The effects of the tension-free vaginal tape on voiding function: a prospective evaluation.

The impact of tension-free vaginal tape (TVT) on voiding function was studied in a cohort of 103 patients. Voiding was assessed with quality of life questionnaires, non-invasive urine flow and voiding pressure-flow studies both preoperatively and 1 year postoperatively. Paired t-tests and Wilcoxon's signed ranks tests were used for analysis. Data from 65 patients were analyzed. Subjective voiding function did not change; however, maximum flow rates decreased by up to 43%: from 29 ml/s to 16 ml/s on free flow studies. This was associated with a 27% increase in detrusor pressure at maximum flow: from 15 to 19 cmH(2)O. Postvoid residuals were not clinically different, changing from a median of 15 ml to 30 ml postoperatively. Thirty-eight patients (37%) required postoperative catheterization for urinary retention (median duration 4 days). We concluded that the TVT sling reduces maximum flow rates without clinically significant effects on detrusor pressure, residual urine or subjective voiding.