(due to a patent processus Evaluation Examine the scrotum and inguinal region to elucidate if a testis is palpable and to identify its location. Retractile testes may be brought back down into the bottom of th e scrotum without tension. Assess for associated congenital defects. If neither testis is p alpable, consider chromosome analysis (to exclude an androgenized female) and endocrine ana lysis (high LH and FSH with a low testosterone indicates anorchia, con \201 rmed with seru m inhibin B). For the impalpable testis, USS is of limited use. Most proceed directly to ex amination under anesthetic diagnostic laparos- copy and treatment. Treatment - Inguinal old. Surgery consists of inguinal exploration, mobilization of spermat ic cord, ligation of processus vaginalis, and securing the testis into a dartos pouch in th e scrotal wall. Risks include testicular atrophy (5%), damage to vas (1 \200\2232%), and re -ascent of the testis. Intra-abdominal testes the testis for orchidopexy as a single or 2-s tage (Fowler \200\223Stephens) procedure. The Fowler \200\223Stephens approach involves ini tial clipping or division of spermatic vessels to provide extra length (the testis then rel ies on collateral blood \202 ow from the vas). Six months later, the testis is then mobil ized on its vas with its new collateral vessels and brought down into the scrotum. Success rates are 785%. Intra-abdominal testes with a short vas may need microvascular autotranspla ntation. This involves high intra-abdominal ligation of the spermatic vessels, the testis i s brought down into the scrotum, and the vessels are re-anastomosed to the inferior epigast ric vessels. Small, atrophic intra-abdominal testes (nubbin) require orchidectomy 9 orchido pexy of the contralateral normally descended testis. UDT: is treated with orchidopexy between 6 \200\22318 months : require a laparoscopic approach to mobilize Overall success rates of orchidopexy vary according to position of the UDT: 92% for inguina l testes, 87% for canalicular testes, and 74% for abdominal testes.3 CHAPTER 16 Pediatric urology 652 Deep inguinal ring Superficial inguinal ring Superficial inguinal pouch Pubic Pubic symphysis Femoral Perineal Normal (a) Abdominal Canalicular Emergent Normal (b) Fig. 16.4 (a) Ectopic sites for the undescended testis; (b) Incomplete descent of the testi s (Reproduced with permission from Taylor & Francis Books, UK). 1 Hack WW, Sijstermans K, van Dijk J, et al. (2007) Prevalence of acquired undescended test is in 6-year, 9-year and 13-year-old Dutch schoolboys. Arch Dis Child;92:17 \200\22320. 2 Brewster S, Cranston D, Noble J, Reynard J (2001) Urology a Handbook for Students. BIOS S cienti \201 c Publishers Limited. 3 Docimo SG (1995) The results of surgery for cryptorchidism: a literature review and analy sis. J Urol 154:1148 \200\22352. This page intentionally left blank CHAPTER 16 Pediatric urology 654 Urinary tract infection (UTI) De \201 nitions: UTI is a bacterial infection of the urine, which may involve the lower ur inary tract/bladder (cystitis) or upper urinary tract/kidney (pyelonephritis) (see b p. 176 ). Classi \201 cation: children may be asymptomatic or symptomatic. Simple UTI: presents with mild dehydration and pyrexia. Severe UTI: presents as fever \211 38 C, unwell, vomiting, with moderate to severe dehydration. Atypical UTI: includes features of serious illness/septicaemia, poor urinary \202 ow, abn ormal renal function, failure to respond to treatment in <48h, and non-E. coli infection. Recurrent UTI: in children, describes either one episode of cystitis with one episode of py elonephritis, \211 2 episodes of pyelonephritis, or \211 3 epi- sodes of cystitis. It may be due to bacterial persistence, unresolved infec- tion, or re-infection. Incidence: up to age 1, the incidence in boys is higher than girls (male: female ratio is 3 :1), but thereafter, the incidence in girls becomes greater (school age males 1%; females 3 %). Pathology: common bacterial pathogens are E. coli, Enterococcus, Pseudomonas, Klebsiella, P roteus, and S. epidermidis. Bacteria enter via the urethra to cause cystitis and ascending infection causes pyelonephritis. Alternatively, there can be haematogenous spread from othe r systemic infections. Risk factors - Age periurethral area and an immature immune system. VUR Previous Genitourinary abnormaliti es ureterocele, posterior urethral valves, labial adhesions. Voiding dysfunction emptying. Gender Foreskin \201 rst year due to bacterial colonization of the glans and foreskin. Fe cal colonization . Chronic constipation : neonates and infants have increased bacterial colonization of the - (see b p. 662). UTI. : pelvi- or vesicoureteric obstruction, : abnormal bladder activity, compliance or : female > male after 1y old. : uncircumcised boys have a 10-fold higher risk of UTI in the : contributes to perineal bacterial colonization. Presentation - Neonates and infants: poor feeding, failure to thrive, abdominal pain, offensive urine, hae maturia. Children: dif \201 culties, changes to continence, abdominal or \202 ank pain, haematuria. fever, irritability, vomiting, lethargy, diarrhea, fever, nausea, suprapubic pain, dysuria, frequency, voiding URINARY TRACT INFECTION (UTI) 655 Investigation Urine analysis and culture: advised with unexplained fever \211 38 C or if symptomatic of UTI. Clean catch specimen where possible. In toilet- trained children, an MS U specimen is considered diagnostic with \211 105 colony-forming units (CFU)/mL in asympto matic children and \211 104CFU/ mL if symptomatic. In young children, a catheterized urine specimen with \211 10CFU/mL) of one pathogen or a suprapubic aspirate with \211 102CFU/m L are diagnostic of UTI. Collection bag specimens are less reliable due to skin \202 ora contamination. Imaging: refer to NICE recommendations (Tables 16.1 \200\22316.3).1 - USS abnormalities (hydronephrosis, stones). DMSA MCUG functional), VUR, and ureteroceles. is the \201 rst-line investigation. It identi \201 es bladder and kidney renogram can demonstrate and monitor renal scarring. detects urethral and bladder anomalies (anatomical and Management Infants <3 months (and children at risk of serious illness): are managed accordi ng to the \200\230feverish illness in children \200\231 guidelines.2 For children aged 3 m onths to 3y, antibiotics are recommended (before urine culture results are available) for s peci \201 c symptoms of UTI and for non-speci \201 c symptoms where the risk of intermedi ate to serious infection is high (i.e. associated anatomical or functional abnormality).2 I n children older than 3y, antibiot- ics are indicated if urine dipstick analysis is positiv e for nitrites 9 leukocyte esterase or if there is good clinical evidence of UTI. Infants < 3 months: pediatric referral and treat with IV antibiotic such as third-generation cephalos porin (cefotaxime or ceftriaxone).2 Infants and children >3 months with pyelonephritis: ped iatric referral; 7 \200\22310 days of oral cephalosporin or co-amoxiclav or IV cefotaxime o r cefri- axone for 2 \200\2234 days followed by oral antibiotics for a total of 10 days. In fants and children >3 months with cystitis: oral antibiotics for 3 days (trimethoprim, nitr ofurantoin, cephalosporin, or amoxicillin), and reas- sess. The choice of antibiotics shoul d be directed by local hospital guidelines. Asymptomatic bacteriuria does not require antibiotics or routine follow-up. Antibiotic prop hylaxis is not recommended following a \201 rst- time simple UTI, but can be considered a fter recurrent symptomatic UTI.3 Advice on preventing UTI should be given, including good i ntake of \202 uids, regular voiding, and treatment of constipation. Follow-up: recurrent UTI or abnormal imaging requires pediatric assess- ment. Long-term fol low-up is needed for bilateral renal anomalies, impaired renal function, hypertension, and/ or proteinuria. Follow-up should include recordings of growth (height, weight), BP, and uri ne dipstick testing. CHAPTER 16 Pediatric urology 656 Table 16.1 Recommended imaging regimen for infants <6 months1 Imaging Responds well to treatment <48h Atypical UTI Recurrent UTI USS during UTI No Yes Yes USS within 6 weeks Yes No No DMSA 4 \200\2236 months following UTI No Yes Yes MCUG No Yes Yes Table 16.2 Recommended imaging regimen for infants/children 6 months to 3y1 Imaging Responds well to treatment <48h Atypical UTI Recurrent UTI USS during UTI No Yes No USS within 6 weeks No No Yes DMSA 4 \200\2236 months following UTI No Yes Yes MCUG No No No* MCUG may be considered for hydronephrosis, poor urinary \202 ow, family history of VUR, o r non-E. coli UTI. Table 16.3 Recommended imaging regimen for children >3y1 Imaging Responds well to treatment <48h Atypical UTI Recurrent UTI USS during UTI No Yes No USS within 6 weeks No No Yes DMSA 4 \200\2236 months following UTI No No Yes MCUG No No No URINARY TRACT INFECTION (UTI) 657 1 National Institute for Health and Excellence (2007) Urinary tract infection: diagnosis, t reatment and long-term management of urinary tract infection in children [online]. Availabl e from: M http:// www.nice.org.uk/CG54. 2 National Institute for Health and Excellence (2007) Feverish illness in children \200\224 assessment and initial management in children younger than 5 years [online]. Available from : M http://www. nice.org.uk/CG047. 