A randomized, nonblinded extension study of single-incision versus transobturator midurethral sling in women with stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: Midurethral sling procedures are the first surgical option in women undergoing surgery for stress urinary incontinence (SUI). Single-incision midurethral-slings (SIMS) were designed to provide similar efficacy to traditional midurethral slings but with reduced morbidity. In this international trial we compared the efficacy of a SIMS (MiniArc) and a transobturator standard midurethral sling (SMUS; Monarc) in the treatment of SUI in terms of subjective and objective cure rates and morbidity over a long-term follow-up.

METHODS: This was a randomized controlled nonblinded extended trial with a follow-up period of 36 months. Women with symptomatic SUI were eligible. The primary outcome was subjective cure, defined as an improvement in the Patient Global Impression of Improvement (PGI-I) score. Secondary outcomes were objective cure (negative cough stress test), disease-specific quality of life, surgical parameters and morbidity. An intention to treat analysis was performed. Differences in dichotomous variables were tested using the chi-squared test. Differences in continuous variables were tested using Student's t test or the Mann-Whitney U test. We hypothesized that MiniArc would be noninferior to Monarc concerning subjective cure.

RESULTS: We randomized 97 women to the MiniArc group and 96 to the Monarc group. The attrition rate was 23% in the MiniArc group and 22% in the Monarc group after 3 years. At 36 months, the subjective cure rates were 86% in the MiniArc group and 87% in the Monarc group (risk difference -0.6%, 95% CI -12 to 11%). The objective cure rates were 89% and 88%, respectively (risk difference 1.3%, 95% CI -9 to 11%). Both procedures were associated with low complication rates.

CONCLUSIONS: After a follow-up of 36 months, MiniArc (SIMS) is non-inferior to Monarc (SMUS) with respect to subjective and objective cure.