone levels  measured from nonencapsulated leydig cells ranged between 45-50 ng/  dL/10(6)/24 h.   Microencapsulated leydig cells are viable and are able to produce  high levels of testosterone. The microencapsulation system renders the  cells nonimmunogenic. These studies suggest that microencapsulated  leydig cells may be able to replace or supplement testosterone in situ-  ations were anorchia or testicular failure is present.    The prenatal diagnosis of patients with bladder disease is now more  prevalent. Prenatal ultrasonography allows for a thorough survey of  fetal anatomy. The absence of bladder filling, amass of echogenic tissue  on the lower abdominal wall, or a low set umbilicus during prenatal  sonographic examination may suggest the diagnosis of bladder exstro-  phy. These findings and the presence of intraluminal intestinal calcifi-  cations suggest the presence of a cloacal malformation.    The natural consequence of the evolution in prenatal diagnosis led to  the use of intervention before birth to reverse potentially life-threatening  processes. However, the concept of prenatal intervention itself is not  limited to this narrow group of indications. A prenatal, rather than a  postnatal, diagnosis of exstrophy may be beneficial under certain cir-  cumstances. There is now a renewed interest in performing a single-  stage reconstruction in some patients with bladder exstrophy. Limiting  factors for following a single- or multiple-stage approach may include  the findings of a small, fibrotic bladder patch without either elasticity or  contractility, or a hypoplastic bladder.   There are several strategies that may be pursued, using today’s tech-  nological and scientific advances, which may facilitate the future pre-  natal management of patients with bladder disease. Having a ready  supply of urologic-associated tissue for surgical reconstruction at birth  may be advantageous. Theoretically, once the diagnosis of bladder  exstrophy is confirmed prenatally, a small bladder and skin biopsy could  be obtained via ultrasound guidance. These biopsy materials could then  be processed and the different cell types expanded in vitro. Using tissue-  engineering techniques developed at our center and described previ-  ously, reconstituted bladder and skin structures in vitro could then be  readily available at the time of birth for a one-stage reconstruction,  allowing for an adequate anatomic and functional closure .   Toward this end, we conducted a series of experiments using fetal  lambs. (48,49). Bladder exstrophy was created surgically in 10 90-95-d  gestation fetal lambs. The lambs were randomly divided into two groups  of five. In Group I, a small fetal bladder specimen was harvested via  fetoscopy. The bladder specimen was separated and muscle and  urothelial cells were harvested and expanded separately under sterile  conditions in a humidified 5% CO, chamber, as previously described.  Seven to ten days prior to delivery, the expanded bladder muscle cells  were seeded on one side and the urothelial cells on the opposite side of  a 20-cm? biodegradable polyglycolic acid polymer scaffold. After  delivery, all lambs in Group I had surgical closure of their bladder using  the tissue engineered bladder tissue. No fetal bladder harvest was per-  formed in the Group II lambs, and bladder exstrophy closure was per-  formed using only the native bladder. Cystograms were performed 3  and 8 wk after surgery. The engineered bladders were more compliant  (p=0.01) and had a higher capacity (p=0.02) than the native bladder  closure group. Histologic analysis of the engineered tissue showed a  normal histological pattern, indistinguishable from native bladder at  2 mo (42). Similar prenatal studies were performed in lambs, engineer-  ing skin for reconstruction at birth (49).    These studies show that the potential for replicating this technology  in humans is possible. Other tissues, such as cartilage, corpora  cavernosa, and skeletal muscle can also be harvested and expanded in  the same manner. Similar studies addressing these tissues are now in  progress in our laboratory.   In addition to being able to manage the bladder exstrophy complex in  utero with tissue-engineering techniques, one could also manage patients  after birth in a similar manner, whenever a prenatal diagnosis is not  assured. In these instances, bladder tissue biopsies could be obtained at  the time of the initial surgery. Different tissues could be harvested and  stored for future reconstruction, if necessary. A tissue bank for exstrophy  complex patients could preserve different cell types indefinitely.   In addition to having an exstrophy complex tissue bank serve as a reposi-  tory of cells for future tissue reconstitution, it could also serve as a resource  to elucidate the cellular, molecular, and genetic mechanisms required for the  development and future prevention of these anomalies.    Based on the feasibility of tissue-engineering techniques in which  cells seeded on biodegradable polymer scaffolds form tissue when  implanted in vivo, the possibility was explored of developing a neo-  organ system for in vivo gene therapy (50).   In a series of studies conducted in our laboratory, human urothelial  cells were harvested, expanded in vitro, and seeded on biodegradable  polymer scaffolds. The cell-polymer complex was then transfected with  PGL3-luc, pCMV-luc, and pCMV§-gal promoter-reporter gene con-  structs. The transfected cell-polymer scaffolds were then implanted in  vivo and the engineered tissues were retrieved at different time-points  after implantation. Results indicated that successful gene transfer could  be achieved using biodegradable polymer scaffolds as a urothelial cell-  delivery vehicle. The transfected cell/polymer scaffold formed organ-  like structures with functional expression of the transfected genes (50).   This technology is applicable throughout the spectrum of diseases  that may be manageable with tissue engineering. For example, one can  envision the use of effecting in vivo gene delivery through the ex vivo  transfection of tissue engineered cell/polymer scaffolds for the genetic  modification of diseased corporal smooth muscle cells harvested from  impotent patients. Studies of human corpus cavernosum smooth muscle  cells have suggested that cellular overproduction of the cytokine, trans-  forming growth factor- 1 (TGF-1) may lead to the synthesis and accumu-  lation of excess collagen in patients with arterial insufficiency resulting  in corporal fibrosis. Prostaglandin E1 (PGE1) was shown to suppress    this effect in vitro. 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Chen F, Yoo J, Atala A (1999) Acellular collagen matrix as a possible “off the  shelf” biomaterial for urethral repair. Urology 54:1.   Atala A, Guzman LF, Retik AB (1999) A novel inert collagen matrix for hypos-  padias repair. J Urol 162:1148-1151.   Yoo JJ, Meng J, Oberpenning F, Atala A (1998) Bladder augmentation using  allogenic bladder submucosa seeded with cells. Urology 51:221.   Atala A (1999) Creation of bladder tissue in vitro and in vivo: a system for organ  replacement. In: Baskin, Hayward, eds, Advances in Bladder Research. New  York: Kluwer Academic/Plenum, pp. 31—42.   Oberpenning F, Meng J, Yoo JJ, Atala A (1999) Bladder replacement with  tissue-engineered neo-organs. Nature Biotechnology 17:149.   Kershen RT, Yoo JJ, Moreland RB, Krane RJ, Atala A (1998) Novel system for  the formation of human corpus cavernosum smooth muscle tissue in vivo. J Urol  159:156(suppl).   Park HJ, Yoo JJ, Kershen R, Atala A (1999) Reconstitution of corporal tissue  using human cavernosal smooth muscle and endothelial cells. J Urol 162:1106.  Nukui F, Okamoto S, Nagata M, Kurokawa J, Fukui J (1997) Complications and  reimplantation of penile implants. Int J Urol 4:52.   Atala A, Cima LG, Kim W, Paige KT, Vacanti JP, Retik AB, Vacanti CA (1993)  Injectable alginate seeded with chondrocytes as a potential treatment for  vesicoureteral reflux. J Urol 150:745.    . Atala A, Kim W, Paige KT, Vacanti CA, Retik AB (1994) Endoscopic treatment  of vesicoureteral reflux with chondrocyte-alginate suspension. J Urol 152:641.  Yoo JJ, Lee I, Atala A (1998) Cartilage rods as a potential material for penile  reconstruction. J Urol 160:1164.   Yoo JJ, Park HJ, Lee I, Atala A (1999) Autologous engineered cartilage rods for  penile reconstruction. J Urol 162:1119-1121.   Atala A, Schlussel RN, Retik AB (1995) Renal cell growth in vivo after attach-  ment to biodegradable polymer scaffolds. J Urol 153:4(suppl).   Yoo J, Ashkar S, Atala A (1996) Creation of fuctional kidney structures with  excretion of urine-like fluid in vivo. Pediatrics 98S:605.   Humes HD, Buffington DA, MacKay SM, Funke AJ, Weitzel WF (1999)  Replacement of renal function in uremic animals with a tissue-engineered kid-  ney. Nature Biotechnol 17:451.   Cilento BG, Atala A (1995) Treatment of reflux and incontinence with autolo-  gous chrondrocytes and bladder muscle cells. Dialog Ped Urol 18:1.   Kershen R, Atala A (1999) New advances in injectable therapies for the treat-  ment of incontinence and vesicoureteral reflux. Reconstruct Urol 26:81.  Machlouf M, Boorjian S, Caffaratti J, Kershen R, Atala A (1999) Therapeutic  delivery of testosterone using microencapsulated leydig cells. J Urol 161:311.  Fauza DO, Fishman S, Mehegan K, Atala A (1998) Videofetoscopically assisted  fetal tissue engineering: bladder augmentation. J Ped Surg 33:7.   Fauza DO, Fishman S, Mehegan K, Atala A (1998) Videofetoscopically assisted  fetal tissue engineering: skin replacement. J Ped Surg 33:357.   Yoo JJ, Atala A (1997) A novel gene delivery system using urothelial tissue  engineered neo-organs. J Urol 158:1066.    Injectable materials have been sporadically used for the treatment of  urinary incontinence for many years. Solomon Berg, aurologist, reported,  at a meeting of the New England Section of the American Urological  Association in the late 1970s, that polytetrafluoroethylene paste could  be efficacious in the treatment of incontinence when injected into the  urethral wall in elderly women . The material, polytetrafluoro-  ethylene, had also been used by surgeons for the injection of the vocal  cords, when there was paralysis of one cord, to improve phonation as  they would later use collagen (2). Kaufman et al. (3) and Lewis et al.  (4) reported rather extensive experience with the use of polytetra-  fluoroethylene paste in males and in females with incontinence. Patient    The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    selection for the use of this injectable agent was not specifically described,  but Politano et al. continued to use the material and to report on efficacy  (5,6). Other workers were unable to duplicate precisely the results  reported by the Miami group (7—9). In addition, complications related  to use of this material began to be reported. Boykin et al. (710) described  complete urinary obstruction following periurethral polytetrafluoro-  ethylene therapy. Hanau et al. (77) described a large Teflon-filled cyst  as a complication of periurethral teflon therapy, which had to be evacu-  ated. Dewan and Fraundorfer (/2) reported migration of periurethral  polytetrafluoroethylene into the skin in a patient who had received the  material for urinary incontinence. This was associated with an intense  itching response. The material was identified in the skin by biopsy. At  the Mayo Clinic, Malizia et al. (/3) reported that polytetrafluoroethylene  particles, following periurethral injection in female dogs and male mon-  keys, migrated to pelvic lymph nodes and the lungs. The material was  identified by the Malizia group by X-ray microanalysis. The somewhat  unpredictable results, and the description of migration of the particles,  lead many workers to abandon polytetrafluoroethylene as a material for  bulking the urethra. However, Herschorn and Glazer (/4) reported a  new series with favorable results from teflon injection in women with  stress incontinence. Moreover, despite the fact that the material does  seem to migrate and to be taken up by regional and distant lymph nodes,  there are no reports of adverse effects in humans related to the material,  other than that reported by Dewan and Fraundorfer (/2).    Investigation of patients with stress incontinence, using video  urodynamics, led to the identification of various subtypes of urethral  dysfunction. Type III stress incontinence, probably the most important  variant, was characterized by an open nonfunctional vesical outlet on  video urodynamic studies when first identified (see Fig. 1) (715). The  incontinence associated with this abnormality of urethral function is  severe. Patients with this kind of incontinence fail standard suspension  procedures for stress incontinence (15—19).   Poor or absent function of the proximal urethral sphincter, or Type IH  stress incontinence, can be diagnosed by video urodynamic studies or  leak point pressure testing. In addition to the demonstration that this  occurs in some women with stress incontinence (20,21), video uro-  dynamic and other studies show that proximal urethral sphincter dys-  function occurs in males incontinent after radical or nonradical  prostatectomy, in most patients with myelodysplasia, in most persons    Fig. 1. Upright cystogram in a young woman with congenital absence of proxi-  mal sphincter function related to myelodysplasia. Note the leakage that occur-  red at an abdominal pressure of 16.    with sacral agenesis, and patients with peripheral neuropathy associated  with radical pelvic extirpative surgery on the rectum or uterus, and in  patients with T12 spinal cord injury (22—27). For these severe kinds of  incontinence, only asling, wrapping the urethra with fascia, an artificial  sphincter, or an injectable agent seems to work effectively (28-29).  However, a study of a series of young women with myelodysplasia    treated with sling procedures for congenital failure of the internal sphinc-  ter showed that the local increase in pressure beneath the sling, within the  urethral lumen, was actually small. Although the sling did effectively  prevent leakage of urine driven by abdominal pressure (30). Parentheti-  cally, children with myelodysplasia treated with the artificial urinary  sphincter placed at the bladder neck have a definite propensity to develop  upper tract deterioration; something not seen in patients treated by slings  (31). Upon investigation, the deterioration in upper tract function turned  out to be related to the greater efficacy of closure of the proximal urethra  brought about by the artificial sphincter when compared to the sling.  The artificial sphincter raised both the detrusor leak point pressure and the  abdominal leak point pressure, leading to back pressure effects on the  ureter. Although slings are somewhat less efficient overall, in terms of  restoration of complete continence, than the artificial sphincter, they are  not associated with upper urinary tract deterioration.   Shortliffe et al. (32) reported the first successful use of injectable  collagen material in women with severe stress incontinence. Although  the patients were greatly improved or cured as a result of the injection,  the effect of the material injected into the urethra was not discernable by  careful, painstaking urethral closing pressure measurements. The con-  cept that incontinence associated with a poorly functional proximal  urethra could be treated successfully if the urethra at, or very close to,  the bladder neck was simply closed or coapted emerged from this data,  and the earlier data in myelodysplastic children. The amount of com-  pressive force required appeared to be relatively low.    Despite the rationale for its use, the early clinical trials with collagen  resulted in less-than-impressive results. Injection of the material did  raise the abdominal leak point pressure, incontinence symptoms often  improved, but the effect was unfortunately, usually transient. At first it  was not appreciated that multiple injections were required for success,  and there was little knowledge about the proper selection of patients for  collagen injection therapy. Patients were often “selected” for collagen  treatment simply because they failed everything else. With experience,  results improved. However, results in women, in virtually any series, are  better than those reported for men. Thus Herschorn and Radomski (33)  reported a 71% dry rate at 1 yr and 46% dry rate at 3 yr without additional  collagen therapy. Faerber reported 83% of elderly women with Type I  incontinence dry at 10.3 mean mo after the last injection (34).   Richardson et al. (35) reported a group of women with intrinsic  sphincter dysfunction treated by collagen, with a mean follow-up of    46 mo; 83% of this group were cured, 5% greatly improved, and 17%  unchanged or worse. The median number of treatments was 2. The mean  increase in the leak point pressure in women who were cured or improved  was 65.4 cm/H,0O and in those who did not improve, the increase in leak  point pressure was only 14. In the initial experience with collagen, the  material was delivered by periurethral injection. Faerber et al. (36)  showed that for equivalent results, only half the amount of collagen was  needed when the material was injected transurethrally. Herschorn et al.  (37) used on average 12.7 mL of collagen in women and 51.8 mLinmen,  when the treatment was administered by the periurethral route.   Cespedes et al. (38), ina large series of men with incontinence related  to radical prostatectomy, used three or more injections spread over a  4- to 6-mo period and achieved a 70% dry or substantially improved  rate. The average amount of collagen used in these male patients was  30 mL. Cross et al. (39) used 9 mL of collagen on average and two  injections separated by 1 mo to achieve a 74% substantive improvement  rate in 139 women, using the transurethral route of injection. Cespedes  et al. (38) and Cross et al. (39) used a dedicated instrument for delivery  of collagen with a stable rigid needle. Despite this, the amounts required  in men are much higher than that required for women.    In an effort to improve results in males, Klutke et al. (40) described  a technique for antegrade injection of collagen. This necessitated per-  cutaneous access to the bladder and then visualization of the anasto-  motic ring from above through the bladder. The procedure was  associated with good results after one injection in early reports. A later  report by Klutke et al. (41) noted at a mean follow-up of 28 mo only,  10% of patients were cured and 35% improved. The mean total volume  of collagen injected was only 14.5 mL. Although this is a small series,  and the results reported are not quite equivalent to those with the tran-  surethral, conventional, injection the amount of collagen used is about  50% of that used in the traditional method.    Early results suggested a possible role for collagen in children (42,43),  but a lack of durability has led to the gradual abandonment of the agent  for treatment of incontinence, even though it is often effective in the  short term (44).    The fact that collagen was efficacious in the short term, but its dura-  bility questionable, led to efforts to develop a more stable, longer-lasting    material for bulking. Hidar et al. (45) reported the results of periurethral  injection of silicone microimplants in 25 women with intrinsic sphincter  dysfunction. The early success was 80%, but at 3 yr, only 60% were  improved. Bugel et al. (46) reported that 26% of men with postprosta-  tectomy incontinence related to both radical or nonradical prostatec-  tomy, were improved at 12 mo, but that was a decline from a 40%  improvement noted at 1 mo following the injection of the silicone  microimplant. Guys et al. (47) used Microplastique in children. At 16 mo,  mean follow-up 33% of the children were “dry.” All of these children  had spina bifida. These results are surprisingly close to those outcomes  reported for collagen in men, women, and children in many series,  including those by Smith et al., Yokoyama et al., Winters et al.,  O’ Connell et al., and Abosief et al. (45—5/). That leads to the conclusion  that it may be tissue factors that determine outcome here, rather than the  material injected.    This is a relatively recent development and consists of small spheri-  cal nonreactive carbon steel spheres in a gel vehicle. The injection pro-  cess is somewhat more difficult than with collagen and a slow injection  technique at low pressure is best. Use of the agent takes practice and the  agent has not been found very useful in men. Scarring of the urethra in  the area of the prostatic anastomosis after radical prostatectomy creates  a situation where the material is very difficult to inject. In women,  however, reasonable results have been reported and these appear to be  relatively durable. The number of published reports on carbon steel  particles is still very small.    In general, longer-lasting results will be seen in older women with  low Valsalva leak point pressure stress incontinence, and little or no  urethral mobility. Reports of short-term success in younger patients  with higher leak point pressures and urethral mobility exist, but collagen  cannot be considered the most durable or effective method for this kind  of incontinence in this age group. Upright video urodynamic studies are  the best way to investigate patients and to determine which patient may  or may not be acceptable for collagen; however, simple pelvic exami-  nation demonstrating a fixed urethra and stress leakage is also a reason-    able and accurate method. If this is combined with endoscopy to evalu-  ate the appearance of the bladder outlet and proximal urethra, a good  idea of the status of the urethra can be gained.    Incontinence after radical prostatectomy is associated with rigidity  and scarring of the area of the urethral-bladder anastomosis and the  short segment of urethra distal to that point, which leads to the external  sphincter proper (see Fig. 2). Injection into these areas is difficult because  the tissue is not very forgiving. Placement of the needle is not as difficult  as it is in women because the urethra is rigid and does not move away  from the needle (see Fig. 3). I like to inject collagen through the anas-  tomotic ring into the tissue just above, if possible. This tissue is softer  and takes the collagen better. The volitional sphincter is a pretty definite  landmark, and asking the patient to close and open his rectal sphincter  shows the operator where the volitional external sphincter is. It is the  urethra superior to this point that one needs to inject, but if this area is  very short and the anastomosis is close to or virtually on the upper edge  of the volitional sphincter, injection is usually futile. In some cases,  injection via the external sphincter into the short suprasphincter seg-  ment is possible. That means the needle entry point is in the main part  of the volitional sphincter. This, however, can be extremely painful.  Whether it is or not seems to be somewhat unpredictable. In general, we  use two syringes of collagen on each side in men and use the same lateral  position for the injection; never at 12:00 or 6:00 because the tissue there  is thin. We are prepared to do four to five injections, separated by  monthly intervals. If there is no change in symptoms after four injec-  tions, and we cannot demonstrate any change in the leak point pressure,  we stop the injections.   Complications of injections in males in the office include syncopal  episodles, possible allergic reactions, and/or urinary retention, although  uncommon. Syncopal episodes may occur following the procedure. This  often happens when a patient gets up and walks around. As such, they  are difficult to anticipate and we now have the patient stay on the treat-  ment table for 15—20 min following the injection procedure so this  simply does not occur. The plane of injection is submucosal, hence, an  atrophic on scared urethral lining may prejudice operative results. How-  ever, the area of the urethra in which the collagen or other material can  be injected for effect is short, beginning at the bladder outlet and ending  just above the midurethral high-pressure zone. The latter is the area of  the volitional sphincter. Injectable materials cannot be delivered in the  area of the volitional sphincter, very efficiently because the operator    Fig. 2. (A) Typical postprostatecomy incontinence. The radio-opaque maker is located  in the external sphincter, which functions normally. The area to be injected is superior  to the external sphincter in the area of the anastomosis. Note contrast leaked into the  bulbous urethra. (B) Leak point pressure testing in a patient with post prostatectomy  incontinence. Despite good function of the external sphincter leakage occurs at a pres-  sure of 80 cm. The effect of external sphincter activity is clear: the urethra is closed  there. but leakage occurs anyway. The injection should be done just at or just distal to  the anastomotic ring.    Fig. 3. Injection sequence starting upper left: showing a wide open anastomotic  ring. Lower left: detail of edema and poor tissue in the area. Upper right: partial  coaptation after 5 mL injection, and reasonable closure after 10 mL injected.    cannot visualize the urethral lumen well, nor can the needle depth be  controlled. The urethra superior to this area is the proper site for injec-  tion and is relatively easily visualized because it is often wide open. The  most effective instrument is a dedicated endoscope for the injection of  bulking agents. There are two or three such instruments. A stabilized  and rigid needle is best. In addition, the needle should move indepen-  dently of the instrument, either manually by moving the needle in and  out, or by clasping the needle in a working element with a Nesbitt-like  feature, so that itcan be moved with one finger (see Fig. 4). If the needle  is not locked to a sliding part of the instrument, two people are required  for the injection. This leads to problems as the operator can inadvert-  ently move the endoscope and displace the needle or change the align-  ment or angle of the needle during the injection process.    The Wolf instrument is what we use (see Fig. 3). Ithas a 30° lens. The  operator locates the bladder neck and moves the endoscope distally,  exposing 1.0-1.5 cm of the proximal urethra. The endoscope is then    Fig. 4. (A) Detail of the instrument that contains an independent apparatus to  move the injection needle. (B) Detail of needle at the tip of the instrument.    angled sharply to the left side of the urethra and the needle placed quickly  into the mucosa and then the submucosa. Once the mucosa is penetrated,  the instrument can be deangulated so that it is again parallel to the long  axis of the urethra and the needle advanced along the urethral wall  toward the bladder neck. We use for anesthesia 1% Xylocaine, about 0.2  mL is injected with a tuberculin syringe into the submucosal plane.  After that, the syringe is changed for acollagen syringe, and the material  is injected slowly. Both the local anesthetic and the collagen, when  injected, should cause swelling of the urethral mucosa toward the ure-  thral lumen. Usually 2.5 mL of collagen are injected in each side. At    12:00 and 6:00, the urethral tissue is relatively thin and it is hard to get  the collagen into the right plane, so injection in this area produces poor  coaptation of the lumen at those sites, which is why we tend to use the  3:00 and 9:00 position.   Patients are pretreated with antibiotics and are observed after the  procedure to he sure they are able to empty their bladder. Although  urinary retention is unusual, when it does occur it is transient. This does  not appear to be caused by the collagen itself, but perhaps is atemporary  effect of the local anesthetic.    The technique is similar, but there is no dedicated instrument, there-  fore changing syringes requires practice and two people. The injection  technique is very different from that of collagen, and local anesthesia  because it increases local tissue pressure, seems to interfere with the  injection process, creating untoward resistance. Thus, a 10-15 min  exposure of the urethra to Xylocaine jelly is preferable to the injection  of local anesthetic. The same landmarks are used, but the material must  be injected very slowly and very superficially. The needle should be  carefully controlled as to the depth that it enters the urethral wall. There  are marks on the needle to enable the operator to do so. About 0.5 cm  is the maximum that the needle should be advanced. Too much pressure  on the device during an injection leads to loss of the gel vehicle, the  carbon steel particles line up in the needle and block it, so that one can  no longer inject. In our limited experience, durasphere material is more  difficult to inject than collagen, but the durability, anecdotally, is better  than that of collagen.   2. Ford EN, Staskowski PA, Bless DM (1995) Antolgous collagen vocal cord  injection: a preliminary clinical study. Laryngoscope 105:944—948.   3. 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(1998) Comparsion of transurethral vs  periurethral collagen in women with intrinsic sphincter deficiency. Tech Urol  4:124-127.   Herschorn S, Radomski SB (1992) Early experience with ultraurethral collagen  injections for urinary incontinence J Urol 148:1797-1800.   Cespedes RD, Leng WW, McGuire EJ (1998) Collagen injection therapy for  past prostectomy incontinence. Urology 54:597-602.   Cross C, English SF, Cespedes RD, et al. (1998) A follow-up on transurethral  collagen injection therapy for urinary incontinence. J Urol 159:106-108.  Klutke CL, Nadlen RB, Tieman D, et al. (1999) Early results with antigrade  collagen injection for post radical prostatectomy stress urinary incontinence.  J Urol 156:1703-1706.   Klutke JJ, Subir C, Audriale C, et al. (1999) Long term results after anti grade  collagen injection for stress incontinence following radical retropubic prostate-  ctomy. Urology 53:974-977.   Chernoff A, Honowitz M, Comhs A, et al. (1997) Periurethral collagen for the  treatment of urinary incontinence in children. J Urol 157:2303-2305.  Leonard MP, Decter A, Mix LW, et al. (1996) Treatment of urinary incontinence  in children by endoscopically directed bladder neck injection of collagen. J Urol  156:637-640.   Sundaram CP, Reinherg Y, Aliabadi HA (1997) Failure to obtain durable results  with collagen implantation in children with urinary incontinence J Urol  157:2306—2307.   Hidar S, Attyaoui F, deLaval J (2000) Periurethral injection of silicone  microparticles in the treatment of sphincter deficiency urinary incontinence.  Progress in Urology 10:2 19-23.   Bugel H, Pfisterr C, Sibert L, et al. (1999) Intraurethral macroplastic injections  in the treatment of urinary incontinence after prostatic surgery. Prog Urol  9:1068-1076.   Guys IM, Simeoni Alias I, Fakhvu A, et al. (1999) Use of polydimethylsiloxane for  endoscopic treatment of urinary incontinence in children. J Urol 162:2133-2135.  Smith DN, Appell, RA, Rackley RN, et al. (1998) Collagen injection therapy for  post prostatectomy incontinence. J Urol 160:264—267.    Yokoyama E (1995) Contingen Bard Collagen implant: The Japanese experi-  ence. Intl J Urol 1:11-15.   Winters IC, Appell RA (1995) Periurethral injections of collagen in the treat-  ment of intrinsic sphincter deficiency in the female patient Urol./Clinics NA  22:673-678.   O’Connell HC, McGuire EJ, Abosief S, et al. (1995) Transurethral Collagen  Therapy in women. J Urol 154:1463-1465.   Abosief S, O’Connell HE, Usui A, et al. (1996) Collagen injection for intrinsic  sphincter deficiency in men. J Urol 155:10-13.    The injection of bulking agents within urology has primarily con-  fined itself to the urethra and the uretero—vesical junction. Since their  inception, the injection of these materials has demonstrated both thera-  peutic benefit with the advantages of being minimally invasive with  reductions in hospital stay, morbitity, and cost . From relatively  simple beginnings (2,3), there has been a significant increase in avail-  able materials, with many more undergoing clinical trial and investigation    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    (4). Their relative abundance along with the amount of research being  performed testifies to the fact that none of these agents are ideal (5). While  the search continues, today’s urologist has multiple choices regarding the  material that best fits their patient’s needs. Choosing which bulking agent  to use can depend upon the clinical setting, the surgeon’s training, and the  availability of materials and instruments. This chapter will detail the  multiple aspects involved with injection therapy including the patho-  physiology of urethral and uretero—vesical junction dysfunction, patient  evaluation, injection techniques, and postoperative care. Following is a  detailed comparison of injectable materials, including a review of pub-  lished results along with the ongoing research of newer agents.    Continence requires that the urethral transluminal pressure exceeds  that of the bladder. Multiple factors are responsible, with significant  differences between men and women. The female urethra measures  approx 3 cm in length, with its mucosal surface cushioned by the pliant  subepithelial tissue formed by the lamina propria and elastic connective  tissue. Surrounding this are the bladder neck smooth muscle fibers and  slow twitch striated rhabdosphincter, which are present along the proxi-  mal two-thirds of the urethra. This complex rests upon the anterior  vaginal wall, suspended along the arcus tendinius within the levator  musculature. Marked deficiencies in a significant portion of these ele-  ments will result in stress incontinence.   The role of the “intrinsic” urethral mechanisms—the seal provided  by the mucosal surface bolstered by the underlying connective tissue  along with the closure provided by the rhabdosphincter—has gained  increasing appreciation in the maintenance of continence. Alterations in  this mechanism have been termed Intrinsic Sphincter Deficiency (ISD)  (6). Female ISD can develop from multiple causes such as inadequate  development, neurologic compromise, vaginal delivery, surgical  trauma, estrogen deficiency, or pelvic radiation. Depending on the  degree of compromise, the intrinsic sphincter mechanisms can be aug-  mented with the injection of bulking agents beneath the submucosa (7).   The “intrinsic” sphincter mechanisms of the male are anatomically  distinct from the female. The continent mechanisms of the male urethra  lie within the bladder neck, prostate, and external sphincter. The bladder  neck and prostate form an integral mechanism, with circular fibers  extending from the detrusor forming the “internal” sphincter. Distal to  this lies the external sphincter, which has an internal component with  circular slow twitch muscle fibers that surround the anterior two-thirds  of the urethra with elastic connective tissue along the posterior aspect.    With two distinct sphincter mechanisms in place, complete dysfunction  can be experienced in one with the other maintaining continence. How-  ever, if both are affected, incontinence will ensue.   Because of the redundant continent mechanisms of the male, exten-  sive alteration is often required to result in severe enough compromise  to cause incontinence. Whereas male ISD can arise from maldevelop-  ment or neurologic compromise, the overwhelming majority of cases  are caused by anatomic alteration. These alterations are in the form of  transurethral incision or resection, open resection, trauma, or attempts  at subsequent repair. Radiation can also affect the tissues, and although  it often does not directly result in incontinence, it can have profound  effects on attempts to correct the condition.    The evaluation if the lower urinary tract prior to injection therapy  requires the establishment of ISD. In addition, overall success with the  patient achieving continence is best assured if the storage parameters of  the bladder are optimal. This would include bladder capacity as deter-  mined by compliance along with detrusor stability. Patient history,  voiding diary, urodynamic study, and cystoscopy may be used to assist  in determining the bladder’s ability to store urine.    Patient history should include the type and severity of incontinence,  precipitating events, prior therapies, voiding pattern, and any additional  factors that may affect outcome. History can be a significant determiner  as to whether the patient is suffering from urge or stress incontinence.  Increases in abdominal pressure that lead to urine leakage typifies  stress incontinence, with urine loss associated with urgency signifying  urge incontinence. Confusion may result if increases in abdominal pres-  sure trigger detrusor instability. In addition, patients with stress incon-  tinence may habitually void frequently in order to keep their bladder  capacity to a minimum and thus avoid leakage, a pattern more associ-  ated with urge incontinence. A voiding diary may be helpful where  history is incomplete or to document actual patterns of storage, leaking,  and voiding. A patient’s voiding pattern may demonstrate their func-  tional bladder capacity and give clues to detrusor function. A patient  who historically has had marked urgency, frequency, and nocturia prior  to developing stress incontinence may have detrusor instability or decreased  compliance, which would make therapy for their ISD suboptimal unless  corrected. However, a low functional bladder capacity may also result    from severe incontinence with near-continuous urine loss, causing the  storage and voiding function of the bladder to remain untested. There-  fore, itis often advisable to obtain more objective information of blad-  der and outlet function beyond history and physical examination, as  provided by urodynamic assessment and cystoscopy.    The physical examination of the incontinent patient can be used to  identify stress urinary incontinence (SUD) in both men and women. With  a semi-ful bladder, one can demonstrate leakage with maneuvers such  as coughing and straining in both the supine and standing position. One  should be careful to differentiate the leakage that occurs simultaneous  with increases in abdominal pressure from that which occurs immedi-  ately thereafter. The latter may be an uninhibited detrusor contraction  triggered by the abdominal pressure, and may not resolve with a urethral  injection. A possible exception to this is if the inciting event is from  urine entering the urethra with such maneuvers. Improved closure of the  urethral lumen as afforded by a urethral injection may decrease this  trigger. Neuropathology can be suggested by alterations in perineal  sensation, loss of anal sphincter tone, and absence of the bulbocav-  ernoses reflex. Vaginal pathology should also be sought, suchas bladder  neck descensus, cystocele, uterine or vault prolapse, and rectocele.   It has been long held that the ideal candidate for injection therapy is the  ISD patient without urethral hypermobility. However, the concept that  injection therapy is not of utility in those patients with combined ISD and  hypermobility (8-70) has been challenged. Herschorn et al. compared  outcomes in 187 patients both with and without hypermobility, noting that  its presence did not significantly affect success . This finding was  confirmed by others, also using the injection of Contigen (CR Bard,  Murray Hill, NJ) (/2), with some finding that patients with hypermobility,  in fact, fare better than those with severe ISD (/3—/4). However, poorer  results were found using other injectable agents, including fat (/5) and  silicone microimplants (/6). The range of results within the literature may  attest to the variable relative contribution of ISD that may be concurrent  with hypermobility. Patients with successful injection results may have  had more significant ISD or were able to compensate for the isolated  hypermobility with augmented intrinsic sphincter function.    The presence and degree of ISD is best evaluated with the measure-  ment of Valsalva leak pressure (/7). The performance of leak pressure  measurement has resisted exact standardization, with variations in    patient position, catheter size, bladder volume, and method to increase  intra-abdominal pressure (/7,/8). Although there are many techniques  used to measure Valsalva leak pressure, it is understood that lower  pressure values associated with leakage indicate more severe cases ISD.   Additional urodynamic testing may be performed in evaluating patients  prior to injection therapy. Measurement of bladder capacity in the face  of extreme ISD may require occlusion of the outlet with a catheter  balloon to allow for adequate filling. At best, a low-capacity bladder as  a result of altered compliance would result in marked frequency; at  worst, an elevation in bladder pressures with “successful” injection  would potentiate renal deterioration. The results with detrusor instabil-  ity are less clear. Intuitively, one would expect that findings of detrusor  instability would result in decreased success . However, others have  found no effect, both in patients with (79) and without (20) neurogenic  disease. A pressure-flow study may demonstrate the presence of both  ISD and obstruction, typically in male patients following radical pros-  tatectomy with a fixed narrowed outlet. If the obstruction is not caused  by the urodynamic catheter occluding the outlet, then it deserves pri-  mary attention. For patients with detrusor acontractility who void by  Valsalva, injection therapy may result in greater difficulty in bladder  emptying. However, this has not been found in patients with normal  voiding (7,21).    Cystoscopy can be a useful tool in evaluating the incompetent outlet  (22). Whereas it may be inexact in determining the degree of ISD, areas  of anatomic deformity can be identified, along with determining the  quality of the tissue prior to injection. Marked scarring or atrophy of the  outlet may predispose for poor results with little tissue available for  injection.    The primary purpose of injection therapy is to augment urethral  coaptation. Adequate increases in urethral resistance can be achieved to  overcome elevations in abdominal pressure without significant alter-  ation of urodynamic voiding parameters (7,23). Although an overabun-  dance of injected material can result in urinary retention, this effect is  usually transient. Ideal implantation is into the connective tissue layer  between the mucosa and the rhabdospincter (24). Injection that is too  superficial into the mucosa results in extravasation and loss of the    material. Injection that is deep within the rhabdosphinter results in out-  ward expansion without urethral lumen compression. Misdirected  injection may also result in rhabdosphincter compromise with a result-  ant increase in leakage. Preoperative assessment should include the  performance of urinalysis to rule out the presence of infection. Both  authors use oral flouroquinolone antibiotic prophylaxis that is contin-  ued for 1 wk following injection. Injection can be performed under local  anesthesia with the placement of 2% lidocaine jelly, either in the office  setting or ambulatory surgery suite. Additional anesthetic agent can be  placed by local injection and infiltration (25).    Injection into the female urethral can either be performed using the  transurethral (TU) or periurethral (PU) method. The TU method requires  placement of the injection needle through the mucosa of the urethra as  directed endoscopically (see Fig. 1). Flexible endoscopic needles can be  passed through routine endoscopes using a catheterizable bridge  (Alberrans), with specific working elements available by most manu-  facturers to enhance control (see Fig. 2). The benefits of the TU method  include the greater familiarity by most urologists with this technique,  with it being easier to place the needle in the desired location under  direct vision. The downside is that each injection leaves a mucosal  defect for potential material egress. Loss of material can be minimized  by not piercing the mucosa directly over the desired site of implantation,  but rather allowing the needle to track in the submucosal plane to the  area to be injected. Injection should be performed with as few injection  passes as possible.   The PU method is performed with use of a 3.5-inch needle outside  and parallel to the urethral lumen to the desired location at the proximal  one-third of the urethra (see Fig. 3). Because the needle length increases  the resistance encountered with injection, it precludes injection with  more viscous agents such as Teflon or Macroplastique. The perimeatal  tissue where the needle will enter at the 3 and 9 o’clock position is  initially infiltrated with local anesthetic. Tip location is inferred by  needle motion or injection under cystoscopic observation. Attempts at  placement under ultrasound guidance without cystoscopic observation  have met with less success (26). Once appropriately placed, there is less  concern regarding direct extravasation of injected material through the  mucosa. However, there is the risk of bladder perforation if the needle  is passed too far or for minimal coaptation if the injection is outside of  the proper plane. Accurate localization of the needle tip can be assured  by initial injection of local anesthetic when one suspects that it is appro-    Fig. 1. TU injection of bulking material into the submucosal space. (A) Needle  placement penetrating submucosa distal injection placement. (B) Injection of  bulking material with elevation of submucosa. (C) Contralateral injection for  complete coaptation of proximal urethra. (D) Images of TU injection of  Durasphere showing coaptation of incompetent bladder neck and proximal  urethra (courtesy of Advanced UroScience).    priately placed (27). There should be an immediate elevation of the  mucosa with minimal volume placed. The use of local anesthetic also  provides additional comfort prior to full injection of the bulking agent.  The additional use of methylene blue has been described (28), although  caution should be used with the small risk of allergic response (29). Few    Fig. 2. Endoscopic working element for transurethral injection (courtesy of  Wolf).    clinical studies have directly compared the methods of PU and TU injec-  tion (30,37), with both looking at injection of bovine glutaraldehyde  crosslinked (GAX) collagen. Although there does not appear to be an  effect on immediate or long-term results, both groups noted a longer  learning curve and higher injection volume with the periurethral method.    Because of the extensive destruction required for the male to expe-  rience stress incontinence, there is often a compromise of the amount of  viable epithelium and submucosa into which the bulking agent can be  injected. Although the sphincter mechanism of the female is also com-  promised, there is usually adequate tissue to allow for the injection of  material between the rhabdosphincter and the epithelium. For male  patients, this results in an increase in the amount of material that must  be injected into an area of more compromised tissue with subsequent  poorer results (32).   Injection is most typically performed by the TU approach, using the  same instrumentation as in female patients. Given the relatively poorer  results in comparison to female patients, the transvesical antegrade  approach has been developed for the injection of bovine GAX collagen  to better access viable tissue at the bladder neck proximal to the external  sphincter (see Fig. 4). Methods have ranged from using a suprapubic  needle, to passing an endoscope through a trocar so as to directly access    Fig. 3. PU injection of bulking material into the submucosal space. (A) Needle  is passed parallel to the endoscope to the proximal urethra. (B) Injection of  bulking material with elevation of submucosa. (C) Contralateral injection for  complete coaptation of proximal urethra following second needle pass.    the bladder neck (33-36). Although published studies that make direct  comparisons are lacking, short-term results by individual authors seem  improved using this approach (37). However, subsequent long-term  results continue to be disappointing (38).    The immediate concern following injection is the ability of the patient  to void. If unable to void, the patient is conservatively managed with  intermittent catheterization with low-caliber catheters to minimize dis-  placement of the bulking agent. In-dwelling catheters are to be avoided  because of the potential molding of the implant with resultant poor  results. If an in-dwelling catheter is unavoidable because of inability of    Fig. 4. Antegrade injection of bulking material. (A) Needle placement into  bladder neck from proximal approach. (B) Injection of bulking material with  elevation of submucosa. (C) Additional injections as required for complete  coadaption.    the patient to self-catheterize, than a small lumen in-dwelling catheter  can be considered. Urinary retention can be caused by the effects of  local anesthesia, edema, and possible overcorrection. Given the tempo-  rary nature of these factors, particularly with agents that undergo some  resorption of the carrier medium, the retention is usually short lived.  Retention may become more problematic as clinicians use newer agents  that promise more of a “what you see is what you get” (WYSIWYG)  effect with maintenance of initial injection volume. Initial bladder drain-  age is less problematic in those male patients injected in an antegrade  approach using a supra-pubic sheath through which a supra-pubic cath-  eter can be placed. Drainage can be assured until the patient is able to  void or for a specified period of time while the bulking agent becomes  “set.” It is unclear if this method of postoperative management results    in better long-term outcome from minimizing tissue motion at the injec-  tion site. Once able to void or bladder drainage is assured by whatever  means, the patient is discharged until subsequent follow-up.    The uretero—vesical junction allows for the low-pressure peristalsis  of urine without reflux. This is created by the anatomic arrangement of the  ureter as is passes through the bladder musculature to form the upper  trigone. A tunnel is formed through the detrusor fibers that result in the  transmission of intravesical pressure against the walls of the ureter caus-  ing it to remain closed between ureteric peristaltic boluses. As the blad-  der distends and the intravesical pressure increases, the actual functional  tunnel length increases along with the intraluminal ureteral pressure  within the vesical hiatus. This tunnel further elongates during the void-  ing phase, preventing reflux during elevations in detrusor pressure that  characterize bladder emptying.   Chronic increases in bladder pressure, ureteral dilation, or inadequate  tunnel length can result in the compromise of the uretero—vesical junc-  tion resulting in the reflux of urine. Injection of bulking agents can be  used to augment the functional tunnel length and coapt the ureteral  lumen. Effective injection requires placement of the material into the  submucosa just beneath the ureteral hiatus.    The presence and degree of significant vesicourteral reflux (VUR) is  best confirmed with voiding cystourethrography. Intravenous pyelog-  raphy (IVP) and cystoscopy can be used to identify anatomic relation-  ships and assess for collecting system duplication. Alteration of voiding  patterns and findings of bladder wall thickening may suggest increased  vesical pressure, which may be the primary cause of the reflux. A history  of dysfunctional voiding may provide information regarding the etiol-  ogy for the reflux. Bladder dysfunction, which results in alterations in  storage pressure can result in reflux, as demonstrated by McGuire’s  sentinal article following patients with myelodysplasia (39). Initial  therapy aimed at the bladder dysfunction with improvements in detrusor  compliance, capacity, stability, and voiding may result in resolution of  the reflux. Finally, if elevated intravesical pressure from whatever cause  is not addressed, reflux will recur. Video urodynamic examination can  delineate not only alterations in storage and voiding pressure, but also  provide information regarding the pressure at which reflux occurs (40).    Fig. 5. Subureteral injection of bulking material. (A) Needle placement beneath  the uretero—vesical junction orifice for injection beneath distal margin of the  orifice. (B) Bulking material is injected with narrowing of orifice.    Actual bladder capacity may be overestimated if the dilated collecting  system(s) hold significant volumes of urine.    Given the pediatric population on which this therapy is primarily  applied, along with the nature of the injection, procedures are performed  under general anesthesia. Injection into the uretero—vesical junction  uses the same instrumentation described for TU injection for inconti-  nence. Injection is performed just beneath the ureteral hiatus with swell-  ing of the tissue beneath the ureteral os as described by O’ Donnell and Puri  (41) (see Fig. 5). Injection that is placed too deep within the musculature of  the bladder diffuses with poorer results (42). As the hiatus is elevated, the  configuration of the meatus changes to a small circular opening. Injection  therapy has been successfully described in patients with reflux associated  with neurogenic bladder (43,44), duplex systems (45,46), posterior urethral  valves (47), and endscopically incised ureteroceles (45,49). Results are  better in treating primary vs secondary reflux (50,51).    Performed on an out-patient basis, the patient is discharged following  recovery from anesthesia. Antibiotic prophylaxis is continued until reso-  lution from reflux is assured. Unlike incontinence, where recurrence is  clinically evident, reflux may recur with little or no symptoms. There-    fore, given the potential for recurrence, ongoing surveillance must be  performed. Furthermore, because of the potential for ureteral obstruc-  tion, initial follow up should include renal ultrasound (52).    What was once only a small field of available materials has increased  exponentially into a large array of potential bulking agents. Table 1 lists  the injectable agents along with their characteristics, grouped together  in rough order of their design. Whereas some of the materials are seeing  their first application as a urological bulking agent, many have or are  being introduced in plastic surgery or as radiologic embolizing agents.  The materials vary in their complexity of production, ease of injection,  initial and long-term maintenance of volume, host reaction, and poten-  tial for migration. They range from synthetically derived materials to  connective tissue matrices to viable autologous tissues with hybrids in  between. Some materials function by providing bulk alone, whereas  others rely on host fibroblast ingrowth and replacement. Given the  multiple clinical settings in which injectable materials are used, there  may not be a single agent with all the ideal characteristics. Tables II, III,  and IV summarize clinical results of available agents used for female  incontinence, male incontinence, and vesicoureteral reflux.    Since its initial injection to treat stress incontinence in the early 1970’ s  (53,54), there has been extensive experience with polytetrafluoro-  ethylene paste (Teflon®, DuPont) as an injection material in urology.  Currently marketed as Urethrin (Mentor Corp., Santa Barbara, CA), it  is available in Europe, but is not FDA approved for urologic use in the  United States. It is an inert substance with a particulate size between  4—40 um that, once injected, is not chemically broken down within the  body. The viscosity of the paste requires it to be injected using a large  bore needle at substantial pressure, requiring a low-caliber pistol-driven  device (see Fig. 6). By heating the injection device, the viscosity decreases,  which can facilitate injection (55). It has been used for both female and  male incontinence, along with reflux. Its use in reflux has been docu-  mented since first introduced by Puri and O’ Donnell in 1984 (56). These  investigators have applied this successfully in children with reflux (4/),  with published data followed out for 10 years (47). Once injected, there  is a persistent inflammatory response to the Teflon particles (57). This  response is cause not only for its efficacy, but also for complication,  with reports of ureteral obstruction (58), bladder outlet obstruction    Name Description Delivery Advantages Concerns  Urethrin® 4—40-um 18-gauge needle Longest Migration  Teflon paste high-pressure experience Inflammatory reaction  injection tool Specialized tool  (clinical investigation)  Macroplastique” 200-um silicone 18/20-gauge needle Extensive Silicone  elastomer high-pressure European Inflammatory reaction  injection tool experience Specialized tool  Possible migration  (clinical investigation)  Durasphere® 212-500-um 18-gauge needle FDA-approved Needle clogs  pyrolytic carbon- special design Radio opaque  coated zircinium Nonmigratory  oxide beads Nonantigenic  Bioglass 120-355-um 16-gauge needle Nonmigratory Limited experience  Ceramic beads Difficult to inject  (no further studies)  Urocol 14—400-um Not reported Easy to produce Migration  hydroxyapatite (no further studies)   particles suspended  in a water, glycerin,  and sodium carboxy  methylcellulose gel    Fig. 6. Teflon injection device with Urethrin syringe and injection needle  (courtesy of Mentor).    (59,60), and local granuloma formation (61—63). Despite this reaction,  subsequent open surgery does not appear to be hampered in cases of  endoscopic failure (64). The major concern associated with the material  has beenits migratory potential given its relatively small particulate size  (65). Migration has primarily been reported to lung parenchyma in  human subjects (66,67), although more distant migration has been  reported (68). Initial animal studies have demonstrated migration to  pelvic nodes, lung, spleen, kidneys, and brain (69). Miyakita demon-  strated in a dog model that it required actual intra-arterial injection to  result in brain emboli, without emboli resulting from low-volume peri-  urethral injection (70). Low volumes are typically used for reflux, with  this concept further extended by Herschorn in treating 46 female patients  with ISD using low-volume periurethral Teflon injections (7/). Larger  volumes are used for male incontinence, with the largest series by  Politano with favorable results (72).    Macroplastique (Uroplasty, Minneapolis, MN) consists of silicone  elastomer with a mean diameter of 200 um suspended in a polyvinylpyr-  rolidone hydrogel. The elastomer size is designed to prevent the migra-    tion that can occur with smaller particles (73,65). The injection of the  viscous material requires substantial pressure, and although it can be  injected through an 18-gage needle for adults and a 20-gauge needle for  children, it requires an injection device (see Fig. 7). Most commonly,  the material is injected in a TU fashion, although it has also been per-  formed periurethally (74). The manufacturer also supplies an injection  device to allow for TU injection in female patients without the use of an  endoscope (see Fig. 8), although the benefits of this method for a urolo-  gist familiar with endoscopy is unclear. Once injected, the PVP hydro-  gel is absorbed and the elastomers are engulfed in an acute and then  chronic low-grade inflammatory response with subsequent collagen    deposition. It has been applied to female, male, and pediatric ISD, along  with vesico-ureteral reflux (VUR) (see Tables 2, 3, and 4). Its benefit in  each of these categories does not vary from other published data of  available agents. Although the material, along with the resultant host  reaction appear to persist, the benefits of the injection tends to wane over  time (74-77). Unlike adverse events involving large volume silicone  gel implants, there has been no reports directly related to the injection  of silicone elastomer as formulated in Macroplastique. The material is  available in Europe, but not yet approved in the United States.    Made of pyrolytic carbon-coated zirconium oxide beads, Durasphere®  (Advanced UroScience, Inc., St. Paul, MN) was FDA approved for  injection for ISD in September 1999. Pyrolytic carbon is biocompatible  and does not require skin testing, being nonantigenic with a record of  artificial heart valve use for more than 30 yr. The material does not  require refrigeration with a shelf life of 6 mo. The suspension is  implanted transurethrally, requiring a specialized 18-gauge needle with  an internally tapered hub to minimize clogging. The gel component of  the preparation results in decreased material leakage from the injection  site. The particle size is 212—500 um, which prevents migration. Once  injected, there is a persistent mild chronic inflammatory response with  minimal granuloma formation. Over 6 mo, this is replaced with collagen  deposition. The material is radio-opaque and can be seen on plain radio-  graph (see Fig. 1D). The multicenter study performed for approval com-  pared the Durasphere to GAX bovine collagen (Contigen) (78).  Twelve-month data included 235 patients with ISD, of whom 115 received  the Durasphere. Of these patients, 43% received a single treatment, 40%  received two treatments, and 13% received three treatments. Of the  patients injected with Duraphere, 66.1% had an improvement of incon-  tinence grade of 1 or more at 12 mo, identical to the Contigen group.  Although there was also significant improvement in pad weight, incon-  tinence episodes, and quality of life, there was no significant difference  in these parameters between the Durasphere and Contigen. Durasphere  did have less material injected (4.83 mL vs 6.23 mL; p<0.001), with a  higher acute urgency and retention rate (24.7%, 16.9%) than in the  Contigen group (11.9%, 3.4%) (p=0.002, p<0.001). This was postulated  by the FDA panel to be caused by the initial inflammatory reaction to  the material. Other adverse events were minimal and equivalent. There  was no evidence of material loss or migration as observed by KUB at  12 mo (see Fig. 10). Postmarket approval studies are underway to evalu-  ate 5-yr data, along with its applicability for male incontinence.    Ceramic beads measuring 120-355 um have been suspended in  hyaluronan for injection. Initial studies using New Zealand white rabbits  with the material injected into the dome of the bladder were followed from  2 to 12 wk at 2-wk intervals (79). Tissue specimens from sacrificed ani-  mals showed no evidence of particle migration. Subsequent work using  Yucatan minipigs with injection of the material into the bladder neck  showed an elevation in the urethral pressure profile without evidence of  migration. Suspensions of smaller particles have also been investigated.  Urocol (Genesis Medical Ltd., London UK) was formed by a ceramic  suspension of 60% hydroxyapatite and 40% tricalcium phosphate. With  a mean particle size of 14 um, the material was readily phagocytized by  macrophages and monocytes in a rat model (65).    Dextran is a polysaccharide that can be crosslinked to form micro-  spheres. Dextranomer microspheres suspended in sodium hyaluronan  (Deflux, Questor AB, Uppsala, Sweden) have been used as a bulking  agent in animals and human clinical studies. Initially applied for VUR  (80), it has since been clinically studied for ISD in female patients (8/).  The material is easily produced and injected, with a particle size of  80-120 um that resists migration (82). Initial human studies have dem-  onstrated its safety with relative ease of injection (81). There was a 20%  retention rate upon injection that may attest to the maintenance of initial  volume. Upon injection, the implant is infiltrated with fibroblasts, in-  flammatory cells, and foreign body giant cells (83). Following the initial  reaction, there is an increase in extracellular matrix with blood vessel  ingrowth. Animal studies have demonstrated a 23% decrease in volume  over 12 mo. Limited human studies have demonstrated short-term ben-  efit with the need for longer term follow-up.    Calcium hydroxylate can be manufactured into particles that range  between 75-125 um in size. Suspended in a gel carrier of water, glyc-  erin, and sodium carboxy methylcellulose, the material can be injected  using a21-gauge needle. Following injection, the carrier is biodegraded  and the calcium hydroxylate particles have fibroblast infiltration with  connective tissue ingrowth. The particles are not encapsulated, and there  is no bone deposition. The material is currently manufactured by  Bioform, Inc. (Milwaukee, WI). Having been studied in an animal  model, it has undergone pilot investigation in the United States in patients  with ISD.    Author Material Method # Patients Types Follow-up Success  Teflon® Lockhart (19) TU 20 urethral 60%  reconstruction  Lotenfoe (133) TU 21 Type I 11 mo 56%  Herschorn (134) PU 46 ISD 24 mo 60%  Lopez (135) TU 128 74 SUI 31 mo 16%  22 Neurogenic 73%  11 Congenital 91%  8 Trauma 62%  13 Other 46%  Kiilholma (/36) TU 22 60 mo 18%  Politano (137) PU 54 6 mo—16 yr 71%  Macroplastique® Henella (138) TU 40 ISD 3 mo 74%  Guys (139) TU 25 ISD 23 mo 44%  Sheriff (140) TU 34 ISD 24 mo 48%  Harriss 97 (141) PU 40 genuine 36 mo 58%  Durasphere® FDA study (142) TU 115 ISD 12 mo 66%  UroVive® Diamond (/43) PU 3 ISD 6 mo 66%  Pycha (144) PU 20 10 Type IM 35.5 mo 100%  6 Type I/III 88%  4 Type N/M 25%    ISD  ISD  54 Type I  70 Type II  63 Type II  8 Type I  20 Type II  12 Type HI  genuine    Author Material Method # Patients Dignoses Follow-up Success  Teflon® Politano (157) TU 720 RRP 67%  TURP 12 mo 88%  simple 74%  Stanisic (158) TU 20 RRP 17 mo  simple  Kabalin (159) TU 13 8 RRP 11-36 mo 25%  5 TURP 20%  Macroplastique® Duffy (28) TU 12 epispadius 11 mo 75%  Bugel (/60) TU 15 9 RRP 12 mo 26%  4 TURP  2 simple  Guys (161) TU 19 neurogenic 23 mo 21%  UroVive® Diamond (90) TU 5 neurogenic 6 mo 63%  Contigen® Aboseif (162) TU 88 47 RRP 10 mo 66%  7 RRP & XRT 57%  7 TURP 43%  24 Other 21%    15%  25%  25%  0%  80%  20%  35%  24%  36%  62%  38%  45%   Puri (176) 143 24—66 mo 88%  Macroplastique” Dodat (177) 253 12 mo 84%  UroVive® Palma (178) 2 3 mo 100%  Deflux® Stenberg (179) 101 3 mo 68%  Contigen® Reunanen (180) 159 48 mo 21-82%   Frey (183) 204 33 mo 63%  Fat Chancellor (/84) 12 6 mo 29%  Chondrogel® Diamond (185) 46 3 mo 83%    Polyvinyl alcohol has been widely applied as an embolizing agent  (84-86). Although this inert biocompatible material is easy to handle  and inject, its particle size range between 20-500 um has led to some  concern regarding its migratory potential (87). Once injected, it results  in a fibrotic reaction that persists over time. Whereas investigation in  urology demonstrated its persistence within the bladder wall of New  Zealand white rabbits at 3 mo (88), its tumorgenic potential has been  raised based on additional animal models (89).    Ethylene vinyl alcohol is a biocompatible polymer that, once in con-  tact with the body tissue or fluids, precipitates into a coherent solid mass  to serve as a bulking agent. Developed as an embolizing agent  (EMBOLYX, Micro Therapeutics, Inc., Irvine, CA) for vascular appli-  cation, URY XJ is being investigated in urology as a bulking material by  a subsidiary company (Genyx Medical, Inc., Irvine, CA). The ethylene  vinyl alcohol is dissolved in dimethyl sulfoxide (DMSO), which acts as  a carrier for injection. Once the dissolved material contacts the body tissue  or fluids, the DMSO rapidly dissipates from the polymer. Atroom tempera-  ture, the material is a nonviscous liquid, easily passing through a 25-gauge  needle. Upon warming to body temperature, the material rapidly solidifies    Fig. 9. Durasphere injection needle demonstrating tapered hub to facilitate  flow and minimize jamming of material (courtesy of Advanced UroScience).    to an inert pliant solid. This rapid formation into a coherent mass would  preclude its migration that may occur with smaller particles. Its ease of  manufacture and introduction would make it readily available as an implant  material and is currently undergoing clinical investigation.    UroVive (American Medical Systems, Minnetonka, MN) is a self-  contained Microballoon System, as previously investigated by Uro  Surge (lowa City, IA). The balloon is made of silicone that is inflated  with up to 0.9 cm? of an inert liquid (polyvinylpyrrolidone hydrogel)  (see Fig. 11). The benefits of this system are that it would be  nonmigratory and retain its volume. Histologic examinations of the  implant in an animal model at 3 mo demonstrated minimal reaction (90).  It appears to be better suited for patients without hypermobility, as noted  by Pycha who followed 10 patients with pure ISD for a mean of 36 mo  with all having continued benefit (paper abstract). This is in contrast to 4/  10 patients with hypermobility that had recurrence of their incontinence.  The few erosions noted occurred with urethral laceration or superficial  injection.   The noninflated system is implanted using endoscopic guidance much  like other injectable agents, however, requiring the use of a 14-gauge  sheath. This system has been applied for both male and female patients  with incontinence (9/), along with patients with VUR (Palma, aua  abstract, Atlanta, 2000). In female patients, the procedure may be best    performed periurethrally to maintain mucosal integrity. The distortion  created by passing the 14-gage sheath and trocar in the periurethral  space can be minimized by stabilizing the urethra by grasping the meatus  with an Allis clamp. Following balloon inflation, the system detaches  with removal of the sheath, remaining filled with its integral check  valve. This device is undergoing further investigation.    Synthetically manufactured (Protein Polymer Technologies, Inc., San  Diego, CA) and injectable through a 25-gauge needle, the material trans-  forms from a polymer solution to a firm, pliant hydrogel. Preclinical  studies have reportedly shown the product to be biocompatible,  nonimmunogenic, resistant to migration, and durable. Preservation of  volume following injection results in the ability to accurately implant  the material without the need to overinject to obtain the desired results.  The material is undergoing clinical investigation.    Hylanuronan is a major component of connective tissue, formed by  repeating dimers of glucuronic acid and N-acetyl glucosamine. This  large polysaccharide helps form the elastoviscous fluid matrix in which  collagen and elastic fibers are embedded. Its chemical structure is the  same throughout nature, and thus is extremely biocompatible. In its  native form, hyaluronan turns over quickly with a half-life of 1-2 d.  Hylan B gel (Hylaform®, Biomatrix Corp., Ridgefield, NJ) is a deriva-  tive of hyaluronan for dermatologic use, with the formation of sulfonyl-  bis-ethyl crosslinks to resist degradation. It is derived from rooster  combs (92), and has not demonstrated any cellular or humoral reaction  in both animal (93) and human investigations (92). It is easily injected  using a 30-gauge needle, and has been compared favorably to bovine  GAX collagen for wrinkles and scars (94). In a series of 177 patients  who were followed for a minimum of 1 yr, the mean duration of effec-  tiveness was 21 wk. It is currently being investigated as an injectable  agent for urinary incontinence under the name Hylagel-Uro®.    Contigen is GAX bovine collagen FDA approved for urologic appli-  cation since 1993. The crosslinking is to stabilize the collagen and pre-  vent degredation. It is also enzymatically treated to remove its antigenic  telemeres and minimize host reaction. Although initially reported in  1989 for urologic use (95), it has been long available to plastic surgery  for dermal injection (Zyderm, CR Bard). It is primarily made up of type I    collagen (95%) with a small amount of type III collagen (5%), sus-  pended in an aqueous medium at a concentration of 35 mg/mL.   Allergic response can occur, with possible sensitization from bovine  products with approx 28% of the patients treated having demonstrated  specific antibodies against bovine type I collagen (96). The allergic  response is primarily IgG, IgA, and IgM mediated, and most typically  results in an irritation and erythema at the injection site. This is more rel-  evant in plastic surgical applications where the potential for a local  reaction is cosmetically undesirable. Whereas IgE-mediated anaphy-  lactic responses have not been reported, systemic side effects such as  arthralgia have occurred (97). To preclude against any reaction, a skin  test is performed with a 1-cm? noncrosslinked aliquote placed subcuta-  neously to test for allergic response. The skin test requires a 4-wk wait-  ing period with a reaction rate of 3%. Even following a negative skin  test, 0.9% of patients will demonstrate an allergic response following  subsequent urethral injection (9S). Some authors have called for the  performance of two sequential skin tests to decrease the potential of  injection into a sensitized individual (99).   The urethral application is relatively simple to inject with the ability  to infuse it through a 21-gauge needle, either transurethrally or peri-  urethrally. Upon injection, there is some immediate absorption of the  aqueous portion with a reduction in the infused volume. This is being  addressed by investigation of a higher concentration formulation of  GAX collagen at 65 mg/mL (GAX 65) that has greater retention of the  infused volume (/00). Although the connective tissue makeup would  seem to invite capillary ingrowth and further native collagen deposition  (105) , the material is relatively inert with subsequent resorption requir-  ing additional injection or alternative therapy. For those female patients  treated for ISD. Ang noted that the mean time to relapse was 13.3 mo  (102), Herschorn demonstrated that the probability of remaining dry was  71%, 58%, and 46% and 1, 2, and 3 yr following successful injection (7 1).    Smooth intestine submucosa (SIS) is an acellular extracellular matrix  derived from porcine small intestine. The material retains its three-  dimensional architecture and contains collagen, proteoglycans, gly-  cosaminoglycans, and functional growth factors. The material acts as a  scaffold for ingrowth of host fibroblasts and muscle cells. Volume  maintenance of this material relies on this host tissue ingrowth, and thus  differs from GAX bovine collagen that appears to persist because of its  inate bulk alone. Injection of the material can be performed using a  20-gauge needle. It has been applied both within (/03) and cross species    (104) with injection into the bladder. When used as a xenograft, reports  indicate that there is more of an inflammatory reaction, with tissue  ingrowth still occurring. The material can be irradiated, which appears  to result in its persistence over nonirradiated SIS. It is postulated that  this may result in partial crosslinking of the collagen, which results in  its persistence until tissue ingrowth can occur (104). This material has  also been investigated as a scaffold seeded with smooth muscle cells  forming a composite graft for bladder augmentation (/05).    The use of collagen has appeal in providing a natural substance as a  bulking agent. However, the lack of long-term efficacy and antigenicity  of bovine GAX collagen has led to further investigation of allogenic  sources. The use of autologous or allogenic tissue eliminates the need to  enzymatically treat the collagen to remove the telopeptides that are the  antigenic component. Because the telopeptides are also essential to the  architecture of the collagen fibers, the preserved morphology may result  in improved host tissue ingrowth and preservation of bulk. Autologous  collagen derived from dermis injected into the bladders of New Zealand  white rabbits demonstrated preservation of the implant with  neovascularization and minimal tissue reaction at 50 d (/06).   Subsequent work by Cozzolino et al. using the same animal model,  compared it to bovine GAX collagen at 3 mo . The authors dem-  onstrated the intact arrangement of the autologous collagen with greater  fibroblastic and vascular infiltration without a marked inflammatory  response in comparison to the bovine collagen implant. The mechanical  and enzymatic dispersion techniques used in these investigations has  been further applied to human dermis. Urologen® (Collagenesis, Inc.,  Beverly, MA) is a cadaveric human tissue matrix, primarily composed  of collagen fibrils, elastic network, and glycosaminoglycans. Pilot data  looking at 18 female patients with ISD showed equivalent results in  comparison to bovine GAX collagen. Preliminary data from on-going  IDE feasibility clinical studies confirm this, whereas noting that aver-  age total treatment volume appears to be less with Urologen in compari-  son to bovine GAX collagen. The manufacturer has similar products  (Dermalogen®, Autologen®) (J08—111) for dermatologic and plastic  surgical use. Results appear to be promising, with a single complication  of a foreign body reaction noted in the literature (772). Using an alter-  native technique of chemical processing with subsequent freeze drying,  Alloderm® (Lifecell, Branchburg, NJ) has also been developed as an  allogenic acellular tissue matrix. Currently used in the plastic surgery    arena, it is available in sheets or micronized into an injectable form  (Cymetra®). Both forms have been compared favorably within plastic  surgery to GAX bovine collagen, with greater tissue ingrowth, reduced  inflammatory response, and persistence in volume (713). Urologic clini-  cal studies are being sponsored as part of a joint venture by Boston  Scientific Corp. (Natick, MA). The potential for disease transmission  using cadaveric sources should be prevented by donor screening and  tissue preparation into acellular preparations.    At a urological historical point when there was increased interest in  agents other than Teflon, attention increasingly turned to fat for injec-  tion. The abundance of available material and its pliant nature would  potentially make it an ideal candidate for autologous injection. Har-  vested from the abdominal wall using liposuction techniques, the mate-  rial can then be immediately injected into the urethra. Relatively large  bore needles are used to minimize adipocyte injury (//4). There is a  range of results from the literature regarding efficacy. Recent initial  interest was raised by Santiago Gonzalez de Garibay reporting on both  men and women with ISD, along with patients with reflux (115).  Santarosa and Blaivas generated interest in the United States in the use  of fat with good results using repeat injections in women with ISD  without hypermobility (/5). The lack of benefit shown in women with  hypermobility was not confirmed in Su’s larger study (//6). Palma  demonstrated that results are improved if patients are given repeat injec-  tions (//7), supporting techniques of small-volume repeat injections  rather than a large-volume single injection. In one study comparing fat  to bovine GAX collagen in female patients with ISD, the 7-mo success  rate using fat showed a 31% cure or improved, significantly less than  collagen at 71% (118). Results using fat for male incontinence are uni-  formly poor, other than anecdotal reports. Its use for treating reflux has  been limited and without encouraging results (779). Success depends in  large part on implant viability with volume maintenance from 0-50%.  Investigation in the plastic surgery arena has demonstrated similar dis-  couraging results with injected material (/20,/2/). Using an animal  model, Matthews demonstrated greater viability if the fat was harvested  from a perivesical source rather than from the abdominal wall (722).  Work outside of urology has demonstrated possible improved results  with better tissue handling, culture techniques, and the addition of  growth factors (123-128). Fat emboli have occurred, with one death  being attributed to this (729).    Cell culture techniques are being applied within urology to allow for  the injection of chondrocytes as a bulking agent. Chondrogel (Curis,  Cambridge, MA) is formed by autologous chondrocytes that are sus-  pended in alginate. The chondrocytes are isolated from a biopsy of the  posterior aspect of the outer ear through a 2-cm incision performed  under local anesthesia (see Fig. 12). Two 4-mm/ pieces of cartilage are  harvested and shipped in a vial containing cell culture medium. The  isolation and culturing of the chondrocytes requires 7 wk preparation,  with the ability to cryopreserve the cells for subsequent injection.  Although they can be stored in their frozen state, once shipped for  implant, the preparation must be injected within a 24—48-hr time frame.  The injection of the material is relatively straightforward with the abil-  ity to pass it through a standard 21-gauge needle. There is an initial loss  in volume secondary to absorption of the alginate that is offset by sub-  sequent chondrocyte growth. The tissue growth that occurs may aug-  ment urethral function 3—6 mo following initial injection Future  injections are possible from cryopreserved material, requiring 4-wk  time frame to thaw and prepare. This material has been applied to both  urinary incontinence from ISD and VUR (/30). It is currently undergo-  ing further clinical trial in the United States.    The ultimate form in the replacement of urethral tissue has been in the  harvesting and implantation of bladder smooth muscle into the urethra  (131). Using an animal model, cultured myoblasts were transduced with  adenovirus to allow identification following injection. Following  implantation, viable myoblasts were identified with myotubule forma-  tion. Whereas this approach may provide for the regeneration of specific  urethral tissue, rather than merely the placement of nonphysiologic bulk,  actual function would need to be demonstrated. Other investigators  have injected fetal bladder tissue for implantation in a refluxing lamb  model, precluding the need for bladder biopsy (/32).    Submucosal injection of bulking materials can be used to treat intrin-  sic sphincter deficiency and the incompetent uretero—vesical junction.  Careful evaluation of bladder function can best assure success and long-  term benefit. Injections are minimally invasive, with at most requiring  brief anesthesia performed in an ambulatory setting. Experience in  female incontinence has been better than in male patients, even with    Fig. 10. KUB of Durasphere implant at 1 and 2 yr (courtesy of Advanced  UroScience).    antegrade techniques to better access viable tissue. Even with success-  ful injection for reflux, patients must have continued surveillance to  monitor for recurrence. The few agents that are currently FDA approved  for use in urology are offset by a large assortment being investigated.  Materials range from inert synthetic bulking agents to connective tissue    Fig. 11. UroVive implant prior to and following inflation compared to pencil  tip (courtesy of AMS).    matrices to viable tissue graft implants. Although the ideal agent  remains to be elucidated, patients will continue to be benefited using  available techniques and materials. As we increase our understanding of  implant technology and lower urinary tract physiology, the injection of  bulking agents will play an increasing role in urology.    . Leonard MP, Decter A, Mix LW, Johnson HW, Coleman GU (1996) Endo-    scopic treatment of vesicoureteral reflux with collagen: preliminary report and  cost analysis. J Urol 155:1716.    . 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Corcos J, Fournier C (1999) Periurethral collagen injection for the treatment  of female stress urinary incontinence: 4-year follow-up results. Urology 54:815.  Gorton E, Stanton S, Monga A, Wiskind AK, Lentz GM, Bland DR (2000)  Periurethral collagen injection: along-term follow-up study. BrJ Urol Int84:966.  Haab F, Zimmern PE, Leach GE (1997) Urinary stress incontinence due to  intrinsic sphincteric deficiency: experience with fat and collagen periurethral  injections [see comments] [published erratum appears in J Urol (1997)  158(1):188]. J Urol 157:1283.   Santiago Gonzalez, de GA, Castro Morrondo J, Castillo Jimeno JM, Sanchez  Robles I, Sebastian Borruel JL (1989) [Endoscopic injection of autologous  adipose tissue in the treatment of female incontinence]. Arch Esp Urol 42:143.  Palma PC, Riccetto CL, Herrmann V, Netto NR Jr (1997) Repeated lipoinjec-  tions for stress urinary incontinence. J Endourol 11:67.   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Blake NS, O’ Connell E (1989) Endoscopic correction of vesico-ureteric reflux  by subureteric Teflon injection: follow-up ultrasound and voiding cystogra-  phy. Br J Radiol 62:443.   Puri P (1990) Endoscopic correction of primary vesicoureteric reflux by  subureteric injection of polytetrafluoroethylene [see comments]. Lancet  335:1320.   Dodat H, Valmalle AF, Weidmann JD, Collet F, Pelizzo G, Dubois R (1999)  [Endoscopic treatment of vesicorenal reflux in children. Five-year assessment  of the use of Macroplastique]. Prog Urol 8:1001.   Palma P, Almeida M, Nardi A, Ricetto L (2000) Self-detachable balloon sys-  tem (UroVive) for complex vesicoureteral reflux (VUR). Am Urolog Assoc  95th Ann Meet.   Stenberg A, Lackgren G (1995) A new bioimplant for the endoscopic treat-  ment of vesicoureteral reflux: experimental and short-term clinical results.  J Urol 154:800.   Reunanen M (1996) Correction of vesicoureteral reflux in children by endo-  scopic collagen injection: a prospective study. J Urol 154:2156.   Leonard MP, Canning DA, Peters CA, Gearhart JP, Jeffs RD (1991) Endo-  scopic injection of glutaraldehyde cross-linked bovine dermal collagen for  correction of vesicoureteral reflux [see comments]. J Urol 145:115.  Haferkamp A, Contractor H, Mohring K, Staehler G, Dorsam J (2000) Failure  of subureteral bovine collagen injection for the endoscopic treatment of pri-  mary vesicoureteral reflux in long-term follow-up. Urology 55:759.   Frey P, Lutz N, Jenny P, Herzog B (1995) Endoscopic subureteral collagen  injection for the treatment of vesicoureteral reflux in infants and children.  J Urol 154:804.   Chancellor MB, Rivas DA, Liberman SN, Moore J Jr, Staas WE Jr (1994)  Cystoscopic autogenous fat injection treatment of vesicoureteral reflux in  spinal cord injury. J Am Paraplegia Soc 17:50.   Diamond DA, Caldamone AA (1999) Endoscopic correction of vesicoureteral  reflux in children using autologous chondrocytes: preliminary results. J Urol  162:1185.    Choonghee Noh, mp, David Shusterman, MD  and James L. Mohler, mp    Urinary incontinence is a frequent complication after radical pros-  tatectomy; rates vary widely depending on the skill and experience of  the surgeon, patient age, and criteria used for reporting incontinence. A  study of a large group of Medicare beneficiaries who underwent radical  prostatectomy showed that almost half of the survey respondents  reported daily urinary leakage, 32% required protection or used a penile  clamp, and 6% required surgical intervention for treatment of urinary  incontinence . Postradical prostatectomy incontinence impairs qual-  ity of life and results in significant patient expense.    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    In males, two separate continence zones are recognized: 1) the proxi-  mal urethral sphincter (PUS) that includes the bladder neck, prostate  gland, and prostatic urethra to the veru montanum and 2) the distal  urethral sphincter (DUS) that extends from the veru montanum to the  bulbar urethra. The DUS has three principal components: 1) the intrinsic  rhabdosphincter that contains slow-twitch fibers capable of sustaining  the tone of the urethral lumen over prolonged periods; 2) the periurethral  extrinsic skeletal muscle layer composed primarily of fast-twitch fibers  that supplement the activity of the rhabdosphincter under stress condi-  tions; and 3) the intrinsic smooth muscle layer, a continuation of the  superficial layer of the detrusor muscle lining the posterior prostatic  urethra (2). After radical prostatectomy, the PUS and proximal portion  of the DUS, including the veru montanum and the prostatic apex, are  removed. Therefore, postoperative continence depends exclusively on  the distal sphincteric mechanism.   In addition to an intact distal urethral sphincter, normal bladder func-  tion (normal bladder capacity and compliance without detrusor instabil-  ity) is required to preserve continence after radical prostatectomy. Any  bladder dysfunction resulting in an intravesical pressure that exceeds  the distal urethral sphincter resistance will result in urinary inconti-  nence (3).    Teflon paste, Polytef,® is a 50% suspension of polytetrafluoro-  ethylene particles in the carrying vehicle, glycerin. Glycerin is quickly  absorbed after injection. Teflon is an inert particulate substance that  causes a foreign body reaction with histiocyte infiltration and encapsu-  lation by fibrous tissue (4). Although Teflon induces chronic inflamma-  tion, it has not been associated with secondary malignancy (5).   Murless (6) first used a sclerosing agent for treatment of urinary  incontinence in 1938 when he injected sodium morrhuate in the anterior  vaginal wall. The resulting scarring compressed the urethra and pro-  duced temporary continence. Arnold reported the use of Teflon injec-  tion for vocal cord augmentation in 1962 (7). Beginning in 1964,  Politano et al. pioneered the use of Teflon for the endoscopic treatment  of urinary incontinence (8). From 1964 to 1978, Teflon injections were  made transperineally. Since 1978, injections were performed trans-  urethrally; the technique was simpler and improved results (8—/0).   Politano reported on more than 1000 injections performed on 720  patients (average 1.4 injections per patient and 18 mL Teflon per injec-    tion). The results of the injection were graded as excellent (when patients  were completely continent and used no protective pads or tissues), good  (when patients improved and required minimal protection), or failed.  Teflon injection was successful in 88% of patients who had incon-  tinence after transurethral resection of the prostate (TURP), 74% of  patients incontinent after open prostatectomy, and 67% of patients  incontinent after radical prostatectomy (8). Postoperative complications  were minimal and consisted primarily of several days of irritative symp-  toms. A few patients had prolonged perineal pain that responded well to  antiinflammatory drugs. He identified three patterns of response to Teflon  injections. The first group improved immediately and remained dry. The  second group resolved their incontinence slowly over a period of 3—7 mo.  The third group was dry immediately postoperatively but began to leak  1-3 wk later. These patients became dry in approximately 3-7 mo. He  recommended waiting at least 6 mo before considering reinjection (8).   Teflon particles have an irregular surface and diameter of 5—100 um;  more than 90% of particles are less than 40 um in diameter. Particles less  than 60 um in size may be injected directly into capillaries, embolize and  give rise to distant granulomas . In addition, Teflon particles are  phagocytized into the reticuloendothelial system and may migrate to  regional lymph nodes and beyond (/2). This phenomenon was first  reported in 1983 when a 76-yr-old man treated for urinary incontinence  with periurethral Teflon was found to have pulmonary Teflon granulo-  mas at autopsy 4 yr following therapy (/3). Animal studies with dogs  and monkeys injected with periurethral Teflon had Teflon particle  migration and resultant granuloma formation in the pelvic lymph nodes,  lungs, brain, kidneys, and spleen . A large granulomatous reaction  may occur at the initial injection site that may persist and enlarge for  several years. Politano has not found any evidence of complications  from Teflon particle migration in 720 cases treated since 1964 (8). Teflon  has been used medically for more than three decades in vascular grafts,  heart valves, aortic implants, cerebral shunts and shunts for hemodialy-  sis and for vocal cord augmentation. In spite of the long and safe use of  Teflon, concerns regarding the possibility of particulate migration and  embolization with granuloma formation have curtailed use of Teflon  injections for treatment of urinary incontinence.    Patients who have postradical prostatectomy incontinence in spite of  treatment with Kegel exercises, bladder relaxants, biofeedback, and    mechanical aids may be considered for Teflon injection. Urinary tract  infection is excluded and chance of prostate cancer cure estimated.  Cystoscopy should be performed to exclude anastomotic and urethral  strictures and visualize the distal urethral sphincter.   Urodynamic evaluation should be performed to exclude detrusor  instability and neurogenic bladder. The need for urodynamic evaluation  in patients with postprostatectomy incontinence was reviewed recently  (/4). In our referral practice experience, 3 of 21 patients considered for  Teflon injection were found to have contraindications for the procedure.  One had unrecognized detrusor failure and his overflow incontinence  was managed with intermittent clean catheterization, and two had detru-  sor instability as the primary cause of urinary incontinence that responded  to imipramine whereas anticholinergics had failed.   Patients are counseled that the chance of resolution of urinary incon-  tinence depends upon the degree of incontinence and post-radical pros-  tatectomy treatments. Overall, 50% of patients will benefit—total  urinary incontinence resolves rarely, whereas mild stress urinary incon-  tinence resolves usually. Salvage radiotherapy probably prevents Teflon  injection success. Resolution of urinary incontinence may require as  many as three treatments. The risks of Teflon injection appear low.    The patient is placed in the dorsal lithotomy position under intrave-  nous sedation and a broad-spectrum antibiotic administered. General or  spinal anesthesia cannot be used as they prevent participation of the  patient in the procedure that is essential for identification of the distal  urethral sphincter. A 22-French cystoscopic sheath with a 12-degree  lens is used to identify the distal urethral sphincter (see Fig. 1). The  patient may perform a Valsalva maneuver to assist with identification  of the distal urinary sphincter. Once the sphincter is identified, sedation  is deepened.   Irrigation fluid is warmed and tubes of Teflon are kept in hot water  at all times. Teflon paste becomes too dense at room or body temperature  to pass through injection needles. A standard injection needle (17 gage) has  been altered by placing a black ring 0.75 in (19 mm) from its tip (Lancet  needle, Cook Company). The needle is passed through the scope and  inserted just distal to the distal urethral sphincter and advanced 0.75 in  so that the needle tip lies within the external urinary sphincter. Teflon  paste is injected at 12 o’clock (see Fig. 2), 3 o’clock (see Fig. 3) and  9 o’clock. The floor is elevated last with a 6 0’ clock injection (see Fig. 4).  Most patients require 3—4 cm? at each site in order to achieve the goal    Fig. 4. Teflon injection at 6 o’clock. Teflon bolster is visible at 9 0’ clock (9).  Teflon is floating freely in urethral lumen (T). (Small, white arrow—urethral  lumen; large, gray arrow—needle).    Fig. 5. Apposition of distal urethral sphincter at completion of Teflon injection.  Teflon is floating freely in urethral lumen (T).    of complete apposition of the distal urethral sphincter (see Fig. 5). The  injections must be performed quickly so that passage of the cystoscope  into the bladder for drainage is not required since loss or compression  of the Teflon bolsters would be risked.   With the bladder full at the end of the case and needle and the cysto-  scope removed, leakage should not occur, but abdominal compression  usually produces a good urinary stream. Patients are discharged to home  when sedation has worn off and they have voided successfully.  Approximately 20% of patients will suffer postinjection urinary retention  and a 12-French coude Foley catheter is placed carefully; the patient  returns for a voiding trial 2-3 d later. Broad-spectrum antibiotics are  continued for 10 d and ibuprofen is prescribed for pelvic discomfort that  occurs in approx 20% of patients. Patients will frequently have imme-  diate continence that worsens over several days as the acute inflamma-  tion from the injections subside and the Teflon bulk is reduced as a result  of loss of the glycerine vehicle. The granulomatous response to Teflon  injection restores Teflon bulk over several months. Therefore, patients  return to clinic in 3 mo to report on continence status. Reinjection is  considered 6 mo postoperatively. Up to three sessions of Teflon injec-  tions are performed before other options may be considered.    Eighteen men incontinent after radical prostatectomy have received  a total of 28 Teflon injections since 1993 (see Table 1). Patients ranged  in age from 51-81 yr. Radical prostatectomy was complicated by blad-  der neck strictures in five men and urethral stricture, periurethral fibro-  sis, and rectal injury in one patient each. Three patients received salvage  radiation therapy. Teflon injection was performed 14 mo to 140 mo and  average 30 mo after radical prostatectomy. Urodynamic study was per-  formed in 15 patients. Average residual urine was 20 cm? and average  bladder capacity was 264 cm?. Detrusor instability was found in 8 patients  (53%) and distal urethral sphincter deficiency was demonstrated in 12  patients (80%).   Nine patients were injected once, eight patients twice and one patient  three times. Each session of injections used an average of 15 cm? of  Teflon: the average amount of Teflon used for first, second, and third  injections were 16, 15, and 8 cm?, respectively. Urinary retention  occurred after 5 of 28 (18%) Teflon injections. There have been no other  complications.   All patients used three pads or more daily to control urinary leakage  prior to Teflon injection; seven patients were totally incontinent. Five  patients are not evaluable because of recent treatment and one patient  failed to return after injection and is lost to follow-up; two irradiated  patients have failed; among 10 nonirradiated patients, two failed, three  are cured, two use a security pad, and four use one or two pads daily.    Collagen is available as a highly purified bovine collagen that is 3%  cross-linked with glutaraldehyde (Contigen®); crosslinking stabilizes  the molecules and reduces the rate of reabsorption. Bovine collagen is  a foreign protein that may elicit cellular and humeral responses; skin  testing is required 30 d before treatment although anaphylactic reactions  have occurred even after negative skin tests (/6). Collagen elicits little  local tissue reaction and granulomas do not occur nor have any reports  described migration of the injected material (/7).   Collagen begins to degrade 12 wk after injection and degrades com-  pletely after 9-19 mo. Repeat injections are therefore required in the  majority of patients. Of 257 incontinent postprostatectomy patients  treated with transurethral injection and followed for a mean of 28 mo    Time Time since  from Post-RP Amount last  Age RP (yr) DI SD incontinence Inj (cc) inj (mo) Results  70 1.3 yes yes 4 pads/d 2 12, 10.5 81 cured  72 1.3 yes yes total 3 28, 22,8 54 cured  74 3:5 yes yes 4-6 pads/d 1 13 16 cured  65 1.3 no yes 4-5 pads/d 1 16.5 4 security pad  74 2 no yes total 1 18 4 security pad  61 2 no no 4—6 pads/d 2 20, 16 58 1 pad  78 1.5 yes no 3 pads/d 1 14.5 3 1 pad  68 2 — — 2—4 pads/d 1 13.5 4 2 pads  77 2 yes yes 4 pads/d 2 18, 16 16 2 pads  64 1.5 yes yes 5-6 pads/d 2 16, 12 3 failed, awaiting AUS  51 4 no yes total 1 5 84 unknown  63 2 no yes 8 pads/d 1 13 3 failed, awaiting reinjection  64 1.3 yes yes 4 pads/d 1 18 13 failed, awaiting reinjection  81 12 no yes total 2 13, 15 3 failed, awaiting reinjection  54 2 yes no total 2 16.5, 16 1 pending  61 3 — — total* 2 17,16 15 failed, AUS  83 2 — — total* 2 16, 11.5 21 failed, AUS  68 3 no yes 3-5 pads/d* 1 15.5 1 pending    DI =detrusor instability; SD = sphincteric deficiency; INJ = Teflon injections; AUS = artificial urinary sphincter; * patients had salvage    (range 12—48 mo), 20% of patients were dry and 39% were significantly  improved. Patients required an average of 4.4 injections (range 1 to 11)  and required an average total of 36.6 cm? of collagen (/8).   Two other injectables offer potential benefits compared to both col-  lagen and Teflon. Autologous fat injection has the advantages of ready  availability, biocompatibility, and lower expense. However, autologous  fat injection has been used in only six men with postprostatectomy  incontinence and may not produce durable results (/9). Silicone rubber  (20), bioglass (21) and, more recently, carbon particles have been sug-  gested for use as injectables for treatment of urinary incontinence.    The artificial urinary sphincter (AUS) may restore continence even  in men with severe or continuous urinary leakage. Revisions (32% of  2606 patients) (22) are frequently necessary due to erosion, infection,  and mechanical problems. Manual dexterity is required to operate the  device, physiological voiding is not attained, and the device and its  placement are expensive. Moreover, many men will require 1 to 2 pads  daily after placement of a single cuff and choose implantation of a  second cuff (23,24). Artificial sphincter implantation cured inconti-  nence in 76% (range, 20% to 96%) and cured or improved incontinence  in 89% (range, 84% to 96%) of 286 men when results described in five  studies were combined (24).    Sling procedures have been used for many years to treat women with  intrinsic sphincter deficiency. A similar procedure has been devised for  use in men with urinary incontinence after radical prostatectomy.  Among 64 patients who underwent the bulbourethral sling procedure  for severe postprostatectomy incontinence, 36 (56%) became dry and  5 (8%) improved significantly. In 17 patients, 23 retightening proce-  dures were performed that increased the success rate to 75%. The revi-  sion, erosion, and infection rates were 27, 6, and 3%, respectively. Many  patients experienced perineal discomfort that may last 3 mo or more and  some patients experienced long-term numbness or pain (25).    Chronic indwelling catheters are associated with a high rate of com-  plications, especially urinary tract infections, and should be used only  when other management options have failed (26). Condom catheters  cause abrasions, dermatitis, penile ischemia or necrosis, and macera-  tion, but the frequency of these complications is unknown. Use of a    condom catheter brings an increased risk of urinary tract infection;  24-h/d users have a higher frequency of infection than nonusers and  nighttime-only users have an intermediate risk of infection (27).    Teflon injection of the distal urethral sphincter for urinary inconti-  nence was pioneered by Politano. In a limited experience, we have  achieved good results with Teflon injection for postradical prostatec-  tomy incontinence. Teflon injection can be performed as an out-patient  procedure under sedation and cures some men who suffer even total  urinary incontinence after radical prostatectomy. Teflon injection offers  more durable results than collagen but may migrate or embolize to cause  granulomas in regional lymph nodes or distant organs. Although Teflon  injection appears safe over four decades of use, newer and more  biocompatible materials may prove better. Teflon injection may be  offered to men who suffer post-radical prostatectomy urinary inconti-  nence prior to resorting to implantation of artificial urinary sphincters  or performance of male bulbourethral sling procedures.    1. Fowler FJ, Barry MJ, Lu-Y ao G, et al. (1995) Effect of radical prostatectomy for  prostate cancer on patient quality of life: results from a Medicare survey. Urol-  ogy 45:1007.   2. Turner-Warwick R (1983) The sphincter mechanisms: Their relation to pros-  tatic enlargement and its treatment. In: Benign Prostatic Hypertrophy. Hinman  F, Jr., ed., New York: Springer-Verlag, pp. 809-828.   3. Leach GE, Chi-Ming Y, Donovan BJ (1987) Post prostatectomy incontinence:  the influence of bladder dysfunction. J Urol 138:574.   4. O’Donnell B, Puri P (1986) Endoscopic correction of primary vesico-ureteral  reflux. Br J Urol 58:601.   5. Dewan PA (1992) Is injected polytetrafluoroethylene (Polytef) carcinogenic?  Br J Urol 69:29.   6. Murless BC (1938) The injection treatment of stress incontinence. J Obs  Gynaecol Br Emp 45:67.   7. Arnold GE (1962) Vocal rehabilitation of paralytic dysphonia. IX. Technique of  intracordal injection. Arch Otolaryngol 76:358.   8. Politano VA (1992) Transurethral polytef injection for post-prostatectomy uri-  nary incontinence. Br J Urol 69:26.   9. Politano VA, Small MP, Harper JM, et al. (1974) Periurethral teflon injection  for urinary incontinence. J Urol 111:180.   10. Kaufman, M, Lockhart JL, Silverstein MJ, et al. (1984) Transurethral polytetra-  fluoroethylene injection for post-prostatectomy urinary incontinence. J Urol  132:463.   11. Malizia, A.A., Reiman HM, Myers RP, et al. (1984) Migration and granuloma-  tous reaction after periurethral injection of Polytef (Teflon). JAMA 251:3277.    . Aaronson IA (1995) Current status of the ‘STING’: an American perspective.  Br J Urol 75:121.   Mittleman RE, Marraccini JV (1983) Pulmonary Teflon granulomas-following  periurethral Teflon injection for urinary incontinence. Arch Path Lab Med  107:611.   Haab F, Yamaguchi R, Leach GE (1996) Postprostatectomy incontinence. Urol  Clin North Am 23:447.   Lipsky H, Wuernschimmel E (1993) Endoscopic treatment of vesicoureteric  reflux with collagen. Five years’ experience. Br J Urol 72:965.  Vandenbossche M, Delhove O, Dumortier P, et al. (1993) Endoscopic treatment  of reflux: experimental study and review of Teflon and collagen. Eur Urol  23:386.   Gorton E, Stanton S, Monga A, et al. (1999) Periurethral collagen injection: a  long-term follow-up study. Br J Urol 84:966.   Cespedes RD, Leng WW, McGuire EJ (1999) Collagen injection therapy for  postprostatectomy incontinence. Urology 54:597.   Santarosa RP, Blaivas JG (1994) Periurethral injection of autologous fat for the  treatment of sphincteric incontinence. J Urol 151:607.   Chaliha C, Williams G (1995) Periurethral injection therapy for the treatment of  urinary incontinence. Br J Urol 76:151.   Walker RD, Wilson J, Clark AE (1992) Injectable bioglass as a potential sub-  stitute for injectable polytetrafluoroethylene. J Urol 148:645.   Hajivassilioiu CA (1999) A review of the complications and results of implan-  tation of the AMS artificial urinary sphincter. Eur Urol 35:36.   Brito CG, Mulcahy JJ, Mitchell ME, et al. (1993) Use of a double cuff AMS 800  urinary sphincter for severe stress incontinence. J Urol 149:283.   Montague DK, Angermeier KW (2000) Postprostatectomy urinary incontinence:  the case for artificial urinary sphincter implantation. Urology 55:2.   Schaeffer AJ, Clemens JQ, Ferrari M, et al. (1998) The male bulbourethral sling  procedure for post-radical prostatectomy incontinence. J Urol 159:1510.  Warren JW (1997) Catheter-associated urinary tract infections. Infect Dis Clin  North Am 11:609.   Ouslander JG, Greengold B, Chen S (1987) External catheter use and urinary  tract infections among incontinent male nursing home patients. J Am Geriatr  Soc 35:1063.    lan K. Walsh, MD, FRCSUROL  and Anthony R. Stone, MD, FRCSED    In the United States alone, more than 10,000 traumatic spinal cord  injuries occur each year, predominantly affecting males in the 20-40-yr-  old age group (/,2). Spinal cord injury may also result from myelopathy,  myelitis, arachnoiditis, vascular disease, or arteriovenous malformations.  Traumatic lesions are most commonly sited at the thoracolumbar ver-  tebral level, corresponding to the suprasacral spinal cord. In patients  with suprasacral, subpontine lesions, the typical neurogenic bladder  behavior pattern emerges as one of involuntary external sphincter con-  traction occurring simultaneously with hyperreflexic detrusor contrac-  tions. This detrusor-sphincter dyssynergia (DSD) results in dangerously  high intravesical pressures, which pose significant risks for the upper  tracts, with complications such as vesicoureteral reflux, hydronephro-  sis, calculus formation, sepsis, and renal decompensation occurring in  more than 50% of patients if left untreated (3). Current management of  DSDis directed toward reducing intravesical pressures with antimuscarinic    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    medication and minimizing intravesical volumes via intermittent cath-  eterization. Most paraplegics, however, lack the level of manual dexter-  ity required to self-catheterize effectively and must rely upon intermittent  catheterization by their care taker. Some paraplegics may also find self-  catheterization either difficult to perform or they may cooperate poorly  with their catheterization regimen. In such cases, drainage may be  ensured by the use of an in-dwelling urethral catheter, but this is limited  by the almost inevitable development of urethral erosion, chronic infec-  tion, and calculus formation. Suprapubic catheterization circumvents  some of these problems, but long-term use is still associated with con-  siderable morbidity in the form of chronic urinary tract infection, squa-  mous metaplasia, and calculus development.   The results of medical management of DSD are consistently disap-  pointing. Centrally acting muscle relaxants are ineffective and periph-  erally acting agents are associated with significant toxicity (4,5).  Administering the skeletal muscle relaxant baclofen intrathecally may,  however, effectively reduce DSD in up to 40% of patients (6).   External sphincterotomy was first introduced by Watkins in 1936 as  a method for ablating outlet resistance and is purported to provide low-  pressure drainage (7). Despite initial enthusiasm, sphincterotomy has  been shown to be hampered by a failure to fully eliminate residual urine,  the potential for significant hemorrhage and the need to repeat the pro-  cedure in up to one-quarter of patients (8,9). Patients are also reliant  upon condom catheter drainage. Less than 50% of patients continue with  this drainage method in the long term (/0). An alternative method to  surgical external sphincterotomy is sphincter ablation by direct injection  of Botulinum toxin. Although less invasive than surgical incision, this  method provides only temporary relief, repeat injections are necessary  every couple of months (71). Balloon dilatation is another alternative, but  this is restricted by recurrent obstruction and excessive bleeding (/2).   In view of the difficulties encountered in establishing low-pressure  bladder emptying in these patients, therapeutic innovations continue to  be introduced. Intraurethral stent placement was first introduced by  Fabian in 1980 as an alternative to long-term in-dwelling urethral cath-  eterization (/3). Intraurethral stents have thus become recognized as a  minimally invasive, effective treatment option for urethral strictures  and prostatic obstruction (/4, /5). The attractive features ofan in-dwelling  stent include potential reversibility and provision of a wide lumen, which  facilitates both urinary drainage and instrumentation. The disadvan-  tages include biocompatibility concerns, hyperplastic reactions, encrus-  tation, infection, and calculus formation (/6). The application of  intraurethral stent placement to the management of DSD has been inves-    tigated in several studies in the last decade and these will be discussed  in this chapter.    Lower urinary tract stents are broadly categorized as being perma-  nent or temporary. Whereas temporary stents (Urospiral, Prostacoil,  Prostacath) have become popular in managing prostatic obstruction and  urethral strictures, clinical experience in managing DSD with these  devices is limited. To date, the most extensive clinical experience reported  in this area has been with the Urolome™ permanent stent (known as the  Medinvent Wallstent in Europe). Temporary stents include the include  the Memokath and Memotherm prostheses.    The Urolume prosthesis (American Medical Systems; Minnetonka,  MN; Medinvent SA, Lausanne, Switzerland) was originally developed  as a self-expanding endoprosthesis to maintain patency of stenotic arteries  following balloon angioplasty. The device exerts a strong, continuous,  outward radial force and has also found clinical application in the non-  surgical treatment of biliary strictures (/7,/8). Its utility in managing  bulbar urethral strictures was first described by Milroy in 1988 (/9). The  stent is composed of a braided, pliable, self-expanding cylindrical mesh  of corrosion-resistant, nonmagnetic super-alloy wire (see Fig. 1). The  radial mesh design exerts an outward force against the urethral lumen to  maintain patency of up to 42-Ch.   Stent placement is performed endoscopically. The stent is packaged  preloaded on a 24-Ch cystourethroscopic insertion tool. Although sev-  eral stent lengths are available commercially, a 3-cm stent appears to be  the most effective for optimum external sphincter bridging (/2). The  insertion tool is introduced into the urethra and advanced to the veru-  montanum under direct vision via a 0° cystoscopy lens. Landmarks for  correct placement are from the distal half of the verumontanum ceph-  alad, thus leaving the ejaculatory ducts exposed and extension into the  bulbar urethra at least 5 mm, beyond the membranous urethra caudally.  Ifnecessary, an additional overlapping stent may also be placed to ensure  complete bridging of the external sphincter. After confirming correct  positioning, the prosthesis is released from the delivery device and self-  expansion occurs. Inaccurate placement can be immediately corrected  by slightly repositioning the device or withdrawing it completely  through a resectoscope sheath with grasping forceps under endoscopic  guidance. An effective point of technique is suprapubic catheter placement    to optimize visibility and postoperative urinary drainage. A condom  catheter is secured at the end of the procedure. Urethral catheterization  in the immediate and early postoperative period is contraindicated due  to the risk of stent displacement. Postoperative plain X-ray further  confirms correct stent positioning (see Fig. 2). Because an in-dwell-  ing foreign material has been introduced into an already compromised  urinary tract, intravenous antibiotic prophylaxis perioperatively and  oral antibiotic coverage postoperatively is mandatory.   