Mitigating ‘inevitable’ anastomotic leaks in left-sided colorectal surgery: a combined strategy using indocyanine green fluorescence, intraoperative colonscopy and patient risk profiling

This study aimed to identify patient-specific risk factors and intraoperative findings obtained from indocyanine green fluorescence angiography (ICG-FA) and intraoperative colonoscopy (IOC), using a structured endoscopic grading scale, to guide surgical decisions and minimize the risk of anastomotic leakage in colorectal surgery. One hundred-eleven patients undergoing elective left-sided colorectal resections were evaluated intraoperatively using both ICG-FA and IOC, with anastomoses classified by a new endoscopic grading scale (Grades 1–5). Anastomoses classified as suboptimal (grade > 3) were taken down and reconstructed or repaired. The primary aim of the study was to determine the rate of anastomotic leakage (AL) using this integrated strategy and subsequently to identify patient-specific risk factors associated with AL. Among 111 patients, 102 patients (91.8%) at the IOC were classified as Grade 1, 4 patients (3.6%) as Grade 2, 4 patients (3.6%) as Grade 3, and 1 patient (0.9%) as Grade 4. The overall AL rate was 10.8% (12 patients). On multivariate logistic regression analysis, only anastomotic level ≤ 12 cm emerged as an independent risk factor of AL (OR 0.064, 95% CI 0.008–0.517, p = 0.010). Among patients who developed an AL, 3 (25%) required surgical intervention, the others were managed endoscopically or conservatively. An integrated approach involving ICG-FA and IOC may aid to construct a technically optimal colorectal anastomosis. Nevertheless, anastomotic leakage can still occur due to factors unrelated to intraoperative technique, particularly low anastomosis height. These factors should prompt routine consideration of protective loop ileostomy and pelvic drainage to mitigate AL clinical consequences.