Urodynamic and clinical outcome of Kock pouch continent urinary diversion

Urodynamic studies of the Kock pouch were conducted in 20 patients 3 to 36 months after radical cystectomy and urinary diversion for invasive bladder cancer. Functional pouch capacity, intrapouch pressure, maximal nipple pressure, maximal nipple closure pressure and functional nipple length with the pouch filled to capacity were measured. Intermittent involuntary pressure spikes resembling bowel peristaltic waves occurred in 5 patients (25 per cent). The mean functional pouch capacity was 280.0 +/- 119.2 ml. (standard deviation) and mean maximal intra-pouch pressure was 41.0 +/- 11.0 cm. water in patients with involuntary pressure spikes. In patients without involuntary pressure spikes these values were 332.7 +/- 114.5 ml. and 11.6 +/- 4.8 cm. water, respectively. For all patients the mean maximal nipple pressure was 72.1 +/- 24.6 cm. water, the mean maximal nipple closure pressure was 58.8 +/- 23.1 cm. water and the mean functional nipple length was 3.4 +/- 0.9 cm. A functional nipple length of less than or equal to 2.5 cm. and/or a low maximal nipple closure pressure (less than 40 cm. water) correlated with a small functional pouch capacity (less than 200 ml.) in 5 patients. Clinically, these 5 patients also required frequent catheterization to provide continence. A maximal nipple closure pressure greater than 60 cm. water and an adequate functional nipple length (greater than 3.0 cm.) correlated with a rather large functional pouch capacity (more than 350 ml.). The degree of continence provided by the Kock pouch appeared to be determined by functional nipple length, maximal nipple closure pressure, functional pouch capacity and maximal intrapouch pressure.