Antithrombotic Therapy Is a Risk Factor for Anastomotic Leakage in Prospective Cohort of Colorectal Surgery Patients

Background: Anastomotic leakage is a serious and potentially lethal complication following colorectal surgery. Careful patient selection is essential to reduce its incidence. This study aimed to identify pre-operative risk factors for anastomotic leakage using a large, multicenter cohort. Study Design: In this secondary analysis of a prospective multicenter cohort, 1,346 patients undergoing colorectal surgery in two teaching hospitals were included. Anastomotic leakage was defined as radiological or surgical confirmation of anastomotic dehiscence, or drainage of pus or enteral content near the anastomosis within 30 days postoperatively. Pre-operative risk factors were selected based on clinical reasoning and analyzed using the Least Absolute Shrinkage and Selection Operator (LASSO) method, followed by multivariable logistic regression. Results: Of the 1,346 patients, 118 (8.8%) developed anastomotic leakage. Identified risk factors included antithrombotic therapy (OR 2.10, 95% CI 1.27-3.44), previous colorectal surgery (OR 1.69, 95% CI 1.04-2.70), male sex (OR 1.99, 95% CI 1.30-3.10), and anastomosis < 5 cm from the anal verge (OR 2.28, 95% CI 1.15-5.67). Conclusions: Antithrombotic therapy emerged as an independent risk factor for anastomotic leakage after colorectal surgery, in addition to known risk factors as male sex, previous colorectal surgery and an anastomosis close to the anal verge. Further research is warranted to clarify this association.