How Much of the Invisible Can Become Visible: Indocyanine Green Fluorescence Cholangiography During Laparoscopic Cholecystectomy—A Review on Biliary Anatomy Visualization, Protocol Heterogeneity and Operative Outcomes

Background and Objectives: In difficult clinical settings, laparoscopic cholecystectomy remains linked to higher conversion rates, prolonged operative time and an increased risk of bile duct injury. Near-infrared fluorescence cholangiography using indocyanine green (ICG) was developed as a real-time intraoperative imaging technique aimed at improving biliary anatomy visualization, reducing the need for cystic duct cannulation or use of ionizing radiation. We hypothesize that the variable performance of ICG fluorescence cholangiography might not be an intrinsic property of the technique, depending instead on the administration protocol, the specifications of the NIR devices and technical factors, patient characteristics, and the severity of the disease. The aim of the present narrative review with systematic search is to critically evaluate the available primary clinical evidence on the role of ICG fluorescence cholangiography as a tool in general and in difficult laparoscopic cholecystectomy, with special focus on biliary anatomy visualization, protocol heterogeneity, operative outcomes and evidence limitations. Materials and Methods: We conducted a systematic literature search in PubMed, Cochrane Library, and Web of Science to identify original studies published between 2015–2026 that evaluated ICG fluorescence during laparoscopic cholecystectomy. Afterwards, findings were synthesized narratively based on clinically relevant themes. Results: A total of 24 studies were included in the analysis. Several studies reported improved visualization of biliary anatomy using ICG fluorescence compared to conventional white-light imaging. Visualization improved with progression of dissection in Calot’s triangle. Potential clinical benefits suggested for technically difficult procedures (acute cholecystitis, severe inflammation, presence of adhesions, obese patients or distorted anatomy) remain uncertain, as these conditions also reduce fluorescence visibility. Some studies reported shorter times to biliary structure identification and achievement of the critical view of safety. Considerable heterogeneity persists regarding several variables: ICG dose and timing, the route of administration, and patient selection. Conclusions: Globally, the main benefits of ICG fluorescence cholangiography are the enhancement of biliary anatomy identification and the improvement of operative efficiency. Future randomized trials using standardized fluorescence protocols are needed to determine the optimal administration routes and doses of ICG and identify whether improved visualization translates into meaningful surgical and clinical improvements.