Collateral intrahepatic circulation in presence of hepatic veins obstruction: The “half-moon”

Abstract

Primary or metastatic liver tumors might involve the hepatic veins. Hepatic vein occlusion is generally caused by direct tumoral invasion and/or tumoral thrombosis. The progressive instauration of venous occlusion enhances the development of an intraparenchymal collateral circulation between the hepatic veins. These intrahepatic venous anastomoses already exist in normal livers and involve the middle hepatic vein in 30% of cases [1,2]. These collateral veins can provide optimal outflow drainage to part of the liver which has an obstructed hepatic vein and an intact portal and arterial inflow.