Fluorescence lymph node mapping using ICG improves lateral lymph node dissection for mid-low rectal cancer: a propensity score-matched cohort

Tech Coloproctol. 2025 Jul 13;29(1):139. doi: 10.1007/s10151-025-03167-7.

Abstract

Background: Patients with lateral lymph node metastasis (LLNM) present particular challenges for both diagnosis and treatment. This study aimed to assess whether indocyanine green (ICG)-assisted lymph node mapping with near-infrared imaging (NIRI) enhances the effectiveness of lateral lymph node dissection (LLND) by further categorizing the lateral lymph nodes in patients with mid-low rectal cancer.

Methods: Submucosal indocyanine green injection was performed on the distal margin of the rectal cancer. In the ICG-LLND group, the lymphatic drainage pathway and distribution of lateral lymph nodes (LLNs) were explored using a laparoscopic NIRI system. Pathological evaluations were conducted for both the ICG-LLND group and the control group.

Results: The ICG-LLND group demonstrated a significantly shorter postoperative hospital stay compared to the control group, both before (P < 0.001) and after (P = 0.001) matching. While blood loss and operating time were similar between groups, the ICG-LLND group had fewer cases of anastomotic leakage (P = 0.206). Postoperative lymph node harvesting was significantly higher in the ICG-LLND group, with more total lymph nodes (P = 0.001) and lateral lymph nodes (P = 0.002) harvested. The number of harvested lymph nodes in the obturator and internal iliac regions was also higher in the ICG-LLND group (P = 0.001), and the number of positive lymph nodes in these regions was significantly greater before (P = 0.027) and after (P = 0.013) matching. Univariate and multivariate analyses showed that ICG-LLND, nCRT, and positive pN stage were associated with increased lymph node harvest.

Conclusions: ICG-LLND improved lateral lymph node harvest, particularly obturator lymph nodes, and shortened postoperative hospital stay without increasing complications. This technique may enhance surgical outcomes in patients requiring lymph node dissection.

Keywords: Fluorescence-guide lymph node mapping; Indocyanine green; Lateral lymph node; Propensity score matching; Rectal cancer.

MeSH terms

  • Aged
  • Coloring Agents
  • Female
  • Humans
  • Indocyanine Green* / administration & dosage
  • Laparoscopy / methods
  • Length of Stay / statistics & numerical data
  • Lymph Node Excision* / methods
  • Lymph Nodes* / diagnostic imaging
  • Lymph Nodes* / pathology
  • Lymph Nodes* / surgery
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Operative Time
  • Optical Imaging* / methods
  • Propensity Score
  • Rectal Neoplasms* / diagnostic imaging
  • Rectal Neoplasms* / pathology
  • Rectal Neoplasms* / surgery
  • Retrospective Studies

Substances

  • Indocyanine Green
  • Coloring Agents