A Novel Dual Replaced Hepatic Arterial System Arising from the Superior Mesenteric Artery: A Newly Described Vascular Trap in Pancreatoduodenectomy

Abstract We report the first documented case of pancreatoduodenectomy (PD) performed in a patient with a periampullary malignancy and a singular, unreported vascular anomaly: dual replaced hepatic arteries (right and left) originating entirely from the superior mesenteric artery (SMA), with the left hepatic artery (LHA) exhibiting an aberrant intrapancreatic course. Preoperative CT identified the anomaly but underestimated its complexity. The LHA originated distally on the SMA, traversed deep within the pancreatic parenchyma giving off branches including an inferior pancreatoduodenal artery (IPDA), and emerged in the pancreatoduodenal groove mimicking the gastroduodenal artery (GDA), posing a profound risk of accidental ligation. Meticulous dissection preserved both arteries. The LHA was subsequently wrapped with a peritoneal patch to mitigate pancreatic fistula risk. Additional venous variations were encountered and managed. The patient recovered uneventfully. This case underscores the critical importance of anatomical vigilance, adaptive surgical technique, and strategies for preserving aberrant vasculature in complex PD.