a 61 year old man presented to our institution with a diagnosis of stage t3a prostate cancer .
his serum prostate - specific antigen level was 5.3 ng / ml , and a transrectal biopsy demonstrated a gleason score of 3 + 4=7 in 20% to 80% of the cores from both lobes .
a combination of suture ligation , bipolar cautery , harmonic scalpel , and holc were successfully used at various stages of the procedure to help achieve hemostasis and for ligation of the vas deferens .
holc were used specifically for control of the lateral pedicle of the prostate during ralrp .
we did not use holc at the bladder neck or the site of vesicourethral anastomosis .
the vesicourethral anastomosis was achieved by using a single intracorporeal knot running 2 - 0 monocryl suture .
also , the patient did not undergo wide dissection of the bladder neck during ralrp .
pathology showed a gleason score of 3 + 4=7 with extracapsular extension , but negative lymph nodes , negative margins , no seminal vesicle invasion , and no angiolymphatic invasion .
three months after surgery , he complained of dysuria and decreased force of the urine stream .
he underwent retrograde cystourethrography in the office , which revealed a bladder neck contracture on the urethra ( fig .
the cystourethroscopy demonstrated a normal - looking urinary sphincter but a very tight bladder neck .
the bladder neck was successfully dilated , and visualization of the bladder revealed the presence of four holc .
the four holc were floating in the bladder without stone formation and had migrated from the previous ralrp ( fig .
, an indwelling urethral catheter was left for 7 days . at the 3 month follow - up after this dilatation ,
the patient was satisfied with his voiding habits and reported having a good urinary stream .
with the recent surge in minimally invasive surgery ( robotic and laparoscopic assisted surgery ) , interest in hemostatic alternatives to suturing has increased .
several automated suturing devices including endostitch ( autosuture , ussc , norwalk , ct , usa ) , lapraty clips ( ethicon , endosurgery inc , piscataway , nj , usa ) , and holc have been used during laparoscopic procedures . among them , holc are a commonly used device and have been shown to be safe and reliable for vascular control in laparoscopic procedures . during ralrp , holc have been used for ligation of the vasa deferentia , seminal vesicle arteries , and prostatic pedicles to prevent excessive electrocautery and possible injury to the neurovascular bundles . however
, several limitations , in addition to the concern for clip migration , have become apparent .
blumenthal et al .   reported the first case of migration of holc into the vesicourethral anastomosis after ralrp .
there have been some reports of intravesical migration of these clips causing urethral erosion , bladder neck contractures , and subsequent calculus formation [ 2 - 6 ] . in all those cases , however , holc lodged in the bladder neck area with stone formation . in our case , the holc were floating in the bladder without stone formation .
of a case in which a metal clip had migrated into the urinary bladder after retropubic radical prostatectomy .
it was hypothesized that inflammation had arisen around the urinary bladder or vesicourethral anastomosis and that this also involved the metal clip , which then eroded the bladder wall and eventually migrated into the bladder .
also , in our case , the mechanism of migration of holc in the bladder is unclear . according to the hypothesis described above
, we can suspect that the holc migrated into the bladder during the serial course . on the basis of these findings , we recommend minimizing the use of holc on tissue immediately adjacent to the anastomosis during ralrp , specifically , the vasa and seminal vesicles , and every effort should be made to retrieve any loose clips after the procedure . these clips are prone to migration and may cause , or significantly contribute to , bladder neck contracture formation after ralrp .
migration of holc into the vesicourethral anastomosis should be considered in patients with symptoms consistent with bladder neck contracture after ralrp .
in addition , in these cases , noncontrast computed tomography scan might be helpful to detect clips .
 hem - o - lok clips ( weck surgical instruments , teleflex medical , durham , nc , usa ) are widely used in robot - assisted laparoscopic radical prostatectomy because of their easy application and secure clamping . to date , there have been some reports of intravesical migration of these clips causing urethral erosion , bladder neck contractures , and subsequent calculus formation . 
 we report the first case of bladder migration of hem - o - lok clips without stone formation after robot - assisted laparoscopic radical prostatectomy . 
 the hem - o - lok clips were found during urethral dilation with a guide wire for bladder neck contracture under cystourethroscopy . 
 the hem - o - lok clips were floating in the bladder without stone formation and were removed by a cystoscopic procedure . 
CASE REPORT
DISCUSSION