Effect of Morbid Obesity on Midurethral Sling Efficacy for the Management of Stress Urinary Incontinence

Objectives The aim of our study was to assess midurethral sling (MUS) failure rate in the morbidly obese (body mass index [BMI] ≥40 kg/m²) population as compared with normal-weight individuals. Our secondary objective was to assess the difference in complication rates. Methods This is a retrospective cohort study. We included all patients who underwent a synthetic MUS procedure from January 1, 2008, to December 31, 2015, in our health system. Failure was defined as reported stress urinary incontinence symptoms or treatment for stress urinary incontinence. Variables collected were BMI; smoking status; comorbidities; perioperative (≤24 hours), short-term (≤30 days), and long-term (>30 days) complications; and follow-up time. Statistics include analysis of variance, χ² test, logistic regression, Kaplan-Meier method, and Cox regression. Results There were 431 patients included in our analysis. Forty-nine patients were in class 3 with a BMI mean of 44.9 ± 5.07 kg/m². Median follow-up time was 52 months (range, 6-119 months). Class 3 obesity (BMI ≥40 kg/m²) was the only group that had an increased risk of failure when compared with the normal-weight group (P = 0.03; odds ratio, 2.47; 95% confidence interval, 1.09-5.59). Obesity was not a significant predictor of perioperative, short-term, or long-term postoperative complications (P = 0.19, P = 0.28, and P = 0.089, respectively) after controlling for other comorbidities. Conclusions Patients in the class 3 obesity group who are treated with an MUS are 2 times as likely to fail when compared with those in the normal-weight category on long-term follow-up with similar low complication rates.