LONG BEACH, Calif. – Among women who underwent midurethral sling surgery for stress incontinence, failure at 12 months was twice as likely if they also had urge incontinence symptoms at baseline, a study has shown.
In a multivariate analysis of 12-month outcomes of the Trial of Mid-Urethral Slings (TOMUS), Dr. Holly E. Richter determined that the risk of treatment failure increased by 94% for every 10-point increase in the MESA (Medical, Epidemiologic, and Social Aspects of Aging) urge score.
Three other baseline factors also emerged as significant independent predictors of treatment failure. Women who had prior urinary incontinence surgery were 96% more likely to experience treatment failure. Those with decreased urethral motility, as judged by a maximum Q-tip excursion angle of less than 30 degrees were 89% more likely to fail. And every 10-g increase in pad weight increased the risk of treatment failure by 6%. The results were adjusted for treatment site and treatment group.
At the annual meeting of the American Urogynecologic Society, Dr. Richter of the University of Alabama at Birmingham pointed out that TOMUS and the Stress Incontinence Surgical Treatment Efficacy Trial (SISTEr) yielded similar results in predicting treatment failure.
“There is one covariate to me that really stands out,” she said at the meeting. “We’ve spent millions of dollars, two big trials, almost 1,200 patients, and I think if we learned one thing, [it’s that] urge incontinence symptoms are problematic. I think that in studies we do in the future regarding women [who] undergo stress incontinence surgery, we need to take a more robust look at this.”
In the TOMUS study, investigators randomized 597 women to receive a transobturator or retropubic midurethral sling. All patients suffered from stress-predominant urinary incontinence.
Twelve months following the surgery, investigators were able to evaluate 563 of the women for objective and subjective cure. Objective cure consisted of a negative stress test, a negative 24-hour pad test, and no behavioral, pharmacologic, or surgical retreatment for stress urinary incontinence (SUI). Subjective cure consisted of no self-reported symptoms of SUI, no self-reported leakage on a 3-day voiding diary, and no retreatment for SUI.
Of the 563 women examined at 12 months, 54% met all the criteria for objective and subjective cure. Of the remaining 46% of women, 42% had both objective and subjective failure, 50% had subjective failure only, and 6% had objective failure only. (No objective failure data were available for the remaining 2% of women in that group).
There were no significant differences between the retropubic and midurethral sling groups in the relationships between each covariate and treatment failure.
Several factors emerged as significant independent predictors of objective versus subjective failure. They included no concomitant surgery (odds ratio, 2.22); increased age (OR, 1.46 per 10 years); increased bother (OR, 1.10 for every 10 points in Urinary Distress Inventory scores); and pad weight (OR, 1.08 for every 10 g).
“This information may assist in counseling women regarding efficacy and setting appropriate expectations for women at increased risk for failure,” Dr. Richter said.
He disclosed receiving research support from Pfizer Inc. and serving as a consultant for Astellas Pharma Inc., Xanodyne Pharmaceuticals Inc., and IDEO. The TOMUS study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases.