Urodynamic Evaluation of Urethral Competency in Women with Posterior Vaginal Support Defects

ObjectivesTo determine whether posterior vaginal wall support defects mask stress incontinence and the effects of these defects on common urodynamic tests used to evaluate urethral competency.MethodsWe performed a prospective analysis of urodynamic evaluation with and without posterior vaginal stabilization in 54 women with Stage 2 or greater posterior vaginal prolapse and 54 women with Stage 0 and 1 posterior vaginal prolapse.ResultsPosterior vaginal stabilization resulted in statistically significant reductions in the Valsalva leak point pressure, maximal urethral closure pressure, and pressure transmission ratios in the case group and inconsistent changes in the control group. Posterior vaginal stabilization unmasked stress incontinence in 12 (54%) of 22 case patients but none of the control patients. Previous incontinence surgery (odds ratio 57.4, 95% confidence interval 5.8 to 568, P = 0.001) was the strongest predictor for occult stress incontinence in patients with Stage 2 or greater rectocele. Also, notable, but less significant, associations were found between hysterectomy (odds ratio 6.7, 95% confidence interval 1.5 to 29, P = 0.01) and severity of rectocele (odds ratio 1.9, 95% confidence interval 1.1 to 3.3, P = 0.02) with occult incontinence.ConclusionsThe results of our study have shown that stress incontinence can be masked in women with Stage 2 or greater posterior vaginal support defects.