Optimizing Laparoscopic Cholecystectomy in Aberrant Biliary Anatomy: A Case of Cystic Duct Insertion Into the Right Posterior Hepatic Duct.

Anatomic variations of the biliary tree, particularly those involving the cystic duct, pose significant challenges during laparoscopic cholecystectomy and can lead to inadvertent bile duct injury (BDI) if unrecognized. We report a rare variant in which the cystic duct inserts into the right posterior hepatic duct, which itself drains directly into the common bile duct - an aberrant configuration not frequently described in the literature. A 65-year-old man with grade I acute cholecystitis underwent preoperative imaging with computed tomography and magnetic resonance cholangiopancreatography, revealing the unusual biliary anatomy. A laparoscopic cholecystectomy was performed using the critical view of safety (CVS) approach, followed by intraoperative cholangiography (IOC) via gallbladder puncture to delineate the anatomy, ensuring accurate identification of the cystic duct and artery. The procedure was completed safely without complications. This case highlights the importance of preoperative imaging, adherence to CVS, and IOC in achieving safe outcomes in the setting of complex biliary anatomy. Despite increasing interest in indocyanine green (ICG) fluorescence cholangiography, its availability remains limited in some centers; thus, conventional techniques remain valuable. We advocate for a multimodal approach to mitigate the risk of BDI in patients with atypical biliary configurations.