Blood Supply and Oxygenation Status of the Liver: From Physiology to Malignancy

To maintain a multitude of vital functions, blood flow to the normal liver and the hepatic oxygenation status has to be kept on a high level (1.0-1.2 mL/g/min and 30-40 mmHg, respectively). There is a longitudinal oxygen partial pressure (pO₂) gradient within the liver sinusoids between periportal inflow and outflow into the central vein leading to a zonation of the O₂ status, which is associated with a zoning of liver functions. Oxygenation of metastatic lesions of colorectal cancers in the liver is poor due to a dysfunctional vascularity and inadequate blood supply. Hepatocellular carcinomas (HCCs) are highly vascularised (arterialised), metabolically very active and present with a predominantly arterial blood supply. HCCs are generally believed to be very hypoxic. However, confirmation of severe hypoxia based on reliable, direct pO₂ measurements in HCCs is still missing.