Evolution of the rectal bladder as a method for urinary diversion.

A critical analysis of previous reports reveals 2 main drawbacks of the rectal bladder: 1) recurrent pyelonephritis with subsequent loss of renal function (30 per cent) and 2) nocturnal urinary leakage (40 per cent). In a randomized prospective study the role of a submucosal tunnel for prevention of reflux was evaluated. We demonstrated objectively that this technique could provide a patent unidirectional flow of urine in the majority of cases (82.5 per cent). Urodynamic measurements, including flowmetry, rectal pressure and anal electromyography activities, indicated that the driving force for voiding is the voluntary increase of the intra-abdominal pressure rather than the intrinsic contractions of the smooth muscles of the rectum. Accordingly, attempts at control of nocturnal urinary leakage were directed towards increasing the resistance offered by the pelvic floor. The efficiency of imipramine hydrochloride to achieve this goal was tested against a placebo in a clinical trial performed in a prospective randomized fashion. This treatment was effective in the control of enuresis in a significant number of patients (75 per cent). We conclude that the rectal bladder with a terminal colostomy is a highly recommended method for permanent urinary diversion when these 2 modifications are used.