The intersection of tumor location and combined bowel preparation: Utilization differs but anastomotic leak risk reduction does not

Background and Objective: Whether bowel preparation utilization rates or effectiveness varies based on tumor location is unknown. Methods: The 2012–2016 American College of Surgeons National Surgical Quality Improvement Program Colectomy Targeted participant user file was queried for patients undergoing elective colorectal resection for cancer. Bowel preparation was classified as combined, mechanical bowel preparation alone, oral antibiotic alone, or none. Cochran–Armitage tests were used for trend analysis. Multivariable analyses stratified by tumor location were performed for the outcome of anastomotic leak. An additional multivariable model including all tumor locations assessed for interaction between bowel preparation and tumor location on an anastomotic leak. Results: A total of 29,739 operations were included and the anastomotic leak rate was 1.9% with combined preparation versus 4.0% without preparation. Combined bowel preparation utilization increased over time as tumor location became more distal (both p <.0001). However, the adjusted effect of combined bowel preparation on anastomotic leak risk reduction did not differ by individual tumor location or across all tumor locations (p =.43 for interaction). Conclusion: Though the utilization rate of combined bowel preparation increased as tumor location became more distal, its risk-reducing effect remained similar. Quality improvement initiatives should focus on increased utilization of combined bowel preparation with an emphasis on tumors in the ascending colon.