Effect of preoperative oral antibiotics and mechanical bowel preparation on the prevention of surgical site infection in elective colorectal surgery, and does oral antibiotic regime matter? a bayesian network meta-analysis.

purposeSurgical site infection (SSI) impacts 5-20% of patients after elective colorectal surgery. There are varying reports on the effectiveness of oral antibiotics (OAB) with preoperative mechanical bowel preparation (MBP) in preventing SSI. We aim to determine the role of OAB and MBP in preventing SSI after elective colorectal surgery. We also determine if a specific OAB regimen will be more effective than others.

methodsThis study investigated the impact of OAB and MBP in patients undergoing elective colorectal surgery. PubMed, MEDLINE, Ovid, Cochrane Central Register of Controlled Trials, ACP Journal Club, and Embase databases were searched for randomized clinical trials (RCTs) published by June 2022. All RCTs comparing various preoperative bowel preparation regimens, including pairwise or multi-intervention comparisons, were included. To establish the role of OAB and MBP in preventing SSI, we conducted a Bayesian network meta-analysis on all RCTs. We further performed subgroup analysis to determine the most effective OAB regimen.

resultsAmong included 46 studies with a total of 12690 patients, patients in the MBP + OAB group were less likely to have SSI than those having MBP-only (OR 0.55, 95% CrI 0.39-0.76), and without MBP and OAB (OR 0.52, 95% CrI 0.32-0.84). OAB regimen C (kanamycin + metronidazole) and A (neomycin + metronidazole) demonstrated a significantly reduced incidence of SSI, compared to regimen B (neomycin + erythromycin) with OR 0.24 (95% CrI 0.07-0.79) and 0.26 (95% CrI 0.07-0.99) respectively.

conclusionsOAB with MBP reduces the risk of SSI after elective colorectal surgery. Providing adequate aerobic and anaerobic coverage with OAB may confer better protection against SSI.