Prehepatic hypertension accounts only for 10% of all cases of portal hypertension and is caused either by prehepatic occlusion of the venous system or by an increased flow through the portal vein. In the course of 24 months we recorded 10 cases of non-cirrhotic thrombosis of the portal vein. Two patients suffered from haematological diseases, two from obstructive jaundice, two from multiple hepatic metastases, one from acute pancreatitis. In two patients with symptoms of upper dyspeptic syndrome the cause of thrombosis was not detected. Clinical suspicion of thrombosis was expressed only in one patient, the remainder were asymptomatic. All patients were examined by ultrasound, incl. Doppler evaluation of the portal circulation. In four patients CT examinations of the abdomen were made with intravenous administration of contrast material, in five fibroscopy of the oesopha- gus and stomach and in one female patient also splenoportography was made. Complete thrombosis of the portal vein was found in one patient. Three times we diagnosed cavernous reconstruction of the portal vein, in one case with complete thrombosis of the v. mesenterica superior and v. lienalis. Partial thrombosis of the portal vein was visualized in six patients, in one case combined with partial and once in association with complete thrombosis of the upper mesenteric vein and in one instance in combination with thrombosis of the vena cava superior.

        Key words: portal vein - thrombosis - ultrasonography of portal hypertension