Mainz Pouch II technique: 10 years' experience

To report the long-term results with the Mainz Pouch II procedure.

Between 1990 and 2000 a Mainz Pouch II ureterosigmoidostomy was used in 123 patients (49 females and 74 males, mean age 43.6 years, range: 1-73). The indications for urinary diversion were cystectomy for bladder cancer in 92 patients, bladder exstrophy and/or incontinent epispadias in 26, irreparable traumatic loss of the sphincteric urethra in four and cloacal malformation (sinus urogenitalis) in one. In all, 102 patients with a follow-up of >/= 12 months were evaluated (mean 46.2 months).

Day- and night-time continence rates were 97% and 95%, respectively. The remaining patients occasionally lose some drops of urine during coughing or straining, or reported minimal soiling of undergarments during the night. The mean voiding frequency was six during the day and once at night. There were 14 ureteric implantation stenoses (7.2% of 194 evaluated reno-ureteric units) and they were treated successfully by open repair (13) or antegrade balloon dilation (one). For metabolic disturbances, 69% of the patients had a capillary base excess of <-2.5 mmol/L and use oral alkalinizing drugs to prevent hyperchloraemic acidosis. There was no clinically evident metabolic acidosis.

Applying the principles of detubularization and spherical reconfiguration to create a low-pressure reservoir and stratifying ureteric implantation between submucosal and serous-lined extramural tunnel techniques succeeded in giving better continence rates and long-term preservation of the upper urinary tract than a classical ureterosigmoidostomy. The Mainz Pouch II ureterosigmoidostomy is simple and reliable as a viable alternative for continent urinary diversion in selected patients.