EFFICACY OF ORAL ANTIBIOTIC PROPHYLAXIS COMBINED WITH MECHANICAL BOWEL PREPARATION IN PREVENTING SURGICAL SITE INFECTIONS FOLLOWING ELECTIVE COLORECTAL SURGERY: A SYSTEMATIC REVIEW

Abstract

Introduction: Surgical site infection (SSI) is a frequent complication in elective colorectal surgery, leading to high morbidity and increased hospital costs. Although mechanical bowel preparation (MBP) has historically been the standard, its efficacy when used alone is now questioned; consequently, the addition of oral antibiotics (OA) has emerged as a strategy for the selective decontamination of the digestive tract. Objective: To evaluate and synthesize evidence regarding the impact of preoperative oral antibiotic administration, combined with MBP, on reducing the incidence of SSI in patients undergoing elective colorectal surgery. Methods: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted in accordance with the PRISMA 2020 protocol. The literature search covered the PubMed, Embase, Cochrane, and Scopus databases. The primary outcome was the overall incidence of SSI, while secondary outcomes included anastomotic leaks and mortality. Estimates were pooled using random-effects models (Odds Ratio – OR; 95% CI), and the certainty of the evidence was assessed using the GRADE system. Results: Twelve RCTs were included, totaling 4,073 patients. The combination of mechanical bowel preparation and oral antibiotics was associated with a 47% reduction in the odds of developing a surgical site infection compared to mechanical bowel preparation alone (OR = 0.53; 95% CI: 0.37–0.75; p < 0.001). A consistent benefit was observed for both incisional surgical site infections (SSIs) (OR 0.52; p = 0.003) and organ/space SSIs (OR 0.63; p = 0.007), with the latter showing high statistical stability (I² = 8.3%). No significant differences were identified regarding mortality or fistula rates. The certainty of the evidence for the primary outcome was moderate. Conclusion: Prophylaxis with oral antibiotics combined with mechanical bowel preparation is effective in preventing postoperative infections and should be considered the standard of care for elective colorectal surgeries, particularly in resections with a high microbial risk.