The first report on the effectiveness of urethral stents to treat DSD  was by Shaw et al. in 1990, using the Urolume prosthesis (20). Since  then, several studies have confirmed the utility of stent placement in this  clinical scenario.   Noll et al. reported that in 22 of 24 male patients with severe DSD,  infravesical obstruction was effectively relieved by Medivent Wallstent  placement (2/). The majority (71%) of these patients had previously  undergone unsuccessful surgical external sphincterotomy.   McInerney et al. reported their series of 22 spinal cord-injured males  with DSD in whom a Medinvent Wallstent was placed across the exter-  nal sphincter (22). Half of these patients had previously undergone  repeated unsuccessful external sphincterotomy and three patients had  artificial urinary sphincters in situ. Stents were placed at or immediately  subjacent to the level of the verumontanum, dependent upon whether  subsequent fertility was of importance. Fifteen (68%) patients were  noted to have effective urinary drainage postoperatively, whereas 3 (14%)    Fig. 2. Plain radiograph demonstrating a Urolume stent correctly positioned in  a patient with extensive spinal injury.    developed bladder neck obstruction. None of the patients with artificial  urinary sphincters drained adequately following stent placement.   In 1993, Chancellor et al. reported their experience with the Urolume  device in 25 spinal cord-injured men with DSD (23). One year following  insertion, voiding pressures and residual urine volumes remained low  and bladder capacity was unchanged. Early (within 6 wk) stent migra-  tion occurred in three (12%) patients and one patient developed pyelo-  nephritis postoperatively. The authors concluded that this simple  technique is an attractive alternative to formal surgical sphincterotomy.   In 1994, Rivas et al. compared Urolume™ implantation with surgical  external sphincterotomy in 46 spinal cord-injured males with DSD over  afollow-up period of 6—20-mo (24). Both modalities were equally effective    in reducing voiding pressures and residual urine volumes without  adversely affecting bladder capacity. Surgical complication rates  (approx 25% of patients) were also similar in the two groups. Stent  placement was, however, less expensive, associated with less bleeding  and had a significantly shorter operating time and hospital stay. Similar  conclusions were reached by Chancellor et al. when they prospectively  compared stent placement, external sphincter balloon dilatation and  traditional surgical external sphincterotomy in 61 patients (25). Juma  et al. highlighted the simplicity of stent insertion, short hospital stay and  low short-term morbidity in their cohort study of 10 patients (26). In  1996, McFarlane et al. reported the results of Urolume implantation in  12 patients with 5-yr clinical follow-up, which included urodynamic  and ultrasonographic studies (27). Although stent migration, erosion or  infection did not occur in this study, stent removal was necessary in two  patients and 50% developed bladder neck obstruction, which required  surgical intervention.   The first large clinical study on Urolume placement was the North  American multicenter trial, which prospectively investigated the  device’s efficacy in 153 spinal cord-injured men with DSD over a  follow-up period ranging from 2 to 33 mo (/2). Approx one-third of the  patients had previously undergone surgical external sphincterotomy,  but such a history did not affect the clinical results. A large portion  (68.6%) of patients were managed with a single stent, and most of the  remainder required two prostheses. The authors reported a statistically  significant reduction in voiding pressures postoperatively, which remained  low (< 40 cm H,O) at 2 yr. Although residual urine measurements were  similarly reduced, bladder capacity was not adversely affected. Stent  epithelialization was observed to begin within 3 mo of insertion and was  virtually complete by 2 yr. Hyperplasia was noted in one third of patients  at 3 mo and one-half at 2 yr, although this was only regarded as being  marked in a maximum of 10% of patients and, in no cases, did this cause  urethral stenosis or urinary obstruction. Clinically significant urinary  tract infection occurred in only four patients postoperatively and  improvement or stabilization of preoperative hydronephrosis was virtu-  ally universal. Autonomic dysrreflexia was reported by approx 70% of  patients preoperatively and 30—40% of patients postoperatively. Ten  cases of stent explantation were performed, most commonly because of  stent migration, of which half occurred in the immediate postoperative  period and subsequent reimplantation was successfully performed in  most cases. Only 8.5% of patients subsequently developed secondary  bladder neck obstruction, which was effectively managed nonsurgically  in half the patients. Complication rates were low, with no significant    bleeding, tissue erosion or calculus formation. The authors conclude  from these impressive results that Urolume stent placement is a simple  and effective alternative to traditional sphincterotomy when managing  these complex cases.   Further urodynamic data was published by Chancellor et al. in 1995  on a subset of 41 patients who had participated in the Multicenter North  American Urolume Trial (28). One-quarter of these patients had a pre-  vious history of failed external sphincterotomy. At 12 and 24 mo, void-  ing pressures remained significantly low (< 40 cm H,O) as did residual  urine volumes (< 100 mL), whereas bladder capacity was unaffected.  Again, no differences were noted between patients with and without a  history of previous external sphincterotomy. Sauerwein etal. also reported  improved urodynamic, radiological, and clinical findings in 51 male  spinal cord-injured patients with DSD at up to 3 yr follow-up (29).   The long-term follow-up of the North American Multicenter Urolume  Trial have been published recently (30). Five-year follow-up results  were available from 15 centers on a total of 160 spinal cord-injured men  with DSD who had undergone Urolume stent placement in the original  study. The overall results were again unaffected by a previous history  of external sphincterotomy. Almost one-third of patients required at  least two insertion procedures to achieve adequate external sphincter  coverage, with a single stent being used in 52% of patients, two stents  in 30%, and three stents in 6.9%. The previously noted significant reduc-  tions in mean voiding pressure and residual urine volumes were main-  tained at 5 yr postoperatively and bladder capacities remained unchanged.  It is, however, worth noting that despite the significant reductions in  residual urine following stent placement, the absolute postoperative  volumes were still high throughout follow-up, averaging 132 cm? at 5 yr.  Of the 115 (72%) patients who suffered from autonomic dysrreflexia  prior to entering the study, this remained resolved in 70% at 1 yr and  improvement was maintained at 5 yr. Sixty-three of eighty-six (85%)  patients who required an in-dwelling urinary catheter preoperatively  remained converted to condom catheter drainage following stent  implantation. Preoperatively, hydronephrosis was present in 16% of a  total of 320 renal units in 160 patients and this reduced to 4% of units  at 1 through to 5 yr. Data on colonization and infection rates were  unavailable for the preoperative and early postoperative periods, but for  the remainder of the study, asymptomatic bacteriuria was present in  over 90% of patients, although symptomatic urinary tract infection pre-  sented in only 3-12%. Erectile function and antegrade ejaculation  remained unaffected by stent placement for the duration of the study.  Regarding to the cystoscopic appearance of the implant site, complete    urothelial stent coverage progressively increased from 49% of patients  at 1 yrup to 96% at 5 yr. A moderate to severe intraluminal hyperplastic  response was observed in 20% of patients at 1 yr and 7% at 5 yr. Intrastent  stenosis developed in only 3% of patients, encrustation was evident in  6%, and calculus formation was not observed. Twenty-four (15%)  patients underwent prosthesis explantation primarily for stent migra-  tion and four of these patients subsequently had a further stent placed  successfully. Although significant bleeding or soft tissue erosion did  not occur, 47 (26%) patients developed bladder neck obstruction, of  whom less than half required surgical incision. Subjective improvement  in bladder emptying was reported by 91% of patients at 1 yr and 74% at  5 yr, whereas physician’s subjective perception of operative success  was 94% at 1 yr and 98% at 5 yr. The authors concluded that Urolume  stenting is an effective, potentially reversible alternative to surgical  external sphincter destruction.   Chancellor et al. prospectively compared the results of Urolume  placement with traditional external sphincterotomy in their recently  published multicenter randomized trial (37). Urodynamic data, voiding  questionnaires, and quality-of-life measurements were analyzed over  2 yr. A significant reduction in maximum detrusor pressures was noted  following both procedures, both performing equally well in this man-  ner. Reductions in residual urine volumes following stent placement  were, however, only significant at 3 mo postoperatively, although  sphincterotomy continued to minimize postvoid residual at 2 yr. Blad-  der capacity was unaffected by either procedure. Postoperative bleeding  was insignificant in both groups and hospital stay was generally shorter  for stented patients. Although a significant improvement in bladder  emptying was more commonly reported by patients with stents, there  was atendency for patients who had undergone sphincterotomy to report  less worry, bother, hampering of daily activities and interference with  social activities. The authors concluded that, overall, stent placement  was as effective as traditional sphincterotomy, but preferable because of  the shorter hospital stay and potential reversibility.   Urolume explantation has now been described in detail and the results  studied by working members of the North American Study Group  (Gajewski et al., personal communication). Removal is acheived by  endoscopically grasping several rows of the prosthesis wire at least 2 mm  from the distal end of the device. Gentle withdrawal permits stent elon-  gation and narrowing, facilitating intact removal of the prosthesis. Fail-  ure to remove the device intact may occur if an insufficient number of  wires are grasped initially, in which case piecemeal retrieval of the  individual wires is required. If stent epithelialization is evident, prelimi-    nary endoscopic tissue resection is necessary to free the prosthesis prior  to its withdrawal. Resection should be performed using low, brief, pure  current settings to avoid thermal disruption of the wire components.  Twenty-one (13%) patients in the original multicenter study required  immediate prosthesis removal at the time of initial insertion, mainly  because of misplacement or migration. Retrieval was reported to be  easy to perform and a device was then correctly placed in the majority  (90%) of the patients. In the longer term, formal explantation was nec-  essary in 31 (20%) of the overall study group at a mean of 22 mo follow-  ing stent placement, most prostheses being removed between 2—4 yr  because of stent migration. Less common indications for removal  included inadequate epithelialization, urinary tract infection, pain, and  squamous metaplasia. Thirty (97%) of these patients had their devices  removed successfully and 6 (4%) underwent successful stent replace-  ment. Roughly half of the stents were removed intact, half were delivered  piecemeal and open removal was necessary in one patient. The degree  of urothelial trauma caused by stent removal was reportedly minimal,  although more marked for piecemeal, removal. There were no lasting  consequences of prosthesis explantation, demonstrating the potentially  reversible role Urolume placement has in treating these patients.    Because permanent sphincter stenting is, by definition, irreversible,  this may render implantation a somewhat less-attractive option for some  patients. Permanent stents may also prove troublesome if epithelializa-  tion is poor and hyperplastic growth leads to urethral occlusion (32).  Concerns about fertility and the potential long-term risk of malignant  transformation also need to be considered by both patient and physician.  In an effort to circumvent these difficulties, some authors have investi-  gated the Memokath temporary urethral stent (Engineers & Doctors  A/S, Hornbaek, Denmark). This second-generation thermosensitive  stent is composed of titanium nickel alloy with shape memory effect.  Stent placement using a delivery catheter is controlled by fluoroscopy,  ultrasonography, or flexible cystoscopy. After deploying and position-  ing the proximal end of the stent at the bladder neck, warm saline (45°C)  is flushed through the stent to expand it’s distal coils in the bulbar  urethra, thus providing bridging of both internal and external sphincters.  Stent replacement is required at 12—18 mo and is easily performed by  cooling the stent with 4°C saline, which renders the stent supersoft,  facilitating endoscopic removal.   Soni et al. deployed the device in 10 male spinal cord-injured patients  with urinary retention (33). Insertion was controlled by fluoroscopy in    seven patients and by flexible cystoscopy in three. Immediate and early  complications included autonomic dysreflexia, bleeding, and urinary  tract infection in a total of four patients. Over a follow-up period of  3-7 mo, all patients were noted to have insignificant residual urine  volumes and stent migration or occlusion did not occur.   Shah et al. studied the efficacy of the Memokath device in managing  DSD (34). Fourteen patients had stents inserted under cystoscopic guid-  ance as an outpatient procedure. Both bladder neck and external sphinc-  ter were stented in 11 patients using 5—7-cm stents and the sphinter alone  was stented with a 4-cm stent in three patients. Over the follow-up  period, which extended to 2 yr, residual volume measurements remained  significantly reduced whereas preoperative hydronephrosis and auto-  nomic dysreflexia were effectively resolved. Regarding to optimizing  bladder emptying, bridging both the external sphincter and bladder neck  was considerably more effective than sphincteric stenting alone. The  authors suggested that the Memokath stent should be the prosthesis of  choice if fertility concerns or patient indecision may influence clinical  decision-making.   As an alternative to formal external sphincterotomy, Low et al.  implanted 26 Memokath stents in 24 high tetraplegic males with DSD  who were unable to catheterise (35). Disappointingly, implantation  failed to improve emptying and 19 (79%) patients required prosthesis  removal because of infection or stent migration.   The Memotherm prosthesis (Angiomed), originally developed as a  permanent stent for the relief of benign prostatic obstruction, has since  undergone modifications to become an essentially temporary device.  This flexible wire mesh is composed of the thermoreactive material  Nitinol, which gains its maximum expansion force at 37°C (see Fig. 3).  This heat-sensitivity facilitates repositioning as for the Memokath pros-  thesis (36).   Garcia et al. recently implanted the Memotherm prosthesis in 24  spinal cord-injured patients with DSD (37). Over a mean follow-up of  15 mo, urodynamically demonstrated leak point pressures and residual  urine volumes remained significantly low. Stent migration occurred in  four patients and two patients developed infection and calculus forma-  tion, necessitating explantation.    DSD poses significant risks to the upper tracts of spinal cord-injured  patients. Clinical management can be particularly difficult if the com-  bination of intermittent catheterization and antimuscarinic therapy is  not possible because of an individual patient’s lack of manual dexterity,    Fig. 3. Memotherm endoprosthesis at (A) 0°C and (B) after flushing with saline  at 37°C.    poor social support or lack of compliance with treatment. Surgical external  sphincterotomy was introduced as a means of circumventing this difficult  situation. The initial enthusiasm for sphincterotomy has become tem-  pered somewhat by the realization that, in the long term, this procedure  is not as effective in eliminating residual urine as was originally thought.  This realization, coupled with the observation that sphincterotomy is  not free from surgical complications, has further encouraged neuro-    urologists to look towards other means of ensuring effective low-  pressure bladder emptying.   The introduction of external sphincter stenting as a treatment for  potentially hazardous DSD in males with spinal cord injury represents  a significant advance in urological practice, with clinical experience  accumulating as time progresses, particularly with the Urolume pros-  thesis. Although initial reports were tempered with concerns about long-  term safety, this would appear not to be a major concern at least at 5-yr  follow-up. The results reported in several publications emerging from  the North American Multicenter Trial appear conclusive that stenting is  as effective as sphincterotomy. The advantages of sphincter stenting  include ease of prosthesis placement which, if performed correctly, is  associated with minimal complications and a short hospital stay.   It must be stated that residual urine is not eliminated by sphincter  stenting and, whereas the figures reported in the literature are an improve-  ment on preoperative values, it should be noted that the volumes them-  selves remain considerable. One-quarter to one-half of patients develop  significant bladder neck obstruction following stent implantation and  this may explain the persistence of inefficient emptying. The develop-  ment of bladder neck obstruction would also suggest that the presence of  a stent itself contributes to outlet obstruction, perhaps by intraluminal  occlusion secondary to the hyperplastic tissue response described in 50%  of patients. To date, the published reports remain unclear on this matter.   It has been suggested that Urolume prosthesis insertion is a poten-  tially reversible procedure. Most Urolume stents are, however, virtually  completely epithelialized as early as 6 mo after placement, which would  be expected to render removal difficult. Formal explantation was nec-  essary in 20% of the large group of patients in the North American  Multicenter study, mainly because of prosthesis migration, although  pain, inflammatory changes, and urinary tract infection also necessi-  tated stent removal in some cases. Only 50% of stents were removed  intact and, in the author’s experience, stent removal can certainly be a  difficult and time-consuming procedure. Only 4% of explanted patients  have subsequently undergone successful reimplantation, further indi-  cating that stent placement should not be considered a procedure which  is easily revised.   Overall, placement of a permanent sphincter stent such as the  Urolume is not superior to traditional sphincterotomy, merely equally  effective. Although considerable experience has been gained with the  use of the Urolume stent, placement of this prosthesis must still be  regarded as being only potentially reversible, because the ease and safety  of device removal remain undetermined. Knowing external sphinctero-    tomy has been seen to perform poorly in the long term, the question  arises as to the utility of a procedure that is similarly efficacious, but  entails the essentially permanent placement of a foreign body in an  already compromised lower urinary tract. The presence of a permanent  prosthesis may additionally lead to the development of squamous meta-  plasia and the possibility of subsequent malignant transformation remains  aconcern. The thermosensitive temporary Memokath and Memotherm  stents thus appear attractive by virtue of their removability, which is  also a particularly important feature if patient indecision or concerns  about fertility are major issues in management. To date, however, clini-  cal experience with temporary stents is limited to only a few European  studies, although these initial reports are certainly encouraging.   The gold standard of managing post-spinal cord-injury DSD remains  the combination of an effective intermittent catheterization regimen (by  patient or carer) together with antimuscarinic pharmacotherapy. In the  authors’ experience, most patients are able to cooperate with such an  approach and alternative methods are only required in a small subpopu-  lation. In the latter group, apart from stent implantation, current options  include in-dwelling catheter, preferably via the suprapubic route (revers-  ible), external sphincterotomy (irreversible), augmentation cystoplasty  (irreversible and still reliant upon the need for catheterization), urinary  diversion (irreversible), and incontinent ileo-vesicostomy (irreversible).  The role of stent placement would appear to be as a suitable, but only  potentially reversible alternative to the equally efficacious but irrevers-  ible external sphincterotomy, and should only be considered if the  patient does not agree to the aforementioned alternatives. Growing  experience with the development and employment of temporary pros-  theses may produce further clinical advances and allow for more routine  use of such devices.    1. Stover SL, Fine PR (1987) The epidemiology and economics of spinal cord  injury. Paraplegia 25:225.   2. DeVivo MJ, Rutt RD, Black KJ, Go BK, Stover SL (1992) Trends in spinal cord  injury demographics and treatment outcome between 1973 and 1986. Arch Phys  Med Rehab 73:424.   3. Blaivas JG (1982) The neurophysiology of micturition: a clinical study of 550  patients. J Urol 127:958.   4. Bianchine J (1980) Drugs for Parkinson’s disease: centrally acting muscle relax-  ants. In: Gilman AG, Goodman LS, Gilman, A, eds., The Pharmocological  Basis of Therapeutics. New York: MacMillan, pp. 475—495.   5. Hackler RH, Broeker BH, Klein FA, Brady SM (1980) A clinical experience  with dantrolene sodium for external urinary sphincter hypertonicity in spinal  cord injured patients. J Urol 124:78.    . Steers WD, Meythaler JM, Haworth C, Herrell D, Park TS (1992) Effects of    acute bolus and chronic continuous intrathecal baclofen on genitourinary dys-  function due to spinal cord pathology. J Urol 148:1849.    . Watkins RH (1936) The bladder function in spinal injury. Br J Surg 23:734.  . Schellhammer PF, Hackler RH, Bunts RC (1973) External sphincterotomy: an    . Perkash I (1976) Modified approach to sphincterotomy in spinal cord injury    . Vapnek J, Couillard D, Stone A (1994) Is sphincterotomy the best management    . Dykstra DD, Sidi AA (1990) Treatment of detrusor-sphincter dyssynergia with    . Chancellor MB, Rivas DA, Linsenmeyer T, Abdill CA, Douglas Ackman CF,    Appell RA, et al. (1994) Multicenter trial in North America of Urolume sphinc-  ter prosthesis. J Urol 152:924—930.    . Badlani GH (1997) Role of permanent stents. J Endourol 11(6):473-475.  . Corujo M, Badlani GH (1997) Epithelialization of permanent stents. J Endourol    . RaillatC, Rousseau H, Joffre F, Roux D (1990) Treatment of iliac artery stenoses    . Roddie ME, Adam A (1992) Metallic stents in biliary disease. Baillieres Clin    . Milroy EJG, Cooper JE, Wallsten H et al (1988) A new treatment for urethral    . Shaw PJR, Milroy EJG, Timoney AG, Mitchel N (1990) Permanent external    . Noll F, Hoch V, Schreiter F (1992) Wall-stent for treatment of bulbar urethral    . McInernay PD, Vanner TF, Harris SA, Stephenson TP (1991) Permanent ure-    thral stents for detrusor sphincter dyssynergia. Br J Urol 67(3):291-294.  Chancellor MB, Karusick S, Erhard MJ, Abdill CK, Liu JB, Goldberg BB, Staas  WE (1993) Placement of a wire mesh prosthesis in the external urinary sphincter  of men with spinal cord injuries. Radiology 187(2):551-555.   Rivas DA, Chancellor MB, Bagley D (1994) Prospective comparison of external  sphincter prosthesis placement and external sphincterotomy in men with spinal  cord injury. J Endourol 8(2):89-93.   Chancellor MB, Rivas DA, Abdill C, Ehrlich SM, Staas WE (1994) Prospective  comparison of external sphincter balloon dilatation and prosthesis placement  with external sphincterotomy in spinal cord injured men. Arch Phys Med Rehabil  75(3):297-305.   Juma S, Niku SD, Brodak PP, Joseph AC (1994) Urolume urethral wallstent in  the treatment of detrusor sphincter dyssynergia. Paraplegia 32(9):616-621.  McFarlane IP, Foley SJ, Shah PJ (1996) Long-term outcome of permanent  urethral stents in the treatment of detrusor-sphincter dyssynergia. Br J Urol  78(5):729-732.   Chancellor MB, Rivas DA, Abdill CK, Staas WE Jr, Bennett CJ, Finocchiaro  MV, et al. (1995) Management of sphincter dyssynergia using the sphincter    stent prosthesis in chronically catheterized SCI men. J Spinal Cord Med  18(2):88-94.   Sauerwein D, Gross AJ, Kutzenberger J, Ringert RH (1995) Wallstents in  patients with detrusor-sphincter dyssynergia. J Urol 154(2 Pt 1):495-497.  Chancellor MB, Gajewski J, Ackman CF, Appell RA, Bennett J, Binard J, et al.  (1999) Long-term followup of the North American Mulricenter Urolume* trail for  the treatment of external detrusor-sphincter dyssynergia. J Urol 161(5):1545—1550.  Chancellor MB, Bennett C, Simoneau AR, Finocchario MV, Kline C, Bennett JK,  etal. (1999) Sphincteric stent versus external sphincterotomy in spinal cord injured  men: prospective randomized multicenter trial. J Urol 161(6):1893-1898.  Corujo M, Badlani GH (1997) Epithelialization of permanent stents. J Endourol  11(6):477-480.   Soni BM, Vaidyanatham S, Krishnan KR (1994) Use of Memokath, a second  generation urethral stent for relief of urinary retention in male spinal cord injured  patients. Paraplegia 32(7):480-488.   Shah NC, Foley SJ, Shah PJ (1997) Use of Memokath temporary urethral stent  in treatment of detrusor-sphincter dyssynergia. J Endourol 11(6):485-488.  Low AI, McRae PJ (1998) Use of the Memokath for detrusor-sphincter dyssyn-  ergia after spinal cord injury-a cautionary tale. Spinal Cord 36(1):39-44.  OsvaldoN, Iglegias Prieto JI, Mancebo Gomez JM, Massarra Halabi J, Cisneros  Ledo J, Perez-Castro Ellendt E (1995) Memotherm as a therapeutic device in  intravesical obstruction. Arch Esp Urol 48(9):933-936.   Juan Garcia FJ, Salvador S, Montoto A, Balvis B, Rodriguez A, Fernandez M,  Sanchez J (1999) Intraurethral stent prosthesis in spinal cord injured patients  with sphincter dyssynergia. Spinal Cord 37(1):54-57.    Christopher R. Chapple, mb,  J. C. Damian Png, mb, Jorgen Nordling, MD  and Euan J. G. Milroy, MD    Benign prostatic hyperplasia (BPH) occurs histologically in approx  50% of men near the age of 60 and in nearly 100% of men by the age of  80 (1). It has been estimated that the prevalence of “clinical” BPH,  defined as an enlargement of the prostate gland >20 gm in the presence  of symptoms and/or a urinary flow rate <15 mL/s and without evidence  of malignancy was 253/1000 in a sample of 705 men aged 40-79 reg-  istered with a group general practice in Scotland (2). In the United  States, Glynn et al. calculated the chance of a 40-yr-old man subse-  quently requiring a prostatectomy as 29% (3).   Transurethral resection of the prostate (TURP) is still the traditional  therapy of choice for symptomatic BPH and represents the gold stan-  dard (4,5), against which other therapies need to be judged. Although    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    mortality has been decreasing over the last decade from 1.2% in 1984  to 0.77% in 1990, it is still significant (6—8) and increases with age from  0.39% in the 65—69 age group to 1.1% in the 75-79 age group and 3.54%  in those older than 85 yr of age (9). This is associated with a significant  morbidity of about 18% (10), which includes a 1% risk of total incon-  tinence; 2.1% risk of stress incontinence; 1.9% risk of urge inconti-  nence; a 1.7% risk of vesical neck contractures, and a 3.1% risk of  urethral strictures (71). This, coupled with increased public awareness  of alternative nonsurgical or minimally invasive treatment options, has  raised a number of questions as to the appropriate therapy in contempo-  rary practice.   One of these alternative surgical options is a minimally invasive  approach using a permanent endoprosthetic stent to tackle the problem  of bladder outlet obstruction, secondary to BPH. The use of such pro-  static stents appear to have a number of advantages, namely: a short  operating time, minimal blood loss, ease of insertion, a short hospital  stay, no in-dwelling catheter post op, and the absence of any expensive  equipment, which is often required in other alternative minimally inva-  sive therapies.   An example of such a stent is the Urolume stent, which is a mesh of  corrosion-resistant nickel superalloy wire woven into a flexible, expand-  able tube. It was originally developed for endovascular use by Hans  Wallsten, a Swedish national, for the prevention of stenoses after  transluminal angioplasty (12,13), but has been used successfully in the  urinary tract for the treatment of urethral strictures (/4,/5) and, more  recently, for the treatment of BPH in patients not fit to undergo a TURP.    The Urolume stent was first used in urology for the treatment of  bulbar urethral strictures that were unresponsive to urethrotomy by  Milroy and Chapple with fairly good results (74). Given its success with  bulbar strictures, it was used for the treatment of 12 patients with pro-  static outflow obstruction who were in a high risk group for surgery by  the same authors (/6). This was successful in resolving the outlet  obstruction in 11 patients with good re-epithelialization of the stent in  6-8 months. In five patients, some amount of stent protruded into the  bladder giving rise to encrustations in two. This study was extended to  include 54 unfit patients with prostatic outflow obstruction 3 yr later  (17). Four patients were unable to void postprocedure as a result of  chronic retention, leaving 50 patients who could void immediately  postop. A number of patients developed irritative urinary symptoms at    1-3 mo after the procedure but this resolved after 9 mo in the majority  of the patients. Symptom scores and peak flows were also significantly  improved after stent insertion by more than two times. Encrustation was  a problem in 14 patients (25.9%) and occurred in those patients with  either a protrusion of the stent into the bladder or when the re-epithelial-  ization was incomplete. Only one patient developed incontinence as a  result of stent encroachment over the distal sphincter mechanism. This  was easily removed. In all, 6 (11.1%) stents had to be removed: 3 because  of problems with positioning, 1 because of distal obstruction secondary  to prostatic adenocarcinoma, and 2 because of severe urge incontinence  in the presence of persistent detrusor instability.   Because of the relatively good results of the Urolume stent in unfit  patients, a number of studies involving fit, healthy men with BPH were  carried out both in Europe and in the United States.   A European series by Milroy et al. (/8) in 140 patients with an 18-mo  follow-up showed similar findings to the earlier studies by Milroy and  Chapple. There were 94 patients with symptomatic BPH and 46 with  acute urinary retention. Both groups showed significant improvements  to their peak urine flows and their symptom scores from a preoperative  mean peak flow of 9.3 mL/s to a postoperative mean peak flow of  17.3 mL/s in the symptomatic BPH group and 13.5 mL/s in the retention  group. Symptom scores were similarly reduced to a mean of 7.6 and 3  (Madsen-Iversen), respectively. Fourteen patients (10%) had their stent  removed: 11 for malposition and 3 for persistent symptoms related to  the stent.   The North American Urolume Prosthesis Study Group’s experience  with the Urolume prostatic stent was reported by Oesterling et al. (/9)  and involved 126 men, of which 95 had symptomatic BPH and 31 had  acute retention of urine. At 2-yr follow-up, symptom scores (Madsen-  Iversen) decreased from a mean of 14.3 preinsertion to 5.4 postinsertion  in the no-retention group and to 4.1 postinsertion in the retention group.  Mean peak flows increased from 9.1 mL/s preinsertion to 13.1 mL/s  postinsertion in the nonretention group and to 11.4 mL/s in the retention  group. Residual urine volumes were similarly improved from 85 mL  preinsertion to 47 mL postinsertion in the nonretention group to 46 mL  inthe retention group. Significant long-term complications that required  stent removal was seen in 17 patients (13%). These were removed  transurethrally without any subsequent effects. The most common causes  of stent removal were stent migration (29.4%) and recurrent obstruction  at the bladder neck or apex (29.4%). Two (11.8%) were removed for  persistent irritative symptoms, two for perineal discomfort, and two for  encrustations secondary to the exposed stents at the bladder neck.    Because of such complications regarding protrusion of the stent into  the bladder neck, modification of the stent was carried out and studied  in 135 fit men with prostate outflow obstruction by Guazzoni et al. (20)  in a multicenter trial in Europe. The modifications carried out allowed  a reduction of the amount of shortening that occurs when the stent  expands. This was thought to facilitate proper stent placement and was  achieved by altering the crossing angles of the wires from 142° to 110°  and using a thicker wire diameter (0.17 mm—0.20 mm). However, it also  resulted in a decrease in the applied pressure/mm of urothelium from  6972 Pato 2941 Pa. Long-term results regarding improvements in symp-  tom scores, uroflowmetry, and residual urine volumes at 18 mo were no  different from the earlier studies, but the modified less-shortening (LS)  Urolume stent had a much higher long-term complication rate (31.1%,  n=42) when compared to the commercially available (CA) Urolume  stent. These included 11 (26.2%) stent migrations, 17 (40.5%) under-  stentings or malpositions, 4 severe epithelial hyperplasia, 2 persistent  irritative symptoms, 2 subsequent regrowth of the median lobe, and 2  urethral strictures. These required the removal of the prostatic stents in  21 (15.5%) patients with the authors commenting that some of the com-  plications, particularly stent migrations and epithelial hyperplasia, are  related directly to the changes made in the modified LS Urolume stents.  This stent was subsequently dropped from use.    The Urolume stent is designed for use with an introducer that is  designed to be used like a cystoscope. General, regional, or local anes-  thesia with urethral lignocaine and intravenous sedation are given and  the patient is placed in the lithotomy position.   Based on our previous experience with prostatic stent insertion, we  have introduced a number of modifications to the original technique  used for device implantation (/6) to ensure correct placement with maxi-  mum stenting of the prostatic urethra and, in particular ,to avoid protru-  sion of the stent into the bladder when the bladder neck is funneled open  at the time of a full bladder.   A cystoscopy is carried out on the patient and, using a purpose-  designed measurement catheter with a foley balloon at its proximal end,  the length of the prostatic urethra is measured under direct vision from  the bladder neck to the distal sphincter mechanism. A stent with alength  0.5 cm less than the measured length of the urethra is inserted. The stent-  insertion device is inserted under direct vision and positioned at the  bladder neck. The outer sheath is then withdrawn a bit, allowing partial  opening of the stent, which is then withdrawn distally to ensure that the    stent lies distal to the bladder neck itself; checking, in particular, that  this is the case at the 12 o’clock position. The outer sheath is then  removed completely to the safety-lock position, the position of the stent,  in particular, relative to the bladder neck is then checked. At this stage,  the stent can be retracted back into the device and repositioned as required.  When the operator is happy with this, the safety lock is removed and the  stent fully deployed.   The stent can be removed by retrograde displacement back into the  bladder followed by extraction via a purpose-designed extraction device.  In the initial series, we removed six stents, four at up to 1 mo, because  of initial problems related to placement. In two patients at longer inter-  vals—11 mo and 18 mo after insertion, in one case because of persisting  incontinence in a patient with severe recalcitrant detrusor instability, the  latter being a patient with Parkinson’s disease. In these two patients, it  was necessary to resect the covering urothelium prior to removal.    Because of the relatively good results with the Urolume stents in  patients with symptomatic BPH who were unfit for a TURP and its  perioperative advantages, namely: a short operating time, minimal blood  loss, ease of insertion, a reduced hospital stay, and no in-dwelling cath-  eter postoperatively, it would, by comparison, appear to provide a suit-  able treatment alternative to TURP for the management of symptomatic  BPH, especially in older patients (9). In order to evaluate the efficacy of  a permanently implanted stent in the fit patient over age 65 with BPH,  we conducted a randomized controlled trial to compare the Urolume  Plus prostatic stent against standard TURP in 86 patients with symptom-  atic BPH.    This prospective randomized trial was carried out in three centers in  the United Kingdom and Denmark, with full ethical committee approval.   Eighty-six surgically fit patients above age 65 on the waiting list for  prostatic surgery with symptomatic and urodynamically proven bladder  outlet obstruction caused by BPH were selected for treatment and ran-  domized to either Urolume insertion or TURP.   Safety and efficacy data before, during, and up to 1 yr after treatment  were collected and analyzed. Reviews were carried out at 1, 3,6, and 12  mo regarding to urinary symptoms, pain and sexual function scores,  urine flow rates (adjusted for voided volume), residual urine volumes,  and pressure flow studies. An IPSS quality-of-life questionaire was    administered at the 1- and 12-mo visits with a BPH impact index at the  same time. Patients with known bladder cancer or intravesical stones,  neurological disease affecting bladder function, urethral stricture dis-  ease, known or suspected prostatic cancer, prostate volume < 30 g,  prostatic urethra < 2.0 cm in length, median lobe obstruction, and those  on current pharmacotherapy for BPH were excluded.   Data was also collected on perioperative and post-operative compli-  cations, length of operating time, and length of postprocedure hospital-  ization. Potential risks identified with the endoscopic treatment of  prostatic obstruction included risks associated with anesthesia, bleed-  ing, infection, incontinence, sexual dysfunction, and urethral stricture  formation. Specific risks identified with stent placement included mis-  placement or placement of an incorrect size stent requiring removal and  replacement, urethral injury, encrustation, erosion, wire fracture, stent  migration, stent shortening, and obstructive reactive hyperplasia. Spe-  cific risks identified with TURP included hemorrhage and clot reten-  tion, retrograde ejaculation, and the TUR syndrome.    Ten patients dropped out of the study before treatment began and a  further four in the TURP arm were found to have bladder neck obstruc-  tion and underwent a bladder neck incision instead of TURP and were  excluded from the study. Of the remaining 72 patients, 14 had urinary  retention and were excluded from the efficacy analysis, but were included  in the safety analysis. Three patients from the Urolume arm failed stent  insertion leaving a final 30 patients on the Urolume arm and 25 patients  on the TURP arm with complete follow-up for a full analysis at 1 yr.   There were no significant differences between the two arms regard-  ing age, IPSS scores, residual urine volumes, prostate-specific antigen  (PSA) levels, prostate volumes, and length. There was, however, a dif-  ference between the peak urine flow rates between the two groups,  which, on adjusting for voided volumes, showed a p value of 0.05 (stu-  dent t-test), which just misses significance (see Table 1)   Data addressing the potential risks of the two treatments were ana-  lyzed in 72 patients from both nonretention and retention groups.    The median operating time was 11.5 min (range: 10—40 min ) for the  Urolume arm compared to 37.5 min (range: 15—100) for the TURP arm.  This was statistically significant (p< 0.001). Three patients out of 39  in the Urolume arm failed stent insertion because of difficulty in releas-  ing the stent in two and a “tight” gland that squeezed onto the stent in one.    Table 1  BPH Impact Index (BII)  None A little Some A lot   1. Over the past month, 0 1 2  how much physical  discomfort did any  urinary problems  cause you?   2. Over the past month, 0 1 2 3  how much did you  worry about your  health because of  any urinary problems?    Four patients out of the 33 undergoing TU resection experienced severe  bleeding requiring transfusion intraoperatively during the TURP. There  were three documented capsular perforations.   The median days of hospitalization were 1 (0-10 d) and 4 (2-9 d) days  for stent insertion and TURP, respectively, and the difference was sta-  tistically significant (p=0.001). All patients with a TURP were catheter-  ized compared to two Urolume patients who had a suprapubic catheter  inserted after failing to void. However, the duration of an in-dwelling  catheter was a median of two days for the TURP arm compared with the  5.5 d for the Urolume arm.   Three patients developed nausea and vomiting in the immediate  postoperative period after TURP compared to none in the Urolume arm.  Early postop hematuria was present in four patients after stent insertion    and four after TURP. All four patients on the TURP arm required blood  transfusions, whereas the hematuria poststent insertion was milder and  required no action.   Five patients on the Urolume arm and 8 patients on the TURP arm had  repeated positive urine cultures during the 1-yr follow-up. One patient  on the Urolume arm developed epididymoorchitis. All patients were  treated with antibiotics and the infections duly resolved with no further  complications.   Two patients on the TURP arm developed persistent hematuria and  one had gross hematuria requiring emergency admission and transfu-  sion 6 wk after the procedure. Two patients on the Urolume arm devel-  oped persistent hematuria. One had a urethral stone on the bare stent at  the 6-mo visit and the other patient had marked intrastent reactive  hyperplasia.   Three patients in each arm required a second intervention during the  1-yr follow-up. Two patients with stents inserted required a second stent  as aresult of shortening discovered during follow-up at 3 and 6 mo. One  recovered uneventfully, whereas the other who initially presented with  acute retention required intermittent self-catheterization for large  residual urine volumes. The third had marked intrastent reactive hyper-  plasia, which required a TU resection. The three patients on the TURP  arm with reintervention included arepeat TURP for residual gland at 3 mo  follow-up, a urethrotomy for a urethral stricture at 6-mo follow-up and  a bladder neck incision for a bladder neck stenosis at 12 mo.   Three patients died during the course of the study. One patient com-  mitted suicide a month after his TURP. Another patient with a Urolume  stent died of acute renal failure secondary to ischemic bowel at 3-mo  follow-up and the third patient died of severe pneumonia and GI hem-  orrhage 8-mo post-Urolume stent insertion. One patient in the retention  group who had a Urolume stent inserted was discovered at 3-mo follow-  up to have prostate cancer on a third set of prostatic biopsies with the  previous two having been reported as normal.    Pain  Data was collected on urethral pain and pain associated with both  erection and ejaculation.    Six patients in the Urolume arm and one in the TURP arm had urethral  pain pretreatment (see Fig. 1). At the one month follow-up, patients with  urethral pain increased significantly to 13 in the Urolume arm and 11 in  the TURP arm, respectively. Although there was statistical significance    Fig. 1. Urethral pain by treatment type and length of follow-up.    in both groups (p=0.013 and p=0.001, respectively) at 1 mo and pre-  treatment, no statistical difference between the two groups was seen.  The number of patients with urethral pain then reverted back to baseline  values at 6 and 12 mo in both arms of the study.    One patientin the Urolume arm and two patients in the TURP arm had  mild pain on erection before treatment (see Fig. 2). This did not change  significantly with time. At the end of 12 mo, one further patient in each  treatment group experienced moderate pain on erection.    One patient in the Urolume arm and three patients in the TURP arm had  mild to severe pain on intercourse before treatment (see Fig. 3). Patients  who have not had intercourse were excluded from the statistical analysis.  At 3 mo, one patient had severe pain and two had mild pain during inter-  course in the Urolume arm compared to none in the TURP arm. This was  Statistically significant. (p<0.05) This improved to three experiencing  mild pain at 6 mo in the Urolume group and both groups having three  patients at 12 mo follow-up with mild pain during intercourse.    Sexual Function  ERECTION  There was no significant change in the number of patients and strength  of erection in both groups before and after treatment (see Fig. 4). They    were approx divided into three equal groups with a third having no  erections, a third having partial erections, and a third having full erec-    Fig. 2. Erection pain by treatment type and time after procedure.    tions. No difference was noted between the two arms before treatment  and at 12 mo.   No difference was also noted in erection frequency between the two  groups.    In the Urolume and TURP arms, 77.8% and 83.3% of patients, respec-  tively, had the ability to ejaculate before treatment (see Fig. 5). This decreased  slightly to 64.7% and 72.7%, respectively, at 3 mo and 75% and 60%, respec-  tively, at 12 mo. Although there appeared to be a trend toward decreased  ejaculatory ability with time in the TURP group, it did not approach statistical  significance. There was no significant change in the Urolume group.   Regarding the nature of ejaculation, 92.9% and 100% of patients in  the Urolume and TURP groups, respectively, had antegrade ejaculation  prior to treatment (see Fig. 6). Although there was a statistically signifi-  cant increase in the numbers with retrograde ejaculation before treat-  ment: -7.1% and 0%, respectively, to 50% and 50%, respectively, at 12 mo    wo  a  S  a  &  3Months R  E TURP  p  2  È  B 6 Months > 3  & Urolume Plus  > l  3 i  2  2 6 Months 5  TURP  kur  12 Months 3 ;  Urolume Plus  |  12 Months ; 3  TURP  LE ea i A a toe AEE,  0% 20% 40% 60% 80% 100%    Fig. 3. Pain during intercourse by treatment type and time after procedure.    after treatment in both groups, there was no statistical difference between  the changes between the two arms of the study.    Of the 20 Urolume patients assessed by cystourethroscopy at 12 months  postprocedure, 75% of the patients had 90-100% epithelialization of  the stent. Ninety percent had at least 70% epithelialization and one  patient had less than 50% epithelialization (see Fig. 7).    Four (20%) patients with the Urolume stents developed encrustations  on their stents. The majority were small calcifications, but one had a  stone sized 1 cm in diameter in midurethra arising from an exposed area  of the stent. The stone was easily removed endoscopically during the  cystoscopic evaluation. There were no intravesical protrusions of the  stents identified at 12 mo.    { , : fi  0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%    Thirteen patients (65%) developed intrastent reactive hyperplasia at  12 mo. Of these, three (15%) had marked hyperplasia with one requiring  TU resection of the hyperplastic tissue. This recurred at 12 mo. The  other two did not require further intervention. It was interesting to note  that neither of these two had any bare wires visible, although one had  encrustations seen within the hyperplastic tissue.   There was one stent migration identified at the 12-mo follow-up. This  was found in the bladder and was completely encrusted. It was removed  transurethrally and a TURP was subsequently carried out.    There were 6 patients with residual hypertrophic tissue after TURP out  of the 12 assessed cystoscopically. Of these, one required a repeat TURP  on the basis of urodynamically proven bladder outflow obstruction.    Pretreatment 14 4  Urolume Plus  Pretreatment 15  TURP  a 3 Months tt 5  Q Urolume Plus  >  È  g  o 3 Months  8  £ TURP 3  S See AE =a  Ga 1  B 6 Months jz | 5  5 Urolume Plus |  ž i  a  © 6 Months  3  5 TURP " |  i  oi i co cam di as |  12 Months 12 4  Urolume Plus  12 Months 5 A  TURP  O O E E V PET OOO E O E O E EEEE  0% 20% 40% 60% 80% 100%    Fig. 5. Ejaculatory ability by treatment type and time after procedure.    Baseline peak flow rates was 9.2 mL/s (SD:2.61) and 7.6 mL/s  (SD:2.19) forthe Urolume and TURP arms, respectively. Both improved  significantly (p<0.001) to 12.7 mL/s (SD:7.60) and 16.1 mL/s (SD: 8.2),  respectively, at 3 mo and 12.8 mL/s (SD: 6.04) and 19.3 mL/s (SD: 8.7),  respectively, at 12 mo after treatment (see Fig. 8). The TURP group also  had significantly better peak flow rates (p=0.028) as compared to the  Urolume group over time. Similar results were obtained with the  adjusted peak flow rates.   If one looks at success rates by percentage improvement (see Fig. 9),  75% of patients after TURP had a 77.8% improvement to their peak flow  rates at 1-yr follow-up, compared to only 30.8% of patients in the  Urolume arm. In the Urolume arm, 57.7% had at least a 25% improve-  ment to the peak flow rates, compared to 94.4% in the TURP arm.    Residual urine volumes were both significantly reduced from a median  baseline of 77.5 mL (range: 0-400 mL) to 35.5 mL (range: 0-177 mL) at    Fig. 6. Type of ejaculation by treatment type and time after procedure.    Fig. 8. Mean peak flow rates by treatment type and time after procedure.    12 mo for the Urolume arm and 50 mL (range: 0-600 mL) to 10 mL  (range: 0-99 mL) at 12 mo for the TURP arm. Although there appears  to be a significant difference between residual urine volumes for the  TURP and Urolume arms at 12 mo (p=0.002), there was no significant  difference between the two groups if the degree of improvement between  the baseline and 1-yr residual volumes was used (p=0.94). The differ-  ence being a result of the initial difference of the baseline residual vol-  umes between the two groups, rather than a true difference as a result of  treatment.   If one looks at percentage improvement of residual volumes, 72.7%  in the Urolume arm and 82.4% in the TURP arm had at least a 25%  improvement to their residual urine volumes. There was no statistical  difference between the two groups. More than half (58.8%) of patients  after TURP had a 75% improvement to their residual urine volumes at  1 yr. This is fairly similar to the 50% of patients in the Urolume arm who  also had a 75% improvement to their residual urine volumes.    Fig. 9. Success rates by percent improvement of peak flow rates at 1 yr.    Mean detrusor pressures at peak flow decreased significantly from  98.1 (SD:6.5) cm H,O to 42.9 (SD:5.3) cm H,O for the TURP arm, and  from 89.6 (SD:5.4) cm H,O to 56.1 (SD:6.9) cm H,O for the Urolume  arm at the 6-mo follow-up (see Fig. 10). Although there was a signifi-  cant difference in the pre- and posttreatment detrusor pressures in both  groups, there was no significant difference between the detrusor pres-  sures of the two groups following treatment.    AUA symptom scores showed a significant drop from a mean baseline  value of 20.4 (SD:7.36, p=0.001) in the Urolume arm and 19.8 (SD:5.39,  p=0.001) in the TURP arm to a mean value of 13.6 (SD:7.12) and 12.3  (SD:6.39), respectively, during the first month after treatment. This  value then decreased gradually to a score of 10 (SD:5.19) and 7.8  (SD:6.41), respectively, at 12 mo (see Fig. 11). There was no significant  difference between the two treatment arms in the ANOVA analysis  (p=0.459).    Fig. 10. Comparison of mean maximum voiding pressures by treatment type  at 6 mo.    The QOL score owing to urinary symptoms revealed 73.3% of the  Urolume arm and 79.2% of the TURP patients who were “mostly dis-  satisfied,” “unhappy,” or “feel terrible” before treatment, compared to  42.3% and 33.3% at 1 mo after treatment and 8% and 10% at 12-mo  follow-up, respectively (see Fig. 12). There was no significant differ-  ence in QOL scores between both arms.   Only two patients (6.7% and 8.3%) in each arm were either “pleased”  or “mostly satisfied” before treatment, compared to 38.5% of the  Urolume arm and 52.4% of the TURP arm at 1 mo after treatment. This  improved to 68% for the Urolume arm at 12 mo and 80% for the TURP  arm. Although the mean values and the median scores (see Table 2) for  the TURP arm was better at 1 and 12 mo compared to the Urolume arm,  there was no statistical difference between the two groups.    This is a QOL index that measures how much the urinary symptoms  affect the various domains of health.    6- - 7 j  Pretreatment 1 Month 3 Months 6 Months 12 Months  Follow-Up    Fig. 11. Follow-up comparison of mean AUA symptom scores by treatment type.    The mean BPH Impact Index decreased from 6.5 before treatment to  1.8 at 12 mo in the Urolume arm. This was not significantly different  from the decrease seen in the TURP group with a pretreatment value of  5.8 changing to 1.8 in 12 mo. No difference between treatment types  (p=0.314) was found in the ANOVA analysis, but there was a signifi-  cant difference in both the groups before and after treatment (p=0.001).    Since the use of Urolume urethral stents in the treatment of benign  prostatic hyperplasia was first reported in 1989 (2/), its use has been  advocated by anumber of authors in unfit patients undergoing prostatic  surgery (16,22,23). The Urolume stent has been evaluated in a number  of studies of unfit patients. In a collaborative study involving 96 unfit    Percentage of Patients by QOL Score  0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%    (Ci Delighted, Pleased, Mostly Satisfied _  Mixed  E Mostly Dissatisfied, Unhappy, Terrible |    men from five European centers, Williams et al. (24) showed that objec-  tive and symptomatic evidence of relief of the bladder obstruction was  evident throughout the 12 mo of the study. Complications included  irritative symptoms in the first 3 mo postinsertion requiring removal in  three patients and encrustations that developed in 14 patients, with 9 of  these resulting in urinary infection. To deal with this, modifications  of the insertion technique have been developed as aforementioned.   In this study, which represents the first randomized study against  TURP involving 86 patients included in the two treatment groups, we  found that the Urolume stent had a distinct advantage over a standard  TURP when the operative procedure and the perioperative course was  reviewed. It only took about 11.5 min to employ a urethral stent, com-  pared to 37.5 min for a TURP. Blood loss was minimal compared to the  four patients who required blood transfusion during the resection.    Table 2  Baseline Characteristics of Patients Randomized Trial Receiving Either  UroLume Insertion or TURP, in Three Centers in the UK and Denmark    Urolume  Characteristic Plus Group TURP tValue pValue  Age at insertion n 30 25  (yr) Mean 72.5 72.3  SD +/-6.73 +/—4.90  Range  62.0—90.0 63.0-84.0 0.14 0.89  AUA Symptom n 28 24  Score Mean 19.8 20.4  SD +/-7.36 +/-6.08  Range 5.0-30.0 11.0-33.0 -0.31 0.76  Peak flow (ml/s) n 30 25  Mean 9.2 7.6  SD +/-2.61 +/-2.19  Range 3.9-15.0 4.2-11.7 2.31 0.03  Adjusted peak n 30 25  flow (ml/s) Mean 0.71 0.58  SD +/-0.27 +/—0.23  Range 0.32-1.39 0.27-1.28 1.97 0.05  Volume voided n 30 25  (ml) Mean 191.6 209.5  SD +/-91.1 +/-107.8  Range 69.0-413.0 48.0-456.0 -0.67 0.51  Residual urine n 28 23  volume (ml) Mean 77.5 50.0  Range  0.0-400.0 0.0-600.0 NA* 0.63*  Length of prostate n 30 22  (cm) Mean 2.5 30  Range 2.0-4.0 2.0-6.0 NA* 0.05*  Prostate-specific n 25 22  antigen (ng/mL) Mean 4.65 4.65  Range 0.6-17.8 0.7-38.5 NA* 0.91*  Obstruction minor 1(3.3)! 1(4.2)    Hospital stay was 1 d, compared to 4 d for a TURP, and only two patients  required a urinary catheter.   