[Collaterals of portal hypertension running through the liver. Part 1. Paraumbilical vein].

Seven cases of portosystemic collateral running through the left lobe of the liver (6 in the medial segment and 1 in the lateral segment) were reported. Six cases were diagnosed by CT and/or ultrasound, and one case was confirmed by autopsy. This collateral originated from the umbilical vein recess of the left portal vein and connected with enlarged vein in front of the left lobe of the liver. All the patients had other portosystemic collaterals of severe and moderate degrees. Paraumbilical veins demonstrated on portography did not differ from ordinary paraumbilical veins in portal hypertension except for prominent tortuosity and dilatation noted in half cases. In markedly dilated cases, intrahepatic portosystemic collateral can be a pitfall in the diagnosis of hepatic tumor on CT. Careful examination of portal hypertension with ultrasound, dynamic CT and/or magnetic resonance imaging will detect such portosystemic collaterals running through the hepatic parenchyma.