Surgical Significance of Replaced Common Hepatic Artery Originating Distally from the Superior Mesenteric Artery during the Whipple Procedure

Abstract

Anatomic abnormalities of the hepatic artery are common in the general population. The most frequent arterial variant found is the aberrant right hepatic artery arising from the superior mesenteric artery, followed by the aberrant left hepatic artery originated from the left gastric artery. The presence of one of these variants during pancreatic cancer surgery may have important implications, such as the high chance of being encompassed by the cephalo-pancreatic tumor, with the possibility of accidental injury or otherwise compromise the R0 resection in attempt to preserve it. We present a 64-year-old man with an ampullary region carcinoma. Cephalic pancreaticoduodenectomy with dissection of the regional lymph nodes was performed. However, laparotomy showed a single common hepatic artery (CHA) arising from the superior mesenteric artery (SMA) and running posterior to the pancreas. The SMA was exposed first to identify the origin of the CHA, very distally at 5-6 cm from its origin, posteriorly to pancreatic head and travelling posteriorly to the superior mesenteric vein (SMV). Then, it ran anteriorly to the portal vein after it branched off the gastroduodenal artery (GDA). The pancreas was transected at the neck and the hepatic artery was completely dissected. Nowadays, we know that oncologic surgery of the head of the pancreas is feasible in the presence of a variant hepatic artery, even though classically it could be a contraindication for surgery. Currently, the use of angio-CT to study the relationship between the tumor site and mesenteric axis is recommended, although they have low sensitivity for detection of arterial anomalies.