“Classic” hepatic artery anatomy occurs in 55% of patients and is described as the right and left hepatic arteries originating in the bifurcation of the common hepatic artery.
The most common variation occurring is in 10% of patients is a replaced right hepatic artery originating off the superior mesenteric artery. It can also originate off of the gastroduodenal artery in 1% of patients and has rarely been described as originating from the aorta.
An understanding of right replaced hepatic artery anatomy is critical when performing laparoscopic cholecystectomy. The replace artery typically runs posterior to the portal vein (as opposed to anterior to the vein in “classic” anatomy). As such, it may run parallel to the cystic duct or loop around the gallbladder neck, making it prone to injury or division.
To gain sufficient visualization of this area, the infundibulum of the gallbladder should be retracted laterally with careful dissection to isolate the cystic artery termination in the gallbladder.
A left replaced hepatic artery arises from the left gastric artery in approximately 10% of patients. This anatomy is most important clinically in the organ procurement process for liver transplants.