Hepatic Arterial Buffer Response in Liver Transplant Recipients: Implications and Treatment Options.

Abstract

The liver blood supply portrays one of the most sophisticated archetypes of circulation. Despite its weight (representing only 2.5% of body weight), the liver receives 25% of the cardiac output, allowing the hepatic parenchyma to be the most richly perfused of any organ. The anatomical distinctiveness of the double afferent blood supply is established between the hepatic artery and the portal vein, ensuring a total blood flow of 100 to 130 mL/min per 100 g of liver. Approximately 20 to 25% of the blood perfusing the liver is well oxygenated, and is provided by the hepatic artery. In addition to hepatic parenchymal cells, the hepatic artery provides the exclusive blood supply to the intrahepatic bile ducts. The portal vein, formed by the confluence of the splenic vein, mesenteric veins, gastric veins, and pancreatic vein, supplies around 75 to 80% of the afferent blood, which is partially deoxygenated.[1] [2] Mixing of arterial and portal blood occurs in the sinusoids, an exclusive, dynamic microvascular structure that serves as the principal site of exchange between the blood and the perisinusoidal space.[3] The hepatic veins (typically three—right, middle, and left) drain the blood from those locations into the inferior vena cava.