Effectiveness of midurethral slings in mixed urinary incontinence: a systematic review and meta-analysis

Mixed urinary incontinence (MUI) is a coexistence of stress (SUI) and urgency urinary incontinence (UUI). There is conflicting evidence on the effectiveness of midurethral slings (MUS) in this condition. The objective of this study is to evaluate the effectiveness of MUS in women with MUI by systematic review of the literature.

Systematic literature search was carried (June 2010) using relevant search terms in Medline, EMBASE, CENTRAL and Google Scholar. Relevant randomised controlled trials (RCT) and prospective studies were selected and then analysed by two independent reviewers. Meta-analysis was performed with random effects model using STATA 8.

There were six randomised trials and seven prospective studies with average to good quality included in this systematic review. There was heterogeneity in outcomes reported. The overall subjective cure from seven prospective nonrandomised studies that included patients with symptomatic ± urodynamically proven MUI was found to be 56.4% (95% confidence interval 45.7-69.6%) at 34.9 ± 22.9 months follow-up. The overall cure of urgency and UUI component was 30-85% at a follow-up of few months up to 5 years. Most of the studies described that this cure does not persist over the time. The cure rate of SUI following MUS varies from 85% to 97%. On meta-analysis of five RCTs which included women with MUI symptoms, the odds of overall subjective cure with TVT versus transobturator tapes are similar at 6-33 months follow-up (OR, 0.9; 95% CI, 0.63-1.27). This was true when a subgroup analysis was performed on women with MUI who were negative for DO on UDS (OR, 1.21; 95% CI, 0.7-2.08)

There is evidence of persistent and good cure of stress component following MUS in women with MUI. The cure of the urge component is variable but less than stress component. Methodologically sound RCTs of retropubic and transobturator tapes with long-term follow-up are needed specifically for women with urodynamically proven and symptomatic mixed incontinence.