The predictive value of preoperative pressure-flow studies in the resolution of detrusor overactivity and overactive bladder after tension-free vaginal tape insertion.

OBJECTIVE: To determine whether preoperative pressure-flow studies (PFS) predict the resolution of detrusor overactivity (DO) and overactive bladder (OAB) symptoms after a tension-free vaginal tape procedure (TVT). PATIENTS AND METHODS: Thirty-five consecutive women with mixed DO and urodynamic stress incontinence (USI) undergoing a TVT had PFS before and afterward reviewed, and the results compared.
RESULTS: There was resolution of OAB symptoms in 51%; the persistence of OAB symptoms was predicted by a significant decrease (20.0 to 14.0 mL/s) in the maximum flow rate after the TVT (P = 0.027) and a significant increase in the detrusor pressure at maximum flow after the TVT (P = 0.04). DO was absent on cystometry in 46% of women after the TVT. Women with persistent DO on cystometry had a significantly lower (P = 0.02) maximum flow rate before the TVT (mean 19.3 mL/s) than those with no persistent DO (mean 26.9 mL/s). This finding persisted when flow rates were corrected for voided volume (P = 0.04). Before and after TVT there were no significant differences between the groups in voiding time and acceleration of flow. USI was objectively cured in 92% of the women.
CONCLUSIONS: Women whose maximum flow rate decreases significantly after the TVT are more likely to have persistent OAB symptoms. The urinary flow rate before the TVT was significantly higher in women with an objective cure of DO after TVT than in women with persistent DO. These findings support an obstructive cause in women in whom DO does not resolve.