Influence of body mass index on short-term subjective improvement and risk of reoperation after mid-urethral sling surgery

Introduction and hypothesis: The objective was to evaluate the impact of body mass index (BMI) on the subjective improvement and risk of reoperation after first-time mid-urethral sling surgery.

Methods: Data were retrieved from the national Danish Urogynaecological Database, including women with first-time surgery with mid-urethral polypropylene slings from 2011 to 2016. The subjective improvement was assessed by the difference in symptoms based on the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) completed pre- and 3 months postoperatively. A reoperation was defined as any new surgical procedure for stress urinary incontinence performed within the study period.

Results: During the study period, 6,414 mid-urethral sling procedures were performed; 80.0% of these women filled out both pre- and post-surgical International Consultation on Incontinence Questionnaire (ICI-Q) forms. 42.4% had a BMI < 25, 34.6% had BMI 25-30, 16.9% had BMI 30-35, and 6.0% BMI >35. The subjective improvement after surgery was high in all BMI categories and there were no differences between the categories. The overall cumulative hazard proportion at 2 years of follow-up was 1.9% (CI 95%: 1.6-2.3) and after 5 years 2.4% (CI 95%: 2.0-2.9). Adjusted for age, smoking, and use of alcohol, the cumulative hazard proportion after 2 years of follow-up was 3.2% (CI 95%: 1.6-6.2) for women with BMI >35 and after 5 years 4.0% (CI 95%: 2.0-7.7), which was the highest proportion of reoperation in the study. The crude hazard ratio was 1.84 (CI 95%: 0.89-3.83) women with BMI >35 and the adjusted hazard ratio was 1.94 (CI 95%: 0.92-4.09).

Conclusions: We found high subjective improvement after the first-time surgery unrelated to BMI. Women with a BMI over 35 had the highest proportion of reoperations, although this was not statistically significant.