The Role of Indocyanine Green in Laparoscopic Low Anterior Resections for Rectal Cancer Previously Treated With Chemo-radiotherapy: A Single-center Retrospective Analysis

Aim: Anastomotic leakage represents the most fearful complication in colorectal surgery. Important risk factors for leakage are low anastomoses and preoperative radiotherapy. Many surgeons often unnecessarily perform a protective ileostomy, increasing costs and necessitating a second operation for recanalization. The aim of this study was to evaluate the role of indocyanine green in assessing bowel perfusion, even in cases of a low anastomosis on tissue treated with radiotherapy. Patients and Methods: Two groups of patients were selected: Group A (risky group) with only low extraperitoneal rectal tumors (<8 cm) previously treated with neoadjuvant chemo-radiotherapy; group B (no risk group) with only intraperitoneal rectal tumors (>8 cm), not previously treated with neoadjuvant therapy. Clinical postoperative outcome, morbidity, mortality and anastomotic leakage were compared between these two groups. Results: In group A, comprised of 35 patients, the overall complication rate was 8.6%, with two patients developing anastomotic leakage (5.7%). In group B, comprised of 53 patients, the overall complication rate was 17% with four cases with anastomotic leakage (7.5%). No statistical difference was observed for conversion rate, general complications, or anastomotic leakage. No statistical differences were observed in clinical variables except for American Society of Anesthesiologist score (p=0.04). Patients who developed complications during radiotherapy had no significant differences in postoperative outcomes compared with other patients. Conclusion: Indocyanine green appears to be safe and effective in assessing the perfusion of colorectal anastomoses, even in the highest-risk cases, potentially reducing the rate of ileostomy. The main limitation remains the lack of a universally replicable standard assessment.