Indocyanine green fluorescence-guided imaging enhances the efficiency and accuracy of inferior mesenteric artery lymph node dissection in rectal cancer.

Background: Indocyanine green fluorescence-guided imaging (ICG-FGI) enhances surgical precision in rectal cancer procedures; however, it is technically demanding. This study evaluated the effects of ICG-FGI on the efficacy of lymphadenectomy during radical rectal cancer surgery.

Methods: This multi-center retrospective cohort study analyzed patients who underwent laparoscopic radical resection for rectal cancer between January 2021 and December 2024. The participants were stratified into two cohorts (ICG and non-ICG groups) using 1:1 propensity score matching to ensure balanced baseline characteristics. The ICG group received a submucosal ICG injection 24 h preoperatively with intraoperative fluorescence laparoscopy navigation, whereas the non-ICG group underwent standard laparoscopy. Linear and logistic regression assessed determinants of lymph node yield and inferior mesenteric artery (IMA) lymph node metastasis, respectively. Diagnostic value of ICG-FGI in detecting IMA lymph node metastasis was assessed.

Result: Patients with rectal cancer were enrolled from two centers with comparable baseline characteristics. Propensity score matching (1:1) yielded 141 matched pairs (ICG vs. non-ICG) for comparative analysis. The ICG cohort exhibited superior lymph node resection (21 vs. 17, P < 0.001) and higher number of patients with metastatic IMA lymph nodes detected (15.6 vs. 5.7%, P = 0.007). Multivariate linear regression analysis demonstrated that ICG-FGI was an independent predictor of enhanced nodal yield. Logistic regression analysis revealed that ICG-FGI technology significantly improved the detection rate of metastatic IMA lymph nodes. ICG-FGI sensitivity for detecting metastatic IMA station was 73.3%. Negative predictive value was 94.33% for non-fluorescent stations. Subgroup analysis revealed 75.00, 54.55, and 86.67% sensitivities for pT2, pT3, and pT4 tumors, respectively.

Conclusion: ICG-FGI improves the precision of lymph node dissection during rectal cancer surgery, enhances pathological staging accuracy via superior detection of metastatic IMA nodes, and guides personalized treatment strategies for advanced-stage disease.