The value of Doppler ultrasound in cirrhosis and portal hypertension

Background: Cirrhosis and portal hypertension affect the flow profile of th e liver vasculature. In these conditions Doppler ultrasound can provide imp ortant information on the hemodynamics of the portal venous system, the hep atic artery and the hepatic veins. Methods: The value of Doppler ultrasound in the assessment of the patient with cirrhosis and portal hypertension wa s determined by reviewing the Literature. Results: Portal venous blood how becomes reversed with advanced portal hypertension. Reversed flow is also d emonstrated in patients with veno-occlusive disease and portosystemic shunt s. Despite general agreement that portal flow velocity is decreased in cirr hotic patients, the absolute values of portal flow velocity in both healthy subjects and cirrhotic patients Vary considerably. Errors in Doppler measu rements, observer variability and collateral pathways contribute to these v ariations. Furthermore, portal blood flow is influenced by numerous factors such as changes in the body position, phase of respiration, timing of meal s, exercise and cardiac output. Finally, portal flow may be unaltered due t o a combination of high inflow from the splanchnic organs and increased res istance within the liver. High resistive index of the hepatic artery is see n in patients with end-stage liver disease, particularly in children with s evere cirrhosis secondary to biliary atresia. However, hepatic artery dow r emains normal in mast patients. Abnormal hepatic vein flow profiles are see n in patients with cirrhosis, but dampening or flattening of the flow profi le has a multifactorial origin (Budd-Chiari, metastases, ascites) and can b e observed in healthy subjects. Conclusions: Although many factors may affe ct the accuracy of volume flow and velocity measurements and the flow profi le of the liver vasculature may change in different situations, Doppler ult rasound is useful in the assessment of the patient with cirrhosis and porta l hypertension.