Hepatic vascular malformations in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder that can involve the liver diffusely in the form of vascular malformations ranging from small telangiectases to discrete arteriovenous malformations. Anatomically, three different patterns of abnormal vascular communications can occur in liver: portal vein to hepatic vein (portovenous), hepatic artery to hepatic vein (arteriovenous) and hepatic artery to portal vein (arterioportal), with the most common being arteriovenous. Only 5 to 8% of patients with these vascular malformations are symptomatic. When symptomatic, patients present with high-output cardiac failure, biliary ischemia (which, when severe, can progress to biliary and hepatic necrosis and lead to acute liver failure), or portal hypertension. Other less common presentations include portosystemic encephalopathy and abdominal angina. Diagnosis is confirmed by Doppler ultrasonography or multidetector computed tomography. The hallmark findings are intrahepatic hypervascularization and an enlarged common hepatic artery. Focal nodular hyperplasia and nodular regenerative hyperplasia are common findings. Symptomatic patients are treated with intensive medical treatment aimed at the predominant clinical presentation. Patients who fail aggressive medical therapy and those with acute biliary/hepatic necrosis should be considered for liver transplantation.