Anastomotic leakage remains a major complication after colorectal cancer surgery. Indocyanine green fluorescence angiography (ICG-FA) allows real-time intraoperative assessment of bowel perfusion; however, its clinical impact remains controversial.

This prospective single-center observational study evaluated the association between intraoperative use of ICG-FA and postoperative outcomes in patients undergoing laparoscopic sigmoid or rectal cancer surgery. Outcomes of patients assessed with ICG-FA were compared with those of a historical control cohort treated without fluorescence imaging.

This was a prospective, single-center observational cohort study conducted at a tertiary academic surgical center. Adult patients undergoing elective laparoscopic resection for sigmoid or rectal adenocarcinoma were included. In the prospective cohort, indocyanine green fluorescence angiography was used intraoperatively to assess bowel perfusion prior to anastomosis creation. The decision to modify the transection line was left to the operating surgeon based on fluorescence imaging.

Study outcomes in the ICG-FA cohort were compared with a historical control group of patients who underwent similar laparoscopic procedures without fluorescence imaging during an earlier period at the same institution. The primary outcome was the incidence of anastomotic leakage within 30 days after surgery, defined according to the International Study Group of Rectal Cancer criteria. Secondary outcomes included anastomotic stricture diagnosed during follow-up, postoperative complications, reoperation rate, length of hospital stay, and 30-day mortality.

All patients were treated according to standard institutional perioperative protocols. Data were collected prospectively for the ICG-FA cohort and retrospectively for the control cohort. The study was approved by the local Research Ethics Board, and all procedures were performed in accordance with the Declaration of Helsinki.

Inclusion Criteria:

• Age ≥ 18 years
• Histologically confirmed or clinically suspected sigmoid or rectal adenocarcinoma
• Elective laparoscopic resection with curative intent and planned colorectal/coloanal anastomosis
• Ability to provide informed consent

Exclusion Criteria:

• Pregnancy or breastfeeding
• Known hypersensitivity to indocyanine green or iodine
• Emergency surgery
• Planned end colostomy without anastomosis
• Conversion to open surgery

Adult patients undergoing elective laparoscopic resection for sigmoid or rectal adenocarcinoma at a single tertiary academic center.