Anatomical variation of arterial blood supply of liver segment IV

There has been a dilemma about the arterial supply of segment IV of the liver, and the subsequent risk of ischaemia, necrosis, hepatic artery thrombosis of segment IV after split-liver transplantation or the associating liver partition and portal vein ligation for staged hepatectomy procedure. We report a rare case of anatomical variation of the arterial blood supply of segment IV of the liver. In this case the proper hepatic artery trifurcated into left, middle and right branches that supplied the liver. Moreover, Segment IV received dual blood supply from both, the middle hepatic artery and the right branch of the proper hepatic artery. Identifying such anatomical variation prior to any liver surgery is essential. It is of particular significance in defining the resection line in liver surgeries. In order to avoid ischaemia, necrosis or cholangiopathy in segment IV, the division of liver parenchyma needs to be based on the anatomy of the arterial blood supply and the intrahepatic blood distribution to segment IV.