Budd-Chiari syndrome involves thrombosis of which vascular structure?

• A. Hepatic artery
• B. Portal vein
• C. Hepatic vein
• D. Inferior vena cava

Answer: (C)

Budd-Chiari syndrome is caused by obstruction of the liver’s outflow, specifically thrombosis of the hepatic veins that drain blood from the liver into the inferior vena cava. When these veins are blocked, blood backs up in the liver, leading to congestive hepatopathy, hepatomegaly, and ascites. The portal vein and hepatic artery are inflow vessels supplying the liver, not outflow paths, so their thrombosis doesn’t produce the same congestive picture. While the IVC can be involved in some cases, the structure most characteristically implicated and tested is the hepatic vein.