Another Brick in the Wall of an Ongoing Discussion– Reduction of Anastomotic Leaks after Colorectal Resection by Preoperative Mechanical Bowel Preparation in Combination with Oral and Parenteral Antibiotics?–A Clinical Retrospective Single Center Study

Background: In colorectal surgery, postoperative Anastomotic Leak (AL) is a serious complication. Besides the surgeon`s experience, bowel preparation may have an impact on AL, but the published data are still inconclusive. The purpose of this retrospective single center study was to investigate the role of preoperative Mechanical Bowel Preparation (MBP) in combination with Oral Antibiotic Bowel Preparation (OBP) and parenteral antibiotics in a certified highvolume colorectal center. Methods: In the period of January 2017 to December 2019, all colon and rectal surgeries were recorded and separated into emergency and elective surgeries. Patients in the elective surgery group were further divided into two groups: patients with Bowel Preparation (BP) and patients without BP and were evaluated concerning to AL, postoperative hospital length of stay and mortality. Results: Between 2017 to 2019, 625 patients underwent colorectal surgery. 262 patients had emergency operations and were therefore excluded from the study. 363 patients underwent colorectal elective surgery (197men, 166 women). 44.0% received Combined Bowel Preparation (CBP), 46.8% received no BP, 3.3% received OBP only, 4.1% received MBP only, and for 1.1% nothing was documented. CBP was not only associated with a reduction in the rate of AL (P=0.038) (14.1% vs. 4.4%), but also with reduction in mortality (P=0.032) (7.6% vs. 1.2%) and length of stay (P=0.016) (14 vs. 11 days). Conclusion: Our retrospective data showed a significant impact of preoperative intestinal preparation with MBP in combination with OBP and parenteral antibiotics on AL, length of stay and mortality. Therefore we strongly recommend the use of this regimen of preoperative BP in elective colorectal surgery.