Transcatheter Arterial Embolization of Hepatic Arteriovenous Shunts in Patients with Hepatocellular Carcinoma

Preprocedure

Most hepatic arteriovenous shunts (HAVS) associated with hepatocellular carcinoma (HCC) occur with advanced stage liver cancer, and these patients typically have a dismal prognosis. Transcatheter arterial embolization (TAE) in this population carries significant risk. Therefore, proper patient selection is critical to determine which patients may benefit from TAE. The Child-Pugh score should be calculated because TAE is poorly tolerated in HCC patients with Child-Pugh class C. We choose transcatheter arterial infusion instead of TAE for those patients. In patients with elevated liver enzymes in addition to increased serum bilirubin levels, there is a propensity for hepatic failure and thus TAE may be contraindicated.

Cross-sectional imaging with computed tomography scanning or magnetic resonance imaging should be performed. Cross-sectional imaging demonstrates the size of tumor, portal venous or hepatic venous invasion, tumor thrombus, and it allows for accurate preprocedural planning. In patients with a tumor burden >70% of total liver volume, TAE is relatively contraindicated. If massive tumors compress bile ducts and cause bile duct obstruction, biliary decompression should occur prior to TAE. Portal venous thrombosis is also a relative contraindication. Finally, in patients with significant HAVS, it is desirable to occlude the shunts by TAE, especially if there is good collateral flow or superselective embolization is performed.

HCC invades portal veins and/or hepatic veins that lead to HAVS and simultaneously leads to venous tumor thrombus. Hepatic angiography demonstrates abnormally early opacification of portal vein and/or hepatic vein branches, with linear opacification showing typical “thread and streak” signs as well as filling defects in the portal/hepatic venous systems.