- Primary (75%): thrombosis of the hepatic vein
- Secondary (25%): compression of the hepatic vein by an outside structure (e.g. a tumor)
- Many patients (10-40%) have Budd-Chiari syndrome as a complication of polycythemia vera (myeloproliferative disease of red blood cells).
- Patients suffering from paroxysmal nocturnal hemoglobinuria (PNH) appear to be especially at risk for Budd-Chiari syndrome, more than other forms of thrombophilia: up to 40% develops Budd-Chiari, as well as cerebrovascular accidents.
Any obstruction of the venous vasculature of the liver is referred to as Budd-Chiari syndrome, from the venules to the right atrium.
Signs and symptoms
The syndrome presents with rapidly progressive abdominal pain, hepatomegaly (enlarged liver), ascites, and later the symptoms of hepatic dysfunction: elevated liver enzymes, encephalopathy.
A slower-onset form of hepatic venous occlusion is also recognised; this can be painless.
Often, the patient is known to have a tendency towards thrombosis, while Budd-Chiari syndrome can also be the first symptom of such a tendency.
When Budd-Chiari syndrome is suspected, measurements are made of liver enzyme levels and other organ markers (creatinine, urea, electrolytes, LDH).
Budd-Chiari syndrome is diagnosed using ultrasound studies of the abdomen, although occasionally more invasive methods have to be used (retrograde angiography). Liver biopsy is sometimes necessary to differentiate between Budd-Chiari syndrome and other causes of hepatomegaly and ascites, such as galactosemia or Reye's syndrome.
With anticoagulant medication, generally unfractioned and warfarin.