Surgical site infections (SSIs) are a leading cause of healthcare-associated morbidity, accounting for up to 40% of nosocomial infections [1]. In patients with gynecologic cancer undergoing laparotomy, SSI rates as high as 35% have been reported, with longer hospital stays, readmission, reoperation, and increased healthcare costs [[2], [3], [4], [5], [6], [7]]. Patients who are obese, malnourished, or undergo large bowel surgery are at the highest risk for SSI [[3], [4], [5], [6], [7], [8], [9]]. Notably, patients with gynecologic cancers who develop postoperative SSI have significantly worse progression-free survival (PFS) and overall survival (OS) [[4], [5], [6], [7]].

In recent years, investigators have sought to identify modifiable risk factors and interventions to reduce infection rates. While individual measures, including suture closure [10], antimicrobial skin glue [11], closure trays [12,13], and immuno-nutrition [[14], [15], [16]] have consistently failed to improve infectious outcomes, studies demonstrate that implementing multi-point infection reduction bundles can reduce infectious morbidity [[17], [18], [19], [20]]. In a prospective study by Lippitt et al., the implementation of a 5-point infection prevention bundle, which included skin and vaginal pre-operation with 4% chlorhexidine, preoperative antibiotic (ABX), mechanical bowel preparation, and appropriate timing of intra-operative ABX, led to significantly improved SSI rates [17]. Specifically, the bundle decreased the incidence of SSI from 20% to 3% in all patients and 33% to 7% in those who underwent colon resection [17].

One barrier to the evolution of surgical and perioperative care is the long-standing dogmatic practices that may not be rooted in high-quality evidence. While prophylactic antibiotics within 60 min of incision are the preoperative standard of care [21] owing to the substantial reduction in infectious morbidity, some surgeons may continue ABX post-operatively following cytoreductive surgery (CRS) with large bowel resection [22]. While the potential risks and benefits of prolonged perioperative ABX have not been explored in patients with gynecologic cancer, studies in patients following cardiac and colorectal surgery demonstrate no SSI reduction, increased rates of C.Difficile colitis, and acute kidney injury with this practice [[23], [24], [25]]. Additionally, newer retrospective data suggests that ABX use during chemotherapy is associated with worse oncologic outcomes in patients with ovarian cancer receiving platinum chemotherapy, as well as recurrent gynecologic cancers treated with immunotherapy [[26], [27], [28]]. Therefore, understanding how additional antibiotics during and after CRS with large bowel resection impact SSI will aid in implementing evidence-based strategies to improve infectious outcomes in patients with ovarian cancer. The objective of this study was to determine whether extended dosing of ABX after CRS with large bowel resection is associated with reduced incidence of SSI and other postoperative and oncologic adverse outcomes compared to standard intra-operative antibiotic dosing in patients with advanced ovarian cancer.