Ultrasound study in the diagnosis of primary Budd-Chiari syndrome (obstruction of the inferior vena cava).

Primary Budd-Chiari syndrome, obstruction of the hepatic portion of the inferior vena cava (IVC), is a rare disorder, but relatively prevalent in the Far East, northern India and Africa. Ultrasound examination was carried out on 9 patients with primary Budd-Chiari syndrome. There were 5 men and 4 women aged 27-60 years. In all the 9 cases, the diagnosis was confirmed by cavography and liver histology. Moreover, 7 of the 9 subsequently underwent radical operation using a patch graft. Ultrasonic study showed several characteristic findings suggestive of the syndrome, and frequencies of the main findings were as follows: 1) an echogenic obstructing membrane; 22.2%, 2) segmental obstruction of the IVC; 77.8%, 3) occlusion of the major hepatic veins at the juxtacaval portion; 100%, 4) enlarged inferior right hepatic veins; 55.6%, 5) abnormal intrahepatic venous structures and collaterals; 88.9%. Of these findings, 5) was the most prominent and most characteristic in the diagnosis of the syndrome. It is necessary for early detection of this entity to evaluate carefully intrahepatic venous abnormalities and patency of either the IVC or major hepatic veins on ultrasonic examination. The careful examination for Budd-Chiari syndrome should be done in cases with cryptogenic liver cirrhosis, particularly in countries where the prevalence of the syndrome is high.