ICG Fluorescence Angiography to Reduce Anastomotic Leak After Laparoscopic Colorectal Resection

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.

Inclusion criteria

• Adults aged 18 years or older.
• Undergoing elective laparoscopic colorectal resection.
• Planned primary colorectal anastomosis.
• Able and willing to provide written informed consent.

Exclusion criteria

• Known allergy to iodine or indocyanine green.
• Severe hepatic dysfunction.
• Severe renal dysfunction.
• Emergency colorectal resection.
• Inflammatory bowel disease requiring extensive resection.
• Previous colorectal surgery involving the planned anastomotic site.