3 Williams G, Craig JC (2011) Long-term antibiotics for preventing recurrent urinary tract infec- tion in children. Cochrane Database Syst Rev 3:CD001534. CHAPTER 16 Pediatric urology 658 Antenatal hydronephrosis De \201 nition Generally de \201 ned as a maximal anteroposterio r renal pelvis diameter (RPD) of \211 5mm on antenatal USS. Incidence The incidence of antenatal hydronephrosis (RPD \211 5mm) is approximately 0.6% o n second trimester (20 weeks \200\231 gestation) USS. The incidence of antenatal USS-detect ed congenital anomalies of the urinary tract is 0.1 \200\223 4%. An increasing degree of hy dronephrosis is related to increased risk of urinary tract pathology and requirement for su rgery.1,2 However, in around 65%, antenatal hydronephrosis will resolve and overall, <5% wi ll require nephrological or surgical intervention.3 Etiology Causes include transient hydronephrosis (48%), physiological hydrone- phrosis (15% ), PUJO, VUR, megaureter, multicystic dysplastic kidney (MCDK), renal cysts, posterior uret hral valves (PUV), ectopic ureter, and ureterocele (also see Table 16.4).3 Table 16.4 Clinically signi \201 cant causes of antenatal hydronephrosis3 Cause Incidence (%) USS features PUJO (see b p. 672) VUR (see b p. 662) Mega ureter (see b p. 666) 11 Most have RPD >15mm with no ureteric dilatation. Bilateral in 10 \200\22340% Ureter dilated to bladder dilatation of pelvicalyceal system 9 4 Dilated ureter >7mm; left side affected more commonly than right side MCDK (see b p. 676) 2 Kidney is replaced by cysts of varying size; 30% risk of abnormality in the contralateral k idney, i.e. PUJO, VUR Ureterocele (see b p. 670) 2 Cystic area in the bladder, usually associated with a duplex kidney and hydronephrosis due to obstruction or re \202 ux PUV (see b p. 674) 1 Bilateral hydroureteronephrosis and distended, thick-walled bladder, dilated posterior uret hra, oligohydramnios, and pulmonary hypoplasia ANTENATAL HYDRONEPHROSIS 659 Antenatal management - 20 weeks \200\231 gestation changes when the bladder empties. Note the gender of fetus. Rep eat USS later in pregnancy if hydronephrosis to assess for persisting or increasing renal d ilatation. Antenatal counseling to discuss differential diagnosis, prognosis, and investiga tions required post-natally. Particularly important for BOO (i.e. PUV), unilateral RPD >30m m, bilateral RPD >15mm, MCKD, and ureterocele. Arrange delivery at an appropriate center fo r cases requiring specialist intervention (i.e. with pediatric urology, nephrology, and neo natal ITU on site). USS. If necessary, repeat the scan to observe for General principles of post-natal management Speci \201 c post-natal investigation and mana gement will depend on the underlying diagnosis and severity of hydronephrosis and are descr ibed individually later in this chapter. The important principles of post-natal management include: - Clinical assessment, including bladder (PUV), abdominal mass (PUJO, MCKD). Start prophylact ic antibiotics immediately (trimethoprim 2mg/kg daily) until the diagnosis is established. Exceptions to this include: RPD <10mm and normal calyces (give UTI advice); MCDK with norma l contralateral kidney and ectopic kidney with no dilatation. Renal function blood tests (p articularly if distended bladder, ureterocele, bilateral hydronephrosis, and unilateral hyd ronephrosis in a solitary kidney). BP reading. Examine for a palpable Imaging - Post-natal USS: generally recommended at 1 and 6 weeks \200\231 post- natal,3 although it c an be delayed longer for lower risk anomalies. If possible, avoid USS in the \201 rst 48h post-delivery as normal urine output is only established after this time. Exceptions that require immediate USS are conditions with obstruction needing urgent surgery \200\224PUV an d ureterocele. MCUG is an urgent clinical indication (BOO/PUV) where it is performed as soo n as possible after birth. Other indications for MCUG include duplex kidney, ureterocele, a nd renal scarring,4 where it is used to detect associated VUR. DMSA : is a static scan whic h provides an accurate measurement of renal split function. It is used to con \201 rm non- function of multicystic kidney, differential function of upper and lower moieties of a dupl ex kidney, and renal damage associated with VUR and UTI (renal cortical scarring). It is pe rformed at 6 \200\22312 weeks old. MAG3 : is a dynamic scan used to identify obstruction wh ere there is no demonstrable re \202 ux and signi \201 cant hydronephrosis persists (RPD >10mm). Usually deferred until the infant is 6 \200\22312 weeks old. It also provides an ap proximation of renal split function and is particularly useful for the diagnosis of PUJO. : is deferred until the child is older (73-6 months) unless there CHAPTER 16 Pediatric urology 660 Consider urgent referral to pediatric urology for: - - BOO Ureterocele associated with obstruction or infection. (PUV). Consider referral to pediatric nephrology or urology for: - - - - - - - - Bilateral Non-re \202 uxing megaureters. Dilatation of a solitary kidney. Dilatation of an y moiety of a duplex kidney. Unilateral Progressive increase in dilatation or cortical thin ning. Differential function <40%. Development of symptoms such as pain/ RPD >15mm with no re \202 ux. RPD >30mm. UTI. (Please refer to local hospital guidelines as these will differ between differ- ent hospita ls and tertiary centers.) 