Definition of Hepatic vein obstruction (Budd-Chiari):

Hepatic vein obstruction is a blockage of the hepatic vein, which carries blood away from the liver.

Causes, incidence, and risk factors:

Hepatic vein obstruction prevents blood from flowing out of the liver and back to the heart. This blockage can cause liver damage. Obstruction of this vein can be caused by a lump (tumor) pressing on the vessel, or by a clot (thrombus) in the vessel.

Most often, it is caused by conditions that make blood clots more likely to form, including:

• Abnormal spread of cells from the bone marrow (myeloproliferative disorders)
• Cancers
• Chronic inflammatory or autoimmune diseases
• Infections
• Inherited (hereditary) or acquired problems with blood clotting
• Oral contraceptives and pregnancy