Case series on the use of the indocyanine green fluorescence real-time imaging technique for lymph node sorting in patients undergoing radical esophagectomy.

Background: There is a clear correlation between accurate postoperative lymph node staging and the survival prognosis of patients. This study aimed to explore the application and value of indocyanine green (ICG) fluorescence real-time imaging technology in lymph node sorting during radical esophagectomy for esophageal cancer.

Methods: From August 2022 to June 2023, the specimens of 66 patients who underwent esophageal cancer resection with lymph node dissection were examined. Among them, 12 cases of ex vivo esophageal specimens underwent secondary lymph node sorting using ICG fluorescence real-time imaging technology after conventional lymph node sorting, while the remaining 54 cases underwent conventional lymph node sorting.

Results: A total of 329 lymph nodes were detected in the 12 patients with an average of 29.75±9.19 nodes per patient. Lymph node metastasis was detected in five patients, of whom, three were diagnosed as N1 (N refers to regional lymph nodes, N1: involves 1 to 2 regional lymph node metastases), and two were diagnosed as N2 (N refers to regional lymph nodes, N2: involves 3-6 regional lymph node metastases). Following the ICG injection of 12 patient specimens, lymph nodes were re-detected in 6 patients of them (above we stated 12 patients), yielding a detection rate of 50%. In total, 17 lymph nodes were detected. There was a statistically significant difference in the total number of lymph nodes detected before and after the injection of ICG (P=0.02). Among the other 54 patients, an average of 34.06±15.66 lymph nodes were detected. There was no statistically significant difference in the total number of lymph nodes detected between the two groups (P=0.21).

Conclusions: The use of ICG fluorescence real-time imaging technology facilitate lymph node identification in resected specimens and will become a powerful technique for precise staging in esophageal cancer treatment.