However, postoperatively both procedures were equally affected by  complications abeit differing in terms of their nature and severity. Three  patients developed nausea and vomiting after the TURP, compared to none  in the Urolume arm. This may be more related to the length of anesthesia,  rather than the effects of the surgery. Itwas, however, interesting to note that  four patients on each arm developed bleeding with the four from the TURP  arm requiring intraoperative blood transfusion. This is probably the greatest  problem with the TURP. One patient who developed clot retention after the  stent insertion, required a bladder washout via the suprapubic catheter. This  was removed after 4 d and the patient was discharged after voiding nor-  mally. Although the Urolume stent is a foreign body in the urethra and needs  time for epithelialization, there was no difference in urinary infection rates  between the two groups. All infections resolved with antibiotics. Urinary  infections have previously been reported in association with stent encrus-  tation (25), but this association was not found in our study.   Persistent hematuria without pyuria was another problem that occurred  in both groups. For those in the TURP arm this was probably related to  a raw resected surface that had not yet fully epithelialized. The two  patients in the Urolume arm with persistent hematuria were found to have  a urethral stone and marked intrastent reactive hyperplasia, respectively.   There was also no difference regarding the reintervention rates in  both arms although the types of reintervention were quite different.  TURP had problems with residual gland, urethral strictures, and bladder  neck stenosis, whereas the Urolume arm had problems with intrastent  reactive hyperplasia and shortening of the stent. Whether this is a result  of incorrect selection of the stent length during the procedure or due to  a true shortening of the stent is unclear.   Urethral pain was a significant problem in both groups with the 1-mo  follow-up with the Urolume arm having nearly twice the number of  patients with moderate or severe urethral pain compared to the TURP  arm. There was no significant difference regarding the frequency of  urethral pain in both groups, although most studies involving stents do  report this to be a problem. Urethral pain decreased markedly at 3 mo  and resolved spontaneously by the 12-mo follow-up in both arms of the  study. No patient required removal of the stent as aresult of urethral pain  in this study. There was no significant pain on erection between the two  groups, but at the 3-mo follow up, there were significantly more patients  with pain during intercourse in the Urolume group compared to the  TURP group (p=0.05). The pain on intercourse in the Urolume arm  improved to a mild pain at 6 mo to baseline at 12 mo.    Where the strength and frequency of erection was concerned, there  was no significant difference between the two groups. There was also  no statistical difference in the ability to ejaculate in both groups. How-  ever, both TURP and stents resulted in retrograde ejaculation in about  50% of patients treated in each arm at the end of 12 mo. There was no  statistical difference between the two groups.   Cystoscopic follow-up showed that 25% of patients with the Urolume  stent had <90% epithelization after 1 yr of follow-up. This led to asymp-  tomatic encrustations in four patients (20%). None were related to uri-  nary infections. Some degree of intrastent hyperplasia was present in  65% of patients with the Urolume stent inserted with 15% showing  marked hyperplasia. One patient required a transurethral resection of  the hyperplastic tissue. The cause of the hyperplasia is still not fully  understood. Whether it is because of the intrinsic reaction of the  urothelium to the stent material or secondary to chronic irritation as a  result of encrustations or infection or a combination of the two is still  open to debate. Stent migration occurred in one patient (3.3%) and was  thought to be caused by an incorrect implantation technique. Residual  hypertrophic tissue after TURP was seen in six patients.   Regarding the efficacy of both treatments, peak and adjusted peak  flow rates were improved significantly after both types of treatment.  Where the peak flow rates after Urolume tended to plateau off 1 mo  poststent insertion, peak flow rates after a TURP continued to improve  with time to give a significantly much better flow rate at 12 mo, com-  pared to the Urolume stent. Using percentage improvements to the flow  rates as an index, 80% of patients had a 50% improvement to their flow  rates compared to only 46.2% in the Urolume arm.   Although the improvement in flow rates in the TURP group were  greater, there was no greater reduction in the mean voiding detrusor  pressures at peak flow in the TURP group compared to the stent group.  Improvements in the residual urine volumes in both groups were also  noted after treatment but there was no difference in the reduction of the  residual urine volumes between the two groups.   When one looks at symptom scores, both treatments had significant  improvement to their scores as a result of treatment. This improved over  the 12 mo, with no statistical difference between the two groups.   QOL scores in both groups were similarly improved after treatment  significantly. Both groups also saw their scores improve over the 12 months  with the TURP arm suggesting a marginal advantage. However there was  no statistical difference between the two groups. The same results were  found with the BPH impact indices.    These results and the results of earlier studies suggest that a perma-  nently implanted Urolume prostatic urethral stent, with its low morbid-  ity via a reduced operating time and hospital stay, is a safe alternative  to TURP. It appears to produce only slightly more postprocedure dis-  comfort and pain during intercourse than a TURP and the majority of  such symptoms resolve eventually. Erection and ejaculatory dysfunc-  tion are also not dissimilar.   The improvement in symptoms and QOL are identical with both  treatments at 1-yr follow-up, but TURP produces a significantly better  flow rate compared to the Urolume stent. However, residual urine vol-  umes and mean detrusor pressures were not significantly different. It  may well be in this assessment that the Urolume stent, because it is  associated with less morbidity, has a distinct perioperative advantage  over a TURP for the elderly fit patient. However, unlike a TURP, its use  is limited by the anatomy of the prostatic enlargement which can be asso-  ciated with technical failure, for instance in the wide or short prostatic  urethra and the presence of an obstructing median lobe hyperplasia. In  the longer term, intrastent hyperplasia and calcifications do occur in an  unpredictable fashion and together with the failure of epithelialization,  represent a problem for use of stents for BPH. For unlike many post-  TURP complications, such complications after stent insertion may  necessitate stent removal.   TURP should still remain as the standard treatment for BPH in the fit  nongeriatric patient until such time when the problems of intrastent hyper-  plasia and epithelialization failure are resolved and probably when longer  term results, with up to 5-yr follow-up, of the Urolume stents are available.    1. 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Gabellon S, Wisard M, Leisinger HJ (1994) A prospective clinical study of the  Urolume endoprosthesis for the treatment of benign prostatic hyperplasia in  inoperable patients. J Urol 151:396A.   Guazzoni G, Bergamaschi F, Montorsi F. et al. (1993) Prostatic Urolume  wallsten for benign prostatic hyperplasia patients at poor operative risk: Clinical  uroflowmetric and ultrasonographic patterns. J Urol 150:1641.   Williams G, Coulange C, Milroy EJG, Sarramon JP, Rubben H (1993) The  Urolume, a permanently implanted prostatic stent for patients at high risk of  surgery: Results from 5 collabrative centres. Br J Urol 72:335-340.   Holmes SA, Miller PD, Crocker P, et al. (1992) Encrustation of intraprostatic  stents—a comparative study. Br J Urol 69:383-387.    Testicular prostheses are used in scrotal reconstruction for multiple  diagnoses, including replacement following orchiectomy for prostate  cancer, traumatic loss, congenital absence, testicular torsion, infection,  or testicular tumor. The ideal testicular prosthesis should conform to the  size, shape, and consistency of the normal testis. It should be made of  a biochemically inert substance, producing little tissue reaction, and  noncarcinogenic. For practical purposes it should be easily sterilizable,  and not change size or shape with time .    The first report of the use of a testicular prosthesis was in 1941 by  Girsdansky and Newman who used a vitallium implant (2). Since then,  others materials have been used including Lucite, glass, Gelfoam,    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    Dacron, polyethylene, and silicone rubber (3). A prosthesis made of a  silicone rubber bag filled with silicone gel became available in 1973,  and was used until 1992.   In 1976, Congress passed an amendment providing the FDA with the  authority to regulate medical devices. Preamendment devices were those  that had been used prior to the creation of the FDA, such as the testicular  prosthesis, and had escaped regulatory scrutiny. In 1990, Congress  passed the Safe Medical Devices Act, which gave the FDA (until 1995)  to review the safety and efficacy of preamendment devices. The act also  mandated that manufacturers of high-risk devices keep easily obtain-  able records of the identity and location of patients using these devices.  Silicon gel-filled prosthetics were included on the high-risk list (4).   In 1992, because of this regulatory action, and probably because of  the question of silicon gel leakage from breast implants and its ques-  tion of association with systemic disease, manufacturers halted pro-  duction of gel-filled testicular implants. (In spite of the fact that no  patient with a gel-filled testicular prostheses had been reported to  develop systemic disease.) In its 1992 policy statement, the AUA  recommended that physicians weigh individual risks, benefits, and  informed desires in consideration of implantation or removal of tes-  ticular prostheses (5).    There is a paucity of data implicating silicone implants in the devel-  opment of alleged human adjuvant disease. Human adjuvant disease is  manifested by symptoms and serological disorders of autoimmune dis-  ease. Rheumatoid arthritis, scleroderma, systemic lupus erythematosus,  and other connective tissue diseases have been linked to human adju-  vant disease. The development of human adjuvant disease has been  linked to silicone gel breast implants, but not yet to gel-filled testicular  implants. Locoregional diseases, such as Kikuchi’s disease, lymphad-  enopathy and lymphoma, which have been associated with breast  implants, have not been linked to testicular implants (6). Moreover,  silicone materials are worldwide, and its exposure is almost universal,  yet the development of these diseases has not been widespread.   What causes the purported immune reaction? There are a few theo-  ries. It may be that the silicone gel, which leaks from the envelope, acts  as an antigen. Alternatively, macrophages may convert silicone to silica,  which is also an antigen. Silica has been found in the area around various  silicone implants. The silicone itself may block the clearance of nor-  mally produced cellular debris to allow an autoimmune reaction. Unfor-  tunately, the exact mechanism is unknown.    Pidutti and Morales reported on 51 patients receiving 63 gel-filled  prostheses between 1978—1991, of which 34 were available for follow-  up. They reviewed hospital admission charts for any problem the patients  encountered since placement of the prosthesis. After a mean follow-up  of 5 yr, they found no evidence of disease linked to human adjuvant  disease (7). Henderson et al. went one step further by giving follow-up  patients a detailed health profile questionnaire, physical exam, and sero-  logic testing (sedimentation rate, rheumatoid factor, C3, C4, IgA, IgE,  IgG, IgM). Of 48 patients, 35 had an undescended testicle, and 13 tes-  ticular torsion, with implant surgery during the years 1979-1992. Seven  patients agreed to follow-up studies, with a mean surgical age of 14 yr,  and follow-up range of 1-7 yr. None of these patients had human adju-  vant disease, but five of seven had one or more abnormal serologic tests.  Their patient population seems younger than women who had breast  implants, so longer follow-up will be necessary before any real conclu-  sion can be obtained.    Currently, there are a couple of types of implants that are worth  reviewing. Silimed, Inc. markets an oval carving block of solid silicon  elastomer, historically used for facial reconstruction. Ithas amesh button  that can be used for an anchoring stitch. It is available in five sizes [see  Figs. 1(A), (B)]. Although it is solid, itis relatively soft. As itis acarving  block, it can be made smaller, if needed.   Mentor has a saline-filled model, which is marketed internationally,  but at the current time is under experimental review in the United States.  The Mentor Saline-Filled Testicular Prosthesis (SFTP) is a Class HI  product, requiring ahuman clinical trial for market clearance. This trial,  called an Investigational Device Exemption, follows patients who have  been implanted with the prosthesis. Once clinical data are collected on  these core trial patients, a premarket approval is submitted to the Food  and Drug Administration, reporting on the safety and effectiveness of  the device. Mentor has completed the enrollment into the core study.  There is currently an adjunct study to allow patients access to the device  while the core study data are being reviewed   The Mentor SFTP approximates the weight, shape, and feel of a  normal testicle. The prosthesis is available in four sizes; extra small,  small, medium, and large. The implant consists of a molded silicone  shell, approx 0.035-in thick, with a self-sealing injection site located on  one of the prosthesis. The injection site allows the surgeon to fill the  implant with sterile, pyrogen-free sodium chloride solution. On the end    SILICONE ELASTOMER  Catalog Ordering Information  CD REFERENCE VOLUME DIMENSIONS  cm? cm  A B  B 3210-023 5,3 20 23  3210-034 12,7 25 34  3210-042 22,6 30 42  3210-047 28,6 32 47  3210-050 45,8 40 50  a m — a —    Fig. 1. (A) Silimed oval carving block is a solid silicone elastomer. (B)  Silimed—catalog ordering information.    opposite of the fill site is a silicone elastomer tab for suturing the prosthe-  sis in place if desired. For study sites, call Mentor at (800) 525-8773 (8).    The major benefit of testicular implants used in scrotal reconstruc-  tion is to restore the appearance of a man’s testicles, and provide psy-  chosocial sexual well-being. Certainly in an adult, who previously had  testicles, such as in patients with prostate cancer, insertion of prostheses  may be an easy decision, as they can know if they experience a change  in body image with orchiectomy. It may be that coping mechanisms are  established in mature males. Some may feel that itis somehow unnatural  to place prostheses, and they have to learn to live without anything in  their scrotum. Others may feel that it is important to make use of what  is available to make them feel whole again.   Unfortunately, not much is known on the role of the testes in male  psychosocial development. It is possible that school-age children do  feel anxiety, and may experience the absence of testicles as a phallic  defect. Placement of prostheses was helpful in various psychiatric reports  (9). Money reports on a patient with Kallman’s syndrome who waited  until age 30 to have implants because he felt he was not ready. In retro-  spect, the patient writes that he “spent a lot of (his) youth on needless  depression... now he felt part of the human race” and . . . the prostheses  “became a natural part of him,” allowing him to be more secure in his role  as a male, both sexually and socially (/0). In dealing with children and  adolescents, it is important to support their decision, and if needed, seek  counseling to help them sort through the options.   Bracka evaluated long-term psychosexual findings in boys who had  hypospadias repair, and found that genital appearance was much more  important in their teenage years than in boyhood . He also found,  however, that those with less initial deformity and those with a better-  looking penis had better self-esteem with more sexual partners. Those  with a more severe initial deformity or ultimately worse-looking penis had  poor self-esteem, and fewer sexual partners. In a similar report on hy-  pospadias follow-up, Berg et al. reported on 39 men who underwent  hypospadias repair between age 3 and 9 yr. Overall, the group tended  to have fewer coital partners, and a later age at initiation of sexual  activity, compared to an age-matched control group (/2).   An important part in dealing with a child with a genital anomaly  psychosexual identity depends not only on appearance, but also on how  the parents deal with the problem. In general, not focusing on the geni-  tals is important, but parents can be sensitive to when it seems problems    arise. Offering children and adolescents educational support with pro-  fessional counseling by surgeons and psychiatrists is important.    In general, any patient with an intrascrotal neoplasm or infection,  infection or abscess anywhere in the body, or uncontrolled diabetes or  other wound-healing impairment should not have an implant. Patients  with tissue damage from radiation, or compromised vascularity are at  higher risk of surgical failure. Until more is known about the relation-  ship of autoimmune diseases to silicone, prosthetics should not be placed  in patients with systemic lupus, discoid lupus, scleroderma, rheumatoid  arthritis, or other connective tissue disorders. Finally, any patient with  severe psychological instability may be better served not having an  implant placed, particularly if he is at risk of poor follow-up.    When the scrotum is small from disuse or previous infection, it can  be difficult to place a prosthesis. One method is to place a small pros-  thesis at first, and steadily increase the size with subsequent operations  over anumber of years. This method can be cumbersome for the patient,  as well as costly. In addition, Marshall found the inadequate scrotal  distention and wound dehiscence were common problems, especially if  orchiectomy had occurred because of inflammatory conditions. In chil-  dren, even if the small prosthesis is placed during infancy, scrotal stretch-  ing is needed after puberty to accommodate an adult size. In addition,  if a solitary testis undergoes compensatory hypertrophy, increasing the  size of the prosthesis will need to be if symmetry is desired (/3).   Lattimer and Stalnecker suggested tissue expansion may be a satis-  factory alternative to multiple prostheses. Tissue expansion minimizes  additional scar from multiple operations. It slowly distends the scrotum,  minimizing pain, and fluid can be withdrawn if the patient is too uncom-  fortable. Expanding the skin beyond the size needed for the implant  allows a more relaxed fit, preventing the implant from overriding the  normal testis. For a successful tissue expansion of the scrotum, they  suggested:    1. Use a 75-100-cm? expander, rather than overfilling a smaller bag.   2. Place the filling port suprapubically in the midline, so that it is easily  accessible, and tolerated.   4. Use an even larger implant when compensatory hypertrophy has  occurred (/4).    A common problem of placement is extrusion of the prosthesis  through the suture line. A high scrotal or low inguinal incision is best  used to keep the suture line from the prosthesis. If the patient lost the  testicle as a result of inflammatory reasons or cancer, it may be best to  wait 6 mo for the scrotum to soften up after initial orchiectomy (15).   I prefer to use a low inguinal incision at the level of the pectineal line  for placement of the prosthesis. Just lateral to the pubic tubercle is a  shallow groove in which the spermatic cord lies. The transverse incision  is made here, which will allow the surgeon to remain outside the exter-  nal inguinal ring, but along the natural path of the spermatic cord. Dissec-  tion through the superficial fat and Scarpa’s layer allows exposure to the  floor, so that a direct path to the scrotum is facilitated. Invaginating the  scrotum may help with determination of the inguinal path. Dissection of  the scrotum with a finger, then a Kelley instrument, allows the surgeon  to thin the dartos. One must be careful not to break through the skin. A  sizer is introduced to evaluate symmetry. Rinse with antibiotic solution,  both soaking the implant and washing the wound regularly. I prefer to  suture the mesh button to the superior portion of the dartos for two  reasons. First, it allows the testicle to “hang,” and will prevent it from  flopping sideways. Second, one is less likely to stitch through the skin,  and one can incorporate this as a first closure of the dartos. Closure of  the fatty pad prevents migration into the inguinal canal. Pursestring may  be the best option (see Fig. 2). Patients are kept on broad-spectrum  perioperative parenteral antibiotics with bedrest and scrotal elevation  for 1 d to minimize edema, and then sent home on broad-spectrum  antibiotics for 3 wk. Activity is restricted for 1 mo to allow resolution  of swelling, and capsule formation (see Fig. 3).    Placementat the time of inguinal exploration in an infant for whom one  finds an atrophied or vanished testicle may be useful. Because the testicle  does not grow much throughout childhood, it may be reasonable to insert  a prosthesis to allow the child to develop a normal body image. The  testicle grows from 1.6 to 2.9 x 1.0to 1.8 cm from age 2 to 10 yr. The adult  testicle is around 5 cm, larger if solitary. Until the late 1980s the smallest  prosthesis available was 2.7 x 4.1 cm, creating an asymmetric appear-  ance in infants and school-age boys (/6). Now Silimed’s smallest is  2.0 x 2.3 cm, and Mentor’s smallest is 1.7 x 2.5 cm for infants.   Placement of a small testicle may not help much to preserve space for  placement of a larger one after puberty, because the size needed in  adulthood is so great. Placement of adult size prosthesis in an infant is  grotesque. The small prosthesis may be useful for normal psychosocial    Fig. 2. Insertion technique (as described by Klein) provides for a cosmetic  incision with access to bilateral inguinal cords if bilateral orchiectomy is per-  formed for prostate cancer (Klein). I prefer an incision this low, but bilaterally  in adolescents for insertion of prosthesis.    Fig. 3. 6-mo postoperative appearance of 12-yr-old patient with bilateral pros-  theses placed for scrotal reconstruction. This patient had bilateral incarcerated  hernias as newborn, with subsequent anorchia. Notice low inguinal incision.    Fig. 4. Insertion technique in infant (Ferro). This is particularly useful if sur-  gery includes inguinal exploration for nonpalpable testicle. A second small  incision allows placement of a pursestring suture in the Dartos muscle which  prevents migration or extrusion of the implant.    development, though. Elder et al. reported insertion of a gel-filled pros-  thesis in 40 children aged 9 mo to 4 yr. After insertion into the scrotum,  the scrotal outlet was closed with a pursestring of nonabsorbable suture  and the prosthesis sutured to the scrotal wall. They had one complication  of a wound infection that did not involve the prosthesis. In a follow-up  phone survey, 94% of the families were happy the prosthesis had been  inserted. Nearly half believed that the child would require a larger pros-  thesis at puberty, whereas one-third had no opinion and felt that the  decision would be left up to the child at adolescence.   Ferro etal. suggested that rather tan struggling to use a pursestring deep  through an inguinal incision in a child, making a second small incision in  the high scrotum for the pursestring is simpler (/7) (see Fig. 4).    In adults with metastatic prostate cancer, a number of options exist.  One option is placement of an intracapsular testicle prosthesis following  subcapsular orchiectomy (/8). After curettage of the testicular tissue,  and cauterization of the arteries and remnant seminiferous tubules, a  prosthesis is placed inside, and a running suture closes the capsule.  Mentor used to manufacture a smaller device with a Dacron mesh run-  ning along the side. Inclusion of the suture line with the imbedded    Dacron mesh could stabilize the implant. Although a simple subcapsu-  lar orchiectomy has an advantage of leaving palpable tissue in the scro-  tum, it is a much less significant mass than with the addition of a  prosthetic device.   Another option at elective orchiectomy is to free the native testicle  from the epididymis, and suture a solid silicone testicle in its place (/9).  This requires a trans-scrotal incision, as its main benefit is to leave the  epididymis and gubernaculum in situ, ultimately limiting mobility of  the prosthetic device. It runs the risk of hematoma from the cord, and  scrotal wound opening.   A suprapubic approach for simultaneous orchiectomy and place-  ment of testicular prosthesis is useful in patients with advanced pros-  tate cancer. A subcutaneous approach to the scrotum keeps the incision  away from the prosthesis. This option is quick and cosmetic, as the  incision is hidden in a lower abdominal crease and covered by pubic  hair (20).   Placement at the time of the initial surgery is a good option for patients  undergoing orchiectomy for prostate cancer, because one can clearly  explain the risks and benefits of the prosthesis, and expect the patient to  understand with reasonable consent. It is not as clear for patients with  more urgent disorders, however.   Patients with a testicle tumor may need chemotherapy and radiation,  which may predispose to wound breakdown. As well, it is an emotion-  ally difficult time for the patient, and obtaining consent may be difficult.  Commonly, patients found to have torsion of the testis are typically  emergent, and consent may also be an issue. With epididymitis, one is  concerned with infection. Marshall showed that complications were  more likely to occur in patients with an underlying inflammatory con-  dition of the scrotum (/3).    Marshall surveyed 488 surgeons for their experience with complica-  tions following placement of a testicle prosthesis. Three-hundred eighty-  seven surgeons reported placing 3031 over a 10-yr period. Reasons for  placement are in Chart 1 (see Fig. 5). (UDT 35%, tumor 23%, torsion  17%, CaP 16%, orchitis/epididymitis 8%, trauma 1%.) In general, most  complications occurred in patients with a history of epididymitis, or if  there was a history of inflammation due to prolonged torsion. In short,  those patients with a reason for scrotal scar were most likely to have  problems with placement of a prosthesis. Overall complications (tran-  sient scrotal contraction 4.2%, persistent scrotal contraction 3.2%,    Fig. 5. Diagnoses as percentage of 2533 patients with 3,031 testicular prosthe-  ses over a 10-yr period (see ref. 13).    wound dehiscence/extrusion 4.1%, infection 1.0%, hematoma 0.8%,  pain 1.3% ) are listed in (see Fig. 6).    Infection can occur with any foreign body. Elsahy reported one patient  who developed severe scrotal and penile lymphedema after chronic,  recurrent infection of a testicular prosthesis (2/).    Five cases have been reported of silicon gel leakage following rup-  ture of the implant, up to 10 yr after implantation. One may have been  associated with a needle stick during a penile operation. Three patients  had a history of excessive pressure on the prosthesis (one racing cyclist,  one jumping on horseback, and one with an elastic device use during  sex). Patient may have pain and deformity of the hemiscrotum. Most  were intracapsular ruptures, facilitating excision and replacement. Sili-  cone may be found outside the capsule, but was not associated with  adenopathy, nor was it associated with systemic disease in any of these  patients (22,6).   The patient may present with pain, without trauma. In an intact device,  ultrasound should show a smooth, homogenous, echo-free space. Rup-  ture causes septation within the device owing to infolding of the outer  shell, with internal echoes. Ultrasonically, this may be referred to as the    orchitis (231) 22 (9.5) 11 (5) 18 (8) 5 (2) 6 (3) 7 31  Torsion (527) 22 (4) 16 (3) 27 (5) 7 (1) 9 (2) 6 (1) 16  Undescended/   testis (1,079) 44 (4) 29 (3) 42 (4) 7 (0.6) 3(0.3) 11 (1) 13  Testicular .   tumor (696) 18 (3) 24 (3) 18 (3) 4 (0.6) 2(0.3) 10(1) ie    ea i e E a a a S a a a  "Complications of prosthesis insertion in patients with trauma and cancer of the prostate are not included in this table. The overall  complication rate was highest in situations of previous scrotal inflammation (epididymitis/orchitis and delayed testicular torsion). It  should be noted that many patients had more than one complication.  tFigures in parentheses indicate per cent.    Fig. 6. Complications following placement of prosthesis in relation to diag-  noses (see ref. /3).    stepladder sign, most likely because of the crumpled edges of the implant  (6). As well, hypoechoic areas can also be seen surrounding the device  (22). Magnetic resonance imaging (MRI) may show the linguini sign,  again representing the edge of the crumpled implant. Although a MRI  is very useful in breast implant evaluation, the size and subcutaneous  position of the testicular implant allow easy evaluation by ultrasound.   The scrotum may be at lower risk for leakage than the chest wall for  breast implants. In women presenting for complaints of psychological  or physical breast implant discomfort, about half were found to have a  ruptured envelope at 15 yr. This number is certainly much lower in  patents with testicular prostheses, as prior to 1992 there were probably  3000 implants placed per year, and so few have been reported (4). The  scrotum is a low-tension area, has less vascularity, and a lower tempera-  ture. Testicle prostheses may also be more mobile, less vulnerable to  pressure injury (23).    Gordan described a patient whose testicular implant extruded 2 yr  after surgery, presumably because of skin erosion of a Dacron tab used  for an anchor stitch on earlier models. Since then, the Dacron mesh has  been imbedded in the wall of the prosthesis (3).    Other problems such as hematoma formation and fluid accumulation  around the prosthesis can also occur. Calcium deposits have been noted,  and in general do not cause a problem unless the prosthesis is mistaken  for a real testicle, and biopsy is performed. Capsule contracture can    occur around any prosthetic device, which may alter its position and  softness. Unresolved issues remain for the very long term, including the  impact of silicone particle shedding, carcinogenesis, and the develop-  ment of autoimmune diseases, none of which have been problematic as  of this writing.    It is important to follow-up for wound check within a month postop-  eratively, and then at 6 mo to look for capsule contraction or implant  migration. Patients should be instructed that any sudden pain or discom-  fort should bring them in for an exam.   Prior to the availability of a gel-filled implant, solid elastomer  implants were occasionally mistaken for testicular tumors. Making sure  an adolescent knows he had a prosthesis placed as a child is important  to avoid this embarrassment. As well, as adolescent visit allows the  patient to educate himself about his condition, as he may otherwise be  too insecure to ask his parents . He has the right of assent to having  the prosthesis upsized, removed, or left alone if it had been placed as an  infant.   If a question exists regarding rupture of a gel-filled prosthesis, ultra-  sound may be useful, as aforementioned. MRI of testicular prosthesis  has been documented (24). On T1 weighted images, both solid and  liquid filled prostheses demonstrated homogeneous low signal inten-  sity; on T2 weighted images, the fluid implants had a uniformly low  signal intensity, and the solid implants had a uniformly high signal  intensity.    Testicular prosthesis can be placed successfully in infancy, child-  hood, or adulthood with good success, and minimal morbidity. Market  scare of the gel-filled breast implant has resulted in minimal current  available options for testicle prosthetics.    1. Puranik SR, Mencia LF, Gilbert MG (1973) Artificial testicles in children: anew  silastic gel testicular prosthesis. J Urol 109(4):735, 736.   2. Girsdansky J, Newman HF (1941) Use of a vitallium testicular implant. Am J  Surg 53:514.   3. Gordon JA, Schwartz BB (1979). Delayed extrusion of testicular prosthesis.  Urology 14(1):59, 60.   4. Randall T (1992) Penile, testicular, other silicone implants soon will undergo  FDA review. JAMA 267(19):2578, 2579.    . Hage JJ, Taets van Amerongen AH, Van Diest PJ (1999) Rupture of silicone gel    filled testicular prosthesis: causes, diagnostic modalities and treatment of a rare  event. J Urol 161(2):467-471.    . Pidutti R, Morales A (1993) Silicone gel-filled testicular prosthesis and sys-    . C Kline, private communication, mentor communication Feb 24: 2000.  . Schiffman A, Straker N (1979) The psychological role of the testicles. A case    report of a 9-year-old boy with agenesis of the testicles. J Am Acad Child Psych  18(3):521-526.    . Money J, Sollod R (1978) Body image, plastic surgery (prosthetic testes) and    . Bracka A (1989) A long-term view of hypospadias. Br J Plastic Surg 42:251-255.  . Berg G, Berg R (1983) Castration complex. Evidence from men operated for    . Lattimer JK, Stalnecker MC (1989) Tissue expansion of underdeveloped scrotum    . Lattimer JK, Vakili BF, Smith AM, Morishima A (1973) A natural-feeling    . Elder JS, Keating MA, Duckett JW (1989) Infant testicular prostheses. J Urol    . Ferro F, Caterino S, Lais A (1991) Testicular prosthesis in children: a simplified    . Merrill DC (1991) Intracapsular testicular prosthesis. Urology 37(1):78, 79.  . Solomon AA (1972) Testicular prosthesis: a new insertion operation. J Urol    . Klein EA, Herr HW (1990) Suprapubic approach for bilateral orchiectomy and    . Eisahy NI (1972) Scrotal and penile lymph edema as a complication of testicular    . Twidwell J (1994) Ruptured testicular prosthesis. J Urol 152(1):167, 168.  . Henderson J, Culkin D, Mata J, Wilson M, Venable D (1995) Analysis of immuno-    . Semelka R, Anderson M, Hricak H (1989) Prosthetic testicle: appearance at MR    Since the implantation of rib cartilage for reproducing penile rigidity  in a fashion similar to the os penis or baculum of lower animals in the  1930s and 40s, surgeons and urologists have pursued the implantation  of penile prostheses for the production of erections satisfactory for  normal coitus. The development of newer synthetic materials associ-  ated with the space program in the 1950s and 1960s allowed advances  in human prosthetic devices to include the treatment of chronic erectile  impotence. The silicone-based prosthetic materials introduced during  that time revolutionized the science of human prosthetics and, subse-  quently, urologic penile prosthetic devices. The era of modern penile    The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    prosthetic surgery began with the reports of Small et al. and Scott et al.  in 1973 (/,2). These surgeons introduced new prostheses which were  the results of the development of penile prostheses, by earlier pioneers.   Small et al. and Scott et al., however, defined the two current classes  of penile prosthetic devices with their reports more than 25 yr ago. Small  et al. described a pair of silicone cylinders comprised of a silicone elas-  tomer outer sheath covering a silicone-filled sponge sized to fill the  corpora cavernosa from the glans penis to the crura . These implants,  which decreased the previously noted prosthetic migration and recre-  ated a physiologic erection, could be sized to the individual patient with  two different girths and four different lengths. Semirigid rod penile  implants, whose successors continue to be implanted today, are suffi-  cient in size and rigidity and simulate the normal erection and provide  stability adequate for coitus (see Fig. 1). Since its introduction, the  Small Carrion penile prosthesis has been the most widely implanted  semirigid rod prosthesis. Initial results from the Small Carrion penile  prosthesis, the archetype of semirigid rod prostheses, were successful in  72-91% of patients in whom they were implanted .   The second group of penile prostheses introduced in 1973 were  designed as inflatable penile prostheses and were developed by Scott et al.  (2). Because the inflatable design promised a more physiologic erection  and a more natural-appearing flaccid penis, the Scott inflatable penile  prosthesis has been widely used. Since implementation of improved de-  signs with decreased mechanical malfunction rates, its use has sur-  passed the semirigid rod penile prosthesis in popularity. A recent  statewide study in North Carolina has documented a more than threefold  prevalence of inflatable penile prosthesis implantation to semirigid rod  devices (3). Whereas the original inflatable penile prosthesis had an  inflate and a deflate pump, the combined inflate/deflate pump in the  current inflatable penile prosthesis has been the design of both Mentor  and American Medical Systems devices for more than two decades.  These inflatable prostheses consist of three components, including  paired silastic or bioflex corporal cylinders that are hollow and can be  sized to the individual patient. These corporal cylinders are connected    to a fluid-filled reservoir placed beneath the anterior abdominal rectus  muscle. The third component consists of a pump mechanism that was  initially designed as two pumps and subsequently united into a single  scrotal pump. The patient can activate this device by palpation of the  pump mechanism in the scrotum and by depressing the inflation portion  to transfer fluid from the reservoir to the cylinders creating a normal  appearing, feeling, and functioning erection. On deflation of the device,  the cylinders empty and a flaccid penis results. The components of this  prosthesis are connected by kink-free silicone tubing tailored and con-  nected by connectors that were first made of stainless steel and currently  of a softer, plastic material. Subsequent designs have introduced con-  nector-free inflatable penile prostheses. Although initial results demon-  strated excellent erections, mechanical malfunction rates varied and  were frequently reported in excess of 60% (4). Multiple design and  material changes over the past two decades have resulted in mechanical  malfunction rates of less than 10% over 5 yr (5—7). Complications, such  as infection, can now be managed with prosthesis-preserving techniques,  which include salvage protocols designed for acute replacement and  irrigation (8).   Current prosthetic devices include the inflatable variety, which can  be divided into multiple component inflatable prostheses of which there  are two- and three-piece models available (see Fig. 2—4). There are also  single-rod inflatable prostheses which have also been termed the  hydraulic hinge penile prostheses (see Fig. 5). These prostheses are    Fig. 3. AMS 700CX inflatable penile prosthesis (American Medical Systems  Inc., Minnetonka MN).    Fig. 4. Ambicor 2-piece inflatable penile prosthesis (American Medical Sys-  tems Inc., Minnetonka MN).    rarely used and are of limited availability in the twenty-first century  (9,10). Semirigid prostheses are also available and can be grouped as  malleable, mechanical, and semirigid. The former contain a central metal  wire for improved positioning and the latter, such as the Dura II pros-  thesis (Timm medical, Augusta, GA), and finally, the original semirigid  rod penile prostheses is still implanted.    Fig. 5. Dynaflex inflatable penile prosthesis (American Medical Systems Inc.,  Minnetonka MN).    In the era of oral agents and minimally invasive treatment options for  erectile dysfunction, most patients with organic and psychogenic erectile  dysfunction undergo penile prosthesis implantation when less-invasive  options have been unsuccessful. Penile prostheses, however, are widely  used in patients who require complex reconstruction of the genitalia.    Penile prostheses have been used for patients with Peyronie’s disease  since their introduction in the 1970s. Peyronie’s disease with penile cur-  vature or penile deformity associated with erectile dysfunction are suc-  cessfully treated with penile implants. Many patients with inadequate  erections will not respond adequately to penile straightening alone  because inadequate erectile function will compromise their ability to per-  form coitus satisfactorily. Straightening alone may be difficult in patients  with severe penile curvature. Severe penile shortening and penile prosthe-  ses have been successfully used to rehabilitate these complex patients,  especially when associated with erectile dysfunction. In counseling  patients about surgical treatment of severe Peyronie’s disease, however,  itis critically important to include the option of penile prosthesis because  this single surgical procedure has excellent success rates, low morbid-  ity, and correct both penile deformity and potential erectile dysfunction.  Expected infection rates are no different from those of patients with  penile prosthesis implantation and no Peyronie’s disease (12). Excel-  lent results have been reported by many investigators using penile  prosthesis implantation, both with and without corpus cavernosum recon-  struction. Although corpus cavernosum reconstruction is occasionally    required to produce penile straightening, the recent introduction of  penile modeling has reduced the number of incisions for reconstruction  of these complex patients. The inflatable penile prosthesis has been  demonstrated to have the best long-term patient satisfaction in the treat-  ment of patients with penile curvature and Peyronie’s disease. Although  functional results are satisfactory with both inflatable and semirigid rod  prostheses, Montorsi et al. reported poor patient satisfaction with semi-  rigid rod penile prosthesis implanted for Peyronie’s disease compared  with excellent patient and partner satisfaction in a similar group of  patients undergoing inflatable prostheses from the same urologic prac-  tice (13,14).   Prior to the introduction of penile modeling as a penile-straightening  technique, the most common method for surgical correction of penile  curvature after penile prosthesis implantation was incision or excision  of the plaque or curvature area with or without grafting. In 1994, Wilson  and Delk first proposed the technique of penile modeling to eliminate  or modify penile curvature after prosthesis implantation (/5). This tech-  nique requires a high pressure inflatable penile prosthesis cylinder such  as the AMS 700CX or Mentor a-1 prosthesis cylinders. Once penile  prosthesis cylinders are implanted, many patients will have penile  straightening with corpus cavernosum dilation alone. Those with con-  tinued penile curvature after prosthesis insertion, however, can undergo  penile modeling. Modeling procedures can be performed for other  causes of penile deformity from corpus cavernosum fibrosis or other  abnormalities. The AMS 700 Ultrex cylinders are less satisfactory and  modeling pressure and implantation of these cylinders may result in  aneurysmal dilation or S-shaped deformity. Similarly, high-pressure  stress on the Mentor Bioflex cylinders has been reported to result in  aneurysmal dilation.   Modeling begins with full inflation of the prosthetic cylinders and  clamping the inflate tubing to protect the inflatable pump. The curved  penis is then grasped with both hands bending the penis over the fully  inflated cylinders of the prosthesis at the area of maximum curvature.  Deflection is maintained for 90 s and reevaluation of the shape is carried  out after straightening and further cylinder inflation. Repeated model-  ing can be carried out until full straightening is obtained. Results of the  modeling procedure have been reported in several series with success  rates in excess of 85% (/5—17). Complications are no greater in penile  prosthesis implantation without modeling and plaque incision is reduced  to less than 10% of patients.   In those patients in whom modeling is inadequate for penile shorten-  ing, plaque excision or incision may be necessary. Igner et al. reported    an 88% satisfaction rate with plaque incision after prosthesis implanta-  tion (18). Patients were able to engage actively in sexual intercourse  during a mean follow-up of 6.9 yr. Ifa significant defect results from this  straightening procedure, patching with material such as Gortex (WL  Gore & Associates) may be necessary for improved cosmetic results and  penile shaft support. The use of an additional foreign body for these  support grafts, however, may lead to increase in infection risks in some  patients. Severe penile shortening may be improved using a circumfer-  ential corpus cavernosum incision with grafting with or without a penile  implant (19).    Dense fibrosis of the corpus cavernosum may be a result of condi-  tions such as penile prosthesis infection, repeated intracavernosal injec-  tions, especially with Papaverine, diabetes mellitus, Peyronie’ s disease,  and priapism. This intense corpus cavernosum fibrosis may be severe  and result in severe changes in corpus cavernosum tissue compliance  with an increased incidence of venous leak, decreased penile turgidity,  and penile shortening. Implantation of a penile prosthesis is the most  often used and most successful method for rehabilitating patients with  these disabling fibrotic conditions (20). Although an infrapubic incision  is most amenable to penile reconstruction using penile prosthesis,  Carbone et al. reported a series of 26 men implanted with AMS 700CXM  prostheses with severe corpora fibrosis through a transverse scrotal  approach (2/). Although this approach is reasonable, flexibility, the use  of multiple corporotomies and creative surgical incisions may be nec-  essary in these complex cases. In corpus cavernosum fibrosis, which is  mild or moderate, dilation may be carried out in a standard fashion but  may require advanced surgical techniques to create a channel satisfac-  tory for penile prosthesis implantation. These techniques may include  the use of an Otis urethrotome, Rosillo cavernotome, and sharp scissor  dissection of the corpora cavernosa. If duration or calcification makes  dilator introduction difficult, sharp dissection using scissors may pro-  vide initial tunneling followed by excision of the scarred corpus tissue,  direct dilation, and multiple corporotomy incisions to dilate under direct  vision. When attempting penile prosthesis cylinder placement in these  difficult conditions, it is critical to have available the downsized inflat-  able penile prosthesis cylinders. These devices are available from both  Mentor and American Medical Systems and include the AMS 700CXM.   The use of a vacuum erection device prior to surgical implantation  has been reported to improve penile length and assist in softening cor-    poral fibrosis (22). Patients are asked to apply the device 2-3 times  weekly without a constriction ring for 8—12 wk. Use of a vacuum erec-  tion device after prosthesis implantation has been reported, but may  result in damage to an implanted device. If all dilation attempts are  unsuccessful, a longitudinal incision of the corpus cavernosum can be  carried out with dissection of the fibrotic tissue from the corpus  cavernosum. This is a difficult procedure and requires significant care  to avoid the urethra and other penile structures. Once performed, how-  ever, a prosthetic cylinder may be placed in an open dissected area and  covered with tunica albuginea, Gortex graft, or other packaged materi-  als (23). If inflation of the prosthesis is unsuccessful, however, the use  of a semirigid rod device may be necessary to permit satisfactory pros-  thesis function.   Penile prostheses and implants have been successfully implanted in  patients with sickle cell priapism with excellent results. Monga et al.  reported the use of penile prosthesis implantation after sickle cell asso-  ciated priapism (24). They suggested an advantage maintaining penile  size and corpus cavernosum compliance by early prosthesis implanta-  tion in patients with severe and repeated sickle cell priapism.    Although nerve-sparing radical prostatectomy has improved the erec-  tions postoperatively in many patients surgically treated for prostate  cancer, as many as 40% of patients who undergo radical prostatectomy  will suffer from post operative erectile dysfunction. Although many of  these men can be managed with oral, intraurethral, or injectable agents,  some patients will require penile prosthesis implantation. Specifically,  those patients who undergo radical prostatectomy without nerve-sparing  procedures may not respond to less-invasive techniques for restoration  of erectile function. Ina subgroup of patients with preoperatively placed  penile prosthesis, the prosthesis can be maintained during radical pros-  tatectomy with excellent function and healing following surgery. There  is no increase in infection rates and prosthetic function is maintained  (5). There is no clear indication for removal of a preexisting penile  prosthesis during or before radical prostatectomy. Some investigators  have suggested the immediate and simultaneous placement of a penile  prosthesis along with radical prostatectomy. Khoudary et al. report 50  men undergoing a combination nerve-sparing radical retropubic pros-  tatectomy and penile prosthesis implantation (25). In comparing these  men with 72 men undergoing radical prostatectomy without penile pros-    thesis implantation, the authors report a mean return to successful sat-  isfactory coitus of 12.7 wk with no patients suffering penile prosthesis  infection and an 8% revision rate, similar to that of patients without  simultaneous radical prostatectomy.   Similarly, patients have excellent function and penile prosthesis sat-  isfaction after definitive radiation therapy for prostatic carcinoma.  Dubocgq et al. reported 35 patients undergoing radiation therapy alone  and eight patients undergoing radiation therapy after radical prostatec-  tomy who also received penile prosthesis for rehabilitation (26). None  of the patients in this series had infection or erosion and 71% of the  patients used their prosthesis at least once weekly, 17% twice a month,  whereas only 12% remain sexually active without penile prosthesis  implantation.    Although many patients have successful restoration of erectile func-  tion with Sildenafil and other minimally invasive treatment alternatives  following spinal cord injury, there is a substantial number of these usu-  ally young men who have erectile dysfunction refractory to simpler  restorative techniques. Results of penile prosthesis implantation in patients  with spinal cord injury assists in both physical and psychological reha-  bilitation. Gross et al. reported 209 paraplegic men who underwent  penile prosthesis implantation for erectile dysfunction (27). Infection  rates in their patients were equivalent to those of nonparaplegic men and  men who underwent penile prostheses exhibited improved self-confidence  and facilitated condom urinary collection. Watanabe et al. also reported  patients undergoing penile prosthesis implantation after spinal cord  injury (28). Of those undergoing penile prosthesis implantation, no  patients had a prosthesis infection or malfunction and all used their  prosthesis at least five times monthly. Frequency of use was greater than  that for patients with injection therapy or vacuum erection device  therapy.    One of the most difficult groups of patients to treat are those patients  with penile loss secondary to congenital absence, trauma avulsion, or  penectomy for cancer of the penis. A variety of phallic reconstruction  techniques are available, the most common currently used is the inner-  vated vascularized pedicle flap from the forearm. After phallic recon-  struction, penile prosthesis implantation permits a functional penis.    Reconstruction with a neourethra allows for more normal voiding and  a penile prosthesis permits sexual activity. Because these phallic recon-  structive techniques involve nerve reconstruction, sensation can be  expected in the majority of patients. Alter et al. describe the use of  inflatable and semirigid rod penile prostheses after phallic reconstruc-  tion. Semirigid penile prostheses have also been successfully used to  create rigidity in these neophalluses.   Difficult penile-prosthesis implantation using reinforcement mate-  rial whether natural or artificial, especially in patients with significant  immunocompromise may result in increased infection rates. Jarow etal.  report the risk of penile prosthesis infection at 21.7% in patients requir-  ing penile reconstruction compared with an overall infection rate of  1.8% (29). Similarly, Carson reports an increased infection rate in patients  requiring Gortex grafts for reconstruction of patients with severe corpo-  ral fibrosis (30). Although this increased infection rate is evident for  complex reconstructions that involve longer operative times, more inci-  sions and additional foreign bodies, the further increased risk of diabe-  tes with penile implants does not appear to be significant.    The first hydraulic artificial urinary sphincter was developed in the  mid-1970s as an outgrowth of the development of the inflatable penile  prosthesis. Because of significant mechanical reliability concerns and  urethral erosion, multiple redesigns and mechanical improvements have  taken place over the past two decades. The current artificial urinary  sphincter available as the American Medical Systems AS800 device  consists of an inflatable cuff sized to the individual patient and placed  around the urethra or bladder neck (37). Associated pressure balloons  provide periurethral pressure to the implantable cuff and the device is  deflated actively by the patient through a scrotally placed deflation  pump. Newer devices are being modified to be used with colonic implan-  tation for fecal incontinence. The advantage of the current device include  the ability to deactivate the cuff at the pump level without surgical  intervention to allow for urethral healing and revascularization prior to  the application of periurethral pressure. Additionally, the current device  permits constant urethral pressure with patient activation to decrease  urethral compromise and free voiding.   The artificial urinary sphincter is widely used in both adults and  children, men and women to restore urinary continence. The reliability  of these devices has been consistently reported. Elliott and Barrett report  323 patients in the largest current series, 72 of whom required only a  single surgical intervention with a mean follow-up of 68.8 mo (32).    Their study examined 272 sphincters placed around the urethra and 51  at the bladder neck. With the newer design artificial urinary sphincter,  mechanical failure occurred in 7.6% of patients with nonmechanical  complications identified in only 9% of patients.   These devices improve the quality of life of both men and women  treated for urinary incontinence. They are most commonly used to  treat incontinence after prostatectomy. Haab et al. reviewed the records  of 68 men who underwent artificial urinary sphincter placement for  postprostatectomy incontinence or neurogenic disease with a mean  follow-up of 7.2 yr (33). Quality of life was assessed in 52 of these  patients by incontinence impact questionnaires and a urogenital dis-  tress inventory. The authors document a decrease in pads per day from  2.75 to 0.97 after surgery. Revisions for mechanical failure and ure-  thral atrophy were required in 25% of patients and four patients  required permanent removal of the prosthesis. By subjective  improvement and overall satisfaction, ratings were 4.1 and 3.9,  respectively, on a scale of 5. These authors concluded that patient  quality of life is positively impacted by the implantation of an artificial  urinary sphincter. Griebling et al. compared collagen injection with  artificial urinary sphincter for the treatment of postprostatectomy  incontinence (34). Of 25 men undergoing collagen injection for  postradical prostatectomy incontinence, only two men received sig-  nificant improvement with 5 of 25 subsequently undergoing artificial  urinary sphincter with subsequent satisfactory control.   Newer concepts in artificial urinary sphincter implantation includes  the use of double-cuff artificial urinary sphincters. This double-cuff  technique has been successfully used in patients with high-pressure  bladders and failed artificial urinary sphincter. Kabalin reported five  men with stress urinary incontinence after artificial urinary sphincter  placement (35). Using a stainless steel T-shaped connector, a second  artificial urinary sphincter cuff was placed distal to the previously  placed cuff. Four of five patients obtained satisfactory continence  with the second cuff, although one man continued to be incontinent.  Kowalczyk et al., however, report a higher erosion rate in those patients  with double cuff artificial urinary sphincters (36). Of 95 patients  implanted with double cuffs, 10 patients sustained erosion of which four  were considered to be caused by the second-cuff implantation. Second-  cuff implantation may be appropriate, however, in those patients who  are physically active and suffer stress incontinence with physical activ-  ity. Placement of a second cuff distal to an initial cuff appears to increase  outlet resistance and increase continent rates in patients undergoing  artificial urinary sphincter placement.    