Hemodynamics in extrahepatic portal vein obstruction and its changes during long-term follow-ups

Thirty-six patients with extrahepatic portal vein obstruction (EHO) were studied. Twenty-one patients, whose age at onset was under 20 years old, were thought to be primary EHO. Ten of 15 patients over 21 years old, had a history of abdominal diseases, and were thus considered to be secondary EHO; only 5 were primary EHO. EHO was classified into three categories, based on selective celiac-superior mesenteric arteriography, and intraoperative trans-splenic and superior mesenteric venography: the hilar obstruction of portal vein, the portal trunk obstruction, and the portal trunk-splenic vein obstruction. Both primary and secondary EHO cases were found to have extended their obstructed region over time by progressing from hepatic hilum to portal trunk obstruction followed by splenic vein obstruction. On the other hand, based on retrograde portography, EHO was classified into the absence of intrahepatic portal obstruction (portal trunk type) and the intrahepatic obstruction (portal branch type) and the portal branch type tended to predominate. Changes of intra- and extra-hepatic portal obstruction were examined by comparing various angiographies of the 14 patients available for between 1 and 26 years of long-term follow-up. While EHO tended to progress with time, no patient showed progress of a intrahepatic portal vein obstruction. From these results, EHO patients are expected to show continuous progression of EHOs during long-term follow-ups, and to have high recurrence rates of gastrointestinal varices after various treatments due to the persistent portal hypertension. However, effective hepatic flow is likely to be maintained because collateral circulation to the liver develops, and intrahepatic portal vein obstruction does not progress, resulting in a good prognosis for EHO.