Urodynamic findings in patients with a urethral kock pouch after radical cystectomy

Abstract

Urodynamic evaluation was performed in 11 male patients, who underwent radical cystectomy with pelvic lymph node dissection for bladder cancer followed by bladder replacement with a urethral Kock pouch, 3 to 21 months after the operation. Frequency of micturition were 4.9±1.5 times (mean±S.D.) during the day-time and 1.5±1.2 times durin the night-time. Tidal volume of micturition ranged from 300 to 550 ml and residual volume from 10 to 30 ml. Urinary continence was completely preserved in all patients (100%) during the day-time and 8 (72.7%) during the night-time. On pouchmetry, maximum capacity of the pouch was 429.2±82.4 ml, and intra-pouch pressure was 16.2±5.4 cmH2O at the capacity of 200ml and 38.7±11.5 cmH2O at the maximum capacity. Maximum intra-pouch pressure on voiding was 80.0±19.4 cmH2O. Uroflowmetry demonstrated intermittent voiding curves in all the patients, with maximum flow rate of 15.2±6.5 ml/sec, voided volume of 405.9±80.7 ml and residual rate of 4.5±2.6%. Maximum intra-urethral pressure at the external urethral sphincter was 28.0±11.3 cmH2O when the pouch was empty and increased in response to pouch filling up to 64.7±27.0 cmH2O. Maximum urethral closing pressure and total profile length on the urethral pressure profile were 30.2±12.4 cmH2O and 20.9±9.0 mm, respectively, with the pouch empty, and 23.2±14.5 cmH2O and 20.0±7.6 mm, respectively, with the pouch full. The bladder replacement using the urethral Kock pouch is a valuable alternative for continent urinary reconstruction provided creation of a low pressure reservoir and preservation of the urethral sphincter function are achieved. On the other hand, long term effects of the high intra-pouch pressure by abdominal strain on the reservoir have not been determined. It is conceivable that this high pressure may cause functional and/or organic changes of the pouch and jeopardize the anti-reflux mechanism at the afferent limb. In a case with high intra-pouch pressure on voiding, evacuation of urine by an intermittent catheterization instead of abdominal strain may be advocated, irrespective of the residual volume. © 1992, THE JAPANESE UROLOGICAL ASSOCIATION. All rights reserved.