0 12 24 36 48 60 72 84 96 108 120  Months    50  0 1 2 3 4 5 6 7 8 9 10 W 12  Years Implanted    Fig. 7. Long-term actuarial survival of AMS 700CX penile prostheses implanted  for treatment of erectile dysfunction (5).    Fig. 8 (A) Malfunctioned penile prosthesis in situ. (B) Penis rigidity and elon-  gation following insertion of MUSE, 250 mcg 30 min prior. (Note: penile  elongation compared with inferior scrotal border, penile glans engorgement,  and penile rigidity.)    In the beginning of the 21st century, urologists and surgeons have  significant numbers of prosthetic devices available for reconstruction  and improvement in patients lives. Prosthetics as simple as the testicular  prosthesis restore the body image and psychological well being of many  young men who have lost a testicle to trauma or malignancy. Patients  with erectile dysfunction who fail less invasive alternatives can be recon-  structed and return to normal sexual function with penile prosthesis  implantation using either inflatable or noninflatable devices. Patient  and partner acceptance, use, and satisfaction have been reported better  than other alternatives including pharmacologic injection (37,38). Inflat-  able devices are more frequently used than semirigid rods, their compli-  cation rates continue to decline and patient satisfaction rates continue to  rise (see Fig. 6, 7). Now, as many as 90% of patients would recommend  a penile prosthesis implantation to both friends and relatives as a result  of excellent mechanical function and reliability (see Fig. 8). The artifi-  cial urinary sphincter which has been developed and redesigned over the  past three decades now provides reliable restoration of continence in  patients with difficult to manage stress and total urinary incontinence.    The introduction of standardized pressure and deactivation concept has  improved the mechanical and physical reliability of these prosthetic  devices. Currently, patients with significant incontinence, which  impacts on their lifestyle and life satisfaction, can be improved with the  implantation of an artificial urinary sphincter with expected function  and satisfaction. The 21st century will continue to experience additional  prosthetic devices to assist urologic surgeons and patients. These devices  may include an artificial bladder, dissolvable ureteral, and urethral  stents, and prosthetic replacements for both urethra and ureter in patients  with traumatic iatrogenics or malignancy resulting in ureteral injury  damage or loss.    1. Small MP, Carrion HM, Gordon JA (1975) Small Carrion penile prosthesis: a  new implant for the management of impotence. Urology 5:479-586.   2. Scott FB, Bradley WE, Timm DW (1973) Management of erectile impotence:  use of implantable inflatable prosthesis. Urology 2:80-83.   3. Jhaveri FM, Rutledge R, Carson CC (1998) Penile prosthesis implantation sur-  gery: a statewide population based analysis of 2354 patients. Int J Impot Res  10:251-254.   4. Carson CC (1999) Reconstructive surgery using urological prostheses. Curr  Opin Urol 9:233-239.   5. Carson CC, Mulcahy JJ, Govier FE (2000) Efficacy, safety, and patient satisfac-  tion outcomes of the AMS 700CX inflatable penile prosthesis: results of a long  term multicenter study. J Urol 164:376-380.   6. Goldstein I, Newman L, Baum N, et al. (1997) Safety And efficacy outcome of  Mentor Alpha-1 inflatable penile prosthesis implantation for impotence Treat-  ment. J Urol 157:833-839.   7. Wilson SK, Cleves MA, Delk JR (1999) Comparison of mechanical reliability  of original and enhanced Mentor alpha-1 penile prosthesis. J Urol 162:715—718.   8. Mulcahy JJ (2000) Long term experience with salvage of infected penile  implants. J Urol 163:481-482.   9. Anafarta K, Yamaan O, Aydos K (1998) Clinical experience with dynaflex  penile prosthesis in 120 patients. Urology 52:1098—1100.   10. Kabalin JN, Kuo JC (1997) Long term follow-up of and patient satisfaction with  the Dynaflex self-contained inflatable penile prosthesis. J Urol 158:456—459.   11. Kearse WS, Sago AL, Peretsman SJ (1996) Report of a multicenter clinical  evaluation of the Dura-II penile prosthesis. J Urol 155:1613-1616.   12. Carson CC, Mulcahy JJ, Govier FE (2000) Mechanical and satisfaction results  of penile prosthesis implantation in patients with Peyronie’s Disease: results of  a multicenter study. J Urol 154A:464.   13. Montorsi F, Quazzoni G, Barbieri L, Maga T, Rigatti P, Graziottina, et al. (1996)  AMS 700CX penile implants for Peyronie’s Disease: functional results, mor-  bidity and patient-partner satisfaction. Int J Impot Res 8:81-85.   14. Montorsi F, Quazzoni G, Bergamaschi F, Rigatti P (1993) Patient-partner sat-  isfaction with semi-rigid penile prosthesis for Peyronie’s Disease: a five year  follow-up study. J Urol 150:1819-1821.   15. Wilson SK, Delk JR (1994) A new treatment for Peyronie’s Disease: modeling  penis over an inflatable penile prosthesis. J Urol 152:1121-1123.    . Montague DK, Angermeier KW, Lakin MM, Ingoeright BJ (1996) AMS 3-piece  inflatable penile prosthesis implantation in men with Peyronie’s disease: com-  parison of CX and ultrex cylinders J Urol 156:1633-1635.   Carson CC (1998) Penile prosthesis implantation and the treatment of Peyronie’s  disease Int J Impot Res 10:125-128.   Eigner EB, Kabalin JN, Kessler R (1991) Penile implants and the treatment of  Peyronie’s disease. J Urol 145:69-71.   Lue TF, L-Sakka AI (1999) Lengthening shortened penis caused by Peyronie’s  disease using circular venous grafting and daily stretching with vacuum erection  device. J Urol 161:1141-1144.   Ragpurkar A, Li H, Dhabuwala CB (1999) Penile implant success in patients  with corporal fibrosis using multiple incisions and minimal scar tissue excision.  Urology 54:145-147.   Carbone DJ, Daitch JA, Angermeier KW, Lakin MM, Montague DK (1998)  Management of severe corporal fibrosis with implantation of prosthesis via  transverse scrotal approach. J Urol 159:125-127.   Soderdahl DW, Betroski RA, Mode D, Schwartz BF, Thrasher JB (1997) The  use of an external vacuum device to augment a penile prosthesis. Tech Urol  3:100-102.   Landman, Bar-Chama N (1999) The initial experience with processed human  cadaveric allograft skin for reconstruction of the corpus cavernosum in repair of  distal extrusion of a penile prosthesis. Urology 53:1222-1224.   Monga M, Broderick GA, Hellstrom WJ (1996) Priapism in sickle cell disease:  the case for early implantation of penile prostheses. Eur Urol 30:54-59.  Khoudary KP, DeWolf WC, Bruning CO, Morgantaler A (1997) Immediate  sexual rehabilitation by simultaneous placement of penile prosthesis in patients  undergoing radical prostatectomy. Urology 50:395-399.   Dubocq FM, Bianco FJ, Maralani SS, Forman ID, Dhabwalla CD (1997) Out-  come analysis of penile implant surgery after external beam radiation for pros-  tate cancer. J Urol 158:1787-1790.   Gross AJ, Saverwein DH, Kutzenburg RJ, Ringent RH (1996) Penile prosthesis  in paraplegic men Br J Urol 78:262-264.   Watanabe T, Chancellor MD, Riras DA, Hirsch IH, Bennett CJ, Finnochiaro  MV, et al. (1996) Epidemiology of current treatment of sexual dysfunction in  spinal cord injured men in the USA. Model Spinal Cord Injury Centers. J Spinal  Cord Med 19:186-189.   Jarow JP (1996) Risk factors for penile prosthetic infection. J Urol 156:402-404.  Carson CC (1996) Increased infection risks with corpus cavernosum reconstruc-  tion and penile prosthesis implantation with corporeal fibrosis. Int J Impot Res  8:155.   Leibovich BC, Barrett WM (1997) Use of the artificial urinary sphincter in men  and women World J Urol 15:316-319.   Elliott DS, Barrett DM (1998) Mayo Clinic long term analysis of the functional  durability of the AMS 800 artificial urinary sphincter: a review of 323 cases.  J Urol 159:1206-1208.   Haab F, Trockman BA, Zimmern TE, Leach GE (1997) Quality of life inconti-  nence assessment of the artificial urinary sphincter in men with minimum of  3.5 years follow-up. J Urol 158:435-439.   Griebling TL, Kreder KJ, Williams RE (1997) Transurethral collagen injection  for treatment of post prostatectomy urinary incontinence in men. Urology  49:907-912.    Kabalan JN (1996) Addition of a second urethral cuff to enhance the perfor-  mance of the artificial urinary sphincter. J Urol 156:1302-1304.   Kowalczyk JJ, Spicer JDL, Mulcahy JJ (1996) Erosion rate of the double cuff AMS  800 artificial urinary sphincter: long term follow-up. J Urol 156:1300-1301.  Sexton WJ, Benedict JF, Jarow JP (1998) Comparison of long term outcomes of  penile prosthesis and intracavernosal injection therapy. J Urol 159:811-815.  Tefilli MB, Dubocq F, Ragpurkar A, et al. (1998) Assessment of psychological  adjustment after insertion of inflatable penile prosthesis. Urology 52:1106-1112.    The first penile implants were performed following World War II for  plastic surgical reconstruction of the penis in soldiers who had sustained  destructive injuries to the genitalia, usually from land mines and burns.  Autologous cartilage and bone grafts were fashioned for internal penile  splinting, but long-term results were poor, partly because of reabsorp-  tion of the material over time (1). These techniques were later expanded  to the treatment of impotence, and the first use of synthetic materials  (acrylic rods) was described by Goodwin and Scott in 1952 (2).    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    Few advances in the field were forthcoming until the late 1960s when  silicone-based materials were developed as part of the space program.  Borrowing from this technology, the modern era of penile prosthetic  surgery began in the early 1970s as Scott et al. reported on the successful  placement of an inflatable device into the corpora cavernosa (3). The  Small-Carrion penile prosthesis, introduced soon thereafter, served as  a prototype for the many malleable devices marketed over the next  quarter century (4). At one time, rod-like devices outsold multicompo-  nent inflatables by a 3-to-1 margin as a result of their ease of placement  and mechanical reliability. Today, the market has shifted, heavily favor-  ing the three-piece inflatable devices viewed as “more physiologic” by  urologists and patients alike. Manufacturers have improved the design  and construction of inflatables, whereas urologists have gained confi-  dence in their ability to safely place the pump and reservoir.   Nevertheless, certain clinical situations remain where implantation  of a semirigid device is preferable to an inflatable prosthesis. This chap-  ter provides a survey of the semirigid devices currently available, their  indications, advantages, and disadvantages.    Although the terms “semirigid” and “malleable” are often used inter-  changeably in the medical literature, there are actually two types of  semirigid rods: malleable and mechanical. American Medical Systems  (AMS) and Mentor each produce malleable systems, whereas Dacomed  is the only manufacturer of a mechanical device.    AMS offers two malleable prostheses, the 600M and the 650. Both  have a stainless steel, woven-wire core redesigned several years ago to  incorporate more numerous and thinner strands. This made bending  easier and reduced the spring-back angle to 45 degrees. The core is  surrounded by a three-layer polyester covering enclosed within a solid  silicone body. Surrounding the body is a trimmable silicone elastomer  jacket. The 650 cylinders measure 13 mm in diameter and are supplied  ina variety lengths with rear-tip extenders for accurate sizing. If needed,  the jacket can be removed, reducing the cylinder diameter to 11 mm (see  Fig. 1). The 600M is a narrower version of the 650 supplied in a 11.5-mm  width that reduces to 9.5 mm when the outer jacket is trimmed.    Mentor also offers two bendable devices, the Malleable and the  AccuForm. They both have a silver-wire core, but differ in its configu-    ration. The Malleable has a single spiral, whereas the AccuForm design  employs a helical wire surrounding a central-wire core that provides  greater flexibility with less springback after ventral positioning. Both  versions are covered by a silicone elastomer with the silver segment  positioned at the bend angle in the penis. A variety of lengths are avail-  able and precise sizing can be achieved by cutting the proximal end of  the rod and attaching a tapered cap (see Fig. 2). Each Mentor device  comes in three widths, 9.5 mm, 11 mm, and 13 mm.    Dacomed manufactures the only mechanical semirigid device cur-  rently available. It is marketed by Timm Medical Technologies. The  Dura II is composed of articulating segments of high molecular-weight  polyethylene. A stainless steel cable composed of seven wires contain-  ing 19 strands each runs through the segments and attaches to fixed posts  on either end by a spring mechanism. The articulating segments are  housed in a polytetrafluoroethylene (Teflon) sleeve coated with a thin  membrane of silicone to prevent tissue ingrowth. The body of the cyl-    inder comes in one length, 13 cm, and sizing is achieved by adding  proximal and distal tips to achieve the desired length. The shortest total  length possible is 15 cm, making this device a poor choice for patients  with a very short penis or those with extensive scarring. Two diameters  are offered—10 mm and 13 mm. The device is capable of bending more  than human penile anatomy will allow (see Fig. 3) and there is no  springback.  GENERAL CONSIDERATIONS    The advantage of semirigid penile implants stem primarily from their  ease of insertion by the urologist, ease of operation by the patient, and  an excellent history of mechanical reliability, superior to that of the  inflatables.   Semirigid penile prostheses can be inserted using either a subcoronal  (circumcising) incision or a ventral penile approach. Some authors  advocate a penoscrotal or infrapubic technique, but these incisions  require a substantially larger corporotomy for safe insertion of the  device. One should avoid “hyperflexing” the cylinder or handling it  with surgical instruments in an attempt to force it through a small corpor-  atomy. These maneuvers can damage the prosthesis and thus reduce its  long-term reliability.   Inadvertent puncture of a semirigid rod while closing the corporotomy  is not the disaster that is is with inflatables. In fact, sutures can be safely  placed through most of these devices to anchor them to the corpus in  cases where a proximal crural perforation has occurred. Salvage or “res-  cue” procedures are also easier with semirigid devices as there are fewer    components, and the scrotal and retroperitoneal spaces have not been  violated.   Malleable and mechanical prostheses can readily be placed in an  ambulatory surgery center under local anesthesia. One simply infiltrates  the base of the penis circumferentially with anesthetic as in performing  a penile block for circumcision. A tourniquet is then placed around the  base of the penis and 25 mL of 0.5% lidocaine without epinephrine is  injected through a 21-gage butterfly needle into the corporal body, as if  creating an artificial erection. After 2 or 3 min, the tourniquet is released  and the anesthetic is allowed to migrate into the rest of the corpora  proximally. Only plain lidocaine should be used as other local anesthet-  ics can be cardiotoxic when given systemically in high doses.   All of the semirigid devices reported herein have an outstanding  record of reliability. In fact, the authors are not aware of any reports  describing spontaneous breakage of the semirigid prostheses currently  available on the market. Manufactures have been quick to identify prob-  lems in earlier models and make the necessary changes in design and  materials to ensure long-term reliability.    There is no single penile implant that can be considered the best  choice for all patients. Although the urologist is probably best able to  determine which prosthesis is most suitable for a given patient, it is  important to involve the patient in the decision-making process. Opera-  tion of an inflatable implant requires a certain degree of manual dexter-  ity and mental capability. Semirigid devices may be a better choice for  patients with neurologic disease (Parkinson’s, multiple sclerosis), severe  arthritis, missing limbs or fingers, and for some elderly patients. In  addition, patients for whom cost is an overriding concern may be better  served by a less-expensive semirigid device.   Although spinal cord-injured men typically respond very well to  sildenafil, some will still require implantation of a penile prosthesis.  Penile retraction, causing difficulty with condom catheter wear, is  another potential indication for prosthetic insertion in this patient popu-  lation. Men with spinal cord injuries have a much higher incidence of  prosthetic infection compared to other patient groups, even diabetics  (5). Itis tempting to use semirigid rods to potentially decrease the inci-  dence of postoperative infection. Unfortunately, paraplegics also have  a higher-than-average rate of device erosion, presumed secondary to  diminished penile sensation. Instrumentation of the penis and urethra  for bladder management may also be a factor. Thus, paraplegics with  good upper extremity function are probably better suited to inflatable    devices. Either way, consideration should be given to suprapubic cath-  eter use for perioperative drainage of urine in these patients.   Semirigid devices have been advocated for patients with extensive  corporal fibrosis, for whom insertion and adequate inflation of a hydrau-  lic device is difficult. Monga et al. suggested that early placement of a  semirigid device may be the optimum management for sickle cell patients  with recurrent episodes of ischemic priapism (6).   The use of semirigid devices in patients with Peyronie’s disease is  controversial. Ghanem et al. obtained good cosmetic results without the  need for plaque surgery in 65% of cases with a patient satisfaction rate  of 88% at 1 yr (7). Adequate penile straightening was also reported by  Montorsi et al., but they observed diminishing patient satisfaction with  time (8). At a minimum of 5 yr postoperatively, only 48% of their  patients were totally satisfied and would repeat the same operation again.  Sixteen percent of their patients chose to substitute the semirigid implant  with a 3-component inflatable prosthesis.   Reports indicate that semirigid devices are a poor choice for patients  with a long penis (9, /0). Adequate rigidity and concealment have been  a problem. If capable, these men are probably better served by an inflat-  able device. In all patients, careful sizing of the cylinders is critical for  optimizing concealment and decreasing the incidence of dreaded com-  plications such as erosion and chronic penile pain.    Patients and their partners may become dissatisfied with a semirigid  device for a variety of reasons, usually stemming from inability of the  implants to adequately mimic a normal, physiologic erection. Reasons  for dissatisfaction include chronic penile pain, numbness, diminished  quality of orgasm, suboptimal penile length and/or girth, difficulty with  concealment, and inadequate rigidity. Contrary to inflatable devices,  difficulties with operating the semirigid prostheses are rarely reported  even in patients with very poor manual dexterity. Autoinflation is also  nonexistent with semirigid devices. Potential reasons for partner dissat-  isfaction include insufficient penile size, sensation of a cold penis, sen-  sation of unnatural intercourse, and dyspareunia. Some reports have  suggested that patient and partner satisfaction diminishes with time  after implatation (8), although others have shown just the opposite .   Because the various semirigid devices are redesigned or modified  every 5-8 yr, long-term data on a particular device usually becomes  available just as it is replaced by a new, “improved” model. Kearse et al.  recently reported a multicenter evaluation of the Dacomed Dura II    prosthesis up to 2 yr after implantation . Patient satisfaction was in  the 85% range and adverse events (usually infection) occurred in only  8% of patients. Dorflinger and Bruskewitz published their results sev-  eral years ago using the AMS 600 malleable device, predecessor of the  AMS 650 (12). They reported a 90% satisfaction rate, adverse events in  9%, and in 66% no difficulty with concealment was encountered. Vir-  tually identical results were also obtained by Moul and McLeod (10).  Several authors have published their personal experience using a variety  of semirigid devices (including the Mentor products) in a broad range  of patients (13—15). Results are remarkably consistent, with satisfaction  rates in the 85 to 95% range and complication rates substantially lower  than those reported for inflatable devices.    In order to optimize success, surgeons who perform prosthetic sur-  gery need to be familiar with all the various devices currently available.  Each model has its own unique set of advantages and disadvantages.  Overwhelmingly, the key factors for achieving consistent positive out-  comes are meticulous operative technique, careful patient selection, and  thorough preoperative patient education. Other than infection or mechan-  ical failure, the primary reason for patients’ and partners’ dissatisfaction  is unrealistic expectations as to what the prosthesis will do. Semirigid  devices provide adequate erections for most patients. They are easier to  implant and manipulate, cost less, and have a lower mechanical failure  rate than inflatable devices. With this in mind, semirigid penile prosthe-  ses are an excellent alternative for some men with end-stage organic  erectile dysfunction.    1. Bergman RT, Howard AH, Barnes RW (1948) Plastic reconstruction of the  penis. JAMA 59:1174.   3. Scott EB, Bradley WE, Timm GW (1973) Management of erectile impotence.  Urology 2:80.   4. Small MP, Carrion HM, Gordon JA (1975) Small-Carrion penile prosthesis.  Urology 2:479.   5. Collins KP, Hackler RH (1988) Complications of penile prostheses in spinal  cord injured patients. J Urol 140:984.   6. Monga M, Broderick GA, Hellstrom WJG (1996) Priapism in sickle cell dis-  ease: the case for early implantation of the penile prosthesis. Eur Urol 30:54.   7. Ghanem HM, Fahmy I, El-Meliegy A (1998) Malleable penile implants without  plaque surgery in the treatment of Peyronie’s disease. Int J Impot Res 10:171.   8. Montorsi F, Guazzoni G, Bergamaschi F, Rigatti P (1993) Patient-Partner sat-  isfaction with semirigid penile prostheses for Peyronie’s disease: a 5-year  followup study. J Urol 150:1819.    9. Chen GL, Kowitz AS, Berger RE (1997) Reinforcement of semirigid penile  implant. J Urol 157:2258.   10. Moul JW, McLeod DG (1986) Experience with the AMS 600 malleable penile  prosthesis. J Urol 135:929.   11. Kearse WS Jr, Sago AL, Peretsman SJ, et al. (1996) Report of a multicenter,  clinical evaluation of the Dura II penile prosthesis. J Urol 155:1613.    Until the early 1970s, most impotence, or what is now known as  erectile dysfunction (ED), was assumed to be of psychogenic origin, and  even urologists had little interest in its treatment. F. Brantley Scott, a  urologist from the Baylor College of Medicine; William E. Bradley, a  neurologist; and Gerald W. Timm, a biomedical engineer (both from the  University of Minnesota) collaborated to develop an artificial urinary  sphincter and an inflatable penile prosthesis. Together with a business-  man, Robert Buuck, Drs. Scott, Bradley, and Timm formed American  Medical Systems (AMS) to manufacture and market these devices.    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    The first inflatable penile prosthesis, made from Dacron-reinforced  silicone elastomer, consisted of four parts: an inflation pump, a deflation  pump, paired nondistensible cylinders, and arectangular fluid reservoir.  In their initial report, they described its use in five patients . This first  inflatable penile prosthesis, used from February 1973 to August 1974,  was implanted in 12 patients with success in 9 (2).   The first prosthesis to reach the market in 1974 was a modification of  this original four-piece device. It had the following design changes: the  Dacron reinforcement was eliminated and a single inflation-deflation  pump was developed. The reservoir was round, flat, and had a peripheral  seam. The cylinders were changed to expandable, single-ply silicone  elastomer tubes. Two subsequent modifications to this device were later  introduced: a seamless, spherical reservoir in 1978 and rear-tip extend-  ers in 1980. This prosthesis remained in use from 1974 to 1983, and its  availability rapidly sparked urologists’ interest in ED.   Furlow reported on 63 men implanted with this prosthesis who had  follow-up ranging from 6 to 24 mo. Seventeen (27%) experienced  mechanical failures in this relatively short period of time (3). Later, he  updated his series with reports on 175 implant recipients followed for  6 to 42 mo. Mechanical failures occurred in 37 (21%) (4). Scott et al.  reported on 245 men implanted with this device between 1973 and 1977.  The implant procedure was successful in 234 cases (96%) and 102 of  these patients (44%) subsequently underwent repeat operation because  of surgical complications, mechanical failures, or patient request for a  new model (5). Malloy et al. reported on implants in 93 men followed  from 6 mo to 4 yr. Complications leading to 31 secondary procedures  occurred in 27 (29%) of the patients (6). Fallon et al. reported on 95 men  implanted with these devices between 1977—1983. Of these, 48% had  been revised, removed, or failed during follow-up (7). We reported on  121 implant recipients. The first 70 patients implanted through a lower  abdominal incision, had a total of 63 revisions in 34 patients. The next  51 implants, through a penoscrotal incision, using rear-tip extenders had  revisions in only 4 patients (8).    A new model of the inflatable penile prosthesis, the AMS 700 Inflat-  able Penile Prosthesis, was introduced in 1983. Itincluded the following  design changes: kink-resistant tubing, thicker cylinders with redesigned  front and rear tips, polytetrafluoroethylene sleeves over the tubing to  prevent cylinder wear, and aredesigned pump to permit easier deflation.  A sutureless connector system was introduced in 1985. This model  remained in use from 1983 to 1987.    Fig. 1. The triple-ply cylinder design used in the AMS Three-Piece Inflatable Penile  Prostheses. Courtesy of American Medical Systems, Inc., Minnetonka, MN.    Malloy et al. reported 290 men implanted with the AMS 700 pros-  thesis who were followed for at least 1 yr. There were three cylinder  failures and eight leaks from kink-resistant tubing. No pump or reser-  voir failures occurred. Life table analysis showed a probability of device  survival of 97.9% at 3 yr (9). Gregory and Purcell reported on 131  implant recipients. Cylinder survival was 98% at 1 yr and 92% at 3 yr.  Tubing leaks occurred in nine patients (/0). Scarzella reported on 325  implant recipients. Three-year cylinder survival was 72% for cylinders  manufactured from 1974 to 1983 and was 86% for cylinders manufac-  tured after 1983 (AMS 700 cylinders) (71). Wilson et al. reported on  395 patients implanted since 1977. In patients implanted before 1983,  there was a 61% complication/revision rate with follow-up of 3-11 yr.  In patients implanted after 1983, only 13% required revision with fol-  low-up to 4 yr (/2).   The expansion of these single-ply AMS 700 cylinders was deter-  mined primarily by the elastic characteristics of the recipients’ corpora  cavernosa. Because this varied from patient to patient, cylinder aneu-  rysms with this device were common (/3).    The first triple-ply cylinders were introduced in 1987 (see Fig. 1).  Fluid pumped into an inner silicone elastomer tube expanded against a  middle woven fabric layer. An outer silicone covering prevented tissue  growth into the fabric layer. The woven fabric controlled expansion of    these cylinders; thus, cylinder expansion was no longer dependent on  the elastic characteristics of recipients’ tissues. The cylinders of this  AMS 700CX prosthesis have diameters of 12 mm when deflated and  diameters of 18 mm when inflated. This implant continues to be used today.   Furlow and Motley reported 63 men implanted with the AMS 700CX  device with follow-up ranging from 8 to 38 mo (average 20 mo). There  were no cylinder aneurysms and only 1 cylinder leak (/4). Quesada and  Light reported 214 men who were implanted with the AMS 700CX  prosthesis. Follow-up ranged from 18 to 84 mo with a mean follow-up  of 55 mo. The probability of survival without revision to 6 yr was 97%  for the cylinders and 90% for the device as a whole. Cylinder leaks  occurred in 0.7% and there were no cylinder aneurysms (/5). Nickas et  al. reported on 55 implant procedures using the AMS 700CX device and  compared them to 252 implants with earlier AMS models of the inflat-  able penile prosthesis (/6). Actuarial 4-yr survival for the AMS 700CX  prosthesis was 85% compared to 46% for the earlier devices. This dif-  ference was primarily a result of lower cylinder complications with the  CX device. We reported 111 CX/CXM implants with follow-up ranging  from 1 to 112 mo (mean 47 mo). There were 10 mechanical failures (9%)  (17). This prosthesis is now available in a model containing paired  cylinders connected to a pump (the AMS 700CX Preconnected Penile  Prosthesis).    The AMS 700CXM prosthesis was originally developed for implanta-  tion in men with smaller penises; however, its main use now is in prosthe-  sis implantation men with fibrotic penises (/8). This is a smaller version  of the AMS 700CX prosthesis. Its pump and reservoir are smaller, and the  cylinders have deflated diameters of 9.5 mm and inflated diameters of  14.2 mm. It was introduced in 1990 and remains in use today.    This prosthesis (see Fig. 2) has triple-ply cylinders with the same  deflated and inflated diameters as the AMS 700CX device (12 and 18 mm).  The middle fabric layer of the Ultrex cylinders; however, expands in  two directions; thus, these cylinders not only increase in diameter with  inflation, they also increase in length. Outside the body, these cylinders  are capable of increasing 20% in length. The amount of penile length  achieved after implantation is determined primarily by the elasticity of  the recipient’s penis. This prosthesis was introduced in 1990 and remains  in use. In 1992, the 700 Ultrex™ Plus Penile Prosthesis was developed.  This device consists of prefilled Ultrex cylinders connected to a prefilled    Fig. 2. The 700 Ultex™ Penile Prosthesis. Courtesy of American Medical  Systems, Inc., Minnetonka, MN.    pump. The reservoir is implanted separately and a single connection is  made between the reservoir and the pump.   We reported on the length expansion obtained following implanta-  tion of the Ultrex prosthesis. In 50 patients, the intraoperative penile-  length measurement between deflation and inflation increased 1 to4cm  (mean 1.9cm). Postoperative measurements were obtained in 46 patients  at a mean of 4 mo. In 28 patients, the intraoperative length expansion  was maintained, whereas in six patients, it decreased by 1 cm, and in 12  patients, it increased by 1 cm (19).   Holloway and Farah reported 145 patients implanted with the 700  Ultrex device. Follow-up ranged from 6 to 62 mo (mean 42 mo). There  was a 13% reoperation rate and an 8% mechanical failure rate (20). We  reported on 152 Ultrex implant recipients with a follow-up of 0.7 to  71.5 mo (mean 34 mo). Mechanical failures occurred in 26 patients (17%)  (17). We found that this was primarily because of cylinder failure  resulting from tearing of the middle fabric layer. In 1993, the middle  fabric layer of the Ultrex cylinders was strengthened to increase  device longevity, while still permitting the same degree of girth and  length expansion. Published reports of cylinder survival with the  modified Ultrex cylinder are not yet available. We have implanted  142 Ultrex devices containing modified cylinders with only three  known cylinder failures; however, further follow-up is needed to    Table 1  Current AMS Three-Piece Inflatable Penile Prostheses  Date Deflated Inflated Length  Model introduced diameter diameter expansion Connections  700CX 1987 12 mm 18 mm no 3  700CXM 1990 95mm 14.2 mm no 3  Ultrex 1990 12 mm 18 mm yes 3  Ultrex Plus 1992 12 mm 18 mm yes 1    determine the reliability of these cylinders. The three-piece AMS  devices currently in use are shown in Table 1.    The AMS Hydroflex prosthesis, used from 1985 to 1990, was devel-  oped to produce a device that would be rigid when inflated and, when  deflated, would lose some of its rigidity. This device consisted of paired  cylinders implanted in both corpora. A small pump in the distal cylinder  was used to transfer a small volume of fluid from a rear-tip reservoir into  acentral nondistensible chamber. This device achieved rigidity without  girth or length expansion. Deflation was obtained by pressing a release  valve just proximal to the pump.   Mulcahy reported on 100 patients implanted with the AMS Hydroflex  penile prosthesis (2/). Follow-up was from 1 to 3.5 yr. There were six  mechanical failures and 15 patients had difficulty learning how to inflate  and deflate the device. Kabalin and Kessler reported on 51 Hydroflex  implant recipients followed from 6 to 33 mo (mean 20 mo) (22). There  were no mechanical failures and 81% of the patients were satisfied with  the device.    The Dynaflex prosthesis was introduced in 1990 as a modification of  the Hydroflex device. Deflation with the Dynaflex prosthesis was  achieved by bending the device to increase pressure for 10 s. When the  bend in the device was released, deflation occurred. This modification  resulted in a prosthesis that was easier to deflate. The central nondis-  tensible chamber was also longer, resulting in improved rigidity with  inflation. Kabalin and Kuo reported on 62 Dynaflex implant recipients  followed for a minimum of 24 and a mean of 50 mo (23). There were six  mechanical failures (9.7%), and 16.1% of the patients were dissatisfied    Fig. 3. The AMS Ambicor® Penile Prosthesis. Courtesy of American Medical  Systems, Inc., Minnetonka, MN.    with the device. Anafarta et al. reported 120 men implanted with the  Dynaflex device (24). Follow-up ranged from 2 to 80 mo (mean 42 mo).  The mechanical failure rate was 7.5%, and 16.7% were dissatisfied  because of difficulty using the device. The AMS Hydroflex and the  AMS Dynaflex prostheses, having been replaced by the Ambicor pros-  thesis (see next section), are no longer available in the United States.    The Ambicor penile prosthesis consists of paired cylinders connected  to a small scrotal pump (see Fig. 3). Like the Dynaflex prosthesis, the  Ambicor has rear-tip fluid reservoirs and acentral nondistensible cham-  ber. The pump is moved from the distal portion of the cylinders to the  scrotum, making this device easier to cycle and creating a longer central  chamber for better rigidity. To our knowledge, there are no published  reports of the use of this device. This device, which was introduced in  1994, is still in use.    When the inflatable penile prosthesis was introduced in 1974, the  principal treatments for men with ED consisted of sex therapy for men  with psychogenic or potentially reversible ED and penile prosthesis  implantation for nearly everything else. Today, the following treatment    options for ED are available: sex therapy, systemic therapy, the use of  vacuum erection devices, intraurethral medications, penile injection  therapy, vascular surgery, and penile prosthesis implantation. Because  of the attractiveness, efficacy, and safety profile of new systemic agents,  many men with ED are presenting for treatment. Medications such as  sildenafil citrate, and others soon to be released, are usually first-line  therapy options, with sex therapy also being employed as appropriate.  Men who fail these first-line treatment options are potential candidates  for penile prosthesis implantation if the remaining treatment options  either fail or are rejected by the patient and his partner.    The ideal penile prosthesis would allow a man to control when he had  an erection and would produce prosthetic flaccid and erect states resem-  bling, as closely as possible, natural penile flaccidity and erection. To  do this with an inflatable hydraulic device, a large volume of fluid must  be pumped into expandable cylinders for erection and must be trans-  ferred out of the cylinders for flaccidity. This requires a device with a  large abdominal fluid reservoir such as the three-piece inflatable pros-  theses produced by AMS and Mentor Corporation. The ideal prosthesis  would provide on inflation penile rigidity, as well as girth and length  expansion. Currently, there is only one device doing this and it is the 700  Ultrex Inflatable Penile Prosthesis. Should this prosthesis be offered to  all potential implant recipients?    We prefer the AMS three-piece inflatable prostheses and offer nearly  all patients these devices based on the following considerations. For  most first-time prosthesis recipients, we offer the 700 Ultrex device,  unless in addition to ED, the man has erectile deformity, for example  owing to Peyronie’s disease. The girth-only expanding AMS 700CX  prosthesis has better straightening characteristics than the Ultrex, and  thus we favor this device for these men (25). We also use the AMS  700CX device for men with long penises because the CX cylinders  produce better rigidity. Only rarely during primary prosthesis implan-  tation do we encounter corpora that will not dilate sufficiently to accept  12-mm diameter cylinders. For these men, we will use the AMS  700CXM implant.   For secondary or repeat penile prosthesis implantation, we will use  the girth-only expanding CX cylinders when length expansion should  be avoided, for example after failed implants owing to urethral erosion  or cylinder crossover. For men with small penises because of fibrotic    corpora, as we see in men who have had priapism or men who have had  an infected penile implant removed, we implant the small-diameter  AMS 700CXM device (18). For all other secondary implants, we con-  sider the 700 Ultrex prosthesis, provided the penis is not long and it has  at least 2 cm of stretch.    Following uncomplicated penile prosthesis implantation, successful  healing without infection, erosion, device migration, or immediate  mechanical failure should occur in about 95% of patients. If a man  undergoes successful device implantation and is not satisfied, it is prob-  ably because his expectations were not met. It should be the goal of  preoperative counseling to provide the patient with realistic expecta-  tions. Penile prosthesis implantation does not ordinarily interfere with  penile sensation or the ability to achieve orgasm and ejaculate. How-  ever, if any of these conditions are absent or not normal, device implan-  tation will not restore them. With today’s three-piece inflatable devices,  penile flaccidity is usually good and most men will feel comfortable  when undressed in a locker room. Although three-piece inflatable pros-  theses, when inflated, resemble normal erections more than other  devices, in nearly all cases, the erection will be shorter than the  recipient’s natural erection. This is true even with the length-expanding  Ultrex prosthesis, although this disparity between prosthetic and natural  erection length is less with Ultrex device than it is with other penile pros-  theses. The most common source of patient dissatisfaction, in our opinion,  is shortness of the erection, and we try to prepare the patient for this. Although  itis not possible to predict prosthetic erect length with certainty, it is usually  close to the patient’s preoperative stretched penile length.    The Infrapubic Approach. With this approach, a vertical or trans-  verse incision is made between the pubis and the penis. The sole advan-  tage of this approach is that it permits reservoir placement under direct  vision. Disadvantages include limited corporeal exposure, inability to  fix the pump in its scrotal pouch, and possible damage to the dorsal  nerves of the penis. Dorsal nerve damage seldom occurs during initial  device implantation with this approach; however, we have seen it inmen  after prosthetic revisions. Possible explanations include dorsal nerve  entrapment in scar or nerve damage from using the electrosurgical unit  to open the corpora at the time of revision.    The Penoscrotal Approach. Penoscrotal approaches include either  a vertical incision over the urethra at the penoscrotal junction or a trans-  verse incision in the upper scrotum just below the penoscrotal junction  (26). Although the urethra could be damaged by the penoscrotal  approach, it is easily seen and avoided. Urethral damage, which rarely  occurs, is almost always confined to the corpus spongiosum and is easily  repaired allowing the implant procedure to proceed. We prefer the trans-  verse scrotal approach, which provides excellent exposure of both crura,  as well as the corpora at the base of the penis. If more distal exposure is  needed because of corporeal fibrosis, this incision can be extended in an  inverted T fashion to the frenular area. This is the only approach that  affords nearly complete corporeal exposure through a single incision.   If the cylinders and pump are implanted separately, the pump can be  fixed in its sub-Dartos pouch by routing each of the three tubes through  separate stab incisions in the back wall of the pouch. The principal  disadvantage of the penocsrotal approach is the blind placement of the  retropubic fluid reservoir.    Many implantors determine cylinder size by placing a reference  suture at the midpoint of the corporotomy and then making distal and  proximal measurements from this reference point. These two measure-  ments are added to determine corporeal length and cylinder size. Using  arigid sizing instrument to determine length on the surface of the corpo-  real bodies over estimates the internal length of the corpora by 1 to 2 cm.  If cylinders are implanted that are slightly too long for the corpora, a  cylinder fold at the base of the penis occurs, which may lead to prema-  ture cylinder failure. With the Ultrex cylinders (which expand in length),  using a cylinder that is too long will result in the S-shaped cylinder  deformity (27).   To avoid this problem, we use 2-cm corporotomies and make the  distal and proximal corporeal measurements from the distal and proxi-  mal ends of the corporotomies, respectively. These two measurements  are added to determine cylinder size; thus, the corporotomy is not  included in this measurement. After the cylinder is placed, we make sure  that it fills the entire corpus cavernosum and that it lies flat inside the  corporotomy. If necessary, the cylinder size can be adjusted by adding  or removing rear tip extenders until the cylinder fit is exact.    The most common cause of cylinder auto inflation is high fluid pres-  sure in the reservoir. The prevesical or retropubic space is the best    location for the reservoir. After the reservoir is placed and filled, a back-  pressure test should be performed to be sure that fluid pressure in the  reservoir is zero. We attach a syringe without a barrel to the reservoir  tube and allow any fluid under pressure to escape into the syringe. We  then apply manual pressure to the bladder area to express any additional  fluid. Finally, the cylinders of the prosthesis should be kept deflated  while healing is taking place so that the pseudocapsule, which forms  around all parts of the prosthesis, will form around the reservoir when  the device is in the deflated state.    The introduction of the inflatable penile prosthesis in 1974 encour-  aged urologists to become more actively involved in the treatment of  ED. Early models of the inflatable penile prosthesis had many mechani-  cal problems resulting in frequent, early revisions. Numerous improve-  ments in device design and implantation techniques over the years have  resulted in today’s devices, which are more reliable.   When inflatable penile prostheses and semirigid rod prostheses were  first introduced, they were almost the sole treatment for organic ED.  Today, a variety of treatment options, including easily used and often  effective systemic therapy, have resulted in greatly increased numbers  of men presenting for treatment of ED. When systemic treatments for  ED fail, other treatments including vacuum erection devices, intra-  urethral medications, and penile injections should be offered. If these  options fail or are rejected by the patient and his partner, penile prosthe-  sis implantation should be considered. Penile prosthesis implantation,  although no longer a first-line treatment option for ED, nevertheless  continues to be an important part of ED therapy.    1. Scott FB, Bradley WE, Timm GW (1973) Management of erectile impotence:  use of implantable inflatable prosthesis. Urology 2:80-82.   2. Fishman IJ, Scott FB, Light JK (1984) Experience with inflatable penile pros-  thesis. Urology 23:86-92.   3. Furlow WL (1978) The current status of the inflatable penile prosthesis in the  management of impotence: Mayo Clinic experience updated. J Urol 119:363-364.   4. Furlow WL (1979) Inflatable penile prosthesis: Mayo Clinic experience with  175 patients. Urology 13:166-171.   5. Scott FB, Byrd GJ, Karacan I, Olsson P, Beutler LE, Attia SL (1979) Erectile  impotence treated with an implantable, inflatable prosthesis. JAMA 241:2609-2612.   6. Malloy TR, Wein AJ, Carpiniello VL (1979) Further experience with the inflat-  able penile prosthesis. J Urol 122:478-480.   7. Fallon B, Rosenberg S, Culp DA (1984) Long-term followup in patients with an  inflatable penile prosthesis. J Urol 132:270-271.    . Montague DK (1983) Experience with semirigid rod and inflatable penile    . Furlow WL, Motley RC (1988) The inflatable penile prosthesis: clinical expe-    . Quesada ET, Light JK (1993) The AMS 700 inflatable penile prosthesis: long-    . Nickas ME, Kessler R, Kabalin JN (1994) Long-term experience with con-    trolled expansion cylinders in the AMS 700CX inflatable penile prosthesis and  comparison with earlier versions of the Scott inflatable penile prosthesis. Urol-  ogy 44:400-403.   Daitch JA, Angermeier KW, Lakin MM, Ingleright BJ, Montague DK (1997)  Long-term mechanical reliability of AMS 700 series inflatable penile prosthe-  ses: comparison of CX/CXM and Ultrex cylinders. J Urol 158:1400-1402.  Carbone DJ, Jr, Daitch JA, Angermeier KW, Lakin MM, Montague DK (1998)  Management of severe corporeal fibrosis with implantation of prosthesis via a  transverse scrotal approach. J Urol 159:125-127.   Montague DK, Lakin MM (1992) Early experience with the controlled girth and  length expanding cylinder of the AMS Ultrex penile prosthesis. J Urol  148:1444-1446.   Holloway FB, Farah RN (1997) Intermediate term assessment of the reliability,  function and patient satisfaction with the AMS700 Ultrex penile prosthesis [see  comments]. J Urol 157:1687-91.   Mulcahy JJ (1988) The Hydroflex self-contained inflatable penile prosthesis:  experience with 100 patients. J Urol 140:1422-1423.   Kabalin JN, Kessler R (1989) Experience with the Hydroflex penile prosthesis.  J Urol 141:58-59.   Kabalin JN, Kuo JC (1997) Long-term followup of and patient satisfaction with  the Dynaflex self-contained inflatable penile prosthesis. J Urol 158:456—459.  Anafarta K, Yaman O, Aydos K (1998) Clinical experience with Dynaflex penile  prostheses in 120 patients. Urology 52:1098—1100.   Montague DK, Angermeier KW, Lakin MM, Ingleright BJ (1996) AMS 3-piece  inflatable penile prosthesis implantation in men with Peyronie’s disease: com-  parison of CX and Ultrex cylinders [see comments]. J Urol 156:1633-1635.  Scarzella GI (1989) Improved technique for implanting AMS 700CX inflatable  penile prosthesis using transverse scrotal approach. Urology 34:388-389.  Wilson SK, Cleves MA, Delk II JR (1996) Ultrex cylinders: Problems with  uncontrolled lengthening (the S-shaped deformity). J Urol 155:135-137.    Ten years after the introduction of the Scott three-piece inflatable  penile prosthesis in 1973 (American Medical Systems, Minnetonka,  MN) (1), Mentor Corporation introduced their first three-piece inflat-  able penile prosthesis, the Mentor IPP (Surgitek, Racine, WI) (2). This  device provided an alternative for improving the mechanical reliability  of the three-piece inflatable penile prosthesis, which had been reported  to be as high as 42% in some series (3). The most important advance that  Mentor brought to the field of penile prosthetics was the introduction of  anew material, known as Bioflex. Biofelx is an aromatic polyether urea  urethane elastomer that provided a tensile strength seven times higher  than that of silicone without sacrificing biocompatibility and hemocom-  patibility (4-6). The physical characteristics of this material, virtually    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    eliminated cylinder failures as a result of aneurysms or wear-induced  abrasion, and provided the widest inflatable cylinder girth expansion  available. As with other devices, continuous modifications of the Men-  tor IPP followed such as: a) modification of the pump in 1983 to improve  patient identification of the deflation valve; b) use of nylon reinforced  tubing in 1984 to eliminate tubing kinks; c) reinforced cylinder base in  1985 to avoid separation of the input tubing from the cylinder; d) use of  a flange to the plastic clamps of the snap-on connectors in 1987 to  improve stability (7), yield improved clinical results (8).    The second generation of the Mentor inflatable penile prosthesis was  introduced in May 1989. The Mentor a-1 was designed to improve  device reliability and reduce device failure from connector leakage.  This inflatable penile prosthesis (see Fig. 1) was the first connectorless,  single pump-cylinder unit. Although continued minor modifications have  occurred over the years, the basic design of the Mentor o-1 has remained  the same for the last 11 yr. Some of these minor modifications to the a-1  included lengthening and reinforcement of the tubing at the exit from  the pump in late 1992. The enhanced version (see Fig. 2) of the Mentor  a-l model increased the 5-yr survival rate from 75.3 for the original to  92.6% and lowered the failure rate of approx 5.6% for the original model  to 1.3% (9). Cylinder, reservoir, and pump malfunctions are rarely ob-  served in contemporary Mentor three-piece inflatable penile prosthesis.  Current data reveals device malfunction consists of tubing fluid leaks  (10-13).    In 1993, Pescatori and Goldstein reported a 16% mechanical failure  rate in the AMS 700 CX as a result primarily of leaks at or near the  connector site. A4% mechanical failure rate was observed in the Mentor  a-l. A common malfunction site in the AMS device was observed in the  tubing from one of the cylinders as its inlet to the pump. One explanation  for the difference was found to be the lower intraluminal device pres-  sures in the Mentor device during inflation and the absence of connec-  tors in the pump cylinder unit. This comparative paper between Bioflex  (Mentor IPP and Mentor a-1) and silicon-based devices (AMS 700 CX  and AMS Ultrex) revealed markedly elevated values of intraluminal    pressures in the second group (see Fig. 3). Such high pressures are  equally transmitted to all of the communicating components, presum-  ably causing malfunctions at the weakest locations. The difference in  intraluminal pressures reflects the compliance characteristics of the wall  of the cylinders. The Bioflex lining material of the Mentor cylinders has  greater compliance with an ability to stretch circumferentially during  inflation and increase girth to values exceeding 21 mm without defor-  mation of the cylinders. The Dacron-Lycra sleeve surrounding the AMS  700 CX cylinder has virtually no compliance, restricting girth expan-  sion to 18 mm (/4). Therefore, during inflation, fluid constraint within  the AMS 700 CX will occur at lower volumes and higher intraluminal  pressures than Mentor devices.   This double-digit mechanical failure rate seen in the AMS devices  has not changed significantly in the last 7 yr. Carson et al. recently  published the results of the AMS 700 CX study group. They found a    Fig. 2. Enhanced Mentor a-1 inflatable penile prosthesis. In 1992, the tubing  was length and reinforced at the exit from the pump.    Fig. 3. Comparison between Bioflex (Mentor IPP and Mentora-1) and silicon-  based devices (AMS 700 CX and AMS Ultrex) revealed markedly elevated  values of intraluminal pressures in the second group.    Fig. 4. Mentor a-1 inflatable penile prosthesis with the enhanced reservoir  (Lock-out valve).    13.8% mechanical failure rate at 5 years with a complication rate of  45%, most commonly secondary to fluid loss or leakage (25).   Based on contemporary data, the failure rate for the AMS 700 CX is  therefore more than 10 times that of the Mentor a-1 inflatable penile  prosthesis. The most-likely explanation for the mechanical failure rates  between the two devices is the difference in the material characteristics  lining the two products. Bioflex is simply a more-appropriate and reli-  able material when used in inflatable penile prostheses.    Autoinflation of the inflatable penile prosthesis is an annoying and  embarrassing clinical complication, which has been reported in various  degrees of severity in up to 20% of cases. Initially, both AMS and  Mentor three-piece implants were reported to have spontaneous autoin-  flation as a complication. In 2000, Mentor Corporation introduced the  enhanced reservoir with the new “Lock-out valve” (see Fig. 4). The new  valve opened to allow fluid flow when the reservoir output was sub-  jected to negative pressure. This occurred as the pump bulb recovers    from a collapsed state during cylinder inflation, and when the reservoir  output was subjected to positive pressure during deflation of the penile  cylinders. Preliminary results reported by the Lock-out Valve Study, a  group of 17 physicians of varied geographical locations and types of  practices, showed 8.6% of mild autoinflation in 70 patients, with a  52-mo follow-up. All physicians reported that the lock-out valve did not  affect the usual surgical procedure in any case (/5). Dr. Wilson also  reported his experience with the Lock-out valve (/6) at the 1999 AUA  meeting in Dallas. Although, his follow-up was only 6 mo, no patients  experienced autoinflation or difficult deflation.    Severe bilateral corporal fibrosis because of priapism, Peyronie’s  disease, trauma, infection, or repeated penile placement are the most  complicated penile implant insertion cases with less than satisfactory  outcomes. These cases have a high incidence of complications (ero-  sions, infections, penile shortening) and prolonged surgical time. Often,  abandon of the inflatable penile prosthesis placement or placement of  malleable penile prosthesis is performed as an alternative to the reinser-  tion of an inflatable implant. Several novel surgical techniques and  instruments such as “cutting-type” dilators have been described in the  past, but limited satisfactory reports of clinical outcome with inflatable  penile implants are available. Controlled, sharp, corporal tissue exci-  sion with extended bilateral corporotomies has been reported to provide  a 94% rate of functioning implants, and a high satisfaction rate mea-  sured by HEF (17). This technique allows the placement of a standard  Mentor a-1 penile prosthesis providing the longest and widest device  possible in these patients who have already lost significant length.   Mentor Corporation, recently introduced the Mentor a-I narrow-  base inflatable prosthesis (see Fig. 5). The a-1 NB cylinders are 3.7 mm  less in diameter than the standard a-1, and have a narrower base (10 mm),  with an acute tubing exit angle of 22.5°, and 9-mm rear-tip extenders,  which allows easier placement within a fibrotic and scarred corpora.  The use of this device in corporal fibrosis has a high rate of functioning  implants (100%) with no infections or malfunctions with a 10-mo  follow-up (18).    Contemporary data indicates that surgical success with inflatable  penile prosthesis is 95-97% (19,20), but surgical success not always  represents patient satisfaction. To answer this important question, we    Fig. 5. Mentor a-1 narrow base inflatable prosthesis. The a- 1 NB cylinders are  3.7 mm less in diameter than the standard a-1, with a narrow base (10 mm),  acute tubing exit angle (22.5°), and 9-mm rear-tip extenders.    (22) (23) (24) (21) (9) (O/E*)  Year 1993 1993 1996 1997 1999  No Pts 112 333 150 434 410/971  Mechanical failure  4 2.7 0 25 5.6/1.3  Infection rate  2 1.2 1 2.8 3.9/4.8  Follow-up (mo) 27 15.4 19 22,2  Reoperative rate  9 4.5 2 6.9 21.7/2.78  Complications 7.5 3 9.2    performed a Phase-?2, multiinstitutional, large-scale retrospective study,  with independently analyzed medical records and questionnaire data  from consecutive eligible patients of seven physician investigators (2/).  