Congenital hepatic shunts

Abstract

Abnormal vascular connections within the hepatic parenchyma are occasionally seen at ultrasonography (US) and require further evaluation. The radiologic findings in 42 children with infantile hepatic hemangioma (n = 28), vascular malformations (n = 10), or infradiaphragmatic total anomalous pulmonary venous return (TAPVR) (n = 4) associated with congenital vascular shunting were retrospectively reviewed. Arteriovenous connections are seen in infantile hepatic hemangiomas and arteriovenous malformations and manifest with aortic tapering at the level of the celiac trunk, hepatic artery enlargement with a low resistivity index (RI), and increased flow velocities in the hepatic veins that may assume an arterialized spectral pattern in late-stage disease. Congenital arterioportal shunts demonstrate a low RI in the hepatic artery, hepatofugal arterialized flow in the portal vein, and rapid development of signs of portal hypertension. Portosystemic shunting may be intra- or extrahepatic. A pulsatile triphasic spectral pattern is seen in the portomesenteric venous system in children with portosystemic shunting, and macroscopic connections between the portal system and the hepatic veins are evident. Infradiaphragmatic TAPVR is associated with a tortuous vessel that parallels the aorta, ends at the intrahepatic left portal vein or the ductus venosus, and has hepatopetal flow. Familiarity with the US features of various congenital abnormal hepatic vascular connections will aid in diagnosis and treatment.