Predictive Value of Urodynamics on Outcome After Midurethral Sling Surgery for Female Stress Urinary Incontinence

Abstract

Urodynamic investigation (UDI) is routinely performed before midurethral sling surgery (MUS) for female stress urinary incontinence to detect factors that may adversely affect the surgical outcome or confirm the diagnosis. A recent review, however, concluded that there was insufficient evidence to demonstrate that the likelihood of incontinence was less among women who had preoperative UDI compared to those without the testing. This retrospective cohort study assessed the predictive value of UDI in the workup of 3 different midurethral sling procedures and determined risk factors associated with surgical failure. Data was obtained from the medical records of 437 patients with incontinence, who underwent UDI before surgical treatment with tension-free vaginal tape (TVT), Monarc, or TVT-obturator procedures. No other urogynecologic surgery was performed at the same time. The mean follow-up period was 14 months. The study cases had been included in prior prospective studies investigating the surgical outcome of the TVT and TVT-obturator procedures in women with female stress urinary incontinence. Women who had no loss of urine after physical exercise were considered to be cured. The report of any amount of leakage was considered a failure. The cure rate in the 437 patients who were treated with MUS was 79%, and there was no statistically significant difference in cure rate between the 3 procedures. Multivariate logistic regression analysis showed that risk factors associated with failure of MUS were mixed urinary incontinence (P = 0.042), previous incontinence surgery (P = 0.022), and detrusor overactivity (P = 0.024). None of the urodynamic parameters evaluated had any predictive value for failure in patients with mixed urinary incontinence or previous incontinence surgery. There was predictive value for patients with detrusor overactivity, which represents only 6% of the patient population. These findings indicate that UDI may have no overall clinically significant predictive value for failure of midurethral sling procedures. Only a small percentage of patients with detrusor overactivity appear to benefit from UDI. The investigators suggest that the current practice of routine UDI before the surgery should be reconsidered.