Description
The condition results from the obstruction of the hepatic venous outflow tract, when the obstruction lies between the small intrahepatic veins and the termination of inferior vena cava in to the right atrium.
There are two categories of Budd- Chiari syndrome.
The first one, so called primary Budd-Chiari syndrome, covers the blockade of the venous system due to thrombosis or to a narrowing of the venous wall, whether they are focal or diffuse . In this category Budd Chiari syndrome is explained by a prothrombic state.
In the second category, so called secondary Budd-Chiari syndrome, tumours, parasites or extrinsic compression are responsible for the blockade rather than a primary disease of the veins.