Surgical site infection risk in cesarean delivery patients with obesity after negative pressure wound therapy: A retrospective cohort study.

BACKGROUND: There are conflicting reports of postoperative efficacy of negative pressure wound therapy in patients with obesity after cesarean delivery. METHODS: Retrospective cohort study for patients with obesity and negative pressure wound therapy or abdominal dressing after cesarean delivery between April 1, 2014 and January 31, 2018. Postoperative surgical site infection was defined from medical record charting or positive wound culture and confirmed by the hospital's Infection Prevention team. Multivariable logistic regression model for surgical site infection was conducted including additional potential confounding variables. Mantel-Haenszel tests were conducted to stratify by body mass index class and operative time, and we performed quasi-Poisson regression to determine which factors were associated with an increased operative time. RESULTS: We included 4,391 Black or White patients with obesity, 696 (15.9%) underwent negative pressure wound therapy and 3,695 (84.1%) abdominal dressing after cesarean delivery. Incidence of surgical site infection after negative pressure wound therapy and abdominal dressing were 6.1% and 3.4%, respectively (2-sample test of proportions P < .001). The multivariable logistic regression (covariates: race, diabetes, body mass index category, insurance, scheduled/emergency, artificial rupture, previous c-section, operative time, age, closure type) found negative pressure wound therapy dressing was associated with an increased risk of surgical site infection (adjusted odds ratio 1.54; 95% confidence interval, 1.01-2.34), as did a Mantel-Haenszel test which was stratified by body mass index (odds ratio 1.62; 95% confidence interval, 1.08-2.43) and a Mantel-Haenszel test stratified by operative time (odds ratio 1.85; 95% confidence interval, 1.28-2.65). Negative pressure wound therapy dressing also led to an increase in operative time in the Quasi-Poisson regression, which was the primary predictor of infection. CONCLUSION: Negative pressure wound therapy was associated with an increased the risk of postoperative surgical site infection after cesarean delivery in our obstetric patients with obesity. Future prospective studies are needed to determine a dressing type and other intervention to decrease postoperative cesarean surgical site infection in women with obesity.