Urodynamic study of storage and evacuation of urine in patients with a urethral Kock pouch

The urodynamics of pouch-urethra function were investigated in patients with a urethral Kock pouch to understand mechanisms involved in the storage and evacuation of urine, and elucidate any problems of long-term outcome.

Urodynamic evaluation was performed in 18 male patients who underwent bladder replacement with a urethral Kock pouch following radical cystectomy.

Good urinary continence was achieved with normal frequency of voiding. On urodynamics pressure within the pouch remained low during the storage phase (mean 33.2 cm. water) but markedly increased during the evacuation of urine (mean 77.3 cm. water). In 8 patients (44%) extremely high pressure within the pouch (80 to 150 cm. water) was noted at voiding. Clean intermittent self-catheterization was initiated in a patient with high pressure within the pouch at voiding in whom pouch-ureter reflux developed 7 months postoperatively. The external urethral sphincter was impaired to some extent postoperatively but it contracted in response to filling of the pouch with a marked increase in urethral pressure from a mean of 31.6 to 66.3 cm. water.

Urodynamic and radiological studies will be necessary periodically since high pressure within the pouch at voiding might jeopardize the antireflux mechanism, leading to reflux and renal impairment.