Low-dose indocyanine green fluorescent cholangiography in ring-like communicating accessory bile duct with impacted lithiasis: A case report

BACKGROUNDLaparoscopic cholecystectomy (LC) remains the gold standard treatment for benign gallbladder diseases.However, iatrogenic bile duct injury (BDI) remains a catastrophic complication, frequently precipitated by unrecognized anatomical variations of the biliary tree.Infrequently encountered variants, such as a ring-like communicating accessory bile duct (CABD), are exceptionally difficult to identify on standard preoperative imaging, leading to a high incidence of missed diagnoses.This case illustrates the potential clinical utility of intraoperative near-infrared fluorescent cholangiography (NIR-FC) utilizing indocyanine green (ICG) optical guidance as a visual adjunct in identifying aberrant ductal pathways during Calot's triangle dissection. CASE SUMMARYA 73-year-old female presented to our department with a 3-day history of continuous right upper quadrant abdominal pain.Initial prospective magnetic resonance cholangiopancreatography reported cystic duct lithiasis, cholecystitis, and gallbladder adenomyomatosis, without identifying biliary anatomical variations.During LC, intraoperative NIR-FC utilizing low-dose ICG clearly visualized an uncommon, hidden ring-like biliary anomaly formed by the main cystic duct, a CABD, the right hepatic duct, and the common hepatic duct.Furthermore, an impacted calculus was visualized as a localized fluorescent filling defect at the confluence of the main cystic duct and the CABD.Assisted by this fluorescent visual roadmap and after confirming that the corresponding hepatic territory retained dominant drainage through the right hepatic duct, the surgical team extracted the calculus, securely ligated and divided the CABD, achieved the critical view of safety, and safely completed the cholecystectomy without BDI or postoperative bile leakage.Repeat ultrasound at short-term follow-up and extended clinical evaluation at 22 months confirmed uneventful recovery without biliary complications. / 30 CONCLUSIONLow-dose ICG fluorescent cholangiography serves as a practical intraoperative optical adjunct that may assist in recognizing complex communicating biliary anomalies and stone impaction, complementing standard surgical dissection during LC.