Proper hepatic artery

Course

The proper hepatic artery is the continuation of the common hepatic artery after it gives rise to the gastroduodenal artery. It courses anteromedial to the portal vein and medial to the common bile duct.

Upon reaching the hepatoduodenal ligament, the proper hepatic artery, portal vein and the common bile duct come together to form the portal triad. The proper hepatic artery terminates near the porta hepatis by dividing into its terminal branches; the left and right hepatic artery.

Branches and supply

The proper hepatic artery gives off three branches; the right gastric artery and the left and right hepatic arteries. The hepatic arteries provide only about 20% of the blood supply to the liver, while the majority of the blood comes from the portal vein.

• Right gastric artery: arises from the proper hepatic artery near the hepatoduodenal ligament, above the superior part of the duodenum. It courses through the layers of the lesser omentum and ascends along the right side of the lesser curvature of the stomach, where it gives off several branches. It ends roughly in the middle of the lesser curvature by anastomosing with the left gastric artery.
• Left hepatic artery: runs vertically towards the umbilical fissure and into the left lobe of the liver, supplying the posterior (I), left posterior (II) and left anterior lateral (III) segments. In addition, it gives off a middle hepatic artery that supplies the left medial segment (IV) of the liver. The left hepatic artery ends within the liver by dividing into medial and lateral segmental branches.
• Right hepatic artery: courses superiorly and turns to the right, crossing behind the common hepatic duct. Here, it enters the cystohepatic (Calot’s) triangle, an anatomical space formed by the common hepatic duct, cystic duct and the inferior surface of the liver. This triangle is used as a surgical landmark to localize the cystic artery, which is given off by the right hepatic artery. The right hepatic artery terminates within the liver, dividing into an anterior segmental branch, which supplies anterior medial (V) and posterior medial (VIII) liver segments; and a posterior segmental branch which supplies the anterior lateral (VI) and posterior lateral (VII) segments.

Anatomical variations

There are quite a number of anatomical variations of the hepatic artery proper and its branches. In the general population, variations in hepatic arterial supply are seen in about 40-50% of cases.

• A relatively common finding is the trifurcation of the common hepatic artery into the right hepatic artery, left hepatic artery and gastroduodenal artery with the absence of the proper hepatic artery.
• In about 40% of cases, the right gastric artery arises from the common hepatic artery, whereas in 15-26% of cases it arises from the left hepatic artery instead of the proper hepatic artery.
• The right hepatic artery arises from the superior mesenteric artery in about 12% of cases.
• The left hepatic artery arises from the left gastric artery in about 11%.