Budd-Chiari syndrome (BCS) is caused by obstruction of hepatic venous outflow at any level from the small hepatic veins to the junction of the inferior vena cava (IVC) with the right atrium, 1 and occurs in 1/100,000 of the general population worldwide. The most common presentation is with ascites, but can range from fulminant hepatic failure (FHF) to asymptomatic forms. Obstruction of hepatic venous outflow is mainly caused by primary intravascular thrombosis, which can occur suddenly or be repeated over time, accompanied by some revascularization, accounting for the variable parenchymal hepatic damage and histologic presentation. Budd-Chiari syndrome is thus a disease, but since it occurs as a manifestation of several other diseases, this term is kept for the present for convenience. [ http://www.ncbi.nlm.nih.gov/pubmed/16265183 ]