The Impact of Surgical Center Volume on Reoperation Risk after Mid Urethral Sling.

Abstract

We sought to determine whether a center's surgical volume affects patient reoperation rates after mid urethral sling (MUS) surgery. We performed a retrospective cohort study evaluating a large managed care organization from 2005 to 2016. The primary outcome was the MUS reoperation rate. Perioperative factors and reoperation of patients were compared using Wilcoxon rank-sum for continuous variables and chi-square for categorical variables. We estimated the adjusted hazard ratio and the 95% confidence interval of reoperation using Cox proportional hazards model. Within the managed care system, 13,404 primary MUSs were performed at 11 centers over the study period (19/105 center years were considered low volume). Higher-volume centers (>58 procedures/year based on concentration curve) performed 93% of surgeries in this cohort. Overall reoperation risk for patients of higher-volume centers was smaller than those of lower-volume centers, 4.9% vs 9.8% at 9 years (hazard ratio 0.45 [p <0.01]). Risk of reoperation for recurrent stress urinary incontinence (SUI) for patients was lower in the higher-volume centers, 4% vs 9.1% at 9 years (p <0.01). Patient of higher-volume centers were less likely to have a reoperation for mesh exposure 0.2% vs 0.7% (p <0.01) or infection 0% vs 0.2% (p <0.01). Patients who had their MUS surgery at a higher-volume medical center were less likely to have any reoperation including for recurrent SUI, mesh exposure or infection. These findings persisted even when controlling for potential covariates including patient demographics and surgeon volume and specialty.