1 Passerotti CC, Kalsih LA, Chow J, et al. (2011) The predictive value of the \201 rst po stnatal ultra- sound in children with antenatal hydronephrosis. J Pediatr Urol 7:128 \200 \22336. 2 Grignon A, Filiom R, Filiatrault D, et al. (1986) Urinary tract dilatation in utero. Clas si \201 cation and clinical application. Radiology 160:645 \200\2237. 3 Woodward M, Frank D (2002) Postnatal management of antenatal hydronephrosis. BJU Int 89:1 49 \200\22356. 4 Mears AL, Raza SA, Sinha AK, Misra D (2007) Micturating cystourethrograms are not necessa ry for all cases of antenatally diagnosed hydronephrosis. J Pediatr Urol 3:264 \200\2237. This page intentionally left blank CHAPTER 16 Pediatric urology 662 Vesicoureteric re \202 ux (VUR) De \201 nition: VUR results from abnormal retrograde \202 ow of urine from the bladder into the upper urinary tract. Epidemiology: overall incidence in children is 1 \200\2232%; younger > older; girls > boys (female : male ratio = 5:1); Caucasian > Afro-Caribbean. The offspring of an affected paren t has up to 70% incidence of VUR; siblings of an affected child have 30% risk of re \202 u x. Screening of offsprings and siblings is controversial and many would only recommend it i f there is signi \201 cant renal scarring in the index case. Pathogenesis: the ureter passes obliquely through the bladder wall (1 \200\2232cm) where it is supported by muscular attachments which prevent urine re \202 ux during bladder \201 lling and voiding. The normal ratio of intra- mural ureteric length to ureteric diameter i s 5:1. Re \202 ux occurs when the intramural length of ureter is too short (ratio <5:1) (P aquin \200\231s law). The degree of re \202 ux is graded I \200\223V (see b p. 408; Fig. 8 .3). The appearance of the ureteric ori \201 ce changes with increasing severity of re \202 ux, classically described as stadium, horseshoe, golf hole, or patulous. Classi \201 cation - Primary re \202 ux An anatomical cause is seen with duplex kidneys (and ureters). The Weig ert \200\223Meyer rule states the lower moieity ureter enters the bladder proximally and la terally, resulting in a shorter intramural tunnel which predisposes to re \202 ux (see b p . 423; Fig. 8.10). A genetic cause is also recognized. Secondary re \202 ux with elevated intravesical pressures, creating damage to the VUJ. Causes include: PUV (re \202 ux seen i n 50%), urethral stenosis, neuropathic bladder, DSD. In \202 ammation associated with infe ction (acute cystitis) can also distort the VUJ, causing re \202 ux. Treatment is of the u nderlying condition. : results from a congenital abnormality of the VUJ. : results from urinary tract dysfunction associated Complications VUR (associated with UTI) can result in re \202 ux nephropathy and renal sca r- ring, causing hypertension (10 \200\22320%) and rarely, progressive renal failure. Presentation Symptoms of UTI (fever, dysuria, suprapubic and abdominal pain), failure to th rive, vomiting, diarrhea. It is important to elicit associated symptoms and signs of bladde r and/or bowel dysfunction: urinary frequency, urgency, prolonged voiding intervals, daytim e wetting, holding maneuvers to pre- vent wetting, and constipation. Investigation - Baseline measurements: height, weight, if there are bilateral renal cortical abnormalities. Urine analysis to assess for bacteriuria and proteinuria. Urine culture if evidence of Ren al tract BP as well as serum creatinine - UTI. USS initially and then annually, as indicated. VESICOURETERIC REFLUX (VUR) 663 DMSA renogram to detect and monitor associated renal cortical scarring (most likely in grad es III \200\223V re \202 ux, younger children, recurrent febrile UTI, and underlying renal tract abnormality on USS). MCUG to diagnose and grade re \202 ux, establish reversible ca uses, and follow-up after 12 \200\22324 months to assess for resolution of higher grade VUR treated conservatively and after endoscopic treatment (Fig. 16.5). (Video)urodynamics if s uspicious of voiding dysfunction. Management The majority of primary VUR grades I \200\223II will resolve spontaneously (80%) ,1 with overall 50% resolution in grades III \200\223V.2 Re \202 ux tends to improve with age as the length of the intramural ureter increases with growth (Table 16.5). General advi ce includes good \202 uid intake, regular voiding, perineal hygiene, treatment of constip ation, and use of probiotics. Provide parents with UTI advice and emphasize the need to see k medical attention early if the child has an unexplained febrile illness or suspected UTI. It is impor- tant to treat any coexisting bladder or bowel dysfunction. Medical treatment The need for antibiotic prophylaxis in VUR remains controversial. A NIH r andomized placebo-controlled study of children with VUR (RIVUR Study) aims to further inves tigate this. The Swedish re \202 ux trial in