Optimal Preoperative Timing of Indocyanine Green Injection for Fluorescence Imaging Efficacy in Laparoscopic Common...

To determine the optimal preoperative timing of indocyanine green (ICG) administration for effective fluorescence-guided imaging during laparoscopic common bile duct exploration (LCBDE).

A retrospective analysis was conducted on 150 patients who underwent ICG-guided LCBDE between June 2024 and June 2025. All patients received an intravenous injection of 2.5 mg ICG and were allocated into five groups according to the interval between ICG administration and surgery: 0-1 hours, 1-3 hours, 3-6 hours, 6-9 hours, and 9-12 hours. Baseline characteristics, intraoperative fluorescence visualization, bile duct-to-liver fluorescence intensity contrast, and perioperative outcomes were compared among groups.

Visualization rates of the cystic duct, common hepatic duct, and common bile duct (CBD) did not differ significantly among groups (P > .05). In contrast, liver fluorescence visualization differed significantly (P = .002) and was lowest in the 9-12 hours group. The bile duct-to-liver fluorescence intensity difference was greatest in the 6-9 hours group. The time to identify the CBD differed significantly among groups (P < .001), with shorter identification times observed in the 1-3 hours, 3-6 hours, and 6-9 hours groups compared with the 0-1 hours group.

Preoperative intravenous administration of 2.5 mg ICG 6-9 hours before LCBDE is associated with optimal biliary fluorescence contrast and improved intraoperative identification of the CBD.