Long-term outcomes of colorectal cancer after indocyanine green fluorescence-guided laparoscopic radical resection: a retrospective cohort study

BACKGROUND AND AIMS: Previous studies on indocyanine green (ICG) in colorectal surgery have mainly focused on lymphatic mapping, sentinel node detection, and the number of harvested lymph nodes. However, evidence regarding long-term oncologic outcomes following ICG fluorescence-guided colorectal cancer (CRC) surgery remains limited. This study aimed to evaluate the prognostic impact of ICG fluorescence-guided laparoscopic radical resection compared with conventional laparoscopic surgery in CRC patients. METHODS: A retrospective cohort study was performed among 367 CRC patients who underwent laparoscopic radical resection between December 2016 and December 2020 in a single center. Patients were divided into ICG-guided and non-ICG groups and matched using propensity score matching (PSM). The primary endpoint was disease-free survival (DFS), while secondary endpoints included overall survival, cancer-specific survival (CSS), number of harvested lymph nodes, and postoperative complications. RESULTS: After PSM, 204 patients were analyzed (133 in the ICG group and 71 in the non-ICG group). The ICG group had a higher mean number of harvested lymph nodes (15.2 ± 8.0 vs. 12.9 ± 5.7, p = 0.036) and negative lymph nodes (13.5 ± 8.3 vs. 11.2 ± 5.9; p = 0.038). The CSS in the ICG group was significantly better than that in the non-ICG group (p < 0.05). Multivariate Cox regression identified ICG-guided surgery as an independent protective factor for CSS (HR = 0.303, 95% CI 0.113-0.812, p = 0.018). Subgroup analysis demonstrated that ICG guidance conferred a survival benefit in stage III CRC patients for both DFS and CSS. CONCLUSION: ICG fluorescence-guided laparoscopic radical resection increased lymph node yield, particularly negative nodes, and resulted in favorable disease-free and cancer-specific survival in CRC patients, with the most pronounced benefit observed in stage III disease.