ICG Fluorescence Angiography to Reduce Anastomotic Leak After Laparoscopic Colorectal Resection

Overview

This prospective randomized controlled trial evaluates whether intraoperative indocyanine green (ICG) fluorescence angiography reduces clinically significant anastomotic leakage after elective laparoscopic colorectal resection with primary anastomosis. A total of 120 adults were allocated in a 1:1 ratio to ICG-guided perfusion assessment or standard visual perfusion assessment, with 60 participants in each group. In the ICG arm, ICG 0.2 mg/kg was administered intravenously after bowel mobilization and before transection, and near-infrared imaging guided selection of a well-perfused transection margin. Participants were followed for 90 days after surgery for grade B or C anastomotic leakage.

Adequate perfusion is essential for colorectal anastomotic healing. Standard intraoperative assessment relies on bowel color, mesenteric pulsation, and bleeding from the cut edge. ICG fluorescence angiography provides real-time near-infrared visualization of bowel perfusion and may identify inadequately perfused segments before anastomosis. Eligible participants undergoing elective laparoscopic colorectal resection with planned primary anastomosis were randomized using closed-envelope allocation. In the experimental arm, fluorescence was evaluated using a standardized ordinal score: 0, no fluorescence within 60 seconds; 1, delayed or patchy fluorescence at 60 seconds; 2, reduced but homogeneous fluorescence within 30-60 seconds; and 3, rapid homogeneous fluorescence within 30 seconds. Time to fluorescence was recorded at a defined region of interest, and transection was performed at an area showing grade 3 perfusion. In the comparator arm, transection and anastomosis proceeded using standard visual assessment without ICG. Postoperative evaluation included clinical surveillance. Contrast-enhanced computed tomography of the abdomen and pelvis was obtained when clinically indicated. Clinically significant anastomotic leakage was defined as grade B or C leakage within 90 days and confirmed by clinical findings, contrast imaging, or reoperation.