In those that returned the questionnaire, 89% of patients with Mentor  a-1 prosthesis fulfilled expectations as a therapy for erectile dysfunc-  tion, including 28% who claimed fulfillment as expected, 31% better  than expected and 30% much better than expected. Satisfaction responses  of 80% or greater were noted regarding intercourse ability and con-  fidence, device rigidity, and function. Interestingly, implantation of    inflatable penile prosthesis did not result in 80% or greater satisfaction  responses in partner relationship changes (as judged by the patient),  partner feelings about the relationship (as judged by the patient), or  increased confidence in social activities and work. Such information is  important when providing preoperative counseling to patients so that  postoperative expectations will be appropriate.    The introduction of penile prosthesis in 1973 revolutionized the field  of sexual medicine. Urologists in conjunction with basic and clinical  researchers have established the contemporary knowledge of erectile  function and dysfunction allowing the development of less invasive  alternatives to the penile implant. Recently, with the advent of oral  therapy, the number of medical visits and urologic referrals for the  sexual medical problem of erectile dysfunction has increased. Patients  with erectile dysfunction are now advised to proceed first with step-care  treatment for erectile dysfunction where first-line therapy (oral agents,  vacuum devices, and sex therapy) and second-line therapy (intraurethral  and intracavernosal pharmacologic administration of vasoactive agents)  are completed prior to any consideration for surgical treatment.   Should penile prosthesis insertion be indicated, the Mentor a- 1 inflat-  able penile prosthesis is the device that provides the widest diameter  penile erection during inflation and the lowest mechanical failure rate.  The Bioflex material has an increased abrasion resistance and higher  tensile strength than silicone-based devices. The superior outcome data  in terms of mechanical reliability have remained durable over the last 10 yr.  In addition, the Mentor a-1 has a high degree of patient satisfaction.    1. Scott FB, Bradley WE, Timm GW (1973) Management of erectile dysfunction:  use of implantable inflatable prosthesis. Urology 2:80.   3. Scott FB, Byrd GJ, Karacan I, Olsson P, Beutler LE, Attia SL (1979) Erectile  impotence treated with an implantable, inflatable prosthesis. JAMA 241:2609.   4. Pescatori ES, Goldstein I (1993) Intraluminal device pressures in 3-piece inflat-  able penile prosthesis: the “pathophysiology” of mechanical malfunction. J Urol  149:295-300.   5. Hackler RH (1986) Mentor inflatable penile prosthesis: a reliable device. Urol-  ogy 28:489.   6. Whalen RK, Merrill DC (1991) Patient satisfaction with Mentor inflatable penile  prosthesis. Urology 37:531.   7. Brooks MB (1988) 42 months experience with Mentor inflatable penile prosthe-  sis. J Urol 139:48.    Merrill DC (1988) Clinical experience with the Mentor inflatable penile pros-  thesis in 301 patients. J Urol 140:1424.   Wilson SK, Cleves MA, Delk JR (1999) Comparison of the mechanical reliability  of Original and enhanced mentor alpha I penile prosthesis. J Urol 162:715-718.  Steinkohl WB, Leach GE (1991) Mechanical complications associated with  Mentor inflatable penile prosthesis. Urology 38:32.   Kabalin JN, Kessler R (1988) Five-year follow-up of the Scott inflatable penile  prosthesis and comparison with semirigid penile prosthesis. J Urol 140:1428.  Earle CM, Watters GR, Tulloch AGS, Wisniewski ZS, Lord DJ, Keogh EJ  (1989) Complications associated with penile implants used to treat impotence.  Aust New Zeal J Surg 59:959.   Montague DK (1990) Penile prosthesis implantation: special considerations. Int  J Impot Res, supp1, 2:3.   Woodworth BE, Carson CC, Webster GD (1991) Inflatable penile prosthesis:  effect of device modification on functional longevity. Urology 38:533.  Goldstein I, Geffin M, and the Mentor Lock-Out Valve study Group. Prevention  of auto-inflation in the Mentor Alpha-1 three piece inflatable penile prosthesis:  preliminary results of the Lock-Out Valve Study. 1999 AUA Meeting.  Wilson SK, Delk JR, Van Buren, Dhabuwala CB. Early results with new Lock-  out Valve to prevent auto inflation of Mentor Alpha 1 penile prosthesis. 1999  AUA Meeting.   Geffin M, LaSalle M, Patel R, Krane RJ, Goldstein I. Clinical outcome of Alpha-1  three piece inflatable penile prosthesis insertion in patients with bilateral severe  corporal fibrosis. 1998 AUA Meeting.   Hakim LS, Pham H. Initial clinical experience with the Mentor alpha-one nar-  row base inflatable penile prosthesis: an effective option for the management of  severe corporal fibrosis. 1999 AUA Meeting.   Merril DC (1989) Mentro inflatable penile prosthesis. Urol Clin North Am  16:51-66.   Furlow WL, Motley RC (1988) The inflatable penile prosthesis: clinical expe-  rience with a new controlled expansion cylinder. J Urol 139:945-946.  Goldstein I, Newman L, Baum N, Brooks M, Chaikin L, Goldberg K, et al.  (1997) Safety and efficacy outcome of Mentor Alpha-1 inflatable penile pros-  thesis implantation for impotence treatment. J Urol 157(3):833-839.  Goldstein I, Bertero E, Kaufman JM. Witten FR, Hubbard JG, Fitch WP, et al.  (1993) Early experience with the first pre-connected 3-piece inflatable penile  prosthesis: The Mentor Alpha-1. J Urol 150:1814-1818.   Randrup E, Wilson S, Mobley D, Suarez G, Mekras G, Baum N (1993) Clinical  experience with Mentor Alpha I inflatable penile prosthesis. Urology 42(3):305-308.  Garber BB (1996) Inflatable penile prosthesis: results of 150 cases. Br J Urol  78(6):933-935.   Carson CC, Mulkahy JJ, Govier FE, and the AMS 700 Cs study group (2000)  Efficacy, safety and patient satisfaction outcomes of the AMS 700CX inflatable  prosthesis: results of a long-term multicenter study. J Urol 164:376-380.    Peyronie’ s disease is a benign condition characterized by the forma-  tion of fibrotic plaques of the tunica albuginea. The French physician  Francois Gigot De La Peyronie first described the condition in 1743.  Dr. Peyronie suggested the etiology of the condition might be chronic  irritation from sexual activity or an inflammatory (venereal) disease .  Two-hundred fifty years later, medical authorities are still puzzled over  the etiology of this annoying condition.   Peyronie’s first theory of continued minor sexual trauma is consid-  ered today the most likely cause of the disease. The consensus thinking  is that the repeated trauma of sex is thought to injure the collagen    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    composition of the tunica albuginea. This results in induration and the  formation of fibrous plaques that decrease the elasticity of the corpora  and cause curvature or constriction of the penis during erection (2).  Despite this widely held opinion, the majority of patients cannot give a  history of injury to the penis during sexual activity   Discrete penile injuries can produce lesions indistinguishable from  Peyronie’s disease. Trauma must not be the only factor, however, since  large series have shown inherited predisposition. In addition, there is a  20% association with Dupuytens contractures of the hand, a disease  inherited via autosomal dominant gene.   The disease affects middle-aged men primarily, although reports of  patients as young as 19 yr old have been recorded. The prevalence in  American men is between 0.3% and 1%, but could well be higher as a  result of patient embarrassment and limited reporting by physicians. In  our series of more than 2000 penile implants, Peyronie’ s disease was the  cause of implantation in between 8—12% of patients.    Peyronie’s disease is thought to have two phases. Initially, the inflam-  matory phase is characterized by penile pain on erection, progressive  curvature or narrowing of erection, and palpable plaque formation. The  second, or chronic phase sets in after 1-1.5 yr. The patient will demon-  strate a stable, painless plaque that rarely may even calcify. The plaque  causes shortening of the affected side of the penis upon tumescence as  the noncompliant tunica fails to stretch with erection. Clinical expres-  sion results in various appearances. The patient may complain of curva-  ture, hourglass deformity, or portions of the penis with restricted girth  when erect. Seventy percent of the curvatures are dorsal. The less-  frequent downward curvatures and lateral deflections are more likely to  interfere with intercourse and tend to precipitate physician consultation.  The patient may have combinations of all of the aforementioned descrip-  tions resulting in corkscrew or a flail penis.   The reported association of Peyronie’s disease and erectile dysfunc-  tion (ED) is variable. In reviewing the literature, it is difficult to ascertain  whether the erectile dysfunction is because of the lack of decent tumes-  cence (proximal or distal flaccidity) or whether the reported dysfunction  is owing to angulation or flail penis. Many authorities have attempted  to link the condition with accelerated aging of the penile arterial vessels  or associated venoocclusive disease precipitated by the noncompliant  plaques. Suffice it to say, the older the Peyronie’s patient, the more  likely he is to report significant sexual dysfunction (3).    Patient evaluation should consist of a detailed history of symptoms  including presence and duration of pain, quality of erection before and  after onset of symptoms, progression of symptoms, and the degree of  penile deformity. Finally, the physician should determine the degree of  impairment associated with sexual intercourse because of the pain (early  phase) or curvature (late). A history of trauma or instrumentation may  be found in a minority of patients.   Genital examination could include a measurement of stretched penile  length and girth at the time of initial evaluation because many of these  men will complain of penile shortening after any surgical intervention.  The hands and feet could be examined for any signs of Dupuytrens  palmar fibromatosis because as many as 20% of Peyronie’s patients will  have this disease.   It is important to document ED for the clinical record particularly if  prosthesis implantation is contemplated. An injection of vasoactive  material will demonstrate the curvature, hourglass deformity, distal flac-  cidity, or diffuse inelasticity of the tunica. Prostaglandin E1 (PGE1) is  the drug of choice for stimulating the erection and, at the same time, the  physician can obtain penile duplex ultrasonography to document asso-  ciated arterial disease or venous leakage. In addition, visualization of  the extent of plaque formation may be possible with the ultrasound.  Duplex ultrasonography is very useful for scientific documentation of  Peyronie’s disease and the degree of sexual impairment (4). In the United  States, ultrasound documentation makes it easier to obtain precertifica-  tion in today’s managed care environment, particularly, if prosthesis  implantation is contemplated. Nocturnal penile tumescence (NPT) may  be useful for the same purpose. NPT may show poor filling and a  decreased number of erectile events (3). In patients complaining of  distal floppiness or flail penis, NPT commonly will record inequality of  tumescence between the proximal and distal penis.    Most non-surgical therapies are directed at the acute stage of the  disease. Oral therapies include vitamin E (an antioxidant known to pre-  vent fibrosis) (5), aminobenzoate potassium (Potaba, used to limit col-  lagen synthesis) (6), colchicine (decreases collagen synthesis and  increases collagenase activity) (7), and Tamoxifen [decreases produc-  tion of transforming growth factor-B (TFG-£)] (8). Most investigations  with these agents have been small series, not well controlled or blinded,  and the results are inconclusive.    Radiation therapy had a period of popularity, but is thought by most  now to cause more harm (penile fibrosis) than good (9). Intralesional  injections have been tried with steroids, collagenase, verapamil (/0),  and interferon , with limited success in small series. In our practice,  we give generous doses of reassurance and rarely use any therapy for the  acute phase. If the patient is insistent, we prefer vitamin E, which is  cheap and well tolerated, and may alleviate the pain (/2).    Surgery must be directed at correction of the problem after the acute  inflammation stage. Several criteria have been established as guidelines  for considering surgical intervention. Peyronie’s disease should be past  the acute inflammatory stage. Lack of pain on erection and stability of  degree of impaired erection signify passage into the chronic state. Con-  tinuation of pain indicates prolongation of the acute phase and surgery  should be delayed. The progression of penile curvature and associated  ED should have been stable for at least 3 mo. Finally, difficulty with  intercourse must be well documented in the clinical record. Some  authorities believe surgery of Peyronie’s disease for palpable lump or  curvature without sexual limitations is meddlesome (/3).   Once the disease is fully stable, the surgical management consists of  either correction of the penile deformity or insertion of a penile prosthesis  in those patients who have significant concomitant ED. The method of  correction of the penile deformity is very controversial. Surgical interven-  tion without prosthesis implantation can be broken into two categories  with numerous technical variations contained within each group. The first  category includes operations, which shorten the long side by corporal  plication or removing ellipses—the Nesbit procedure. The second group  of operations lengthens the short side. This is accomplished by incision/  excision of the plaque with grafting (natural tissue or synthetic).   In patients with associated impotence, Peyronie’s disease is corrected  by prosthesis implantation with modeling and/or plaque incision/exci-  sion with or without grafting (natural tissue or synthetic). The scope of  this chapter does not allow for a full discussion of all the surgical options  for Peyronie’s disease. Discussion will focus on the appropriate use of  penile implant surgery in the treatment of Peyronie’s disease after a  brief mention of the other two categories of operation.    Originally described in 1965, Nesbit initially reported his operation  as a surgical correction of congenital penile curvature in young men (/4).    The technique was to shorten the long side of the penis by plication with  sutures or elliptical excision and closure. Pryor reported the application  of the Nesbit operation to Peyronie’s disease with good results (/5).  Unfortunately, penile shortening complaints and postoperative devel-  opment of ED troubled long-term follow up of Nesbit procedures for  Peyronie’s disease. Pryor, in a recent publication, claims experience has  diminished these drawbacks because of a combination of better patient  education (“the shortening is rarely troublesome and was only more  than 2 cm in 17 of 359 men”) (14) and better preoperative assessment  of associated ED (availability of penile duplex doppler).    Devine and Horton introduced this popular method of treatment of  Peyronie’s disease in 1974 (/6). The plaque is excised and the tunical  defect is replaced with a dermal graft obtained from the abdominal wall,  buttock, thigh, or iliac crest skin. Austoni, in a series of 481 patients,  reported disturbing long-term results with the Devine operation citing  the need for further corrective surgery (17%) and a high percentage of  erectile impairment (20%) (17). Other covering tissues have been, sub-  stituted for dermis, e.g., dura, tunica vaginalis, fascia, cadaver fascia,  split thickness skin, and vein. Synthetic grafts have been fashioned from  a variety of fabrics, with GoreTex and Dacron being the most popular.  Currently, the method of Lue utilizing autologus saphenous vein is in  vogue (18).   Patients need to be informed of the risk to their erectile function with  all these procedures. Some patients will have their deformity corrected,  but then need pharmacological treatment to achieve an erection (/9). If  the resulting impotence is severe enough, they may require secondary  placement of penile implant. Discussion about the risks of injury to the  neurovascular bundle and subsequent decreased penile sensation also  needs to be emphasized. Although loss of penile sensation is rare as a  complication of plaque resection, ED seems fairly common (20). In our  opinion, plaque excision and grafting is a formidable surgical exercise.  For patients in whom a complex repair will be necessary, we suggest the  option of a penile prosthesis (21).   For patients without ED, we prefer simple Nesbit plication of the short  side. We avoid Nesbit elliptical excision or the more-extensive surgery of  plaque excision and grafting. Our feeling is that any procedure that inter-  rupts tunical integrity by incision may lead to impairment of erections.  Furthermore, because 70% of Peyronie’s disease occurs on the dorsum of  the penis, elliptical excision or plaque resection usually requires elevation  of the neurovascular bundle. Dorsal nerve injury and consequent decreased    penile sensation may be possible during dissection of the neurovascular  bundle. This complication, unfortunately, has no treatment.    Men with both ED and Peyronie’s disease should be considered as  candidates for implant surgery. Penile prosthesis placement is most  appropriate for men who have significant ED or flaccidity distal to the  plaque. Because the other surgical interventions aforementioned may  be associated with penile shortening and subsequent development or  exacerbation of ED, the candidate pool for prosthesis placement can be  expanded to include men with short penises and partially impaired erec-  tile function. In our practice, all men over age fifty are counseled to  consider prosthesis placement. Many of these older men will demon-  strate poor rigidity distal to the plaque after an injection of PGE1. Addi-  tionally, penile duplex Doppler may demonstrate impairment of penile  blood flow (arterial or venous) in these older subjects increasing the  possibility that impotence will result as a result of any straightening  procedure without prosthesis placement.    The simple placement of a pair of semirigid rods may be enough to  straighten the curvature without the need for adjunctive procedures.  Insertion of the semirigid prosthesis is not difficult because the  Peyronie’s plaques are subtunical and usually do not obliterate the corpo-  ral space. In our view, prosthetic girth is a more important factor than  prosthesis length in correction of curvature by malleable prosthesis  placement. It is important to dilate to 14 mm to facilitate 13-mm pros-  thesis insertion. This additional girth, compared to smaller diameter  rods, helps overcome the deformity because girth (i.e., axial rigidity)  not length, is believed to be the most important contributing factor to  penile rigidity (22,23). Proper sizing of the length of the rods in a  Peyronie’ s patient is imperative. If there is any question of intracorporal  measurements, the shorter length should be chosen. In fact, Mulcahy  advises 0.5-cm downsizing of rod implants in all patients to facilitate  comfort and concealment (24). Despite the apparent shortening of one  side of the penis because the Peyronie’s disease, the operating surgeon  should attempt to place rods of the same length in Peyronie’s patients.  Failure to place equal lengths or placement of excessively long rods may  lead to pain and difficulty bending (and thus concealing) the penis. In  our view, sizing of malleable prostheses is more crucial than size selec-  tion of inflatable ones.    Many different styles of semirigid or malleable prosthetic devices  have been successfully utilized in Peyronie’s disease, even soft silicone  rods without imbedded wires (25).   After implantation of rods, it is necessary to judge the straightening  and glandular deviation. Ghanem reported 7 of 20 (35%) patients not  satisfied with straightening by rod implantation (Duraphase, Acuform,  AMS 600) alone (26). In 19-42% of Peyronie’s patients, it will be  necessary to perform plaque incision along with semirigid prosthesis  placement (27,25). If the deformity persists after insertion of the rods,  itis easy to overcome by relaxing incision(s) with electrocautery on the  short side. This results in lengthening of the concavity and resultant  straightening. The tunical defects do not require closure—the gaping of  the tunica adds the required length to the short side to accomplish  straightening.   Use of subcoronal incision for placement of the malleable prosthesis in  Peyronie’s disease has an advantage over the traditional penoscrotal  approach (28). The subcoronal incision will facilitate degloving of the penis  if additional straightening by incision of the short side is needed. The  subcoronal incision is only useful in circumcised men or uncircumcised  men who consent to circumcision in association with the implantation.  Preputial edema and eventually phimosis will result from use of the incision  with failure to circumcise. If circumcision is not possible, the ventral penile  incision described by Mulcahy is an excellent substitute (24).    There are no reported series utilizing either the Mentor Mark II or the  AMS Ambicor for patients with Peyronie’s disease. In our experience,  these prostheses are compromised in both flaccidity and erection, and  less mechanically reliable (29) when compared to three-piece devices.  There seems to be little reason to ever implant a compromised two-piece  device in anybody (30), particularly a Peyronie’s patient in whom maxi-  mum rigidity is needed to facilitate straightening.    One of the original inventors of the AMS inflatable penile prosthesis,  F. Brantley Scott, conceived the modeling procedure (3/). Dr. Scott had  noted orthopedic surgeons molding broken bones over metal rods and  postulated that the concept might be useful in correction of Peyronie’s  disease deformities. Unfortunately, during Dr. Scott’s active clinical  years, the AMS cylinder was composed entirely of silicone and did not  have a fabric insert to limit distention. The limitless distensibility of the  pure silicone cylinder did not provide enough rigidity against deformation    to act as a fulcrum for disrupting the plaque. Knoll, in 1990, reported  results with AMS inflatable penile prosthesis in 67 men with Peyronie’s  disease without modeling. Half of the patients also required a relaxing  incision through the tunica albuginea at the point of greatest concave  curvature (32).   In 1985, AMS introduced the PND (nondistensible) cylinder to facili-  tate plaque resection over an inflatable implant. The CX (controlled  expansion) cylinder was an improvement over the PND and utilized  three-layer construction with a layer of woven polyurethane fabric (simi-  lar to Dacron) sandwiched between two silicone layers. This allowed  limited girth expansion, but restricted aneurysmal dilatation when the  cylinder was bent. These distention-controlled cylinders now had suf-  ficient rigidity to be used in overcoming Peyronie’ s disease. In addition,  a second inflatable implant manufacturer, Mentor, introduced a new  three-piece implant with cylinders constructed of Bioflex (similar to  polyurethane). These cylinders were partially distensible and also gen-  erated enough rigidity to permit modeling. Whereas Dr. Scott concep-  tualized the modeling procedure, Wilson and Delk reported the first  large series in 1994 using AMS CX, AMS Ultrex, Mentor IPP, and  Mentor Alpha cylinders (33).   At the turn of the new century, the modeling procedure for treatment  of Peyronie’s disease has achieved worldwide acceptance (34). In the  Textbook of Erectile Dysfunction Ralph and Pryor wrote, “operative  modeling of the penis over a prosthesis may look and sound horrible but  gives a good result in any deformity” (/4). In another recent textbook,  Hellstrom considered the approach effective, but, “rather simplistic” (35).    Mentor a-1, AMS 700 CX inflatable cylinders of equal lengths are  placed and the 2-cm corporotomies are closed with multiple interrupted  sutures of 00 Vicryl or Dexon. Running closure of the corporotomy  seems more likely to rupture during modeling and the resultant  corporotomy edges are more fragmented than if interrupted suturing  is used.   Mentor a NB, AMS 700 Ultrex cylinders are not recommended (36).  In our experience, the a NB cylinder may develop cylinder aneurysm  and rupture through the suddenly gaping corporotomy, if the corporotomy  sutures break (see Fig. 1 A). The Ultrex, because it is a lengthening cylinder,  does not generate enough rigidity to overcome the curve without additional  tunical incision (37). Montague reported corporoplasty was necessary in 10    Fig. 1. (A) Alpha NB cylinder with aneurysm caused by modeling. (B) CX  cylinder with abrasion of outer silicone layer caused by modeling.    of 38 patients undergoing the modeling procedure if Ultrex cylinders were  utilized. This compared with none of 34 patients requiring plaque incision  if the CX cylinders were implanted prior to the modeling procedure (38).  Fishman and the authors of this chapter had similar poor experiences using  Ultrex cylinders in Peyronie’s disease (39).   After cylinder placement, the reservoir is placed in the prevesical  space and filled with normal saline. The system is connected and the  prosthesis is inflated to the absolute maximum distention. The pump is  not placed in the scrotum, but remains outside the incision during the  modeling manipulations. The tubing from the cylinders is crossclamped  with rubber shod hemostats to prevent pump damage from excessive  backpressure. During the modeling, it is also advisable to protect the  corporotomies by grasping the base of the penis with thumb on one cor-  porotomy and first two fingers on the other. This supports the corpor-  otomies preventing suture rupture during the maximum inflation and  subsequent modeling (see Fig. 2).   The penis is forcibly bent in a direction opposite the curvature in a  maneuver similar to breaking a twig with both hands. The pressure on  the penis is maintained for 90 s. The modeling probably results in split-  ting and rupturing of the fibrotic plaques. The operating surgeon can  often hear snapping or feel movement of the cylinders as previously  nonpliant tunica is expanded. After 90 s, the clamps protecting the pump  are removed and additional fluid may be added to the cylinders. Addi-  tion of fluid to cylinders previously maximally distended is now pos-  sible because some expansion of restricted corporal capacity has  occurred. The clamps are then reapplied, corporotomies reprotected and  the modeling procedure is repeated for another 1.5 min (see Fig. 3).  There is nothing magical about 90 s, but persistence of bending, rather  than a quick fracture achieves straightening. Requiring a set amount of    Fig. 2. Protection of corporatomies with thumb and fingers. Protection of pump  with rubber shod clamps.    Fig. 3. The modeling procedure. (A) Preop appearance after PGE injection. (B)  Modeling. (C) Implant alone without modeling. (D) After two modeling sessions.    time enforces the discipline that repeated long periods of modeling are  necessary to the success of the straightening.   After two modeling sessions, the prosthesis is deflated completely.  The assistant pulls on the suture guides of the cylinders and the surgeon  reinflates the prosthesis only as far as necessary to achieve a rigid erec-  tion. This complete deflation and subsequent reinflation accomplishes  two important features. It allows reseating of the cylinders distally  improving the appearance. It also allows the surgeon to evaluate the  straightening at the degree of inflation that will be used by the patient.  Maximum inflation is used for correction of the curvature, but the patient  will never maximally inflate. He will only inflate enough to achieve a  satisfactory erection and it is at this inflation level, not maximum infla-  tion that the results of the modeling procedure should be judged.   A wise man once said, “perfect is the enemy of good.” It is not nec-  essary to continue to repeat the modeling procedure in order to achieve  an absolutely straight erection. Twenty (37) to thirty (32) degrees (see  Fig. 4) is considered a successful operation and will be appreciated by  the patient. Adequate straightening is usually achieved with two mod-  eling sessions. Rarely is a third session necessary. Early in our experi-  ence, modeling was occasionally not sufficient to achieve satisfactory  results. The original paper reported 8% of patients required additional  corporplasties. In these patients, the penis was degloved and relaxing  incisions were made on the short side. Gaping of the transverse incision  resulted in lengthening along the concave side of the curvature and  consequent penile straightening. The incision was left open or closed in  a Heineke-Mikulicz fashion. Our latest experience of the last 5 yr shows  incisions are not necessary (/2).   Tunical incision after prosthesis insertion is best accomplished with  the electrocautery. If electrocautery is needed for relaxation of curva-    Fig. 5. (A) Aneurysm at site of tunical incision. (B) Aneurysm at surgery.    ture not overcome by the modeling procedure, cutting or coagulating  current should be set below 35 W because cylinders can be injured with  higher settings (40). Deflation of the cylinder prior to incision gives an  additional measure of safety. All but the smallest tunical defects will  require closure or synthetic graft. Mentor or Ultrex cylinders having less  distention control compared to CX cylinders, always require implant  coverage to prevent subsequent aneurysm. The CX should be less likely  to require a graft because its inside fabric wrap controls its expansion.  Nevertheless, our experience has shown that coverage/closure of wide  gaps is still needed with CX (see Fig. 5) to prevent subsequent bulging  of the cylinder through the tunical defect.   There are several reasons to avoid corporoplasty if possible.  Corporoplasty at penile prosthesis implantation increases operative time  and usually requires mobilization of the neurovascular bundle. Simul-  taneous use of graft material with penile prosthetic devices has been  reported to increase the risk of infection (4/). For these reasons, it is  fortunate that corporplasty and graft coverage is only rarely necessary.    Review of our large database of more than 200 Peyronie’s patients  subjected to three-piece implant and the modeling procedure shows a  consistent urethral laceration complication rate of 4%. We had hoped  limiting the modeling to two or three sessions would decrease the inci-  dence, but it has remained constant through the years. The laceration  always occurs at the meatus and is heralded by blood at the meatus and  visual confirmation of the cylinder tip in the fossa navicularis (see Fig. 6).  On several occasions, we have detected (perhaps, caused) the urethral  laceration upon modeling at the teaching visit (see #6 caveat later). If  urethral laceration occurs, it is necessary to remove the offending cyl-    inder and tie off the tubing leaving the rest of the prosthesis in place. It  is not necessary (in fact, it is not possible) to close the meatal laceration  and the urethral Foley catheter is only used for 2-3 d. The cylinder can  be replaced after 8 wk by an additional surgery. Some patients are con-  tent with a one cylinder erection, particularly if the Mentor cylinder was  utilized.   Corporal rupture at a site other than the sutured corporotomy occurs  in 2% of patients. In our experience it is much more likely to occur in  Asian men. It can be corrected by degloving the penile skin and repair-  ing the defect. Increased corporal pain, edema, and petechias are com-  mon accompaniments to the modeling procedure and can be resolved  with nonsteroidal antiinflammatories.   We had wondered if modeling might cause the implant to need revi-  sion more often for mechanical failure or medical cause (including  reoperation for straightening) when compared to patients implanted but  not modeled. We recently reported long-term follow-up of 200 patients  in whom the modeling procedure was utilized for correction of the  Peyronie’ s disease after implantation with both AMS CX and Mentor a  cylinders. We compared revision free survival experience of these  implants with 900 similar implants in non-Peyronie’s patients. There  was no significant difference in survival experiences of the two study  cohorts when all reasons for revision were considered together. No  significant difference in survival was observed in revision as a result of  mechanical failure, patient dissatisfaction, infections, and medical/  iatrogenic reasons. There was a difference in the mechanical survival    Fig. 7. (A) Implant only. (B) After first model. (C) Corporotomy rupture. (D)  After two modeling sessions.    between the two devices used in the modeling procedure. In the  Peyronie’s patients, mechanical survival of the Mentor a-1 was superior  to that of the AMS 700CX (42). There was no difference in the mechanical  reliability between the devices in the non-Peyronie’s patients indicating  that the trauma of modeling may predispose the AMS cylinder to future  failure. We have previously reported detection of occasional abrasion of  the outer layer of silicone after modeling (see Fig. 6B) (24).    1. Before placement of the pump in the scrotum and closure, it is impor-  tant to verify that the corporotomies have remained closed, since the  modeling procedure often results in suture breakage (see Fig. 7).   2. Straightening continues for over 1 yr with use of the implant and the  patient can be counseled to inflate and model at home if his result was  less than satisfactory. The most difficult curvature to correct is in the  patient with a short penis and distal upward curvature (see Fig. 8). It is  difficult to gain enough purchase on the end of the short penis to effec-  tively model. Fortunately, residual curvature after implantation in these  patients always corrects with time and implant usage.    Fig. 9. After placement of prothesis and modeling, the penis is curved in flac-  cidity but straight in erection. (A) Flaccid; (B) Erect.    3. The patient must be warned that his penis will be curved in flaccidity,  but straight in erection (see Fig. 9). This is exactly the opposite of his  condition prior to implantation with the modeling procedure. The flac-  cid penis now has some rigidity because of the cylinders. The cylinders  act as a stent and the penis will be carried in flaccidity with a curve to  short side.   4. Early in our experience, a few patients are not satisfied with initial  straightening. In these patients, we attempted another modeling under  anesthesia 3—12 mo after the original implantation. The secondary  procedure was not successful, probably because of the restrictive teth-  ering of the fibrous capsule that had formed around the cylinders. We  now know that in patients who are unhappy with the straightening of  the modeling procedure, it is necessary to make secondary tunical  relaxing incisions over the inflated prosthesis.   5. The patient should be advised to wear his penis pointed cephalad ini-  tially. This encourages capsule development around the cylinders,  which promotes the physiologic cephalad extension of the erection.   6. At the teaching visit (usually 4—6 wk), the penis is modeled with the  patient fully awake. Sometimes capsule development around the cyl-  inder may have started, which would inhibit straightening. At this early  stage of capsule formation, it is possible to feel reexpansion of the  tunica accompanying this maneuver.    Success with surgical correction of Peyronie’s disease depends upon  the patient’s ability to have sexual intercourse with a straightened penis.  If the patient has ED after the Nesbit procedure or plaque resection and  graft replacement, the operation can be considered a failure even though  penile straightening has been accomplished. If any degree of tumes-  cence problem is present before surgery, careful consideration for inflat-  able prosthesis placement and the modeling procedure should be  discussed with the patient. In our view, this treatment has the greatest  potential for trouble-free straight erections for the rest of his life. For  urologic surgeons, penile prosthesis implantation with the modeling  procedure is straightforward with minimal complications. More impor-  tantly, our patients receive a straightened penis useful for coitus.   2. Ralph DJ, Mirakian R, Pryor JP, Bottazzo GF (1996) The immunological fea-  tures of Peyronie’s disease. J Urol 157:282-284.   3. Stecker JF, Devine CJ (1985) Evaluation of erectile dysfunction in patients with  Peyronie’s disease. J Urol 132:680-681.    Ralph DJ, Hughes T, Lees WR, Pryor JP (1992) Pre-operative assessment of  Peyronie’s disease using colour Doppler sonography. Br J Urol 69:629-632.  Scardino PL, Scott WW (1949) The use of tocopherols in the treatment of  Peyronie’s disease. Ann NY Acad Sci 52:390-396.    . Shah PJR, Green NA, Adib RS, et al. (1983) A multicentre double-blind con-    trolled clinical trial of potassium para-aminobenzoate (Potaba) in Peyronie’s  disease. Prog Reprod Biol 9:47-60.    . Akkus E, Carrier S, Rehman J, et al. (1994) Is colchicine effective in Peyronie’s    . Ralph KJ, Brooks MS, Bottazo GF, Pryor JP (1992) The treatment of Peyronie’s    . Hall SJ, Basile G, Bertero EB, et al. (1995) Extensive corporal fibrosis after    . Levine LA, Merrick PF, Lee RC (1994) Intralesional verapamil injection for the    . Benson RC, Knoll LD, Furlow WL (1991) Interferon alpha 2 b in the treatment    . Pryor JP, Farell CF (1983) Controlled clinical trial of vitamin E in Peyronie’s    . Ralph D, Pryor JP (1999) Peyronie’s disease. In: Carson C, Kirby R, Goldstein I,    eds., Textbook of Erectile Dysfunction, Oxford: Issis Med. Media, pp. 515-517.    . Nesbit RH (1965) Congenital curvature of the phallus: report of three cases with    . Pryor JP, Fitzpatrick JM (1979) A new approach to the correction of the penile    . Devine CJ, Horton CE (1974) Surgical treatment of Peyronie’s disease with a    . Austoni E, Colombo F, Mantovani, et al. (1995) Chirugia radicale e conser-    vazione dell’ erezione nella malantia di La Peyronie. Arch Ital Urol Nefrol Androl  67:359-364.    . Brock G, Kadioglu A, Lue TF (1993) Peyronie’s disease: a modified treatment.    . Melman A, Holland TF (1979) Evaluation of the dermal graft inlay technique for    . Udelson D, Nehra A, Hatzichristos DG, et al. (1998) Engineering analysis of    penile hemodynamics and structural dynamic relationships: Part 1 clinical impli-  cations of penile tissue mechanical properties. Int J Impot Res 10:15-24.    . Mulcahy JJ (1997) Overview of penile implants. In: Mulcahy JJ, ed., Topics in    Clinical Urology, Diagnosis and Management of Male Sexual Dysfunction,  New York: Igaku-Shoin, pp. 218-230.   Mulcahy JJ (1999) Unitary inflatable, mechanical and malleable penile implants.  In: Carson C, Kirby R, Goldstein I, ed., Textbook of Erectile Dysfunction, Oxford:  Issis Med Media, pp. 413-421.   Subrini L (1984) Surgical treatment of Peyronie’s disease using penile implant:  survey of 69 patients. J Urol 132:47-49.   Ghanem HM, Fahmy I, El Meliegy A (1998) Malleable penile implants without  plaque surgery in the treatment of Peyronie’s disease. Int J Impot Res 10:171-173.    Eigner EB, Kabalin, JN Kessler R (1991) Penile implants in the treatment of  Peyronie’s disease. J Urol 145:69-71.   Wilson S (1997) Penile prosthesis implantation: pearls pitfalls and perils. In:  Helstrom WJG, ed., Male Infertility and Sexual Dysfunction, New York:  Springer, pp. 529-549.   Dubocq F, Tefill EL, Gheiler HL, Dhabuwala CB (1998) Long-term mechanical  reliability of multicomponent inflatable penile prosthesis: comparison of device  survival. Urology 52:277-281.   Wilson SK (1997) Management of Penile Implant Complications. In: Mulcahy  JJ, ed., Topics in Clinical Urology, Diagnosis and Management of Male Sexual  Dysfunction, New York: Igaku-Shoin, pp. 231-253.   Knoll LD, Furlow WL, Benson RC (1990) Management of Peyronie’s disease  by implantation of inflatable penile prosthesis. Urology 36:406—408.   Wilson SK, Delk JR (1994) A new treatment for Peyronie’s disease: modeling  the penis over an inflatable prosthesis. J Urol 152:1121-1123.   Pacik D, Kumstat P, Dolezel J, Turjanica M (1995) Implantation of an inflatable  penile prosthesis as an effective alternative to surgery of impaired erection.  Rozhledy v Chirugii 74:363-366.   Hellstrom WJG, Bryan WW (1997) Treatment of Peyronie’s disease. In:  Helstrom WJG, ed., Male Infertility and Sexual Dysfunction, New York:  Springer, pp. 481-491.   Wilson SK, Cleves MA, Delk JR (1996) Ultrex cylinders: problems with uncon-  trolled lengthening (the “S”-shaped deformity). J Urol 155:135-137.  Kowalczyk JJ, Mulcahy JJ (1996) Penile curvatures and aneurysmal defects  with the Ultrex penile prosthesis corrected with insertion of the AMS 700 CX.  J Urol 156:398-401.   Montague DK, Angermeier KW, Lakin MM, Ingleright BJ (1996) AMS 3-piece  inflatable penile prosthesis implantation in men with Peyronie’s disease: com-  parison of CX and Ultrex cylinders. J Urol 156:1633-1635.   HakimLS, Kulaksizoglu H, Hamill BK, et al. (1995) Guide to safe corporotomy  incisions in presence of underlying inflatable penile cylinders: Results of in  vitro and in vivo studies. J Urol 155:366-368.   Knoll LD, Furlow WL, Benson RC, et al. (1995) Management of nondilatable  cavernous fibrosis with the use of a downsized inflatable penile prosthesis  J Urol 153:366-368.   Wilson SK, Cleves MA, Delk JR (2001) Long term follow up a treatment for  Peyronie’s disease: modeling the penis over an inflatable penile prosthesis.  (2001). J Urol 165:825-829.    Rapid advances in the pharmacology of erectile dysfunction (ED)  have brought more patients in to inquire about alternatives and com-  mence treatment. Viagra is now a household word with name recogni-  tion similar to Coca-Cola and Nike. Patients will more commonly choose  the least-invasive effective treatment for this disorder, namely, oral  medication. However, severe cases of ED may not respond to medica-  tions or, in patients with severe scarring of erectile bodies, deformed or  limited erections may result. Penile implants are still a very effective  therapy with the highest satisfaction rate of all ED alternatives among  both patients and partners . They are effective when medication has  failed and will overcome the effects of scar tissue in the corpora  cavernosa to both straighten and strengthen inadequate erections. When  implants were introduced almost three decades ago, repairs were common  (2). Vendors have eliminated or reinforced areas that would be a source  of wear or malfunction, and surgeons have developed more-reliable    The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    techniques of implantation, thus reducing the incidence of reoperation.  Repair rates of 15% at 5 yr and 30% at 10 yr are now realistic (3).    One of the most serious problems associated with penile implant  insertion is infection. The organisms usually enter the wound at the time  of surgery, but there have been reports of seeding of the implant from  distant sources via hematogenous spread (4). The incidence of infection  has been reported from 0.6% (5) to 8.9% (6), but, in most series, aver-  ages between 1 %-—3%. With repairs, the reported infection rate seems to  be higher at 13.3% in a series reported by Jarow (7). He also noted the  incidence was even higher at 21.7% when reconstructive procedures  were necessary. Thomalla et al.’s series confirms this with a 37% infec-  tion rate during tertiary procedures (6). In cases of reoperation for repair  orreconstruction, the presence of scar tissue, reduced blood flow, longer  operating time, or the introduction of foreign materials such as Gortex or  Dacron to rebuild the tunica albuginea can promote bacterial growth.  Patients with diabetes mellitus tend to have a higher rate of many types  of infection as elevated glucose levels in tissues are a good culture  medium. Jarow’s series found no statistically significant increase in  implant infections among diabetics (7), but Fallon and Ghanem reported  a threefold-greater incidence of infection in their diabetic population  receiving a penile implant . Bishop et al. suggested that glycosylated  hemoglobin levels, an indicator of control of diabetes mellitus in the  patient’ s recent past, could be used as a predictor of infection associated  with penile prosthesis implantation in this group (8). However, ina large  series reported by Wilson et al., glycosylated hemoglobin and other  parameters such as glucose level and insulin dependence could not reli-  ably indicate the development of postoperative infection (9). Patients  with spinal cord injury and a neurogenic bladder tend to have a higher  incidence of urinary tract infections and decubitus skin ulcers. Prosthe-  sis infections were not more common in this group, according to Diokno  and Sonda (/0). However, Wilson and Delk found a ninefold-greater  incidence of infection among spinal cord-injured men in their series  (11), and Dietzen and Lloyd related a 30% incidence of infection in this  patient population receiving a penile implant (/2). This group of patients  also has diminished or absent sensation in the genital region and the  incidence of erosion of a penile implant, especially the semirigid rod  type, is higher than in the nonneurogenic population as a result of fric-  tion and excessive pressure against the device, which would cause pain  and discomfort if sensitivity was intact. Whether an infection led to the  erosion, or a primary erosion is associated with concomitant infection,    is not documented in many cases. Patients with a renal transplant can  undergo penile implant placement without a greater chance of device  infection (/3) and this author has placed a penile implant in three patients  after cardiac transplantation without complications. The brand of pros-  thesis, incision site, number of components, or prior pelvic irradiation  do not seem to influence the incidence of implant infection. Licht et al.  found infection present on wound culture in up to 40% of penile implant  cases operated on for mechanical malfunction (/4). There was no clini-  cal suspicion of infection in any of these patients. Nine percent of these  subsequently developed a clinical infection.   The performance of procedures such as herniorrhaphy, circumcision,  or hydrocele repair in association with penile implant surgery has been  implicated in an increased incidence of infection. Fallon and Ghanem  (1), and Thomalla et al. (6), reported higher infection rates with simul-  taneous circumcision. If one is considering such a combined operation,  the initial procedure should be insertion of the penile implant with clo-  sure of that incision. A second incision and performance of the associ-  ated procedure can then be undertaken. This reduces the duration of the  open wound for penile implant placement and avoids possible contami-  nation from manipulation of the scrotum, foreskin, or other body surface  during the associated procedure. Endoscopic procedures such as tran-  surethral prostatectomy or internal urethrotomy should not be performed  simultaneously with prosthesis insertion.    Prior to the surgery urinary tract infections should be treated. The  urinary tract is usually not entered during implant surgery, but spilling  of urine on the operative field during the procedure is a possibility.  Sterilizing the urinary tract in neurogenic bladder patients is sometimes  difficult and unpredictable, and placing a catheter in this group during  surgery might be prudent to prevent leaking of urine onto the operating  field. The skin of the pelvis and genital region should be inspected for  infected lesions such as furuncles, sebaceous cysts, or comedomes.  These should be removed prior to the antiseptic skin prep lest they be  expressed during manipulations of the penile and scrotal skin during  prosthesis insertion. Thoroughly washing the pelvis and perineal area  with a strong antiseptic soap solution for 3 d at home prior to the surgery  is recommended. The surgical site is shaved in the operating room prior  to the procedure, and this is followed by a strong iodine skin prep. An  alternative antiseptic prep is used if the patient is allergic to iodine.    Laminar flow systems and the surgical isolation bubble (SIBS) may  reduce contamination, but are costly, cumbersome, and rarely used.   The most common organism associated with prosthesis infections in  all series has been coagulase negative staphylococcus (Staphylococcus  epidermidis). In a recent series, 58% of infections were caused by  this organism (/5). Other bacteria less commonly seen are Pseudomo-  nas aeruginosa, Proteus mirabilis, Serratia marcessens, Escherichia  coli, enterococcus, and Staphylococcus aureus. Candida albicans and  anaerobic bacteria such as bacteroides fragilis have been rarely isolated  when infected implant wounds have been cultured. Most urologists use  prophylactic antibiotics in association with penile implant placement.  The literature has demonstrated the effectiveness of these agents in  potentially contaminated procedures involving bowel, gallbladder, and  uterus where bacteria may enter the wound from an open viscus (/6).  However, no study has been reported documenting the effectiveness of  use vs nonuse of prophylactic antibiotics during penile implant surgery.  Infectious disease specialists have taken issue with their use in these  circumstances. The operating field is sterile, numerous other precau-  tions have been taken to prevent infection, and using such agents is  expensive, may promote the development of resistant organisms, and  may lead to toxic reactions or the development of allergies. If one decides  to use prophylactic antibiotics, they should be started prior to the inci-  sion, usually with placement of the intravenous line. Ideally, this should  occur | h prior to opening the wound so that tissue levels will be optimal  at the start of the procedure. They should be continued for 48 h after  surgery. By that time, the wound is sealed and contaminating organisms  can no longer gain entry. Vancomycin and an amino glycoside are the  best combination to empirically treat prosthesis infections. S. epidermi-  dis, the most common pathogen, is eradicated 99% of the time by Van-  comycin. The gram negative organisms, which are less commonly  found, are neutralized by the amino glycoside. Excessive and prophylac-  tic use of Vancomycin, however, is discouraged because of the potential  for resistant organisms developing. Alternative prophylactic antibacteri-  als are a quinolone or a third-generation cephalosporin, which have  reasonable coverage against both staphylococcus and gram negative  organisms. Prophylactic antibacterials for eradicating anaerobic and  fungal infections are rarely used because of their infrequent occurrence.  During the procedure, the wound is frequently irrigated with a solution  containing antibacterials such as bacitracin and gentamicin. An Asepto  syringe dispenses this cleansing solution rapidly and forcefully to wash  away any organisms that might stray into the operative field.    Signs and symptoms associated with an infected penile implant may  be subtle or dramatic. Fishman and Scott found that 56% of infections  are manifest within 7 mo of surgery, 36% between 7 and 12 mo, and  2.6% after 5 yr (17). Increasing pain, cellulitis, fever, fluctuance, and  drainage from the wound, especially after squeezing on parts of the  device, are signs of an acute infection. An exposed part of the prosthesis  must be considered infected. Low-grade pain that never improves or  increases in intensity postoperatively, persistent fixation of the pump to  the scrotal wall, and increasing white blood cell count or sedimentation  rate are indications of possible infection. When the diagnosis of infec-  tion is questionable, a trial of an oral quinolone antibiotic in high doses  for 4—6 wk may be informative. If pain or swelling improve and then  recur when the antibiotic is discontinued, then an infection is likely  present.   The question sometimes arises as to when one should explore the  prosthesis for a suspected infection. Certainly, an exposed part, persis-  tent purulent drainage, cellulitis that does not recede, progressive fixa-  tion of the pump to the scrotal wall, and increasing pain are definite  indications for surgical intervention. If fluctuance over a part such as the  pump is present, the skin over the fluctuant area may be prepped with  iodine solution and the fluid carefully aspirated and sent for culture. Not  all fluctuant areas represent infection as seromas can form around pros-  thesis parts as well.    When an infection is certain or highly suspect, removal of the implant  is necessary. Oral or systemic antibacterials alone will not eradicate the  organisms. With time, a sheath of fibrosis surrounds the prosthesis, as  part of the body’s healing process. This has relatively poor blood sup-  ply, thus limiting the inflammatory response in the area. In addition,  many bacteria produce a biofilm or slime, which surrounds the implant  and provides a hiding place for bacteria where antibiotics are less able  to diffuse. Bacteria may also adhere to the surface of some implants. If  the implant is removed, healing will occur with time. If purulent infected  material is contained within the corpora cavernosa, irrigating drains  should be placed within these cavities and antibacterial washes contin-  ued for 72 h (18,19). Vancomycin 1 gm/L and gentamicin 80 mg/L are  used as the initial irrigants and 10 cm? are placed through each drain and  left in place for 20 min 3x/d. At 48 h, culture and sensitivity reports    are available and more appropriate antibacterials can be substituted if  necessary. Closing the wounds with these drains in place has resulted in  less postoperative morbidity than leaving the wound open to granulate  with wet to dry dressings. After 6 mo when the wound has healed and  inflammation resolved, one can return for reinsertion of a new prosthe-  sis. However, because of the scar tissue that has now formed in the  corpora cavernosa, creating cavities for the cylinders will be difficult,  and the resulting erection will have a ventral bowing and be noticeably  shorter (about 2-in shorter) than that created with the original implant.   A new concept has evolved in recent years termed rescue or salvage.  The implant is removed completely, together with all foreign materials  such as sutures, Gortex, or Dacron. The wound is thoroughly washed  with a series of irrigating solutions listed in Table 1. A red rubber Robin-  son catheter is used to instill the solutions to the extremities of the  corporal bodies and all other cavities containing foreign body parts (see  Fig. 1). The operative field is changed including new gloves, gowns,  drapes, and instruments and a new prosthesis is placed at the same  procedure with closure of the wound without drains. The success rate  using this technique was 82% in 55 patients with a mean follow-up of  3 yr (15). The antibiotic solution is designed to neutralize bacteria,  hydrogen peroxide gives superoxygenation to eradicate anaerobes, the  iodine solution kills 99% of organisms, and the pressure wash loosens  and washes away the slime or biofilm produced by many bacteria.  Variations of salvage have been used, but the principles of the most  successful techniques have involved complete removal, washing, and  immediate reinsertion (20,21).   The rationale and success of salvage has been demonstrated in other  medical areas where the presence of prosthetic or graft material is essen-  tial for the preservation of life or limb. Bandyk et al. found that infec-  tions of aortic vascular grafts were characteristically containing    Fig. 1. A red rubber catheter is passed to all parts of the body which contained  prosthesis parts. Copious amounts of irrigation are used through this catheter.    organisms of low virulence with few systemic symptoms and almost  exclusively a result of S. epidermidis (22). They successfully replaced  15 consecutive aortic grafts in situ with no recurrent graft infections.  Hip prostheses (23) and prosthetic heart valves (24) have been salvaged  with a 90% success rate. A theory for such good results in eradicating  these infections involves the characteristics of S. epidermidis. The  unique environment provided by a foreign body may enhance the ability  of this organism and others to establish a foothold.   Local tissue trauma during insertion, the immediate microenviron-  ment around the foreign body, which is acidic and hypovascular, and the  appearance of anew surface with no intact cellular barrier provide oppor-  tunity for bacteria to adhere and grow (25). A foreign material placed in  the body usually acquires a thin fibrous tissue capsule composed of a  variety of proteins (26). This acellular surface coating may provide  binding sites for otherwise nonpathogenic bacteria. Evidence shows  that staphylococcal species adhere to foreign surfaces with much greater  affinity than do other bacteria.   Parsons et al. removed penile implants that were painful and irrigated  the wound with a solution of protamine and vancomycin before replac-  ing a new prosthesis (27). Systemic vancomycin was used pre- and    postoperatively and a success rate of 90% in eradicating infection was  achieved. Teloken et al. successfully salvaged three penile implants  with a protocol using rifampin antibiotic irrigations (28).   