Hepatic ArteryEdit
The hepatic artery is the arterial vessel that supplies oxygenated blood to the liver, a central organ in metabolism, detoxification, and immune function. It forms part of the hepatic arterial system that travels with the portal triad in the hilum of the liver, alongside the portal vein and bile ducts. In the typical arrangement, the hepatic artery proper originates from the common hepatic artery, which in turn arises from the celiac trunk. The liver, however, receives a dual blood supply: arterial blood from the hepatic artery and venous blood from the portal vein, the latter delivering most of the organ’s blood volume. The hepatic artery contributes a smaller share of total hepatic inflow but delivers a higher oxygen content, which is crucial for the high metabolic and synthetic demands of liver tissue. The arterial bed also supplies the bile ducts through a peribiliary vascular network.
Anatomy
Origin and course
The hepatic artery proper usually arises as a branch of the common hepatic artery, a branch of the celiac trunk. It then travels in the hepatoduodenal pathway within the portal triad to reach the liver, where it divides into right and left hepatic arteries to perfuse the respective lobes. In some individuals, arterial variants are present: a replaced or accessory hepatic artery may originate from other arteries, such as the superior mesenteric artery (Replaced right hepatic artery or Replaced left hepatic artery), or from the left gastric artery. These variants are clinically important for surgery and radiology because they alter the usual vascular map encountered during procedures around the porta hepatis and the liver parenchyma. For the standard anatomy of the hepatic arterial system, see hepatic artery proper and common hepatic artery.
Blood supply and function
Within the liver, arteries run alongside the portal triad in the perisinusoidal space and terminate in the hepatic microcirculation. The hepatic artery supplies oxygenated blood to the hepatic parenchyma, biliary tract, and the walls of blood vessels within the liver. Although the hepatic artery accounts for roughly a quarter of total hepatic blood flow, its higher oxygen tension supports the high metabolic rate of hepatocytes and the energetically demanding processes of detoxification and bile production. The arterial input also intersects with the hepatic portal circulation through the hepatic arterial buffer response (hepatic arterial buffer response), a regulatory mechanism that helps stabilize overall liver perfusion when portal inflow changes, such as during digestion or vascular disease.
The arterial supply is particularly important for the biliary system. The peribiliary plexus, formed by branches of the hepatic arteries, provides the primary vascularization of the bile ducts, an essential consideration in hepatobiliary surgery and in conditions affecting the biliary tree. See also the concept of the Portal triad for the functional organization at the porta hepatis.
Variants and anomalies
Anatomical variation in hepatic arterial supply is common and has practical implications for hepatic surgery, liver transplantation, and interventional radiology. In addition to the classic pattern, some individuals have a replaced hepatic artery differing from the usual origin: a replaced right hepatic artery from the Superior mesenteric artery or a replaced left hepatic artery from the Left gastric artery. Others may have accessory hepatic arteries supplying additional arterial branches to the liver. Awareness of these patterns reduces risk during procedures around the gallbladder fossa, hepatic hilum, and when planning selective arterial therapies. For a broader discussion of these patterns, see Hepatic artery variants.
Clinical significance
In clinical practice, knowledge of hepatic arterial anatomy influences surgical planning for liver resections, biliary procedures, and liver transplantation. Hepatic artery thrombosis is a serious complication after liver transplantation or major hepatic surgery, potentially compromising graft viability or regenerating tissue. Interventional radiology techniques, including transarterial chemoembolization (Transarterial chemoembolization) or embolization, rely on precise arterial mapping to target hepatic tumors while preserving healthy tissue. The dual blood supply context—arterial plus portal venous input—also informs expectations about tissue tolerance during temporary arterial occlusion and the resilience of hepatic tissue under various therapies.
Understanding the hepatic arterial system, its variants, and its connections to the biliary and parenchymal compartments provides a foundation for both diagnostic interpretation and therapeutic intervention in hepatology and related surgical fields. See also the broader discussions of Liver structure, Portal vein, Bile duct, and Liver transplantation for related topics and clinical contexts.