Metronidazole and Cefazolin Versus Cefazolin Alone for Surgical Site Infection Prophylaxis at Time of Benign Hysterectomy

Objectives: This study aimed to identify whether cefazolin plus metronidazole at time of benign hysterectomy decreases surgical site infection (SSI) rates compared to cefazolin alone. Methods: A retrospective observational study was performed of all patients who underwent elective nononcologic laparoscopic hysterectomy with a single surgeon from July 2022 through November 2024 before and after universal addition of metronidazole to standard cefazolin prophylaxis to evaluate the rate of a sensitive measure of SSI, as defined by either documented exam findings of purulent drainage, localized erythema, or tenderness at the vaginal cuff or abdominal incisions, as well as by antibiotic prescription for a site-specific indication within 30 days. Results: Of the 55 hysterectomies performed during the study period, 48 were included in the final analysis, and the rate of SSI decreased in the post-intervention group from 27.8% (5/18; 95% confidence interval [CI], 9.7%–53.5%) to 3.3% (1/30; 95% CI, 0.1%–17.2%) ( p = 0.022). Conclusions: The addition of metronidazole to cefazolin for antibiotic prophylaxis prior to benign hysterectomy was associated with a decreased rate of a sensitive measure of SSIs in this cohort.