Association of bowel preparation with surgical-site infection in gynecologic oncology surgery: Post-hoc analysis of a randomized controlled trial.

OBJECTIVE: To determine the relationship between bowel preparation and surgical-site infection (SSI) incidence following colorectal resection during gynecologic oncology surgery. METHODS: This post-hoc analysis used data from a randomized controlled trial of patients enrolled from 03/01/2016-08/20/2019 with presumed gynecologic malignancy investigating negative-pressure wound therapy among those requiring laparotomy. Patients were treated preoperatively without bowel preparation, oral antibiotic bowel preparation (OABP), or OABP plus mechanical bowel preparation (MBP) per surgeon preference. Univariate and multivariable analyses with stepwise model selection for SSI were performed for confirmed gynecologic malignancies requiring colorectal resection. RESULTS: Of 161 cases, 15 (9%) had no preparation, 39 (24%) OABP only, and 107 (66%) OABP+MBP. The overall SSI rate was 19% (n = 31)-53% (n = 8/15) in the no preparation, 21% (n = 8/39) in the OABP alone, and 14% (n = 15/107) in the OABP+MBP groups (P = 0.003). The difference between OABP and OABP+MBP was non-significant (P = 0.44). The median length of stay was 9 (range, 6-12), 6 (range, 5-8), and 7 days (range, 6-10), respectively (P = 0.045). The overall complication rate (34%; n = 54) did not significantly vary by preparation type (P = 0.23). On univariate logistic regression analysis, OABP (OR, 0.23; 95% CI: 0.06-0.80) and OABP+MBP (OR, 0.14; 95% CI: 0.04-0.45) were associated with decreased SSI risk compared to no preparation (P = 0.004). On multivariate analysis, both methods of preparation retained a significant impact on SSI rates (P = 0.004). CONCLUSION: Bowel preparation is associated with reduced SSI incidence and is beneficial for patients undergoing gynecologic oncology surgery with anticipated colorectal resection. Further investigation is needed to determine whether OABP alone is sufficient.