Budd–Chiari syndrome is a condition caused by occlusion of the hepatic veins that drain the liver. It presents with the classical triad of abdominal pain, ascites and hepatomegaly. Examples of occlusion include thrombosis of hepatic veins.
The acute syndrome presents with rapidly progressive severe upper abdominal pain, jaundice, hepatomegaly (enlarged liver), ascites, elevated liver enzymes, and eventually encephalopathy. The fulminant syndrome presents early with encephalopathy and ascites. Severe hepatic necrosis and lactic acidosis may be present as well. Caudate lobe hypertrophy is often present. The majority of patients have a slower-onset form of Budd–Chiari syndrome. This can be painless. A system of venous collaterals may form around the occlusion which may be seen on imaging as a “spider’s web.” Patients may progress to cirrhosis and show the signs of liver failure.