chil- dren has reported that prophylactic ant ibiotics and endoscopic surgery decreases (febrile) infection rates in girls, but not in bo ys, as compared to surveillance alone.3 Currently, low-dose antibiotic prophylaxis is given to keep the urine sterile and lower the risk of renal damage in young children ( \211 1y old) with a history of febrile UTI4 and u ntil re \202 ux resolves in higher grades of VUR (III \200\223V). Whilst on treatment, gro wth, BP, and urine should be monitored (for proteinuria and bacteriuria), with an annual re nal tract USS. If the child remains well, antibiotics may be discontinued when they are toi let-trained (dry day and night). If febrile UTI recurs after conservative or surgical resol ution of VUR, reinvestigate for bladder dysfunction and recurrence of VUR.4 Longer term fol low-up into adolescence is recommended if there is any renal abnormality on USS or DMSA, ev en if VUR has resolved.4 Surgery Indications for surgery include: high-grade VUR (girls bene \201 t more than boys) , breakthrough febrile UTI despite antibiotic prophylaxis, and non- compliance with medical therapy. Circumcision reduces the risk of UTI in boys with VUR5 and is used for those with anatomical anomalies and recurrent or breakthrough UTI. Surgical techniques include endoscopic injection, ureteric re-implan- tation performed by o pen surgery (98% success) or laparoscopically. Endoscopic injection of De \202 ux is the \201 rst-line surgical treatment. Indications for ureteric re-implantation include failu re of De \202 ux , duplex renal system, and renal ectopia. Endoscopic injection De \202 ux is a hyaluronic acid/dextranomer bulking agent which is injected intramurally within the distal ureter and also at the ureteric ori \201 ce ( \200 \230HIT \200\231 CHAPTER 16 Pediatric urology 664 technique) with 80 \200\22390% success rates, although recent studies have sug- gested that repeat treatments may be required.6 De \202 ux is most effective for VUR grades I \200 \223III. It has replaced the traditional subtrigonal injection ( \200\230STING \200\231) of bulking agent (collagen) into the ureteric ori \201 ce. Open surgery - Intravesical methods the ureter and advancing it across the trigone (Cohen repair), or rein sertion into a higher, medial position in the bladder (Leadbetter \200\223 Politano repair) . The aim is to place the mobilized ureter into a submucosal tunnel whose total length is \201 ve times the diameter of the ureter in order to prevent further re \202 ux. Success rates with open surgery are around 98%. Extravesical techniques directly onto the bladder a nd constructing a tunnel of detrusor muscle around it (Lich \200\223Gregoir procedure). : involve opening the bladder, mobilizing : involve suturing the distal ureteric end Table 16.5 Example of the percentage incidence and spontaneous resolution of VUR according to grade7 Grade of VUR Incidence (%) Spontaneous resolution (%) I 7 83 II 54 60 III 31 46 IV 6 9 V 2 0 1 Arant BS Jr (1992) Medical management of mild and moderate vesicoureteric re \202 ux: fo llow-up studies of infants and young children. A preliminary report of the Southwest Pediat ric Nephrology Study Group. J Urol 148:1683 \200\2237. 2 Smellie JM, Jodal U, Lax H, et al. (2001) Outcome at 10 years of severe vesicoureteric re \202 ux managed medically: report of the International Re \202 ux Study in Children. J P ediatr 139:656 \200\22363. 3 Brandstr m P, Esbj mer E, Herthelius M, et al. (2010) The Swedish re \202 ux trial in children: III. Urinary tract infection pattern. J Urol 184:286 \200\22391. 4 Peters CA, Skoog SJ, Arant BS, et al. (2010) Summary of the AUA Guideline on management o f primary vesicoureteric re \202 ux in children. J Urol 184:1134 \200\22344. 5 Singh-Grewal D, Macdessi J, Craig J (2005) Circumcision for the prevention of urinary tra ct infection in boys: a systematic review of randomized trials and observational studies. A rch Dis Child 90:853 \200\2238. 6 Holmdahl G, Brandstr m P, L ckgren G, et al. (2010) The Swedish re \202 ux trial in ch ildren: II. Vesicoureteral re \202 ux outcome. J Urol 184:280 \200\2235. 7 Skoog SJ, Belman AB, Majd M (1987) A nonsurgical approach to the management of primary ve sicoureteric re \202 ux. J Urol 138:941 \200\2236. VESICOURETERIC REFLUX (VUR) 665 Fig. 16.5 MCUG demonstrating grade III VUR and intrarenal re \202 ux (shown by arrow) in a child. Image kindly provided with permission from Professor S. Reif. CHAPTER 16 Pediatric urology 666 Megaureter Classi \201 cation Megaureter is the term for a dilated ureter, usually larger than 7mm in diameter, which may be a primary condition or secondary to another underlying p roblem. It can be classi \201 ed into four different groups: - - - - Obstructed. Re \202 uxing. Non-re \202 uxing, non-obstructed. Re \202 uxing and obstruct ed. Primary megaureter can be re \202 uxing or obstructed and is associated with