Congenital veno-venous malformations of the liver: widely variable clinical presentations.

Background and Aim: Congenital portosystemic veno-venous malformations are rare abnomalities that often remain undiagnosed. Typically they are classified by their anatomical characteristics according to Morgan (extrahepatic, Abernethy malformations type Ia,b and II) and Park (intrahepatic, types 1-4). However, their clinical presentation is less dependent on the anatomical type.
Method: We reviewed the clinical characteristics of six cases drawn from our files (from 1970 to 2006).
Results: One patient, a 25-year-old male, had extrahepatic shunting whereby the liver receives only arterial blood because the portal vein (PV) connects with the inferior caval vein (ICV) (Abernethy Ib); he presented with episodes of jaundice and pruritus. Three patients had extrahepatic shunting with patent intrahepatic portal veins, but with shunting of splenomesenterial blood towards the ICV (Abernethy II); these included a 66-year-old male with hepatic encephalopathy, a 17-year-old female with (porto?-)pulmonary hypertension without portal hypertension, and a 33-year-old female with epidsodes of acute pain secondary to spontaneous bleeding within a primary liver tumor. Two patients had intrahepatic shunting; these included an 8-year-old boy who was diagnosed incidentally during work-up for abnormal liver enzymes with a communication between right PV and ICV (Park type 1), and a 59-year-old male with multiple PV-ICV-shunts in several liver segments (Park, type 4) who presented with hepatic encephalopathy.
Conclusion: Patients often present with signs of hepatic shunting (encephalopathy, pulmonary hypertension, hepatopulmonary syndrome, and/or hypoglycemia) with relative sparing of the synthetic liver function in the absence of portal hypertension. Some shunts present with space-occupying lesions (focal nodular hyperplasia, hepatocellular carcinoma, nodular regenerative hyperplasia, etc.) or biliary atresia. Finally, some cases are detected incidentally.