Preoperative mechanical bowel preparation with oral antibiotics reduces surgical site infection after elective colorectal surgery for malignancies: results of a propensity matching analysis.

Background: Surgical site infections (SSIs) are a major postoperative complication after colorectal surgery. Current study aims to evaluate prophylactic function of oral antibiotic (OA) intake in combination with mechanical bowel preparation (MBP) relative to MBP alone with respect to postoperative SSI incidence.

Methods: A retrospective analysis of eligible patients was conducted using the databases of the Gastrointestinal Surgery Centre, Third Affiliated Hospital of Sun Yat-sen University from 2011 to 2017. Data pertaining to postoperative hospital stay length, expenses, SSI incidence, anastomotic fistula incidence, and rates of other complications were extracted and compared. A propensity analysis was conducted to minimize bias associated with demographic characteristics. Subgroup analyses were performed to further explore protective effects of OA in different surgical sites.

Results: The combination of OAs and MBP was related to a significant decrease in the incidence of overall SSIs, superficial SSI, and hospitalization expenses. The MBP + OA modality was particularly beneficial for patients undergoing left-side colon or rectum resections, with clear prophylactic efficacy. The combination of MPB + OA did not exhibit significant prophylactic efficacy in patients undergoing right hemi-colon resection. Age, surgical duration, and application of OA were all independent factors associated with the occurrence of SSIs.

Conclusion: These results suggest that the combination of OA + MBP should be recommended for patients undergoing elective colorectal surgery, particularly for operations on the left side of the colon or rectum.

Trial Registration: NCT04258098. Retrospectively registered.