Delayed salvage has had comparable results. This involves removing  the prosthesis, placing drains for wound irrigation, and returning in 72 h  after the infection has been eradicated to place a new prosthesis. Cul-  tures at the time of removal document that the appropriate antibiotics are  being used and more specific antibiotics can be substituted at 48 h, if  necessary. The prolonged hospitalization and second trip to the operat-  ing room are more costly, the cavities containing the cylinders have  contracted, and the wound is difficult to close, especially in the thin  patient, because of the inflammatory process present at this juncture,  making delayed salvage less practical. Salvage procedures where parts  of the device have been left behind have been less successful. Furlow  and Goldwasser removed an infected pump and replaced it with a new  pump in the opposite hemiscrotum leaving the cylinders in place (29).  Bacteria can migrate along tubing to other parts of the device and although  infection may not be obvious at the time, symptoms may become evi-  dent in the future as bacterial propagation occurs. A success rate of 73 %  was seen with this type of procedure. Removal of a prosthesis or salvage  should be performed promptly when infection is evident. To leave such  a prosthesis in place, hoping infection will clear, may result in increased  pressure within the penile shaft from edema and inflammation. Glans  penis and distal corporal necrosis have been seen associated with infec-  tion and also in the absence of infection (see Fig. 2). This is usually a  slowly progressive process resulting from diminished blood supply, not  necessarily the infection itself. Prompt removal of the prosthesis helps  take the pressure off the ischemic tissue, thus allowing more adequate  tissue perfusion.   The avoidance of urethral catheters, the use of loose noncompressive  dressings, and making longitudinal incisions parallel to the shaft of the  penis, rather than circumferential incisions, will help avoid diminished  distal blood flow, especially in high-risk patients such as those with  advanced diabetes mellitus or severe peripheral vascular disease. Sal-  vage has been successfully performed in patients with cylinder erosion  to the external surface of the penis. In such cases, the entire device is  removed, the wound cleansed as aforementioned, and a new device  inserted. A distal corporoplasty is performed to reseat the cylinder on  the previously eroded side more medially in a more secure location (30)  (see Fig. 3). Consideration should also be given to using a pair of nar-  rower cylinders in such a circumstance, because a tight girth fit may  have contributed to the original erosion.    Fig. 2. Necrosis of the glans penis in a patient with Peyronie’s disease and no  vascular risk factors. Removal of the implant halted the progression of the  necrosis. Cultures taken at the time of explant showed no growth.    Fig. 3. Erosion of a penile implant cylinder. A successful salvage procedure  combined with distal corporoplasty was performed to reseat the cylinder in its  proper location.    Contraindications to salvage would include bilateral cylinder erosion  into the urethra, necrotizing infections, severely toxic patients such as  those in diabetic ketoacidosis or septicemia, and immunosuppressed  patients. The greatest success with salvage has been in those patients in  whom the infection is manifest long after surgery, is not associated with  extensive cellulitis, and is caused by less-virulent organisms such as  S. epidermidis. Salvage has been successful in those patients with exten-  sive purulence and marked cellulitis caused by virulent organisms when  preceded by abscess drainage and culture and appropriate systemic  antibiotics for a number of days prior to the salvage procedure. In such  cases, sterilization of the tissues with systemic antibiotics followed by  sterilization of the cavity containing the prosthesis by the surgical irri-  gations has given a gratifying result.   Infection of a penile implant was once a catastrophic complication,  which necessitated removal. Now, with salvage and reconstructive pro-  cedures, most infections can be successfully treated and patients restored  to sexual function using the modality for treating erectile problems with  the highest satisfaction and success rate, i.e., the penile implant.    1. Fallon B, Ghanem H (1990) Sexual performance and satisfaction with penile  prostheses in impotence of various etiologies. Int J Impot Res 2:35—42.   2. Apte SM, Gregory JG, Purcell MH (1984) The inflatable penile prosthesis,  reoperation and patient satisfaction: a comparison of statistics obtained from  patient record review with statistics obtained from extensive follow up research.  J Urol 131:894-895.   3. Carson CC, Mulcahy JJ, Govier FE (1999) Efficacy and safety outcomes of the  AMS 700 CX inflatable penile prosthesis: results of a long term multicenter  study. J Urol 161 Suppl:259, Abstr 999.   4. Carson CC, Robinson CN (1988) Late hematogenous infection of penile pros-  theses. J Urol 139:50-52.   6. Thomalla JV, Thompson ST, Rowland RG, Mulcahy JJ (1987) Infectious com-  plications of penile prosthetic implants. J Urol 138:65—67.   7. Jarow JP (1996) Risk factors for penile prosthetic infection. J Urol 156:402-404.   8. Bishop JR, Moul JW, Sehelnik SA, Peppas DS, Gormley DS, McLeod DG  (1992) Use of glycosylated hemoglobin to identify diabetics at high risk for  penile prosthetic infections. J Urol 147:386-388.   9. Wilson SK, Carson CC, Cleaves MA, Delk JR (1998) Quantifying risks of penile  prosthesis infection with elevated glycosylated hemoglobin. J Urol 159:1537—1540.   10. Diokno AC, Sonda LP (1981) Compatibility of genitourinary prostheses and  intermittent self catheterization. J Urol 125:659-667.   11. Wilson SW, Delk JR (1995) Inflatable penile implant infection: Predisposing  factors and treatment suggestions. J Urol 153:659-661.   12. Dietzen CJ, Lloyd LK (1992) Complications of intracavernous injections and  penile prostheses in spinal cord injured men. Arch Phys Med Rehab 73:652-655.    Sidi AA, Peng W, Sanseau C, Lange PH (1987) Penile prosthesis surgery in the  treatment of impotence in the immunosuppressed man. J Urol 137:681, 682.  Licht MR, Montague DK, Angermeier KW, Lakin MM (1995) Cultures from  genitourinary prostheses at reoperation: Questioning the role of staphylococcus  epidermidis in periprosthetic infection. J Urol 154:387-390.   Mulcahy JJ (2000) Long term experience with salvage of infected penile  implants. J Urol 163:481, 482.   Nichols RL (1981) Use of prophylactic antibiotics in surgical practice. Am J  Med 70:686-692.   Fishman IJ, Scott FB, Selim AM (1987) Rescue procedure: An alternative to  complete removal for treatment of infected penile prosthesis. J Urol 137:Suppl  202A: Abst 396.   Maatmann TJ, Montague DK (1984) Intracorporeal drainage after removal of  infected penile prosthesis. Urology 23:184, 185.   Kim JC, Lunati FP, Khan SA, Waltzer WC (1995) T-Tube drainage of infected  penile corporeal chambers. Urology 45:514-515.   Kaufman JM, Kaufman JL, Borges FD (1998) Immediate salvage procedure for  infected penile prosthesis. J Urol 159:816-818.   Fishman IJ, Scott FB, Selim A, Nguyen TA (1997) The rescue procedure: an  alternative for managing an infected penile prosthesis. Contemp Urol 11:73-80.  Bandyk DF, Bergamine TM, Kinney EV, Seabrook GR, Towne JR (1991) In situ  replcement of vascular prostheses infected by bacterial biofilms. J Vasc Surg  13:575-583.   Carlson AS, Josefsson G, Lindberg L (1978) Revision with gentamicin-impreg-  nated cement for deep infections in total hip arthroplasties. J Bone Joint Surg  (AM) 60A:1059-1064.   Slaughter L, Morris JE, Starr A (1973) Prosthetic valvular endocarditis: a 12  year review. Circulation 47:1319-1326.   Gristina AG, Giridhar G, Gabriel BL, Naylor PT, Myrvik QN (1993) Cell biol-  ogy and molecular mechanisms in artificial device infections. Int J Artif Organs  16:755-763.   Ingraham FD, Alexander E Jr, Matson DD (1947) Synthetic plastic materials in  surgery. N Engl J Med 236:362-368.   Parsons CL, Stein PC, Dobke MK, Virden CP, Frank DH (1993) Diagnosis and  therapy of subclinically infected prostheses. Surg Gynecol Obstet 177:504—506.  Teloken C, Souto JC, Daros C, Thorell E, Souto CAV (1992) Prosthetic penile  infection: Rescue procedure with rifamycin. J Urol 148:1905, 1906.   Furlow WL, Goldwasser B (1987) Salvage of the eroded inflatable penile pros-  thesis: A new concept. J Urol 138:312-314.   Mulcahy JJ (1999) Distal corporoplasty for lateral extrusion of penile prosthesis  cylinders. J Urol 161:193-195.    Upon introduction to treat male erectile dysfunction (ED) in the  1970s, penile prosthesis implantation revolutionized our practice for  managing ED. Even in the era of effective oral medications for ED, sales  of penile prostheses have been relatively stable in the past decade .  It is possible to foresee the continuous need for penile prostheses as  more and more patients are seeking treatment for ED, thanks to the  recent media coverage and the improved knowledge of the general  population about ED. The modifications and improvements of penile    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    prostheses have maximized the device’s reliability and longevity. The  5-yr survival of some models has reached more than 92% (2,3). It is our  belief that the modern inflatable devices are very mechanically reliable.  Reoperations for penile prosthesis implantation are now more likely for  infection, patient dissatisfaction, or physician error than for mechanical  breakdown. Before 1990, about 57% of the reoperations at the Mayo  Clinic were for mechanical failure or device malfunction (4). The  mechanical failure of some current devices has been as low as 0.8%/yr  for the first 3.5 yr and then 3.1% in the next 1.5 yr of observation (2).  However, reoperation for penile prosthesis implantation is a challenge  even for the experienced prosthetic urologist. In this chapter, we discuss  the techniques of reoperation for penile prosthesis implantation under  different situations.    Establishment of diagnosis for patients who need reoperation is  straightforward. A history of previous penile implantation with removal  of the prosthesis and a simple physical evaluation of the patient will  establish the diagnosis for penile fibrosis. The majority of patients with  prosthesis infection will present with erythematous and fluctuant areas  over the corporeal bodies and/or scrotal pump. Some patients may have  drainage of pus from these areas, with or without fever. Erosion and  impending erosion of implants can be easily identified by physical  examination. For erosion of implants into the bladder and urethra, some  imaging studies or cystoscopy may be needed. Mechanical failure will  not be a diagnostic dilemma because the device will simply not produce  arigid penis suitable for intercourse. However, identifying the problem-  atic parts of the device may not be established before the surgery. If the  system is filled with diluted contrast material, pelvic X-ray will indicate  complete loss of fluid. Pelvic X-ray may also reveal a break in the metal  core in some semirigid devices, or malposition of components of a  device; but this kind of conventional radiology study may not be accu-  rate. Most prostheses are now filled with saline that will preclude evalu-  ation by conventional radiology. As a matter of fact, some authorities do  not believe that contrast medium would help the diagnosis of the cause  of the device failure because the contrast would be absorbed after leak-  ing from the device (5). Aneurysms of cylinders, S-shaped deformity of  cylinders, and SST deformity caused by inadequate cylinder length  should easily be diagnosed by physical examination. Prolonged pain  after penile implantation (more than 6 wk) can be very difficult to deal  with because the etiology of this pain is not well understood. Subclinical    infection, malposition of the device, and autonomic neuropathy in dia-  betes mellitus have all been proposed as explanations. Sometimes this  prolonged pain can be caused by inappropriate sizing of the cylinders;  i.e., they are too large in diameter or too long for the corporeal space. By  using magnetic resonance imaging (MRI), Moncadaetal. have reported  that buckling of cylinders could be the cause of prolonged penile pain  and reoperation to correct the buckling cylinder resolved the pain in all  their cases (6).    Patient education is one of the most important strategies to achieve  patient and partner satisfaction for penile prosthesis implantation. This  is particularly true for reoperation. It is imperative for the prosthetic  urologist to ensure that the patient and partner have proper expectations  and an understanding of common anticipated complications associated  with a reoperation. Our previous study showed that patients who have  had more than one reoperation should be prepared that they are more  likely to need a third or fourth (or even more) reoperations (7). The patient  needs to be informed that reoperation, particularly the reoperation  involving corporeal reconstruction, may have 10 to 20 times-higher  infection rates (8). The patients with diabetes should have their  glycosylated hemoglobin (Hgb A1-C) checked, as a poorly controlled  diabetic may not be suitable for a salvage procedure (9). However, this  is debatable because Wilson et al. did not find the association between  diabetic control and prosthesis infection (/0). Patients with cavernosal  fibrosis or scar should be informed that a replacement device will not  reproduce the original cosmetic result and that penile shortening may  occur. In patients who have had a prior urethral erosion or urethral tear  during dilation, we warn them of the risk of reentry into the urethra and  the potential need for temporary urinary diversion by means of a perineal  urethrostomy or suprapubic cystotomy. Penile numbness may occur,  particularly with an infrapubic approach for penile reimplantation. This  numbness may be transient or permanent. Return of full sensation may  take as long as 12-18 mo.    General principles are no different from those used in a primary  penile implant except in certain situations, such as ina salvage operation  (to be discussed later). For penile prosthetic surgery, the most common  infecting organism is the opportunistic Staphylococcus epidermidis  (11). We routinely give 1 g cefazolin intravenously with the induction    of anesthesia. However, if the patient is a diabetic or has a history of  prior infection with the prosthetic device, the best antibiotic is a vanco-  mycin-gentamicin regimen. We use a single dose of vancomycin (1 g  intravenously) and gentamicin (5 mg/kg, intravenously) preoperatively.  For a patient with multiple histories of prosthetic removal because of  infection, 3 d of cephalexin preoperatively are also used to maximize the  prevention of reinfection. We also suggest that these patients have a  Hibiclens scrub every day for 3 d preoperatively.   The incision site is shaved after the induction of anesthesia. A 10-15 min  surgical scrub with povidone-iodine is mandatory in our institute. The  surgeon and all assistants will have 10 min standard surgical scrub.  Povidone-iodine solution is applied to the surgeon’s hands before sur-  gical gloves are worn or povidone-iodine solution is used between the  glove layers for double gloving. A Foley catheter is inserted to facilitate  urethral identification. If the patient has had multiple infections and is  uncircumcised, we prefer to perform a circumcision before revision of  the penile prosthesis, allowing time for it to heal. We do not like to  perform acircumcision at the time of surgery unless asubcoronal approach  is being used for a semirigid or self-contained inflatable device. Even  under those conditions, if the foreskin shows any signs of infection,  placement of the prosthesis should be delayed until this infection is  cleared. If a penoscrotal or infrapubic incision is to be used, we do not  believe there is a need for circumcision. However, we routinely obtain  the patient’s consent for possible need of circumcision, particularly if  reseating of the cylinder tip in the corpus cavernosum under the glans  penis is needed or degloving of penile skin is necessary for complex  penile implantation.   The choice of surgical approach varies according to the condition that  requires reoperation. A study by Garber and Marcus demonstrated that  the infection rate was not different when scrotal or infrapubic surgical  approaches were used (/2). We recommend use of a bipolar electrode  for electrocoagulation of bleeding vessels to decrease the possibility of  injury to neural and arterial structures. This is not mandatory if the  penile neurovascular anatomy is well understood by the surgeon and  care is taken during the dissection. We like to have a handheld Doppler  unit available in case there is concern about the penile arterial supply.   The vancomycin-gentamicin regimen is given for 24-h postopera-  tively. Oral cefazolin or ciprofloxacin is given thereafter for 2-3 wk to  patients who underwent reoperations for a noninfection cause, and for  4—6 wk to patients who underwent reoperation as a result of infection or  for a complex reoperation (9, //,/3).    The most common and difficult problem in dealing with reoperation  of patients with penile implants is corporeal fibrosis. The etiologies for  corporeal fibrosis are Peyronie’s disease or its treatment, priapism,  penile trauma, and intracavernosal injection. However, the most com-  mon corporeal fibrosis in reoperative prosthetic surgery is caused by the  removal of a previously implanted device secondary to infection or  erosion (/3—15). After removal of an infected penile prosthesis, corpo-  real fibrosis can be very severe and fibrosis contraction will then result  in a shortened penis. Reimplantation of penile prosthesis cylinders into  such a scared corporeal body becomes a technical challenge in pros-  thetic urology. However, successful reimplantation surgery can be  obtained by keeping the following four steps in mind. These include: 1)  ideal corporeal dilation; (2) appropriate choice of prosthesis; 3) com-  plete closure of the corpora cavernosa; and 4) maximizing penile length.   Techniques to manage fibrotic corpora vary according to the fibrotic  severity, the location, and the surgeon’s preference and experience. We  often use combination incisions, such as an infrapubic and circumci-  sion-like incision for penile degloving for safe and accurate corporeal  dilation (see Fig. 1). Certainly, multiple openings in the corpora allow  for better access to dissect or serially dilate intracorporeal fibrotic tis-  sue. Sometimes, a plane between the fibrous scar tissue and the tunica  albuginea can be developed with sharp dissection. However, we found  that in many cases, a complete bivalving of the dense fibrotic corporeal  tissue is necessary with coring out of the fibrotic tissue under direct  vision and sharp dissection to make a suitable space for a penile device.  This technique allows us to avoid urethral injury and has been very  successful in the majority of our complex cases. We also found that  Carrion-Rossello cavernotomes could be very helpful in the dilatation  of the scarred corpora (see Fig. 2). These cavernotomes are sized 9-12 mm  with cutting rasp-like surfaces, which enhance passage through the fib-  rotic tissue. Some prosthetic urologists use careful scissor dissection to  create a narrow cavity adjacent to scar tissue, which can be achieved  with Metzenbaum scissors by dissecting scar away from the tunica  albuginea of the corpus cavernosum or by bluntly dissecting through  scar with the scissors (75). After a narrow cavity is created down to or  near the ischial tuberosities, the Otis urethrotome can be used for sharp  incision of the tissue in a direction away from the urethra. However,  great care should be taken not to cut through the tunica albuginea. This  technique requires experience to know the direction of the crus, and    Fig. 1. Two-incision approach very often necessary to operate on the patient with  severe fibrosis. The upper and lower Allis clamps are on the edge of the corpora  cavernosa. The excised fibrotic tissue that has been removed by direct dissection  is marked with an arrow. The two incisions that have been used in this case are an  infrapubic incision and a circumcision incision allowing for full exposure of the  corpora cavernosa tissue. In this particular slide, the left cylinder has been placed  and this photograph is prior to placement of the right cylinder. The attached pump  is shown also in the picture after placement of the left cylinder.    Fig. 2. The rasping end of the Carrion-Rosello cavernotomes is shown. The  rasp are smooth as they are introduced in a forward direction and have a cutting,  rasping surface as they are removed for dilating tissue in a corpora cavernosa  that has significant fibrosis.    Fig. 3. A demonstration of the new penile cavernotome as proposed by  Mooreville and Wilson.    what tissue can be incised and what must be avoided. When operating  distally to create a cavity to the subglandular area, fibrotic tissue inci-  sion in both directions through multiple sites can be made to create the  cavities with the urethrotome, cavernotome, or sharp scissors. Rajpurkar  et al. reported their success with multiple incisions and minimal scar  tissue excision in extensive penile fibrosis patients (/3). They use a  midline perineal incision in all their cases. A2-cm corporotomy is made  on the corpus cavernosum and minimal scar tissue is excised at the site  of corporotomy to facilitate the initiation of corporal dilation. The initial  dilation is performed from the corporotomy site to the ischial tuberosity  almost under direct vision starting with Metzenbaum scissors. The 7—11  gage Hegar dilators and/or Dilamezinsert were then used for further  dilation. An additional subcoronal incision is made if necessary and  dilation of the distal fibrotic area is carried out under direct vision  through the distal corporotomy. It is exemplary, and to their credit, that  they could achieve successful dilation and implantation without using  any cavernotome or Otis urethrotome. No urethral perforation and only  one crural perforation were reported in their study. A new penile cav-  ernotome that allows drilling a space in fibrotic corpora was recently  reported by Mooreville et al. (/5) (see Fig. 3-4). This cavernotome set    Fig. 4. The action necessary to remove fibrotic tissue with the cavernotome  shown in Fig. 3.    consists of five cavernotomes with diameters from 6 to 13 mm. The head  of the cavernotome is blunt and tapered for 1 cm. The height of the  6-cm-long working blade is 1 mm. This working blade rises from a  beveled surface, which allows 1-mm shavings of tissue to be resected.  As reported by authors, the dilation of fibrotic corpora was easier and  quicker because extensive corporeal resection was not necessary. How-  ever, great care should be taken to avoid possible corporeal perforation.   Even with optimal corporal dilation, the standard penile prosthesis  cylinder will be unable to be placed in the majority of cases of severe  fibrosis without corporeal reconstruction. We now have more choices  for penile prostheses than at any time before. As a matter of fact, we are  now routinely preparing downsized versions of prostheses [Mentor a-1  (narrow base) and AMS 700 CXM] for patients with severe corporeal  fibrosis. We have found the Mentor a-1 (narrow base) to be very useful  because of its narrow-base feature, better girth expansion and softer tip  than the AMS 700 CXM. Carbone et al. also reported their experience  in the management of severe corporeal fibrosis with placement of the  AMS 700 CXM prosthesis (/4). In all 26 men with severe corporeal  fibrosis, the AMS 700 CXM prostheses were successfully implanted    with primary closure of the tunica albuginea without need of corporeal  reconstruction.   For tunica albuginea closure, we preplace sutures to prevent possible  needle puncture to the prosthesis. This is particularly necessary in a  resident-training institute. If corporeal closure is performed after the  cylinder is placed, it is imperative to use a protector for cylinder protec-  tion from needle perforation. In some circumstances, even with the use  of a downsized device, the edges of the tunical albuginea cannot be  approximated over the cylinders. Corporeal reconstruction using syn-  thetic material will be needed, even though there has been controversy  about increased risk of infection with the use of synthetic material (/4)  (see Fig. 5A). We like to use a Dacron netting overlaid on either side by  silastic material, which allows some elasticity (see Fig. 5B).   Even after successful penile prosthesis implantation in patients with  extensive penile fibrosis, some patients will complain of insufficient  penile length for satisfactory sexual intercourse. It is important to dis-  cuss limitations of the reoperation for penile implantation thoroughly to  make sure that patients understand the penile shortening is caused by  severe fibrosis and scar contraction. Use of AMS 700 Ultrex or Ultrex-  plus with a hope of length enhancement has been disappointing. Daitch  et al. also demonstrated that Ultrex cylinders exhibited an increased  mechanical failure rate (3). If functional penile length will not reach  more than 10 cm after implantation of a penile prosthesis, then release  of the suspensory ligament, V-Y flap advancement, and/or lower  abdominal tissue debulking may gain an additional penile length.  Knoll et al. reported their experience in 11 patients with extensive  cavernous fibrosis who underwent penile prosthesis implantation with  a modified suprapubic V-Y advancement flap and lower abdominal  tissue debulking (/6). An additional 3.5- to 6.5-cm functional penile  length was obtained.    Infection after the insertion of a penile prosthesis is the most devas-  tating complication. Previous dogma has advised immediate removal of  the penile implant and reinsertion of a prosthesis 3—6 mo later, which  almost always results in corporeal fibrosis, scaring, and penile shorten-  ing. Because more successful salvage procedures were reported, imme-  diate replacement of the infected penile prosthesis has become possible.  We previously reported our successful salvage operation in 17 out of 21  patients (7). We placed a fenestrated drain along with the new prosthesis  to allow for intermittent irrigation for 5-7 d with Dabs antibiotic solu-    Fig. 5. (A) A closure of a defect in a corpora cavernosa with a gortex patch. (B)  The covering of the defect in the corpora cavernosa with a patch of dacron  netting that is covered with silicone (not commercially available).    tion (500 mg neomycin, 80 mg gentamicin, and 100 mg polymyxin in  1000 mL normal saline).   Brant et al. in 1996 proposed a 7-step vigorous intraoperative irriga-  tion protocol in their immediate salvage procedure for infected penile  prostheses (see Table 1) (17). Do not use intraoperative irrigation if the  reservoir site is intraperitoneal. The pump location is usually changed.    Kanamycin 80 mg/L, bacitracin | g/L  One-half strength hydrogen peroxide  One-half strength povidone-iodine  Pressure irrigation with 5 L NS containing  1 g vancomycin and 80 mg gentamicin   One-half strength povidone-iodine  One-half strength hydrogen peroxide  Kanamycin 80 mg/L, bacitracin | g/L    Salvage was successful in all 11 patients, even though one patient had  a repeat salvage procedure. Their contraindications for immediate sal-  vage attempt included necrotic infections, diabetic patients with puru-  lence in the corporeal bodies, rapidly developing infections, and erosion  of the device cylinders. Kaufman et al. used this 7-step irrigation pro-  tocol in their immediate salvage procedure in seven patients for infected  penile prosthesis with success in six patients (9). They suggested that a  salvage procedure could be successful even for patients with diabetes  with visible pus in the corpora. Mulcahy recently summarized his long-  term experience with this salvage protocol and 7-step sequential irriga-  tion in managing penile prosthetic infection (78). He obtained 82% (45  of 55 patients) infection-free rate after 6-93 mo follow-up.   Knollcompared delayed and immediate salvage techniques in manag-  ing penile prosthetic infection . A delayed salvage procedure (3 d)  included complete removal of all prosthesis, intraoperative antibiotic  irrigation with Dabs solution of all locations where a component of the  device was placed, and placement of drains in these locations. This was  followed by postoperative intermittent drain irrigation with Dabs solu-  tion every 8 h clamped for 20 min for 3 d and subsequent reimplantation  of a new three-piece device. An immediate salvage procedure was per-  formed by following the same kind of protocol as aforementioned by  Brant et al. Knoll found that an immediate salvage appears as successful  as a delayed salvage procedure.    Erosion of a penile prosthesis is uncommon, but it can be calamitous.  The most common sites of erosion are the distal cylinder and scrotal  pump (see Fig. 6). The etiology of cylinder erosion is mostly because of  loss of distal penile sensation in the patient with spinal cord injury,    Fig. 6. A patient who presents with scrotal erosion of pump and tubing attached  to the pump without purulent discharge. This case was successfully salvaged  by removing the old pump and placing the new pump on the opposite side of  the scrotum after thorough antibiotic irrigation.    diabetes, or postradiation. Erosion can also result from oversizing of the  prosthesis, or failure to keep the prosthesis deflated when not in use.  Management of erosion associated with obvious infection should fol-  low the principles for treating infection as aforementioned. We attempt  to perform salvage surgery for every patient with erosion without frank  purulent material.   Erosion of the reservoir into the bladder or into the bowel is a rare  occurrence. This is often owing to the tension on the tubing leading from  the reservoir or a small reservoir cavity that exerts pressure on the bal-  loon, pushing it into the viscus. This will need to have the affected bowel  segment resected or bladder closed, and the reservoir replaced into a  new site with an adequate cavity without tension on the tubing (19).   Scrotal erosion may be salvaged by transferring the pump or pump/  reservoir combinations to the opposite scrotum. Impending erosion of  the proximal cylinders or the rear-tip extenders in the perineum can  often be repaired through a perineal incision.   Distal erosion or impending erosion of the penile prosthesis can be  repaired with a variety of methods. Mulcahy described a distal corporo-  plasty to repair lateral impending erosion . He reseats the cylinder in  a more medial and secure position under the glans penis by creating a  new cavity for the cylinder behind the back wall of the fibrotic sheath    containing it. One of the authors has used this technique for more than  10 yr and has always found normal appearing corporeal tissue after  making an incision into the dorsal medial wall of the old cylinder sheath.  This corporeal tissue can easily be dilated to make a space for inserting  the cylinder in the appropriate subglanular position. In Mulcahy’ s report,  all 14 patients who underwent corporoplasty using this technique had  satisfactory results after 2-yr follow-up (1). Alter et al. reported their  successful two-stage procedure with prefabricated tunica vaginalis fas-  cia flaps to repair recurrent penile prosthesis extrusion in two patients  (20). A variety of synthetic and natural substitutes has also been used for  corporeal reconstruction to repair the distal erosion. These include poly-  ester, polypropylene mesh, polytetrafluoroethylene (PTFE), rectus fas-  cia, and fascia lata. Recently, there was a report of the use of human  cadaveric allograft skin for reconstruction of the corpus cavernosum in  the repair of distal erosion of a penile prosthesis (27). Smith et al. treated  five patients with impending erosion of penile prosthesis with PTFE  distal wind sock graft (22). All patients had satisfactory and functional  erections after 32 mo follow-up. Again, as aforementioned, use of syn-  thetic material has been controversial as a result of a possible increased  risk of penile prosthesis infection. We agree with Smith et al. that the  simple addition of a synthetic graft will not increase the rate of penile  prosthesis infection.   Urethral erosion is a more difficult problem to manage. As a preven-  tive measure, it is recommended that a temporary proximal urinary  diversion be performed in patients who are undergoing self-intermittent  catheterization and desire a penile implant. We prefer perineal urethros-  tomy. When urethral erosion is diagnosed, the eroded cylinder should  be removed and inserted at a later date after the urethra heals com-  pletely. It is important to determine whether there is a communication  with the cylinder on the opposite side during the surgery. If this cylinder  is not involved, it can be left in place to help maintain the length of the  penis; otherwise this cylinder should be removed also if it is communi-  cating with the erosive process. Whether the remainder of the prosthesis  should be kept or removed depends on the duration of the erosion and  the associated infection. Should any question about the infection of a  multicomponent exist, the device should be removed and a salvage  procedure performed.    The two most common position problems include inappropriate cyl-  inder length and a high-riding pump or reservoir/pump combination in    the scrotum. We have also seen a case in which the pump was located  behind the testis possibly because of migration as the patient complained of  gradual difficulty finding the pump for inflation. The malpositioned  pump or reservoir/pump combination can be easily corrected by simple  open surgery. If there is difficulty in replacing a pump or reservoit/pump  combination into the ipsilateral scrotum, the contralateral scrotum often  can be used. If the original tubing appears to be too short to allow  adequate placement, we recommend placing a new pump.   A difference in length between two cylinders can sometimes be addressed  by Yachia corporeal plasty on the convex side of the curvature. How-  ever, erectile deformities after placement of AMS 700 Ultrex are best  corrected by replacement with AMS 700 CX cylinders (23).   An inappropriate cylinder length can cause glans bowing or SST  deformity. The effective way to correct this type of deformity is with the  Ball procedure (24). In this procedure, a circumcising or hemicircum-  cising incision is made and the plane between the glans and the distal  portion of the tunica albuginea of the corpora cavernosa is developed by  sharp dissection. Place a nonabsorbable soft suture through the glans  substance and through the tunica albuginea adjacent to the cylinder  head. When all sutures are in position, securely tie the sutures dorsally,  ventrally, or laterally, wherever the glans needs to be secured over the  cylinder head. Sometimes, the cylinders are too short, which should be  corrected by adding rear-tip extenders to the cylinders or replacing them  with longer cylinders. Improper placement of the cylinders, such as  crossover into the other corpora, can be corrected through a circumci-  sion incision for the distal penile crossover or a perineal incision for  crossover in the crural corpora.    True mechanical failure for inflatable penile prostheses includes tub-  ing leak, pump leak, reservoir leak, and cylinder aneurysm. When  mechanical failure occurs, as a rule of thumb, every effort should be  made to replace a three-piece prosthesis with a similar prosthesis if  possible. Patients are usually dissatisfied if this is not done. Some authors  suggested that AMS 700 prostheses over 3 yr old should be totally  explanted and replaced with a new multicomponent prosthesis (5). Oth-  ers suggested replacing all parts after 5—6 yr if a three-piece inflatable  device develops a mechanical problem (19).   Replacement of involved components can be done by isolating the  connecting tubing to observe for tubing fracture; particularly where  excessive angulation of the tubing is present as it joins to the connector.    Kim et al. has found that the input tube exited through a separate stab  wound has higher incidence of tubing fracture than when the input  tubing runs alongside the cylinder within the corpus and exits through  the corporotomy (25). If fracture is observed, bypass it by connecting  intact parts of the tubing. Sometimes it may be difficult to identify the  defective part or parts. Some authors suggested using an ohmmeter;  others used pressure testing to locate the defect (/9). We like to replace  any part, if not all, when there is doubt about the integrity of any com-  ponent of the device. Modern reservoirs are usually not a source of  mechanical failure. Encapsulation of the reservoir can be managed by  hydrodilation and rupture of the restricting capsule using a hand-held  syringe through a scrotal incision. An aneurysmal defective cylinder  should be replaced and corporoplasty should be performed to maintain  the tunical strength and prevent replacement cylinder aneurysm (23).  When there are mechanical problems in a unitary hydraulic device or  rod-type penile prosthesis, both cylinders should be replaced. This is  also true for two-piece prostheses and three-piece devices without con-  nectors as both the cylinders and pump are part of one continuous sys-  tem. A two- or three-piece IPP is recommended replacement of unitary  hydraulic devices.    Persistent pain beyond 4—6 wk in the absence of fever, elevated white  count, erythema, or purulent drainage should be carefully evaluated.  Even though we may not be able to identify the etiology in many cases,  the penile pain, as aforementioned, can be caused by inappropriate sizing  of the cylinders. As reported by Moncada et al., buckling of cylinders  could cause prolonged penile pain after prosthesis implantation. This pain  can be resolved by reoperation to correct the buckling cylinder (6).    Reoperation after insertion of a penile prosthesis continues to be a  challenge for prosthetic urologists. However, if the surgery is well  planned, it can be very successful.    1. Mulcahy JJ (1999) Distal corporoplasty for lateral extrusion of penile prosthesis  cylinders. J Urol 161:193.   2. Wilson SK, Cleves MA, Delk JR II (1999) Comparison of mechanical reliability  of original and enhanced Mentor Alpha I penile prosthesis. J Urol 162:715.   3. Daitch JA, Angermeier KW, Lakin MM, et al. (1997) Long-term mechanical  reliability of AMS 700 series inflatable penile prostheses: comparison of CX/  CXM and Ultrex cylinders. J Urol 158:1400.    . Lewis RW, Morgan WR (1995) Failure of the penile prosthesis. In: Cohen MS,    Resnick MI, eds., Reoperative Urology, Boston: Little, Brown and Company,  pp. 235-243.    . Wilson SK (1997) Penile prosthesis implantation: pearls, pitfalls, and perils. In:    Hellstrom WJG, ed., Male Infertility and Sexual Dysfunction, New York:  Springer, pp. 529-548.    . Moncada I, Hernandez C, Jara J, et al. (1998) Buckling of cylinders may cause    prolonged penile pain after prosthesis implantation: a case control study using  magnetic resonance imaging of the penis. J Urol 160:67.    . Lewis RW, Mclaren R (1993) Reoperation for penile prosthesis implantation.    . Jarow JP (1996) Risk factors for penile prosthetic infection. J Urol 156:402.  . Kaufman JM, Kaufman JL, Borges FD (1998) Immediate salvage procedure for    . Wilson Sk, Cleves MA, Delk JR II (1996) Glycosylated hemoglobin and the risk    . Knoll LD (1998) Penile prosthetic infection: management by delayed and    . Garber BB, Marcus SM (1998) Does surgical approach affect the incidence of    . Rajpurkar A, Li H, Dhabuwala CB (1999) Penile implant success in patients    with corporal fibrosis using multiple incisions and minimal scar tissue excision.  Urology 54:145.   Carbone DJ Jr, Daitch JA, Angermeier KW, et al. (1998) Management of severe  corporeal fibrosis with implantation of prosthesis via a transverse scrotal  approach. J Urol 159:125.   Mooreville M, Adrian S, Delk II JR, Wilson SK (1999) Implantation of inflat-  able penile prosthesis in patients with severe corporeal fibrosis: introduction of  a new penile cavernotome. J Urol 162:2054.   Knoll LD, Fisher J, Benson RC Jr, et al. (1996) Treatment of penile fibrosis with  prosthetic implantation and flap advancement with tissue debulking. J Urol  156:394.   Brant MD, Ludlow JK, Mulcahy JJ (1996) The prosthesis salvage operation:  immediate replacement of the infected penile prosthesis. J Urol 155:155.  Mulcahy JJ (2000) Long-term experience with salvage of infected penile  implants. J Urol 163: 481.   Mulcahy JJ (1997) The complex penile prosthesis. In: Hellstrom WJG, ed., Male  Infertility and Sexual Dysfunction, New York: Springer, pp. 549-562.   Alter GJ, Greisman J, Werthman PE, et al. (1998) Use of a prefabricated tunica  vaginalis fascia flap to reconstruct the tunica albuginea after recurrent penile  prosthesis extrusion. J Urol 159:128.   Landman J, Bar-Chama N (1999) Initial experience with processed human cada-  veric allograft skin for reconstruction of the corpus cavernosum in repair of  distal extrusion of a penile prosthesis. Urology 53:1222.   Smith CP, Kraus SR, Boone TB (1998) Management of impending penile pros-  thesis erosion with a polytetrafluoroethylene distal wind sock graft. J Urol  160:2037.   Kowalczyk JJ, Mulcahy JJ (1996) Penile curvatures and aneurysmal defects  with the Ultrex penile prosthesis corrected with insertion of the AMS700CX.  J Urol 156:398.   25. Kim SC, Seo KK, Yoon SH (1999) Fracture at the input tube-cylinder junction  of AMS 700 inflatable penile prostheses as a complication of a modified implan-  tation technique in a series of 99 patients. Urology 54:148.    Implantation of a penile prosthesis in the setting of corporeal fibrosis  can be a significant challenge. This condition occurs most commonly  following removal of a previously implanted penile prosthesis for infec-  tion or erosion (/,2). Additional etiologies of corporeal fibrosis include  priapism (3), penile trauma (4), Peyronie’s disease (5,6), intracavernosal  injection therapy (7), and idiopathic (8). The extent of fibrosis within the  corporeal bodies may vary, and it may occur unilaterally or bilaterally.  The primary problem presented by the fibrosis during penile prosthesis  implantation is interference with satisfactory dilation of the corporeal  bodies and subsequent corporotomy closure. Following surgery, the  main problem encountered is often patient dissatisfaction regarding    The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    functional erectile length. This can be a significant issue that must be  extensively reviewed with the patient preoperatively to ensure that he  understands the inherent difficulties of the surgical procedure and has  realistic expectations.    As in any patient, a careful history is important. The presence of  corporeal fibrosis may be suspected based upon a history of any of the  conditions aforementioned. The premorbid status of the erect penis  should be elucidated, as well as the timing of the onset of erectile dys-  function (ED). If the patient has a history of intracavernosal injection,  the duration of treatment and agents used should be recorded. A history  of erectile curvature or erectile discomfort should be documented if  present. Although rare, a patient with idiopathic corporeal fibrosis may  present with primary ED. A review of previous surgical procedures on  the penis is also important in operative planning.    Careful palpation of the stretched penis should be carried out to iden-  tify areas of tunical or intracorporeal fibrosis. These are generally docu-  mented with a drawing. We also assess penile extensibility and corporeal  compliance. It should be noted whether the patient is circumcised, and  the possibility of circumcision at the time of the implant needs to be  discussed if one feels that adjunctive distal penile incisions might be  required.    In patients who have not undergone previous evaluation and treat-  ment for ED, a nocturnal penile tumescence study is obtained. This  would primarily include those with a history of priapism, penile  trauma, or previous treatment for Peyronie’s disease. We have also  used biothesiometry in these situations to document vibratory thresh-  olds preoperatively. The index finger, penile shaft, and glans penis are  assessed bilaterally (9,/0). The thresholds detected by the patient  during both increasing and decreasing amplitude of vibration are  recorded. This is primarily useful for comparison to postoperative  biothesiometry in patients complaining of changes in penile sensa-  tion. Except in unusual circumstances, we have not found penile  imaging studies to be very helpful in the surgical treatment of patients  with corporeal fibrosis.    Implantation of a penile prosthesis in the setting of corporeal fibrosis  is one of those cases during which the surgeon must be familiar with a  variety of techniques to aid with corporeal dilation and closure. There  do not seem to be any highly reliable preoperative predictors of surgical  difficulty and the patient needs to be aware of this. In our standard  implant procedure , we make an upper transverse scrotal incision  and dilate the corporal bodies through 2-cm corporotomies using Hegar  dilators. If corporeal fibrosis does not allow this, there are adjunctive  procedures and devices that can help to accomplish a successful implant.    When fibrosis impedes corporeal dilation, the most common initial  maneuver is the use of Metzenbaum scissors to create a channel through  the fibrosis. The scissors are advanced and intermittently spread, using  the opposite hand to palpate the tips of the scissors and monitor their  location. The tips are directed dorsolaterally to decrease the risk of  urethral injury. Once the distal or proximal corporal body has been  reached, the scissors are spread and then withdrawn. Hegar dilators are  then used to fully dilate the corpora. If it remains difficult to pass Hegar  dilators, the Dilamezinsert! may be used to aid sequential dilation. Some  authors have advocated the use of the Otis urethrotome as another option  for corporeal dilation (/0, /2). The instrument should be positioned away  from the urethra, and multiple cuts may be needed at different locations  to allow subsequent passage of Hegar dilators. We have not used the  Otis urethrotome in this setting.   In addition to the aforementioned, two special dilators or cavern-  otomes have been manufactured for use in the presence of corporeal  fibrosis. The Carrion-Rosello cavernotome” has a smooth surface along  one aspect of its circumference while the other is covered with rows of  small pointed edges that provide arasping action (see Fig. 1). The smooth  aspect is oriented toward the urethra as the dilator is inserted to the distal  or proximal end of each corporeal body. They are available in sets of 4,  with diameters of 9, 10, 11, and 12 mm. Our experience is that these  devices can aid dilation in difficult situations, however, they are at times  a bit difficult to withdraw following insertion through dense fibrosis. A  more recently developed penile cavernotome? is designed as a cutting    'Lone Star Medical Products, Houston, TX.  2UROAN - XXI, Electromedicina, Spain.  3Uramix, Inc., Landsdowne, PA.    dilator, with a blunt distal tip and a 6-cm-long working blade with a  height of 1 mm (see Fig. 2). The blade does not extend beyond the  diameter of the dilator, and arises from a beveled surface that allows the  actual resection of small shavings of tissue if necessary. The dilator is  advanced slowly with an oscillating motion or by rotation. It is available  in sets of 5, with diameter ranging from 6-13 mm. Use of this device in  16 patients with severe corporeal fibrosis has been reported (/3), with  successful implantation of an inflatable penile prosthesis in all cases.  Operative time was reduced and no patient required a synthetic graft.  Four patients required a secondary procedure to correct impending dis-  tal corporeal erosion of a cylinder tip. These new dilators seem to have  the potential for easier dilation of fibrotic corpora, and it will be inter-  esting to monitor future results as experience increases.    A major advance in the management of patients with corporeal  fibrosis occurred with the introduction of the downsized inflatable  penile prosthesis. Our experience has been primarily with the AMS    Fig. 2. Cutting penile cavernotome. (From Mooreville M, Adrian S, Delk JR,  II, Wilson SK (1999) Implantation of inflatable penile prosthesis in patients  with severe corporeal fibrosis: introcuction of a new penile cavernotome.  J Urol 162:2005. With permisison, and courtesy of Michael Mooreville, MD.)    700 CXM* (see Fig. 3), which was introduced in 1990. Originally devel-  oped for men with smaller penises, it is now used primarily in patients  with corporeal fibrosis. The deflated cylinder diameter is 9.5 mm and  inflated diameter 14.2 mm, which is a significant advantage when cor-  poreal dilation is difficult. The addition of rear-tip extenders allows the  cylinder input tubing to exit almost directly out of the corporotomy, and  may therefore lessen the degree of dilation required for proximal    Fig. 3. AMS 700 CXM inflatable penile prosthesis. (Courtesy of American  Medical Systems, Inc., Minnetonka, MN.)    insertion. Studies have shown that this device can often obviate the need  for corporeal reconstruction with synthetic grafts in patients in whom it  would have been otherwise necessary (/4,/5). In addition, the rate of  infection was decreased to 4—5% and the majority of patients have had  a satisfactory functional outcome.    When dense corporeal fibrosis precludes adequate dilation using the  aforementioned techniques, or when it is difficult to localize the dilator  within the distal corpus, additional corporotomy is often helpful. In  order to aid distal dilation, exposure to the corporeal body is gained via  a subcoronal skin incision or by extending the transverse scrotal inci-  sion distally in the midline (see Fig. 4). A dilator or scissors can then be  advanced as far as possible, followed by a secondary corporotomy over    Fig. 4. Skin incisions for exposure of distal corpora. (A) Subcoronal incision.  (B) Transverse scrotal incision extended distally in midline.    the tip (see Fig. 5). Alternatively, initial advancement of a dilator is not  an absolute requirement and the tunical incision can merely be made  along the distal corpus (/6). Distal dissection and dilation with  Metzenbaum scissors can then be accomplished virtually under direct  vision (see Fig. 6). The area between the corporotomies is then dilated  from both directions until a satisfactory diameter has been reached.  If this maneuver fails, extended corporotomies may be required. The  initial corporotomy incision is lengthened and often includes the major-  ity of the shaft of the penis back to the proximal corpus (see Fig. 7). This  allows dilation proximal and distal to the tunical incision, and nay be  accompanied when necessary by excision of a sufficient amount of the  intervening fibrotic tissue to allow prosthesis insertion (17,18). With  the emergence of special dilators and the downsized inflatable penile    Fig. 6. Secondary corporotomy: scissors dissection and dilation of distal corpus.    Fig. 7. Extended corporotomy. (A) Proposed tunical incision. (B) Extended  corporotomy with stay sutures in place.    prosthesis, extended corporotomy was required in only 8% of men with  corporeal fibrosis in a recent study (/5).    Although increasingly uncommon, there may be situations where the  tunica albuginea cannot be closed over a prosthetic cylinder following  secondary or extended corporotomy. Corporeal reconstruction with a  synthetic graft is therefore required, most commonly using a polytetra-  fluoroethylene (PTFE) patch. The patch is tailored to the tunical defect  allowing full coverage of the prosthetic cylinder, and sutured in place  with a running 3-0 polypropylene or PTFE suture (see Fig. 8). An early  report of experience with this technique in 30 men with corporeal fibro-  sis demonstrated an infection rate of 30% (19). However, there have  been several smaller series using a similar approach with no infectious  complications (20-22). In general, however, most surgeons seem to  agree that it is preferable to avoid corporeal reconstruction with syn-  thetic grafts when possible, in order to minimize the potential risk of  infection and distal cylinder migration.    The postoperative care following penile prosthesis implantation in  the setting of corporeal fibrosis is similar to that following a standard  implant . A Foley catheter is left indwelling overnight. Based upon  surgeon preference, a small suction drain may be placed in the subdartos  space and brought out through a stab incision in the inguinal region  opposite the reservoir. Most patients are discharged after a 23-hr hospi-  tal stay, although an occasional patient may stay longer for pain control  following an extensive reconstructive procedure. Patients with corpo-  real fibrosis are treated with ciprofloxacin or a cephalosporin for 1 wk  postoperatively. An attempt is made to maintain the penis in an upward  orientation during the first month to prevent ventral tethering. Patients  can generally resume intercourse 6—8 wk postoperatively.    Injury to the urethra may occur during difficult corporeal dilation. In  these complex cases, if such an injury is recognized intraoperatively the  implant procedure should probably be aborted. Orienting scissor tips  and dilators laterally, with localization of the distal aspect of the device  by palpation as it is advanced can minimize the risk of urethral injury.  The appropriate use of a secondary or extended corporotomy can also  help in this way. A second complication of dilation is tunical perfora-  tion, whichis most common within the proximal crura during the implant  procedure. Distal perforations may present postoperatively as impend-  ing lateral or distal erosion in the region of the glans penis. A proximal  crural perforation can, at times, be bypassed with larger dilators, pre-  cluding the need for formal repair. Several techniques for managing this  problem have been described, and primarily involve placement of syn-  thetic material such as PTFE or a rear-tip extender as a windsock into  the proximal crus (23). A plug and patch technique has also been reported  (24). Late distal erosion laterally may be managed with a procedure  described by Mulcahy (25), in which the distal cylinder tip is relocated  using natural tissues. A windsock technique has also been reported (26).   With current techniques, infection rates in the setting of corporeal  fibrosis are similar to those associated with standard prosthesis inser-  tion (13-15). This may be related to a decreasing need for corporeal  reconstruction and facilitation of the implant procedure with decreased  operative time (27). Periprosthetic infection may be managed with a  salvage procedure (28) when feasible. Prosthesis removal may result in  further shortening of an already fibrotic penis, but will be required in  some individuals.    . Gasser TC, Larsen EH, Bruskewitz RG (1987) Penile prosthesis reimplantation.   . Macaluso JN, Sullivan JW (1985) Priapism: review of 34 cases. Urology 25:233.  . Orvis BR, McAninch JW (1989) Penile rupture. Urol Clin North Am 16:369.  . Furlow WL, Swenson HE, Lee RE (1975) Peyronie’s disease: a study of its    . Devine CJ, Horton CE (1987) Bent penis. Semin Urol 5:251.  . Larsen EH, Gasser TC, Bruskewitz RG (1987) Fibrosis of corpus cavernosum    . Knoll LD (1995) Use of penile prosthetic implants in patients with penile fibro-    . Montague DK, Angermeier KW, Lakin MM (1996) Penile prosthesis implanta-    tion. In: Marshall FF, ed., Textbook of Operative Urology, Philadelphia: WB  Saunders, ch. 85, pp. 712-719.    . Carson, CC (1989) Infections in genitourinary prostheses. Urol Clin North Am    . Mooreville M, Adrian S, Delk JR I, Wilson SK (1999) Implantation of inflat-    able penile prosthesis in patients with severe corporeal fibrosis: introduction of  a new penile cavernotome. J Urol 162:2054.   Knoll LD, Furlow WL, Benson RC, Bilhartz DL (1995) Management of  nondilatable cavernous fibrosis with the use of a downsized inflatable penile  prosthesis. J Urol 153:366.   Carbone DJ, Daitch JA, Angermeier KW, Lakin MM, Montague DK (1998)  Management of severe corporeal fibrosis with implantation of prosthesis via a  transverse scrotal approach. J Urol 159:125.   Herschorn S, Barkin M, Comisarow R (1986) New technique for difficult penile  implants. Urology 27:463.   Fishman IJ (1989) Corporeal reconstruction procedures for complicated penile  implants. Urol Clin North Am 16:73.   Knoll LD, Furlow WL (1992) Corporeal reconstruction and prosthetic implan-  tation for impotence associated with non-dilatable corporeal cavernosal fibro-  sis. Acta Urol Belg 60:15.   Herschorn S, Ordorica RC (1995) Penile prosthesis insertion with corporeal  reconstruction with synthetic vascular graft material. J Urol 154:80.   