Does body mass index influence the outcome of midurethral sling procedures for stress urinary incontinence?

Whether midurethral sling (MUS) procedures are as effective in obese women as they are in women of normal weight is still a matter of controversy. The objective of this study was to determine if body mass index (BMI) influences the outcome of MUS procedures for stress urinary incontinence (SUI).

We searched electronic databases including EMBASE, MEDLINE, Web of Science and Ovid evidence-based medicine reviews to identify studies that explored the association between BMI and outcomes of MUS procedures. The studies were rated using the Newcastle-Ottawa scale; the meta-analysis was performed using Review Manager 5.3 software.

This review included 11 studies, 6 prospective cohort studies and 5 retrospective studies, with a total of 2,846 patients. The objective success rates of MUS in patients with BMI >25 kg/m² (overweight and obese) were lower than in patients with BMI 18.5 - <25 kg/m² (normal weight; RR = 0.93, 95 % CI 0.89 - 0.97; P = 0.002). The objective success rates were not significantly different between the overweight group (BMI 25 - <30 kg/m²) and the obese group (BMI ≥30 kg/m²; RR = 0.95, 95 % CI 0.89 - 1.01; P = 0.08). There were no significant differences in subjective outcomes among the different BMI groups: BMI ≥25 kg/m² versus 18.5 - <25 kg/m² (RR = 1.03, 95 % CI 0.97 - 1.10; P = 0.29), and BMI ≥30 kg/m² versus 25 - <30 kg/m² (RR = 0.98, 95 % CI 0.92 - 1.04; P = 0.55).

The objective success rates of MUS were lower in overweight and obese patients; however, the subjective outcomes of MUS were not significantly different among normal weight, overweight and obese patients. The MUS procedure is as effective in obese women as in women of normal weight, and therefore surgeons should not consider BMI >25 kg/m² as a risk factor when discussing the suitability of the MUS procedure in a patient with SUI.