Background: This article aims to analyze and to simplify the optimal dose and time of intravenous indocyanine green (ICG) administration to achieve the identification of the cystic duct and the common bile duct (CBD).
Methods: A consecutive series of 146 patients was prospectively analyzed and divided into three groups according to the time of ICG administration: at induction of anesthesia group (20-30 min); hours before group (between 2 and 6 h); and the day before group (≥6 h); and two groups according to the dose of ICG: 1 cc (2.5 mg) or weight-based dose (0.05 mg/kg).
Results: The CBD was better visualized in the at induction of anesthesia group (85.4%), in the hours before group (97.1%) (p = 0.002) and in the 1cc group (p = 0.011). When we analyzed the 1 cc group (n = 126) a greater visualization of the CBD was observed in the at induction of anesthesia group (86.7%) and in the hours before group (97.1%) (p = 0.027).
Conclusion: Due to its simplicity and reproducibility, we suggest a dose of 2.5 mg administered 2-6 h before the procedure is the optimal. However, ICG administered 30 min prior to the surgery is enough for adequate visualization of biliary structures.