Management of Type 9 Hepatic Arterial Anatomy at the time of Pancreaticoduodenectomy: Considerations for Preservation and Reconstruction of a Completely Replaced Common Hepatic Artery

Recognition and management of aberrant hepatic arterial anatomy for patients undergoing pancreaticoduodenectomy (PD) are critical to ensure safe completion of the operation. When the common hepatic artery (CHA) is noted to emanate from the superior mesenteric artery (Michels' type 9 variant), it is vulnerable to injury during the dissection required for PD. While this anatomy does not preclude an operation, care must be taken to avoid injury, often by identifying the CHA throughout its entire course before beginning the dissection of the portal venous structures. The oncologic principle that cautions against resection of a pancreatic cancer when it involves the CHA in its standard position may not universally apply to tumors that focally involve the CHA in the type 9 anatomic variant. In highly selected patients, surgical resection may be entertained as disease biology may be analogous to local involvement of the gastroduodenal artery in a patient with standard anatomy. Here, we review the indications, techniques, and outcomes associated with arterial resection and reconstruction during pancreatectomy among patients with a pancreatic tumor involving a common hepatic artery arising from the superior mesenteric artery.