Extended-duration antibiotics are not associated with a reduction in surgical site infection in patients with ovarian cancer undergoing cytoreductive surgery with large bowel resection

Objective(s) To evaluate whether extended dosing of antibiotics (ABX) after cytoreductive surgery (CRS) with large bowel resection for advanced ovarian cancer is associated with reduced incidence of surgical site infection (SSI) compared to standard intra-operative dosing and evaluate predictors of SSI. Methods A retrospective single-institution cohort study was performed in patients with stage III/IV ovarian cancer who underwent CRS from 2009 to 2017. Patients were divided into two cohorts: 1) standard intra-operative dosing ABX and 2) extended post-operative ABX. All ABX dosing was at the surgeon's discretion. The impact of antibiotic duration on SSI and other postoperative outcomes was assessed using univariate and multivariable Cox regression models. Results In total, 277 patients underwent cytoreductive surgery (CRS) with large bowel resection between 2009 and 2017. Forty-nine percent (n = 137) received standard intra-operative ABX and 50.5% (n = 140) received extended post-operative ABX. Rectosigmoid resection was the most common large bowel resection in the standard ABX (89.9%, n = 124) and extended ABX groups (90.0%, n = 126), respectively. No significant differences existed between age, BMI, hereditary predisposition, or medical comorbidities (p > 0.05). No difference was appreciated in the development of superficial incisional SSI between the standard ABX and extended ABX cohorts (10.9% vs. 12.9%, p = 0.62). Of patients who underwent a transverse colectomy, a larger percentage of patients developed a superficial SSI versus no SSI (21% vs. 6%, p = 0.004). Conclusion(s) In this retrospective study of patients with advanced ovarian cancer undergoing CRS with LBR, extended post-operative ABX was not associated with reduced SSI, and prolonged administration of antibiotics should be avoided unless clinically indicated.