A cystocele may compensate for latent stress incontinence by stretching the vaginal hammock

To examine why anatomical correction of a cystocele may cause stress incontinence in a patient with no prior history of this condition.

The study group consisted of 5 patients, aged 45-63 years, with stress incontinence induced by supporting a cystocele with a pessary. The patients were otherwise continent. Testing was performed in a semirecumbent sitting position under perineal ultrasound control. The patients were asked to strain and cough before and after supporting the bladder neck with both sponge-holding forceps and a ring pessary.

In all 5 patients, urine loss on stress was noted with bladder base support by forceps and pessary insertion. With both, asymmetrical downward stretching of the vagina and bladder base was observed. When the cystocele was allowed to balloon outwards, the asymmetrical pattern converted to a symmetrical 'funnelling' of the anterior and posterior walls of bladder neck.

This study appears to support the hypothesis that, in addition to urethral narrowing, a ballooning cystocele may restore urethral closure by removing laxity from the vaginal hammock. Correction of a cystocele may cause incontinence by removing a fortuitous, but abnormal compensatory mechanism.