either a simp lex renal system or a duplex. Obstruction is due to either a stenotic or aperistaltic dista l ureter, which results in a dilated and tortuous ureter proximally. Secondary megaureter may be: Unilateral \200\224secondary to obstruction or scarring from s tones and tumor or following ureteric surgery (i.e. subtrigonal injection of bulking agent around the ureteric ori \201 ce, \200\230STING \200\231). Bilateral cases are due to neur opathic bladder dysfunction. BOO (i.e. PUV), prune belly syndrome, and Incidence Megaureter affects approximately 1 in 2000 children. Males are more com- monly af fected than females; the left ureter is more commonly affected than the right side. Presentation Megaureter is the underlying cause for prenatal ultrasound-detected fetal hydr onephrosis in around 4% of cases,1 associated with a dilated ureter (>7mm) (see b p. 658). After birth, UTI is the most common presenta- tion. When associated with an undetected obst ructed megaureter, this may present as urosepsis with an infected, obstructed system, which is a urological emergency and requires urgent decompression and antibiotics. Investigation - Renal tract week to assess for the persistence of ureteric dilatation. Repe at USS checks will then be guided by the underlying diagnosis, i.e. if there is no renal co mpromise or obstruction, at 6 weeks, and again at 1y. MCUG BOO), otherwise deferred until t he infant is 3 \200\2236 months old. It can help to distinguish between obstruction and re \202 ux and may also identify the cause of obstruction. MAG3 renogram: provides a measurem ent of split renal function and helps to differentiate between obstructed and non-obstructe d megaureter. An ipsilateral PUJ obstruction may be identi \201 ed in 13%. It is usually p erformed 6 \200\22312 weeks after delivery. USS: should be performed within the \201 rst post-natal : is performed early if there is concern of obstruction (i.e. MEGAURETER 667 Conservative management Empirical treatment is to start antibiotic prophylaxis at birth whi lst the diagnosis is being established (trimethoprim 2mg/kg daily). If the differ- ential r enal function is >40%, patients can be managed with expectant or conservative treatment and follow-up renal tract USS. If the ureteric dilatation resolves or improves and the child r emains well, they may dis- charged at the age of 5 with UTI advice. Prophylactic antibiotic s can be continued if infection is a feature, however, recurrent, breakthrough, or severe U TI would be an indication for surgical intervention. Surgical treatment Up to 12 months old Endoscopic or open cystotomy and insertion of a uret eric stent is the procedure of choice in this young age group. De \201 nitive surgical cor rection with ureteric re-implantation is deferred until after 6 to 12 months old if possibl e as this is associated with less morbidity and better outcomes. After 12 months old The aims of surgery are to excise the stenotic or aperistaltic distal u reteric segment and perform an intravesical ureteric re-implantation with a Cohen repair, b ringing the ureter across the trigone in a submucosal tunnel. For more severely dilated and capacious ureters, it is often necessary to taper the ureter before re-implantation. This can be achieved by placation of the ureter (Starr technique), folding of the ureter (Kalicinski technique), or by ureteric excision. The choice of re-imp lantation surgery is then a Leadbitter \200\223Politano repair which has the advantage of c reating a longer anti-re \202 uxing submucosal tunnel. This is often coupled with a psoas hitch to help prevent kinking and further obstruction of the ureter. For bilat- eral cases of megaureter, a transureteroureterostomy can be performed. Here, one ureter is excised dis tally and attached to drain into the con- tralateral ureter so only one ureter drains urine from both kidneys into the bladder. This ureter can then be plicated and re-implanted as b efore. Nephroureterectomy is indicated if the megaureter is associated with a non-functioni ng or poorly functioning kidney. Follow-up after surgery Renal tract USS and MAG3 renogram should be performed after 1y to r eassess the degree of ureteric dilatation and for pelvicalyceal dilatation. Prophylactic an tibiotics may be continued in children with persistent re \202 ux, but can be stopped once the child is fully toilet-trained if they remain well. 1 Woodward M, Frank D (2002) Postnatal management of antenatal hydronephrosis. BJU Int 89:1 49 \200\22356. CHAPTER 16 Pediatric urology 668 Ectopic ureter An ectopic ureter is caused by the ureteric bud which arises from an abnorma l (high or low) position on the mesonephric duct during embryo- logical development. There is a direct correlation between the location of the ectopic ureter and the degree of ipsila teral renal hypoplasia or dysplasia.1 Eighty percent is associated with a duplicated collec