Efficacy Of Various Modes Of Bowel Preparation to Prevent Surgical Site Infection Following Elective Colorectal Resection

Abstract

Purpose: Administration of a mechanical bowel preparation (MBP) has long been standard before colorectal surgery with the aim of preventing complications such as surgical site infection (SSI). Newer evidence suggests that MBP does not reduce the risk of infection and that oral antibiotic (OA) use may be important in reducing post-operative infectious complications, however, there is little evidence comparing MBP, OA, and combination preparations. Our goal was to determine the relationship between type of bowel preparation and SSI in patients undergoing elective colorectal resections Methods: All patients within the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database undergoing elective colorectal resections from 2012 to 2013 were identified. The primary outcomes of interest were: any post-operative SSI, wound SSI, and organ/space SSI. Secondary outcomes were anastomotic leak, post-operative ileus, cardiac complications, renal complications, death, unplanned readmission, and length of stay (LOS). Univariate models were used to compare frequencies of patient and surgical characteristics across types of bowel preparation, and propensity adjustment was used to study the relationship between type of bowel preparation and all outcomes of interest. Results: Among the study sample, 25.5% received no bowel preparation, 40.8% received MBP, 3.3% received OA, and 30.4% received OA+MBP. A total of 1,844 patients (9.5%) developed any type of post-operative SSI. 1,231 (6.4%) developed a wound SSI and 672 (3.5%) developed an organ/space SSI. MBP was not associated with a reduced risk of any type of SSI compared to no bowel preparation. Both OA and OA+MBP were significantly associated with a decreased risk of any SSI and wound SSI compared to both no preparation and compared to MBP. No differences were observed for any SSI or wound SSI between OA and OA+MBP. Compared to no preparation, OA+MBP was associated with a decreased risk of anastomotic leak and post-operative ileus. No differences were observed between MBP and OA, or between these preparation methods and no preparation, for these secondary outcomes. There were no significant associations between type of bowel preparation and cardiac or renal complications, mortality, or readmissions. Both OA and OA+MBP were associated with a reduction in LOS. Conclusion: These results suggest that a combination oral and mechanical bowel preparation may be most effective at preventing SSI after elective colorectal resection and that OA alone may also be effective. Future prospective studies comparing combination and OA preparations may be warranted to explore this relationship further.