Association of negative pressure wound therapy and surgical site infections in patients undergoing cytoreductive surgery: An entropy balanced analysis

Background and Objectives: Surgical site infections (SSIs) after cytoreductive surgery (CRS) +/- hyperthermic intraperitoneal chemotherapy (HIPEC) are a major cause of potentially avoidable morbidity. We explored the association of negative pressure wound therapy (NPWT) with SSI in patients undergoing CRS/HIPEC. Methods: Retrospective analysis of consecutive patients undergoing CRS/HIPEC for non-gynecologic cancers. Exposure was the receipt of NPWT versus traditional skin closure. Primary outcome was SSI within 90 days of surgery. We performed multivariable logistic regression (before and after entropy balancing) to evaluate the association of exposure with outcomes. Results: A total of 251 patients were included, of which 43 (17%) received NPWT and 26 (10.4%) developed SSIs. Baseline demographics and clinicopathologic characteristics were similar between the two groups with some exceptions: Patients who received NPWT had a higher Peritoneal Carcinomatosis Index (median 19 vs. 11, p = 0.002) and operative time (10 vs. 8.2 h, p = 0.003) but were less likely to undergo HIPEC (84% vs. 95%, p < 0.05). After entropy balancing, on multivariable logistic regression, NPWT was not associated with 90-day SSI (odds ratio = 0.90; 95% confidence interval = 0.21-3.80; p = 0.89). Conclusion: NPWT was not associated with a reduction in SSIs. These findings prompt a reevaluation of the routine use of NPWT in CRS/HIPEC.