Primary Budd-Chiari syndrome.

Primary Budd-Chiari syndrome is characterized by a blocked hepatic venous outflow tract at various levels from small hepatic veins to inferior vena cava, resulting from thrombosis or its fibrous sequellae. This rare disease affects mainly young adults. Multiple risk factors have been identified and are often combined in the same patient. Myeloproliferative diseases of atypical presentation account for nearly 50% of patients; their diagnosis can be made by showing the V617F mutation in Janus tyrosine kinase-2 gene of peripheral blood granulocytes and, should this mutation be absent, by showing clusters of dystrophic megacaryocytes at bone marrow biopsy. Presentation and manifestations are extremely varied, so that the diagnosis must be considered in any patient with acute or chronic liver disease. Doppler-ultrasound, computed tomography or magnetic resonance imaging of hepatic veins and inferior vena cava are usually successful in demonstrating non-invasively the obstacle or its consequences, the collaterals to hepatic veins or inferior vena cava. The disease is considered to be spontaneously lethal within 3 years of first symptoms. A therapeutic strategy has been proposed where anticoagulation, correction of risk factors, diuretics and prophylaxis for portal hypertension are used first; then angioplasty for short-length venous stenoses; then TIPS; and ultimately liver transplantation. Treatment progression is dictated by the response to previous therapy. This strategy has achieved 5-year survival rates approaching 90%. Medium-term prognosis depends on the severity of liver disease. Long-term outcome might be jeopardized by transformation of underlying conditions and hepatocellular carcinoma.