George VK, Shah GS, Mills R, Dhabuwala CB (1996) The management of  extensive penile fibrosis: a new technique of minimal scar-tissue excision. Brit  J Urol 11:282.   Seftel AD, Oates RD, Goldstein I (1992) Use of a polytetrafluoroethylene tube  graft as a circumferential neotunica during placement of a penile prosthesis. J  Urol 148:1531.   Mulcahy JJ (1987) A technique of maintaining penile prosthesis position to  prevent proximal migration. J Urol 137:294.    Szostak MJ, DelPizzo JJ, Sklar GN (2000) The plug and patch: a new technique  for repair of corporal perforation during placement of penile prostheses. J Urol  163:1203.   Mulcahy JJ (1999) Distal corporoplasty for lateral extrusion of penile prosthesis  cylinders. J Urol 161:193.   Smith CP, Kraus SR, Boone TB (1998) Management of impending penile pros-  thesis erosion with a polytetrafluoroethylene distal wind sock graft. J Urol  160:2037.   Jarow JP (1996) Risk factors for penile prosthetic infection. J Urol 156:402.  Mulcahy JJ (2000) Long-term experience with salvage of infected penile  implants. J Urol 163:481.    Insertion of the artificial urinary sphincter (AUS) in the male is pres-  ently still the most effective treatment for stress incontinence secondary  to sphincter dysfunction. The AUS was one of the initial successful  applications of a prosthetic implant in management of the genitourinary  system. Historically, Foley is credited for introducing the first artificial  urinary sphincter in 1947 (1). The device consisted of an inflatable cuff,  made of latex, that was placed around the corpus spongiosum just distal    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    Fig. 1. The original artificial sphincter introduced in 1973 named AS 721.    to the penoscrotal junction. It was connected by tubing to a valve and  syringe that were kept by the patient in his trouser pocket. The cuff was  inflated to prevent incontinence and deflated to empty the bladder.  Unfortunately, pressure necrosis and infections occurred, which led to  fistulas and other unmanageable complications.   The modern AUS was introduced by Scott et al. in 1973 (2). This  device was made of silicone rubber and consisted of three major com-  ponents: the reservoir, an occlusive cuff, and two pumps. The reservoir  contained fluid used to activate the device and was implanted in the  prevesical space. The cuff encircled the bulbous urethra or the vesical  neck and the inflate and deflate pumps were placed in each hemiscrotum  or labium (see Fig. 1).   Experience with this initial prosthesis was favorable with an overall  success rate of 60%-—70% (3). Most of the complications and failures  encountered with this device were attributable to urethral erosion and  infection. Other problems that could be repaired included mechanical  failures such as tube kinks, valvular failure, and device leakage.   Although the device was fairly successful, there were clearly areas  for improvement. Over the next 10 yr, through the efforts of American  Medical Systems (Minnetonka, MN) and several urologists active in  implanting the AUSs, the device was constantly modified in an effort to  simplify the design, improve reliability, and reduce the complication    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 265    and reoperative rates. In 1983, American Medical Systems (AMS) intro-  duced the latest AUS model, the AMS800 (see Fig. 2). This model has  been very successful and has changed very little since then. The modi-  fications that occurred appear to have significantly improved the dura-  bility and reliability of this AUS. The current device is constructed of  a wear-resistant, biocompatible silicone elastomer and consists of three  components all connected by special kink-resistant color-coded sili-  cone tubing: a soft, pliable, dip-coated silicone cuff that is placed around  the urethra or bladder neck, a seamless pressure-regulating balloon  placed in the prevesical space of Retzius and a pump placed in the  scrotum or labia majora with a flow resistor that acts to slow cuff refill,  allowing adequate voiding time, and a deactivation button that, when  engaged, prevents cuff refill altogether. This button is located on the    cephalad portion of the pump mechanism (easily palpated through the  skin). By squeezing it, one can move a poppet valve to a position such  that fluid cannot be transferred. Reactivation is accomplished with a  sharp squeeze on the pump that releases the poppet. An important point  in sphincter deactivation is that some fluid in the pump is necessary to  unseat the poppet valve. To accomplish this, we generally allow the  pump to refill to the point where only a shallow dimple is palpable  before deactivating the device. This feature was an important addition  to the AUS in that Furlow showed that deactivation for 6-8 wk after  implantation (to allow for periurethral swelling to decrease and tissue  healing) decreased the incidence of infection and erosion with artificial  urinary sphincters (4). The ability to deactivate a sphincter is also an  important feature when the patient requires Foley catheter drainage or  undergoes instrumentation, events that increase the risk for cuff erosion  or infection. In these situations, the cuff should always be emptied and  then the device be deactivated (as aforementioned).   The AMS800 system is fluid filled and works hydraulically. The  occlusive force of the cuff is determined by the pressure of a regulating  balloon, and the balloon is manufactured so that precalibrated reservoirs  are available in different pressure ranges: 51—60, 61-70, 71-80, and  81-90 cm H,O. The intraabdominal prevesical location of the reservoir  also permits the transmission of abdominal pressure changes to the cuff,  helping reduce leakage with straining maneuvers (5). The patient  squeezes the pump to empty the cuff, transferring fluid to the regulating  balloon. As the cuff empties, the occlusive force on the urethra is  removed, and the patient can void. Resistors in the pump mechanism  delay cuff refill for approx 2-3 min, allowing the patient adequate time  to empty his bladder (see Fig. 3A, 3B).    Male patients who are considered for implantation of an AUS fall into  one of four groups: neuropathic bladder dysfunction (mainly congeni-  tal), postprostatectomy incontinence, congenital anomalies, and trauma.  A recent surge in radical prostatectomy surgery has led to more men  with significant urinary incontinence as a result of sphincter dysfunc-  tion. This group consists of the most common indication for insertion of  AUS in adult men.   Before considering an incontinent patient for AUS implantation, one  must realize that an AUS is a treatment for incontinence because of  sphincteric incompetence only (5,6). Thus, the importance of preopera-    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 267    Fig. 3. Hydraulic cycling mechanism for the AUS. (A) Squeezing the pump  will transfer fluid from the cuff to the balloon (see arrow). (B) The pressurized  balloon will transfer the fluid from the balloon to cuff gradually (takes 1-2  minutes) because of the resistor in the pump.    tive evaluation cannot be overemphasized. Patients must be screened to  ensure they are mentally and physically capable of using an AUS. In this  manner, it is helpful to show the patient the actual device in vitro and  observe his skills at cycling the device. Dementia or physical inability  to squeeze the pump is a contraindication to placing the device, which  would put the patient in retention if he were not able to use it properly.   The history of urinary incontinence should be delineated to deter-  mine its cause. Physical examination should include a neurologic exam-  ination to identify neuropathologic disturbances. During this evaluation,  particular attention should be paid to the patient’ s upper extremity motor  skills. Physical examination should define or confirm the clinical  impression as to the type of incontinence present. Urinary tract infection  should be ruled out and eradicated. In addition, the cause of such infec-  tion should be elucidated, because recurrent infection in the presence of  prosthesis may lead to prosthesis infection. Appropriate urodynamic  testing should be done to document not only the mechanism of incon-  tinence, but also the state of detrusor function. Ideal candidates for the  AUS are patients with irreversible sphincteric dysfunction and normal  detrusor function. Extensive experience with this device has shown that  areflexia and hyperreflexia are not absolute contraindications. How-  ever, before any implantation, appropriate provisions should be made to  ensure that the bladder can be emptied regularly to avoid chronic reten-    tion and that hyperreflexia can be suppressed to avoid urge inconti-  nence. Ideal bladder capacity should be =400 mL with pressures of  <40 cm H,O, although capacity of >150 mL have been implanted  successfully. Failure to identify bladder function problems could lead to  elevated bladder storage pressures and upper tract and renal deteriora-  tion in the presence of an AUS. One can treat incomplete bladder emp-  tying by performing a flap urethroplasty at the time of sphincter  implantation as advocated by Scott et al. (7) to ensure complete bladder  emptying or with intermittent self-catheterization (8,9), both of which  have been shown to be compatible with the AUS implant. Hyperreflexic  or hypertonic bladder may be managed with anticholinergics, and if this  is not effective, bladder augmentation with bowel segments has been  successful with the AUS (/0). If hyperreflexia can be controlled with  drugs or by other means, implantation of a sphincter is feasible. Oth-  erwise, urge incontinence will persist and upper tract deterioration  could occur.   Recently, a new mode of therapy has been added to the urologist’s  armamentarium in the management of urge incontinence unresponsive  the behavioral techniques and bladder relaxant pharmacological  therapy. We have now limited experience of using the Medtronic Cor-  poration (Minneapolis, MN) Interstim™ neuromodulation program in  combination with an AUS implant. This device consisting of a wire  electrode inserted into the sacral foramen and connected into a generator  implanted subcutaneously into the superior aspect of the buttocks, pro-  vides programmed electrical pulses to the bladder and sphincters via the  sacral reflex arc . It is theorized that such electrical pulses will  modulate the bladder function to normality. It is therefore feasible that  a patient with stress incontinence secondary to intrinsic sphincter defi-  ciency, but with concommitant intractable urge incontinence or even  chronic nonobstructive retention may be screened and if appropriate,  receive the Interstim implant and if stress incontinence persists, receive  the AUS. Likewise, patients with AUS and associated intractable urge  incontinence may be evaluated for Interstim implant and if found appro-  priate, be implanted with Interstim.   Currently our workup includes a detailed history and physical exami-  nation including neurologic with postvoid residual urine determination.  If intrinsic sphincter deficiency is suspected, patients then undergo fur-  ther evaluation. All patients undergo flexible cystoscopy with particular  attention paid to bladder neck and sphincteric function during provoca-  tive maneuvers. In males, endoscopic evaluation can also identify not  only bladder neck with sphincteric incompetence but also potential  urethral disorders (contracture, stricture, and so forth). Special attention    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 269    should be directed to the bulbous urethra, the area in the urethra where  the cuff is usually implanted to assure that there are no signs of scarring,  false passage, or strictures. Patients also undergo urodynamic testing,  including acystometrogram, for evaluation of bladderinstability or hyper-  reflexia, bladder capacity, and sensation. Atthe completion of cystometry  with the bladder full, cough stress test is performed to provoke stress  incontinence. Leaking of fluid at the instant of cough confirms the pres-  ence of stress incontinence. Urethral profilometry and leak point pres-  sure measurements are not essential when provocative cough stress test  is positive.   The most common reason for insertion of an artificial urinary sphinc-  ter in adult males is for postprostatectomy incontinence. It is recom-  mended that AUS implantation be delayed for at least 6 mo after the  prostatectomy to allow time for possible spontaneous resolution. Inser-  tion of the AUS in males can be performed at essentially two sites: the  vesical neck and the bulbous urethra. For postprostatectomy inconti-    nence, however, we recommend placement of AUS only at the bulbous  urethra site primarily because of the significant postoperative changes  at the bladder neck in these patients (see Fig. 4). In male children, the  indication is generally for incontinence secondary to neurogenic dys-  function, most commonly caused by myelomeningocele. Generally in  these patients, the sphincter should be placed at the bladder neck. These  patients may need to receive intermittent self-catheterization and may  be non-ambulatory, they will be in seated positions for long periods of  time. A bulbar urethral position is of concern in this situation because  it would theoretically expose the cuff to extended periods of pressure  increasing the risk for erosion and infection. Potential problems with  bladder neck placement in prepubertal males and subsequent prostate  growth disrupting AUS function have not been reported. When one is  implanting sphincters in children, it is advised to use conservative  measures for management of incontinence initially and delay AUS inser-  tion until at least 6 yr of age to allow for anatomic, emotional, and social  maturation (/2).    Patients are given antibiotics preoperatively on a prophylactic basis  parenterally at least 2 h before surgery. The urine should be proved free  of infection prior to hospitalization. In patients whose incontinence is  managed with external devices, careful examination preoperatively is  necessary to rule out cutaneous inflammation or erosion of the external  genitalia. If any is present, surgery should be deferred until the skin is  healed and uninflammed. All Foley catheters should be removed, if  possible, 7 d prior to surgery and the urine sterilized. For those who are  on clean intermittent catheterization, a urine culture is obtained 1 wk  earlier and appropriate antibiotic coverage started 3 d preoperatively.   The procedure is performed under spinal anesthesia in the lithotomy  position. In elderly men, care is taken when positioning the legs. Arti-  ficial hips, arthritic joints, and diminished thigh abduction ability may  require special attention.   The entire lower abdomen, external genitalia, and perineum are  shaved and a careful wide surgical scrub is performed and draped for  access to the bulbous urethra and suprapubic area. A drape is sutured or  stapled to cover the anus to isolate it from the perineal exposure. A 16-F  Foley urethral catheter is passed into the bladder and the bladder is  drained.   For bladder neck insertion in men, a suprapubic transverse or vertical  incision is performed followed by the usual entry into the perivesical    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 271    Fig. 5. Circumferential dissection of 2 cm. length bulbous urethra at the distal  edge of the bulbocavernosus muscle. Note the 2 cm. wide sizer around the  urethra.    space followed by exposure of the endopelvic fascia and the prostate and  bladder neck area. The endopelvic fascia is then incised and the prostate  and bladder neck are dissected free anteriorly and laterally. The dorsal  complex of vessels and nerves are not transsected in most cases unless  there is not enough space at the region of the prostatic bladder neck area.  Using aright-angle clamp, blunt dissection is carried out to separate the  posterior aspect of the prostate and bladder neck from the anterior rectal  wall similar to the maneuver in the bulbous urethra. A 2-cm-wide space  is created so that the tape measure can be passed between the bladder  neck and rectal wall space to measure the circumference of the bladder  neck/prostate area that will be enclosed by the cuff.   Once the cuff is inserted around the bladder neck, which is usually a  6-7-cm cuff, the cuff tubing is then brought up anteriorly. The balloon  is placed in the superior prevesical space. Pressurization of the cuff is  identical to the bulbous urethra technique. The tubings of the balloon  (same choice as the bulbous urethral technique) and of the cuff are  brought out of the prevesical space at the midline. The rectus muscles  are approximated loosely at the midline and the rectus fascia closed by  heavy absorbable sutures. The pump is then inserted, usually into the    right hemiscrotum (same technique as the bulbous urethral insertion)  and connections made over the rectus fascia avoiding any redundancy  of the tubing.   For a bulbous urethral placement, a midline perineal incision is made  over the bulbous urethra, which is dissected just distal to the bulbocav-  ernosus muscle (see Fig. 5). The cuff is not positioned at the bulbocay-  ernosus muscle for several reasons. First, the muscle atrophies over time  causing the cuff to loosen. Second, if the muscle is divided and the cuff  placed beneath the bulbocavernosus muscle, contraction of the bulb-  ocavernosus muscle may cause the cuff to act erratically. Third, the more  distal position of the cuff will prevent compression of the device while the  patient is sitting, thereby reducing inadvertent opening of the cuff, and  theoretically, decreasing the likelihood of atrophy and erosion. A 2-cm  length of urethra must be dissected so that the cuff passes easily around  the urethra (see Fig. 6). Care must be taken to prevent entering the tunica  of the corpora spongiosum during the dissection to prevent significant  bleeding and urethral injury. Once the urethra is dissected circumferen-  tially, the proper size cuff needs to be determined. A measuring device  is included in the AUS kit, which allows one to determine cuff size. The    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 273    Fig. 7. Suprapubic incision to create a space for the balloon in the prevesical  space behind the rectus muscle.    cuff should not be too snug, especially if the patient has had previous  radiation therapy. The most common cuff size used in the male urethra  is 4.5 cm. An antibiotic-soaked gauze is placed in this perineal incision  while the abdominal incision is made.   Next, a pocket is created for the balloon reservoir by making a small  transverse skin incision approx two-finger breadths above the pubic  symphysis. The rectus fascia is incised and the rectus muscle is open at  its midline. A space is created behind the rectus muscle in the perivesical  area (see Figs. 7 and 8). Many of these men have had previous radical  prostatectomies and this area may be scarred. Creating the space more  cephalad along the rectus muscle will often lead to easier dissection of  the perivesical space. The pocket created should be of sufficient size to  prevent undo pressure on the balloon reservoir. The most common bal-  loon size is 61—70 cm H,O. In patients who have had radiation therapy  or advanced diabetes, we use a 51-60 cm H,O balloon. An antibiotic-  soaked gauze is placed in this space while the sphincter is prepared.   The pump along with the proper size cuff and balloon is opened and  placed in antibiotic solution. It is imperative to remove all air from the   e Cysto-Conray-II: dilute 60 cm” with 15 cm® sterile water  e Urovist cysto: dilute 50 cm” with 50 cm’ sterile water    system to prevent an airlock. This is accomplished by instilling an iso-  tonic contrast solution composed of 50 cm? of 25% hypaque mixed with  60 cm? of sterile water. Other filling solutions can be used in the artifi-  cial sphincter (see Table 1). Patients with an iodine allergy should have  the device filled with normal saline. The solution is instilled into the cuff  and balloon using a syringe fitted with adapters designed to insert into  the prosthesis tubing. With gentle tapping and aspiration, the air is  removed. After removal of the air, the tubing to each device is clamped  with rubber shod hemostats to prevent damage and leakage. The balloon  is instilled with 22 cm? of contrast solution and the tubing clamped. The  cuff is left empty and free of air. The pump is filled with fluid by squeez-  ing it with both the inflow and outflow tubing in the solution. Once full  and free of air, both tubes are clamped with rubber shod hemostats.   Next, the balloon is placed in the previously created pocket in the  perivesical space. The pocket should be of sufficient size to be certain  no pressure is placed upon the balloon. The rectus muscle and rectus  fascia are closed and the tubing is brought out the midportion of the  suture line.   A right-angle clamp is then passed around the previously dissected  urethra. The cuff, empty of fluid or air is passed around the urethra and  the tab is secured over the cuff button. The tab at the end of the cuff is  trimmed so as not to protrude. The cuff is placed so that the tubing from the  cuff is positioned to the left side (see Figs. 6 and 8). Next, a hemostat or  tubing passer is passed anterior to the rectus fascia in the subcutaneous  tissue, along the left inguinal region, and punctures through the tissue  along the left side of the bulbous urethra at the level of the cuff. The  tubing from the cuff is brought through this tunnel and externalized  above the rectus fascia. A rubber shod is once again placed on the end  of the tubing (see Fig. 8). Next, the cuff must be calibrated. To do this,  the bladder is filled with irrigating fluid and the Foley catheter is  removed. A temporary connection is made between the balloon filled  with 22 cm? of isotonic fluid and the empty cuff. Prior to making any  connection, fluid should be instilled in the end of each tubing to remove    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 275    Fig. 8. Cuff tubing is routed to the left side to meet the tubing from the right-  sided pump placement for easy non-angulated connection.    the small amount of air that accumulates in this region. The rubber shods  are removed and fluid is allowed to flow into the cuff. The cuff is  visualized to inflate and compress the urethra. Continence may be tested  at this point by manually compressing the bladder with the cuff full and  empty. The tubing is once again clamped and a syringe is used to aspi-  rate and measure the amount of fluid in the cuff. The Foley catheter is  then replaced. The fluid in the balloon reservoir is then adjusted for a  final volume that equals 20 cm? plus the volume held by the cuff.  The pump is then placed by passing a large clamp anterior to the rectus  fascia on the right and into the scrotum (see Fig. 9A). The jaws of the  clamp are opened and the clamp withdrawn. The pump is then placed  within this space and “milked” down into a dependent anterior scrotal  position, just beneath the dartos fascia (see Fig. 9B). Once the pump is in    Fig. 9. (A) Clamp into the right anterior hemiscrotum. (B) Pump “milked”  down into the anterior compartment of the right hemiscrotum.    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 277    position, it is held in place by placing a babcock clamp on the scrotum,  around the tubing.   The next goal is to complete the connections. The pump has two tubes  distinct from each other but similar to the reservoir and cuff tubing (Fig. 10).  Similar tubes connect to each other. Straight connectors along with a  crimping tool are used to complete the connection. Itis important to trim  the tubing so that there is minimal redundancy, decreasing the likeli-  hood of kinking. Itis necessary to keep the tubing clamped with a rubber  shod proximal to the area to be trimmed. Connections are made after  removing the air at the end of the tubing by instilling isotonic solution.  The integrity of the connection should be determined by gently pulling  on the tubing after making the connections. The tubing is covered with  tissue by approximating Scarpa’s facia over the tubing.   Once the connections are complete, the rubber shod clamps are removed  and the system is allowed to cycle. The system is tested by compressing    the pump several times forcing fluid from the cuff to the reservoir. The  cuff can be observed to deflate and fill. After the system is tested, one  must lock the sphincter in the open position with the cuff deflated. By  deactivating the sphincter with the cuff open, the urethra heals as vas-  cularity is not compressed by the cuff. The deactivation period is 6 wk.  The technique for deactivating the sphincter is important to prevent  malfunction of the sphincter. When the pump is compressed, fluid is  first forced out of the pump and then out of the cuff. When the system  cycles, fluid returns to the pump first followed by the cuff. A button is  on the side of the pump, which deactivates the sphincter. This button  should be compressed when fluid returns to the pump, but prior to filling  of the cuff. If the sphincter is deactivated with the pump empty of fluid,  it will make reactivation difficult because it relies on forcing fluid  through the valve lock to activate the sphincter. Next, the incisions are  closed in the usual fashion and sterile dressings are applied.    Because the artificial sphincter is a prosthetic device, the patient who  receives an AUS and the physician who implants it must be committed  postoperatively to regular follow-up and care. Both must also be willing  to deal with potential infections and mechanical problems that can arise  and accept the possibility that reoperations may be required.   Our postoperative care routine begins in the operating room soon  after the device is implanted. The device is tested while the patientis still  under the anesthetic. Once successful cycling has been accomplished,  the cuff is opened. The pump is allowed to refill until a slight dimpling  is palpable, and then the device is deactivated. If the device is deacti-  vated immediately after opening, the cuff reactivation may be extremely  difficult, in that some fluid is needed in the pump to unseat the poppet  used to deactivate the cuff. The patient is then taken from the operating  room with a Foley catheter that remains for 24 h.   After removal of the Foley catheter, the patient is again incontinent  because the sphincter is deactivated in the open position. All patients are  aware of this preoperatively. Our patients remain in the hospital overnight  to receive intravenous antibiotics and on discharge are orally maintained  on7 dofantibiotics. During the patient’ s stay, the abdominal (and perineal)  wounds are inspected and the pump position is checked. Patients are  instructed as to pump position and encouraged to check position at least  once daily and apply light traction as needed. We believe that this may  help maintain pump position during scarring and healing and also help get  the patient familiar with manipulating the device.    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 279    At 6 wk postoperatively, the patient returns for a follow-up exam and  pump activation. At this time, the patient is re-instructed on the use of  the device and given a trial run. If a patient can successfully use the  device, he or she is followed regularly (or more frequently if problems  arise) at least once a year.    1. Cannot activate sphincter: The most common cause preventing sphinc-  ter activation is the sphincter being deactivated with insufficient fluid  in the pump. We generally allow the pump to refill to a point where a  shallow dimple is palpable before deactivating the device. This will  assure sufficient fluid in the pump to release the poppet valve and allow  free flow through the system. Engaging the poppet valve with insuffi-  cient fluid in the pump can be a difficult problem because the sphincter  relies on forcing the fluid within the pump past the poppet valve by  sharply squeezing the pump. One can feel a “pop” when the valve  opens. The first maneuver to overcome this problem is to stabilize the  pump and squeeze forcibly over the entire surface of the pump. This  may create enough pressure in the system to open the valve. If this is  not successful, the following maneuver can be performed: Above the  actual pump mechanism is a hardened silicone case in which the deac-  tivation button is located. One can squeeze forcibly on the narrow sides  of this silicone case 90° from the button. Squeezing this area will  distort the control valve allowing fluid to flow into the pump facilitat-  ing activation. In rare instances, operative intervention is needed to  replace the pump mechanism.   2. Inability to squeeze pump: Pump failure is most often caused by  obstruction of fluid flow by debris, airlock, blood, or crystals from the  contrast solution or antibiotics. Another cause is kinking of the tubing.  Prevention is the best treatment for this problem. It is imperative to be  certain that the system is free of air and that blood or tissue debris are  not introduced within the system. To prevent kinking, the tubing should  be trimmed so that there is minimal redundancy. The likelihood of  kinking has been decreased with the introduction of kink-resistant tub-  ing by the manufacturer This complication is rare and treated by  replacement of the affected parts.   3. Urinary retention: When urinary retention in the immediate postopera-  tive period occurs, one must immediately rule out an activated system  caused by an inflated cuff. Thus, one should cycle the sphincter and  deactivate the device with the cuff empty. Immediate bladder empty-  ing should occur. If urinary retention persists, a pelvic X-ray should be  performed to assess the cuff. If contrast is found to be filling the cuff,  this may suggest a malfunction of the sphincter. If the sphincter is    cycled and the cuff remains inflated, in spite of being deactivated in the  open position, the pump needs to be replaced as the pump mechanism  is probably defective. Second, the cuff may be too tight or there may  be significant postoperative edema in the periurethral area causing  retention. This can be assessed with flexible urethroscopy to assess the  area compressed by the cuff. In the female, retention can be managed  with intermittent catheterization with the device deactivated to allow  time for the edema to resolve. In our experience, male retention rarely  resolves and is usually secondary to a small cuff. Thus in the male, we  recommend immediate replacement of the cuff with a larger size to  prevent urethral damage from compression. Urinary retention occur-  ring as a late complication may be due to inadvertent deactivation with  the cuff closed, inflammation and edema from infection or erosion, or  in men with recurrent bladder neck contracture. The patient must be  seen immediately and evaluated. Ifan indwelling Foley must be inserted,  the cuff must be deactivated in an open position.   4. Urinary incontinence: Incontinence immediately after the sphincter is  activated may be secondary to a large cuff, low cuff filling pressure,  leak in system, detrusor instability, or malfunction of sphincter. A  pelvic X-ray should be performed with the cuff in the activated and  deactivated state to be certain that the cuff fills and empties appropri-  ately. The film can also demonstrate an empty or partially filled bal-  loon suggesting a leak within the system. If a leak is demonstrated or  suspected, surgical repair should be undertaken. Only the affected  component needs replaced and the revised sphincter should be tested  prior to leaving the operating room. Another source of error can occur  when filling the balloon reservoir and calibrating the system. The res-  ervoir for a 61-70 cm H,O balloon should have 20 cm? of fluid, plus  the amount of fluid held by the cuff.   Leakage occurring after continence was achieved may be secondary  to mechanical failure, erosion, urethral atrophy, or detrusor instability.  Urodynamics can be performed to rule out detrusor instability. If detru-  sor instability is identified, this can be treated with anticholinergic  medication. A retrograde urethral pressure profile can be performed to  ascertain the resistance at the level of the sphincter. The maximum  pressure to break through the urethra at the level of the cuff should be  equal to the balloon pressure. When the cuff pressure is inadequate as  in leakage or atrophy, the maximum breakthrough pressure is lower  than the balloon pressure. Cystoscopy with the cuff empty can identify  erosion and ischemia. If secondary to erosion, the cuff should be  removed and a catheter placed until the urethra heals. If secondary to  atrophy, several options exist. One can increase the balloon pressure to  71-80 cm of water. However, this maneuver does not consistently  improve continence and may lead to erosion. A smaller cuff can be    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 281    placed, and this may be areasonable option in the female, but in the male  the smallest cuff size is 4.0 cm and this may not resolve the inconti-  nence. The two best options in the male are to place a new cuff ina more  proximal position, at the level of the bulbocavernosus muscle (/3).  This has been shown to be effective. Second, two cuffs can be placed  along the urethra doubling the surface area compressed, increasing  resistance, without diminishing tissue perfusion (/4).   5. Infection: Infection is a devastating complication of the AUS and most  often leads to removal of the device. The infection rate has been reported  to be as high as 16%; however, 1—3% is currently the most common  incidence (/5),exceptin patients who had radiation therapy preimplant,  where the reported infection rate is 10% (16). The infection is usually  in the early postoperative period and is thought to occur secondary to  seeding of the prosthesis at the time of surgery. The most common  organism is Staphylococcus epidermidis. Delayed infection may be  secondary to hematogenous spread from other sources such as geni-  tourinary or dental infections. Infection usually presents as erythema  or induration at the prosthetic site. The scrotum or labia is the most  common site of infection. The overlying skin can become thinned and  the pump can erode through. Urethroscopy should be performed to rule  out cuff erosion. Early infections may not be associated with fever or  leukocytosis and patients should be made aware of subtle signs of  infection. A patient found to have an infection should be admitted to the  hospital and receive broad spectrum antibiotics with good gram posi-  tive coverage. On occasion, a sphincter can be salvaged with antibiot-  ics, however, most often the device needs to be removed. A new  sphincter can be placed 3—6 mo after removal of the device and reso-  lution of the infection. Prevention is the most important defense against  infections. Diabetics should have their blood sugar well controlled.  The incidence of prosthetic infections have been reported to be higher  if the sphincter was placed concomitantly with bowel reconstruction of  the bladder. Thus, a staged procedure should be performed. Appropri-  ate preoperative and postoperative antibiotics need to be administered.  Identification and eradication of bacterial infections 1-2 wk prior to  sphincter placement must occur in patients on intermittent catheteriza-  tion. An aggressive surgical scrub needs to be performed and the device  should be soaked in antibiotic solution and the incisions aggressively  irrigated with antibiotic solution prior to inserting the prosthesis.   6. Erosion: Erosion of the cuff through the urethra has a reported inci-  dence of 0-19%. Since the introduction of delayed activation, the cur-  rent erosion rate is 1-3% (15,17). Erosion may be caused by infection,  decreased vascularity secondary to radiation changes, increased cuff  pressure, undersized cuff, and catheterization through a closed sphinc-  ter. Erosions manifest as perineal pain, urethral discharge or bleeding,    hematuria, irritative voiding symptoms or new onset incontinence. A  common cause of erosion is a result of placement of a Foley catheter  with the sphincter in the closed position. This leads to compression of  the urethra between the catheter and the cuff, which may lead to ero-  sion. Itis imperative that a urologist knowledgeable in artificial sphinc-  ters cycle and lock the sphincter in the open position when an indwelling  Foley is placed. Patients are encouraged to carry a medical card stating  they have an AUS or to wear an Medic-alert bracelet in the event of an  emergency. Diagnosis of erosion is made by urethroscopy. Treatment  involves removal of the cuff and placement of a urethral catheter for  approx 3 wk. A retrograde urethrogram is performed prior to catheter  removal to be certain that the urethra is healed. A new cuff can be  placed at a different site usually after 3 mo. Once again, prevention is  important. The cuff size should be appropriate. If the patient has had  previous radiation therapy a 51—60 cm H,O balloon should be placed  to decrease the pressure on the urethra. In addition, delaying activation  of the sphincter for 6 wk can decrease the likelihood of erosion. Patients  who are at risk or who have a history of erosion should be instructed  to deactivate the sphincter at night and wear a pad for leakage. This  diminishes the amount of time the urethra is compressed, allowing for  increased blood flow to the urethra. In addition, if a catheter needs to  be placed (i.e., for other surgical procedures), the sphincter needs to be  deactivated to prevent compression of the urethra between the cuff and  catheter.    Since the development of the AMS sphincter in 1973, numerous  modifications of the device and insertion techniques have gradually  improved the effectiveness of the AUS and reduced the reoperation and  complication rates.   By far and away, most experience has been accumulated on adult males  in whom the AUS has been implanted for the problem of intrinsic sphinc-  ter deficiency. Generally, male type III stress urinary incontinence occurs  after prostatectomy, and results with the AUS in this group have been very  successful. In 1988, Marks and Light reported on 37 patients, 95% of  whom achieved socially acceptable levels of incontinence and 81% of  whom were completely dry (/7). This group suffered three erosions  (9%) and two infections (5%) and required four revisions (11%) (20).  Gundian et al. from the Mayo Clinic reported on their experience with  96 patients, 83% of whom had incontinence requiring =2 pads/day. This  group of patients also reported a 90% satisfaction rate (/5). Finally,    Chapter 17 / AUS for Treatment of Male Urinary Incontinence 283    Malloy et al. reported a 76% complete continence rate in 42 males in  whom the AMS800 device was implanted (78). We have met with simi-  lar success upon review of our long-term data (>2 yr) with insertion of  the AMS800 AUS.    Clearly the use of the AUS should be part of the armamentarium in  the management of refractory incontinence caused by intrinsic sphinc-  ter deficiency for every urologist. The current device, the AMS800, has  proved successful and effective in the short and long term. Meticulous  care in the patient workup preoperatively and during insertion is neces-  sary, however, if maximum success is to be met. Proper indications for  insertion are type II urinary incontinence caused by intrinsic sphincter  deficiency. This should be well documented with endoscopic, uro-  dynamic, or video fluoroscopic evaluation. All patients and their fami-  lies should be well educated about potential outcomes and problems,  particularly given that the device is a prosthesis. Before implantation,  the patient’s ability to use the sphincter from a physical and motiva-  tional standpoint should be thoroughly assessed.   Because of the risks for infection, erosion and mechanical malfunc-  tion, extreme attention to detail and meticulous surgical technique are  required during insertion. Finally, to meet with continued success after  insertion, the patients must be monitored closely as long as the device  is in place. Patients and physicians should be aware of signs of potential  problems, changes in voiding habits, or signs of voiding dysfunction or  infection. We also recommend that they carry a medical identification  card to identify them as having an AUS in case of an emergency. If a  catheter is to be placed, the device should first be deactivated, and if the  patient undergoes any abdominal surgery, a urologist with knowledge  of AUS insertion and function should be available to assist in patient  circumoperative management. With careful preoperative evaluation,  intraoperative technique, and postoperative follow-up, problems can be  dealt with effectively if they arise, and incontinent patients can achieve  a significant improvement in their quality of life.    1. Foley FB (1947) An artificial urinary sphincter. J Urol 50:250.   2. Scott FB, Bradley WE, Timm GW (1973) Treatment of urinary incontinence by  implantable prosthetic sphincter. Urology 1:252.   3. Diokno AC, Taub ME (1976) Experience with the artificial urinary sphincter at  Michigan. J Urol 116:496.   4. Furlow WL (1981) Implantation of a new semiautomatic artificial genitourinary  sphincter: experience with primary activation and deactivation in 47 patients.  J Urol 126:741.    . Light JK (1985) The artificial urinary sphincter in children. Urol Clin North Am    . Mundy AR (1991) Artificial urinary sphincters. Br J Urol 67:225.  . Scott FB, et al. (1981) Implantation of an artificial urinary sphincter for urinary    . Diokno AC, Sonda LP (1981) Compatibility of genitourinary prostheses and    . Gonzalez R, Nguyen DH, Kolielat N, Sidi AA (1989) Compatibility of    . Schmidt RA, Jonas U, Oleson KA, et al (1999) Sacral nerve stimulation for    . Belloli G, Campobasso P, Mercurella A (1992) Neuropathic urinary inconti-    nence in pediatric patients: management with artificial sphincters. J Pediatr  Surg 27:1461.    . Couillard DR, Vapnek JM, Stone AR (1994) Proximal artificial sphincter cuff    . Brito CG, Mulcahy JJ, Mitchell ME, et al. (1993) Use of a double cuff AMS 800    . Gundian JC, Barrett DM, Parulkar BG (1989) Mayo Clinic experience with use    of the AMS800 artificial urinary sphincter for urinary incontinence following  radical prostatectomy. J Urol 142:1459.    . Martins FE, Boyd SD (1995) Artificial urinary sphincter in patients following    major pelvic surgery and/or radiotherapy: are they less favorable candidates.  J Urol 153:1188-1193.   Marks JL, Light JK (1989) Management of urinary incontinence after prostate-  ctomy with the artificial urinary sphincter. J Urol 142:302.   Malloy TR, Wein AJ, Carpiniello VL (1989) Surgical success with AMS M800  GU sphincter for male incontinence. Urology 33:274.    Urinary incontinence (UI), defined as the involuntary leakage of urine  sufficient to be a problem, afflicts approx 13 to 14 million Americans  and, according to the National Institute of Diabetes and Digestive and  Kidney Diseases (NIDDK), 11 million of them are women. One half of  the residents of nursing homes are incontinent. In 1995, Americans  spent approx $27.8 billion on the management of UI. Based on NIDDK  statistics, the average patient with UI spent $3941 annually on the  problem.   Among the various therapies available for management of UI, are use  of pharmacological agents, bladder retraining, and surgical procedures,  such as cystourethropexies, sling procedures, or injection of bulking    From: Urologic Prostheses:  The Complete, Practical Guide to Devices, Their Implantation and Patient Follow Up  Edited by: C. C. Carson © Humana Press Inc., Totowa, NJ    agents. In patients who have failed conventional treatments, the artifi-  cial urinary sphincter (AUS) is a reasonable alternative.   In 1973, F. Brantley Scott, along with Dr. Bradley and Dr. Timm,  developed and implanted the first AUS. Since then, approx 3000 AUS  devices have been implanted. American Medical Systems, the corpora-  tion that manufactures the device has made many improvements in its  components and quality. The 800 model was first introduced in 1979,  has undergone several modifications including introduction of kink-  proof tubing and a more efficient and resilient narrow back cuff. Two-  hundred and thirty-nine females have undergone implantation of the  AUS by the authors since 1973. Of these, 108 received the earlier models  (AUS 791/792) and 68 received the AS 800. The majority of these patients  suffered from urethral sphincter incompetence of varying etiologies includ-  ing myelomeningocoele, pelvic floor weakness with stress incontinence,  and neurogenic bladders. In all of them, more conservative attempts at  restoring continence had failed. Many other centers have used the AUS  for treatment of urinary incontinence in females. In this chapter, the  authors will review their and other’s experience with this device.    The basic objective of the AUS is to provide patients with dynamic  control of the resistance to the bladder outflow as opposed to simply  obstructing the outlet as with a sling procedure or with collagen injec-  tion. The latest device is the American Medical System AS 800 (see  Fig. 1), which consists of three components made of medical-grade  silicon: an occlusive cuff of variable length positioned around the blad-  der neck, a pump with a locking mechanism placed inside the labia  majora, as well as a dip coated pressure control balloon implanted in the  paravesical space (see Fig. 2). All of these components are intercon-  nected with nylon-reinforced nonkinking silicon tubing. The system is  filled with either normal saline or, preferably, an isotonic contrast solu-  tion that allows visualization of the device on X-ray. Normally, the  device is in a closed position with the cuff inflated and uniformly com-  pressing the bladder neck and proximal urethra. When the patient needs  to urinate, she compresses the labial pump, which transfers fluid from  the cuff to the balloon thereby permitting urine outflow.   The 2.0-cm-wide occlusive cuff is a longitudinal silicon balloon that  incorporates a narrower (1.7 cm) outside Dacron layer with a snap-like  closure. It is available in various lengths from 4.0 cm to 11.0 cm. The  narrower backing improves the efficiency of the cuff and decreases  the incidence of tissue pressure atrophy. An additional internal coating    Fig. 1. American Medical System AS 800 (used with permission from Ameri-  can Medical Systems, Inc., Minnetonka, MN).    of a silicon material improves the pliability and the decreases the wear  at the fold sites of the cuff.   The pressure-regulating balloon is available in variable pressure  spectrums, ranging from 51-60 cm H,O to 81-90 H,O, allowing the  surgeon to determine the most appropriate pressure for the individual  patient. Itis implanted intraabdominally, adjacent to the bladder, so that  the same abdominal pressures that are exerted on the bladder are also  impacting on the balloon and thereby transferred to the cuff, preventing  stress leakage. The balloon is connected to the pump via reinforced  silicon tubing.   The pump, which is positioned in the labia majora, consists of the  pumping chamber and an ingenious control assembly that has a unique  resistor and valve systems that assure delayed refill of the cuff as well    as instantaneous transfer of pressures from the balloon to the cuff. In  addition, the control assembly pump has a button that allows the cuff to  be locked in either an open or closed position. Locking the cuff in an  open position minimizes the risk of injury to the urethra during catheter-  ization or other manipulations. These new features of the AUS have  improved the reliability of the device.    Females with UI of multiple etiologies are potential candidates for  the AUS implant. Among these are women (or young girls) with neuro-  genic bladders caused by myelomeningocoele, sacral agenesis, spinal  trauma, or peripheral neuropathies and women with stress incontinence  that has not responded to more conservative measures. The typical patient  is a woman who has adequate bladder compliance and capacity, but  whose bladder neck and urethral sphincter are nonocclusive as in Type IH  stress incontinence.   Potential candidates for the AUS are evaluated with a comprehensive  history and physical exam, as well as with extensive urodynamic test-  ing, which includes simultaneous pressure flow and EMG studies, void-  ing cystourethrography, and cystoscopy. The physician should seek out    evidence for bladder instability or urgency, previous urological and/or  gynecological surgery, symptoms of neurological disorders (e.g., mul-  tiple sclerosis or peripheral neuropathies), and history of recurrent uri-  nary tract infections. Bladder compliance and associated capacity should  be adequate to make the patient socially continent with the bladder neck  closed. In some women with small bladder capacity or poor compliance  despite anticholinergic medication, implantation of the AUS has resulted in  increased bladder capacity. However, if there is persistent elevated intra-  vesical pressure with small bladder capacity, augmentation cystoplasty  should be seriously considered. Patients with evidence of outflow obstruc-  tion as a result of detrusor sphincter dyssynergia or anatomical obstruction  are treated with a bladder flap urethroplasty at the time of AUS implantation  or are managed with intermittent self-catheterization postoperatively. If  intermittent catheterization will be required postoperatively, then the patient  should be properly prepared preoperatively with instruction in the proper  technique for clean intermittent self-catheterization.   In addition, a careful evaluation of the patient’ s past surgical or pelvic  trauma is essential so that any scarring may be anticipated, especially in  the area of the urethral vaginal septum. Pretreatment of postmenopausal  women with estrogen cream will usually make the vaginal tissues more  supple and resilient. The patient is apprised of the risk of the surgery and  the possibility of device failure at any time subsequent to the surgery.  Patients must be highly motivated to have the surgery, and they must  have the manual dexterity as well as the mental competence and initia-  tive to operate the device. Young girls who refuse to pump the device  in order to urinate may cause significant deterioration of their renal  function. The surgeon and patient must accept the fact that the patient  will have to be followed regularly (at least annually) to assure stability  of renal function. In addition, should the patient require abdominal or  pelvic surgery in the future, she should apprise her urologist so that  accidental injury to the device can be avoided.    Two surgical approaches have evolved for implantation of the AUS.  The main difference concerns the implantation of the cuff. The original  technique described by Scott was a retropubic approach . The alter-  native approach is transvaginal dissection of a track around the urethra  for cuff placement in combination with a suprapubic inguinal incision  for placement of the other components (2).   In either case, the patient’s urine must be sterile and she must be prop-  erly prepared. The patient is shaved in the operating room immediately    prior to the 10-min preparation of both the abdomen and the vagina.  Surgery should not proceed if there are any open lesions in the surgical  field. The patient is usually given a loading dose of a broad-spectrum  antibiotic 1 h before surgery. Traffic in the operating room is mini-  mized, and the surgical team wear surgical hoods to decrease possibility  of shedding into the wound.   The positioning of the sphincter cuff is the most challenging part of  the operation. The plane between the bladder neck and the vagina is not  very distinct, even in females who previously have not had surgery in  that area. Patients who have undergone multiple conventional anti-  incontinence procedures and young girls who have had bladder neck  reconstruction offer the surgeon very few anatomic landmarks to work  with. Two basic approaches have been advocated for implantation of the  cuff. The original approach, as described by Scott was retropubic. More  recently, a transvaginal perineal approach has been advocated.   The patient is placed in a lithotomy position with thighs parallel to her  abdomen in order to maximize working area for the surgeon and the  assistants. In addition, this position makes feasible an intraoperative  cystoscopy to evaluate urethral patency. A 10-min surgical scrub of  both the abdomen and the vagina is performed.   In the abdominal approach, the retropubic space is entered via a  Cherney incision that transects both rectus muscles and optimizes pel-  vic exposure (see Fig. 3). The pelvic fascia is incised on either side of  the bladder neck. The latter is usually well defined with the help of an  intravesical Foley catheter balloon, but if there is any doubt about the  anatomy because of extensive local scarring, the bladder is opened from  above to facilitate visualization of the bladder neck and the ureteral  orifices. Bilateral blunt and careful sharp dissection with angled scis-  sors with simultaneous transvaginal palpation allows one to develop a  space through the proximal urethrovaginal septum. An instrument that  was developed specifically to expedite this portion of the operation is  the Cutter clamp, which consists of two hollow detachable arms that fit  together at the level of a clamp proximally and at the distal curved ends.  The latter are configured into male and female tips that fit together.  Once the endopelvic fascia is incised and the bladder neck is identified,  the clamp is positioned in the area of the proposed cuff site (see Fig. 4).  The arms are tightened in the clamp, and cystoscopy as well as vaginal  examination allows the surgeon to rule out entrapment of excess tissue  of either the bladder or vagina. Appropriate adjustments can then be  made. Once it is determined that the correct plane has been chosen a  cutting blade is advanced from the male clamp into the hollow of the  female end, thereby cutting through the urethral vaginal plane (see Fig. 5).    The female arm is then unclamped and removed to expose the cutting  blade. A 1-0 polypropylene suture is advanced through a hole in the  blade and the latter is then gently removed, pulling the attached suture  through this newly created space. A right-angle clamp is then attached  to the suture and is gently guided along the new track. The space is  carefully stretched to approx 2 cm to accommodate a cuff.   The cuff length is determined by measuring the loose circumference  around the bladder neck with a cuff sizer. The cuff is then positioned in  this space and snapped closed. Care must be exercised to avoid twisting  of the cuff in the course of positioning it around the bladder neck. The  length of the BN cuff ranges from 6—10 cm. The pressure-regulating  balloon is then implanted in a paravesical space, assuring that there is  no contact between it and the cuff. Rubbing of two silicon components  can ultimately lead to thinning of the silicon and leakage. The pressure  range of the balloon that is selected is determined on the basis of a    Fig. 4. Use of Cutter Clamp for implantation of AUS cuff.    variety of factors including the quality and vascular supply of the blad-  der neck, the intravesical pressures, and whether there was a past history  of pelvic radiation. If there is evidence of poor tissue quality, then a  lower pressure balloon is selected (51—60 cm H,O). Otherwise, higher  pressure balloons can be used. The balloon is filled with a volume of  either saline or isotonic contrast material equal to 16 cm? plus the vol-  ume in the cuff, usually a minimal volume of 21 cm?. The balloon and  cuff tubings are brought through the abdominal muscles and fascia in  order to help fix them in place. The deactivation pump is advanced into  a space created in one of the labia majora with the help of an extended  nasal speculum. The latter minimizes local trauma by bluntly dissecting  a pouch for the pump. After the balloon is filled with an appropriate  amount of saline or contrast-plus-water solution, the redundant tubing  is amputated and Quick connectors are used to connect the appropriate  tubes. Great care must be taken to keep any blood products from getting  into the system because the resultant fibrinoid material will clog the  valves or resistors resulting in a malfunction. The wounds are then  checked for hemostasis, irrigated with copious amounts of antibiotic  solution, and closed securely in multiple layers. Drains are avoided to    Fig. 5. Use of Cutter Clamp for implantation of AUS cuff.    minimize the risk of infection. The cuff is left deactivated for approx  4—6 wk. An X-ray of the lower abdomen is taken on the first post-  operative day in order to document the location of the various compo-  nents and their size. If, in the course of the cuff placement, the urethra  or bladder was entered, the longer deactivation period may better allow  for adequate healing. The patient is prescribed broad-spectrum antibi-  otics for approximately 10 d post-op. An icepack to the perineum mini-  mizes local pain and decreases swelling. 
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