Comparison of tension-free vaginal taping versus modified Burch colposuspension on urethral obstruction: a randomized...

To determine whether the tension-free vaginal tape (TVT) procedure affects the mechanics of voiding in women with genuine stress incontinence (GSI).

Between July of 1997 and July of 1999, 116 women with GSI in the absence of pelvic prolapse underwent a randomized controlled study of TVT vs. modified Burch colposuspension. The trial was conducted by using a standardized protocol, including strict criteria for excluding preexisting bladder outlet obstruction (BOO). Urodynamic studies including free flowmetry, filling (provocative) and voiding cystometry, and 1-hour pad test were performed before and at least 1 year after the operation. The Blaivas and Groutz nomogram was used as another criteria to assess the pre- and postoperative BOO.

Eighteen women were excluded from the study as a result of having preexisting BOO and an additional 8 were lost to follow-up. The comparison between pre- and postoperative variables for each procedure revealed that maximal flow rate of noninvasive uroflowmetry was significantly lower after operation in both groups (P = 0.009, P = 0.010, respectively). Detrusor pressure at maximal flow and urethral resistance were significantly higher and micturition volumes significantly lower after operation in the Burch group (P < 0.001, P < 0.001, P = 0.029, respectively). The difference between pre- and postoperative distribution of the obstruction nomogram of the Burch group was significantly different (P = 0.023).

Based on strict exclusion criteria for preoperative BOO, our findings strongly suggest that with a median 22 months (range, 12 to 36 months) of follow-up, a properly performed tension-free vaginal tape procedure does not cause urethral obstruction.