Pathogenesis of nocturnal urinary incontinence after ileocaecal bladder replacement. Continuous measurement of urethral closure pressure during sleep.

Urethral closure pressure was recorded in four patients during sleep in order to determine the pathogenesis of nocturnal incontinence after radical cystectomy and ileocaecal bladder replacement. The sleep stages were determined by electroencephalography. The resting pressure in the intestinal bladder was low and increased only slightly during filling. The maximum urethral pressure decreased during sleep but the urethral closure pressure remained positive when the intestinal bladder was not contracting. The peristaltic contractions in the intestinal bladder continued during sleep, causing incontinence. The nocturnal incontinence is probably a result of the reduced level of consciousness that makes it impossible to increase the tone of the external urethral sphincter during contractions of the intestinal bladder.