Alteration of intrahepatic microcirculation in cirrhotic livers.

From a hemodynamic point of view, hepatic vascular resistance and portal inflow determine the level of portal pressure. Factors that determine hepatic vascular resistance include both structural and dynamic components. Among the structural components are histological characteristics such as steatosis, fibrosis, regeneration nodules, and neo-angiogenesis. Dynamic structures include cells with contractile properties such as hepatocytes, hepatic stellate cells, sinusoidal endothelial cells, and Kupffer cells. The contributions of the interactions between four cells in cirrhotic livers resulted in hepatic endothelial dysfunction, hepatic microcirculatory dysfunction, hepatic venous dysregulation, hepatic fibrogenesis, and subsequently increased intrahepatic resistance and portal hypertension in cirrhosis. The pathogenic mechanisms that trigger the associated abnormalities in hepatic microcirculations include persistent endotoxemia, increased hepatic oxidative stress, activated endocannabinoids substances, pathogenic sinusoidal remodeling, and hypoperfusion in cirrhotic livers. Cumulative data suggested that various therapeutic strategies targeting hepatic microcirculation provided effective improvement of the systemic abnormalities of cirrhosis. Accordingly, the mechanistic and therapeutic approaches focusing on the disarrangement of hepatic microcirculation will be introduced in this article.