Assessment of liver blood flow regulation mechanism by ultrasound

The constancy of hepatic blood flow is important for several homeostatic roles. This paper reviews studies related to liver blood flow regulation mechanism. The liver has mechanism maintain a constant hepatic blood flow and compensate for portal flow changes. A reduction in portal flow leads to reduced intrahepatic distending pressure, resulting the hepatic arterial buffer response causes dilation of the hepatic artery, thus buffering the Portal flow change. This mechanism is exclusive to this specific vascular bed and offer a great illustration of multiple integrative regulation of a significant homeostatic organ. Ultrasound provides noninvasive accurate information on the liver hemodynamic and assess the flow in the hepatic artery and the portal vein specially diameter of vessels. Aim: The aim of this study was to evaluate the dual hepatic blood supply in normal individual and compared altered in the hepatic artery buffer response with chronic hepatic diseases. Materials and methods: The current review focuses on researches that evaluate the mechanisms involved in maintaining a steady hepatic arterial buffer response (HBF), such as the impact of portal blood flow on hepatic artery flow, or assessing the intrinsic regulation of hepatic arterial blood flow by measure the hepatic arterial buffer response intraoperative in patients with or without cirrhosis using an ultrasound transit-time flowmetry, or by duplex ultrasound, Moreover studies to understand the role of hepatic flow in liver atrophy.