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

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.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.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.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.