ting system. A duplex kidney has an upper and a lower moiety, each with its own renal pelvi s and ureter. The two ureters may join to form a single ureter or they may pass down indivi dually to the bladder (complete duplication). In this case, the upper renal moiety ureter a lways opens onto the bladder below and medial to the lower moiety ureter (Weigert \200\223M eyer rule), predis- posing to ectopic placement of the ureters and ureteric ori \201 ces ( see b p. 423; Fig. 8.10). Incidence: about 1 in 2000. Female to male ratio is \211 3:1. Mo st ectopic ure- ters in females are associated with a duplex kidney whereas most ectopic ur eters in males are associated with a single renal system. Other drainage sites of ectopic ureters - - Females: Males: deferens, epididymis, bladder neck. bladder neck, urethra, vagina, vaginal vestibule, uterus. posterior urethra, seminal vesicl es, ejaculatory duct, vas Presentation May present with an antenatal diagnosis of hydronephrosis and dilated ureter t o the bladder. Later presentations include acute or recurrent UTI. Obstruction of the ectop ic ureter can lead to hydroureteronephrosis which may present post-natally as an abdominal mass or pain. - Females: when the ureteric opening is below the urethral sphincter, girls present with pers istent vaginal discharge or incontinence despite successful toilet training. Males: so boys do not develop incontinence. UTIs may trigger epididymitis (usually recurrent). the ureter is always sited above the external urethral sphincter Investigation - Post-natal hydronephrosis. USS is performed immediately if obstruction is s uspected (i.e. ectopic ureter associated with ureterocele), otherwise it is performed at we ek 1 and 6 post-natally. MCUG ureter (or lower renal moiety). MAG3 renogram: is used when M CUG has excluded re \202 ux and is used to investigate for obstruction and estimate split renal function. DMSA renogram: is used to assess split renal function and differential func tion between upper and lower pole moieties of a duplex kidney to help plan surgery. Assesse s for renal cortical scars when re \202 ux is present. Cystourethroscopy MRU lower renal m oieties. USS: may demonstrate ureteric dilatation and : is used to assess whether there is re \202 ux into the ectopic : may identify the ectopic ureteric ori \201 ce. : identi \201 es duplex systems and gives information on upper and ECTOPIC URETER 669 Treatment Commence prophylactic trimethoprim (2mg/kg daily) whilst conducting post-natal in vestigation. An ectopic ureter without an ureterocele, but associated with upper renal moie ty dilatation, requires urgent treatment to decompress the system and avoid the, complicati on of an infected, obstructed system (pyoureteronephrosis). Management is mainly expectant if there are no symptoms and no evi- dence of acute obstruct ion or dilatation. Where an ectopic ureter is asso- ciated with a poorly functioning renal upper pole moiety or single-system kidney, surgery is an option. This includes open or lapa roscopic upper moiety heminephrectomy or total nephrectomy with excision of the associated ureter. Ureteropyelostomy and uretero-ureterostomy can be considered in duplex systems wher e the upper renal pole has reasonable function. Where some useful function is retained in a single-system kidney, the distal ureter can be resected and re-implanted into the bladder. 1 Mackie GG, Stephens FD (1975) Duplex kidneys: a correlation of renal dysplasia with posit ion of the ureteric ori \201 ce. J Urol 114:274 \200\22380. CHAPTER 16 Pediatric urology 670 Ureterocele De \201 nition: an ureterocele is a cystic dilatation of the distal ureter as it drains in to the bladder. Incidence: 1 in 5000 \200\22312,000 clinical pediatric admissions1 (although 1 in 500 are f ound at autopsy).2 Female to male ratio is 4:1, predominantly affecting Caucasians. Ten per cent of ureteroceles are bilateral. Classi \201 cation Ureteroceles may be associated with a single or duplex renal system. Ei ghty percent are associated with the upper moiety of a duplex kidney. They are ureteroceles. Intravesical (20%): the ureterocele is completely con \201 ned with in the blad- der. These tend to be associated with single systems and are more com- mon in males. Subtypes include: - - further classi \201 ed into intravesical or extravesical Stenotic Non-obstructed when \201 lled by peristalsis of urine. : small, stenotic ureteric ori \201 ce associated with obstruction. : large ureteric ori \201 ce that tends to balloon open Extravesical (or ectopic) (80%): when the ureterocele extends to the blad- der neck or uret hra and tend to occur with duplex systems; most com- monly in females. Subtypes include: - Sphincteric ori \201 ce is wide and usually opens proximal to the external sphincter. Sphi ncterostenotic ureteric ori \201 ce is stenosed. Cecoureterocele : ureterocele prolapses p osterior to