Objective: To estimate rates of revision surgery after insertion of mesh midurethral slings and explore whether physician specialty, annual operative volume, or hospital type are associated with this outcome.
Methods: A population-based retrospective cohort of women undergoing midurethral sling procedures over a 13-year interval (2004-2017) in Alberta, Canada was created using administrative health data. The primary outcome was subsequent surgery for revision of midurethral sling, defined by a composite of surgical procedures. Exposures included annual number of midurethral sling procedures performed by the surgeon, surgeon specialty, facility type, patient age, and concomitant prolapse repair. Mixed effects logistic regression using linear spines was used to test a-priori hypothesis that annual surgical volume would be inversely related in a nonlinear fashion to risk of revision.
Results: In the cohort of 19,511 women, cumulative rates of revision surgery were 3.84% (95% CI 3.54-4.17) at 5 years and 5.26% (95% CI 4.82-5.74) at 10 years. The first year after midurethral sling placement was the most vulnerable window, with 0.40% (95% CI 0.31-0.49) undergoing revision within 30 days and 2.15% (95% CI 1.95-3.52) within 1 year. Concomitant prolapse repairs (odds ratio [OR] 1.24, 95% CI 1.04-1.48) and surgeon's annual volume were associated with revision. After 50 cases per year, odds of revision declined with each additional case (OR 0.99/case, 95% CI 0.98-0.99, OR 0.91/10 cases, 95% CI 0.84-0.98) and plateaued at 110 cases per year. Surgeon specialty, hospital type, and patient age were not associated with outcome.
Conclusion: One in 20 women undergo revision surgery within 10 years after midurethral sling placement. Higher physician surgical volume is associated with decreased risk, with the decline occurring at a threshold of 50 cases annually. Minimum caseload parameters for surgeons performing midurethral sling procedures may improve quality of these procedures.