Incidentally discovered duplicated cystic duct during open pancreaticoduodenectomy: a case report

True duplication of the cystic duct draining a single gallbladder is an exceptionally rare biliary anomaly, with fewer than 40 cases reported in the English literature. Failure to recognize this variant during complex hepatobiliary surgery carries significant risk of bile duct injury. We report a 60-year-old male undergoing open pancreaticoduodenectomy for pancreatic adenocarcinoma in whom an H-type duplicated cystic duct was incidentally identified during dissection of Calot's triangle. Both ducts were individually clipped and divided; ductoplasty was performed to facilitate biliary reconstruction. The procedure was completed without biliary complications. A systematic PubMed and Scopus search confirmed this as the first reported case of duplicated cystic duct encountered during pancreaticoduodenectomy, extending the spectrum of surgical contexts beyond cholecystectomy and hepatic resection. This case underscores the importance of meticulous dissection and heightened anatomical vigilance in pancreatic oncologic surgery.