Use of Near-Infrared Indocyanine Green Imaging to Identify and Manage an Obstructing Cystic Duct Stone During Hot Cholecystectomy: A Case Report.

Indocyanine green (ICG) near-infrared (NIR) fluorescence imaging is increasingly used to enhance visualization of biliary anatomy during laparoscopic cholecystectomy. Its ability to identify cystic duct pathology, however, has rarely been reported. We present a case of a 69- year-old woman with acute cholecystitis and recent ERCP for choledocholithiasis who underwent hot laparoscopic cholecystectomy. Real-time NIR imaging demonstrated absent fluorescence in the cystic duct and gallbladder, indicating an obstruction. Palpation confirmed an impacted stone, which was milked back into the gallbladder, restoring fluorescence. Fluorescence guidance enhanced anatomical clarity and procedural safety despite significant inflammation. This case highlights the diagnostic value of ICG fluorescence in detecting cystic duct obstruction during complex emergency cholecystectomy.