the urethra and anterior to the vagina, but the ori \201 ce is within the blad der (affects girls only). Can cause urethral obstruction. Blind ectopic : ureterocele extends into bladder neck and urethra. The : similar to sphincteric ureterocele, but the : similar to sphincteric, but no ureteric ori \201 ce. Presentation: most present with antenatal hydronephrosis. Later pres- entation in infants m ay be with symptoms of UTI, an abdominal mass, or pain. Association with ureteric duplicati on increases the risk of re \202 ux and re \202 ux nephropathy. Extravesical ureteroceles can also cause BOO and bilateral hydroureteronephrosis (urological emergency) or ureteric obstruction and unilateral hydroureteronephrosis, which require urgent assessment and inter vention. A prolapsing ureterocele can present as a vaginal mass in girls. Investigation - USS renal tract: shows a thin-walled cyst in the bladder often associated with a duplex sys tem and ectopic (dilated) ureter. If there are concerns about obstruction, USS should be pe rformed immediately after birth with a view to urgent surgical treatment. MCUG (re \202 ux into the lower moiety of an associated duplex kidney is seen in 50%). This should be perfo rmed early in the post-natal period if there is evidence of BOO, otherwise defer 3 \200\223 6 months. : can identify ureterocele location, size, and associated VUR URETEROCELE 671 MAG3 DMSA demonstrate renal cortical abnormalities in the presence of re \202 ux. : can be used for diagnosis and endoscopic treatment. Cystoscopy renogram: is used to exclude obstruction. renogram: is used to assess renal moiety function and Treatment Commence prophylactic antibiotics at birth (trimethoprim 2mg/kg daily). Urgent su rgical intervention is required for obstruction. - : emergency treatment for infected Endoscopic incision/puncture or obstructed ureteroceles. Puncture is also indicated for elective management of intravesical ureteroceles with norma l renal function. Rarely, these may require further surgery, including ureterocele excision and ureteric re-implantation to preserve renal function and prevent re \202 ux. Uretero-u reterostomy or uretero-pyelostomy (from upper to lower pole moiety): option for ectopic ure teroceles associated with a duplex system, with good function in the upper moiety and no re \202 ux in the lower moiety. Upper pole heminephrectomy : option for ectopic ureterocele associated with a duplex system with poor function in the upper moiety and no re \202 ux i n the lower moiety. Upper pole heminephrectomy, ureterocele excision, and ureteric re-impla ntation: option for ectopic ureterocele associated with a duplex system with poor function in the upper moiety and re \202 ux in the lower moiety. Nephroureterectomy with poor funct ion in both renal moieties or for poor renal function in single system. : indicated for signi \201 cant lower moiety re \202 ux 1 Malek RS, Kelalis PP, Burke EC, et al. (1972) Simple and ectopic ureterocele in infants a nd child- hood. Surg Gynaecol Obst 134:611 \200\2236. 2 Uson AC, Lattimer JK, Melicow MM (1961) Ureteroceles in infants and children: a report ba sed on 44 cases. Pediatrics 27:971 \200\2237. CHAPTER 16 Pediatric urology 672 Pelviureteric junction (PUJ) obstruction De \201 nition: a blockage of the ureter at the j unction with the renal pelvis, resulting in a restriction of urine \202 ow.* Epidemiology: childhood incidence is estimated at 1 in 1000. Boys are affected more than gi rls (ratio 2:1 in newborns). The left side is more often affected than the right side (rati o 2:1). They are bilateral in 10 \200\22340%. Etiology In children, most PUJ obstruction is congenital. Intrinsic obstruction may be due to aberrant development of ureteric/renal pelvis muscle, aberrant insertion of the ureter i nto the renal pelvis, abnormal collagen, or ureteric folds or polyps. Extrinsic causes incl ude compression of the PUJ by aber- rant crossing vessels. Coexisting VUR is found in up to 25%. Presentation PUJ obstruction is the most common cause of hydronephrosis (without ureteric d ilatation) found on antenatal USS. Infants may also present with an abdominal mass, UTI, an d haematuria. Older children present with \202 ank or abdominal pain (exacerbated by diur esis), UTI, nausea and vomit- ing, and haematuria following minor trauma. Investigation If prenatal USS has shown a large or bilateral hydronephrosis, a follow-up re nal tract USS should be performed soon after birth. If there is a prenatal unilateral hydro nephrosis (and the bladder is normal), the scan is deferred until day 3 \200\2237 (to allow normal physiological diuresis to occur, which may spontaneously improve or resolve the hyd ronephrosis). MAG3 renogram is performed at 6 \200\22312 weeks for diagnosis and to assess split renal func- tion. Signi \201 cant obstruction is unlikely if the anteroposterior ren al pelvis diameter is <15mm.