Purpose or Case Report: Congenital portosystemic venous shunts (CPVS) are rare vascular abnormalities in which the portal blood drains into a systemic vein. They are results of embryogenetic alterations during the complex development of the portal system in early gestational period. Anatomically they are classified into two groups; extrahepatic and intrahepatic. Extrahepatic shunts were first described in 1793 by Abernethy and are thus also called Abernethy malformations. Presentation of CPVS can be highly variable and consequences severe.

CASE1:
An 8 year old boy was admitted to our hospital due to severe abdominal pain. Doppler ultrasound (US) revealed an abnormal intrahepatic tubular vascular structure. The computed tomography angiography (CTA) confirmed a direct vascular connection between the left portal vein and the dilated left hepatic vein. The right portal vein was small in size, indicating main portal blood flow through the left side bypassing the liver. The treatment for this intrahepatic CPVS was embolization of the shunt. The boy has been well since the procedure.

CASE2:
A routine medical check-up in a 14 year old girl discovered abnormal liver function tests. Abdominal US showed a huge mass in the right lobe of the liver and a big mass of similar structure in the epigastrium. Portal vein was not identified. CTA showed a short main portal vein connected directly to the inferior vena cava, consistent with the Abernethy malformation. The big mass in the epigastrium was shown to be a tumor in the caudate lobe of the liver. Focal nodular hyperplasia (FNH) was considered for liver lesions due to the imaging findings and known association with the Abernethy malformation. Biopsy confirmed the diagnosis. The girl is currently waiting for liver transplantation, as it is the treatment of choice for this extrahepatic CPVS.
Methods & Materials:
Results:
Conclusions: CPVSs are rare vascular abnormalities with less than 400 cases reported in the literature. The first imaging method for the evaluation is usually the US. A thorough inspection of the portal venous system with Doppler is necessary and is often diagnostic. A CTA is the method of choice to confirm the diagnosis and to define the precise anatomical variant of the shunt. The precise anatomical definition of the shunt is important because different variants require different treatment to prevent damage and complications. Early diagnosis of CPVS is important because consequences of CPVS are severe.