Effect of liver transplantation on hepatic hemodynamics: Methodology and mechanisms

End-stage liver diseases are associated with profound derangement of hepatic hemodynamics including portal hypertension, portal systemic shunting, reduced portal venous blood flow, elevated hepatic arterial blood flow and hyperdynamic systemic circulation. Orthotopic liver transplantation (OLT), which has increasingly become a therapeutic option for the treatment of end-stage liver diseases, reverses some but not all of these hemodynamic abnormalities. Here we review our current understanding of the physiological control of liver blood flow and the changes thatoccur in liver disease. The blood flow methodology currently used in both human and animal studies is described. The results of studies on physiologically relevant animal OLT models indicate that OLT per se is without effect on hepatic hemodynamics. The abnormal hemodynamics found in some human patients after OLT wouldappear to be dependent on the presence of pre-existing portal systemic shunts before transplantation. The mechanism underlying the slow return to normal hepatic hemodynamics in these OLT patients is not fully understood.