Surgeon volume and reoperation risk after midurethral sling surgery

Abstract

Emerging research supports that fewer complications occur in patients who undergo surgery by higher surgical volume surgeons. The midurethral sling surgery has been involved in recent warnings and litigation, which further supports a need to understand features that enhance its safety and efficacy. The purpose of this study was to measure the impact of a surgeon's volume on their patient's rate of reoperation after midurethral sling surgery. This was a retrospective cohort study that evaluated all surgeons who performed synthetic mesh midurethral sling surgery for stress urinary incontinence at a large managed care organization with >4.5 million members from 2005-2016. Physicians Current Procedural Terminology and International Classification of Diseases, version 9/10, codes were used to identify the procedures and the reoperations that were performed. The system-wide medical record was queried for demographic and perioperative data. The primary outcome was the overall reoperation rate after midurethral sling surgery. Concentration curves were used to identify the impact of a surgeon's surgical volume on their rate of reoperation. Demographics, characteristics, and reoperation of patients were compared with the use of chi-square test for categoric variables and Wilcoxon rank sum test for continuous variables. Poisson regression models with a robust error variance were used to calculate the unadjusted and the adjusted risk ratios of reoperation with the use of age, body mass index, marital status, race, parity, vaginal estrogen use, sling type, smoking, diabetes mellitus, and menopausal status as covariates. Two hundred twenty-seven surgeons performed 13,404 midurethral sling surgeries over the study period; patients had a mean of 4.4 years of follow up. Higher-volume surgeons (>40 procedures/year, ≥95th percentile) performed 47% of the surgeries in this cohort and had an overall lower rate of reoperation (3.6% vs 4.2%; 95% confidence interval, 0.67-0.94; P=.04) compared with lower-volume surgeons. Higher-volume surgeons had a lower rate of reoperation for surgical failure (2.7% vs 3.6%; 95% confidence interval, 0.55-0.92; P<.01). Rates of reoperation for complications were similar between the 2 groups (1.1% vs 0.9%; 95% confidence interval, 0.82-1.13; P=.32). For patients whose condition required a reoperation secondary to complication, the rates of reoperation for urinary retention (0.9% vs 0.6%; P=.06), mesh exposure (0.2% vs 0.3%; P=.31), hemorrhage/bleeding (0.1% vs 0.0%; P=.11), pain (0.1% vs 0.1%; P=.52), and infection (0.0% vs 0.0%; P=.37) did not differ between higher- and lower-volume surgeons. The risk ratio for reoperation that compared higher- and lower-volume surgeons was 0.83 (95% confidence interval, 0.67-0.98; P=.01) in the adjusted model. Although the reoperation rates were low for both higher- and lower-volume surgeons, higher-volume surgeons had lower overall rates of reoperation after midurethral sling surgery. This effect is seen most dramatically in reoperation for surgical failure, in which patients who have surgery with a higher-volume surgeon are 25% less likelytohave postoperative stress urinary incontinence that leads to reoperation.