Veno-occlusive disease
(Sinusoidal Obstruction syndrome)
Hepatic veno-occlusive disease is caused by occlusion of the terminal hepatic venules and hepatic sinusoids rather than of the hepatic veins or inferior vena cava
Venous congestion produces ischemic necrosis that can lead to cirrhosis and portal hypertension.
Common causes include irradiation, graft-vs-host disease resulting from bone marrow (or hematopoietic cell) transplantation, pyrrolizidine alkaloids from crotalaria and senecio plants (e.g medicinal bush teas) and other hepatotoxins (e.g dimethylnitrosamine,alatoxin,azathioprine,some anticancer drugs).
Initial manifestation of the veno-occlusive disease include sudden jaundice,ascites, and tender ,smooth hepatomegaly .Onset is within the first 2 wk of the transplantation in the bone marrow recipients,who either recover spontaneously within a few weeks( patients with mild cases may respond to an increase in immunesuppression) or die of fulminant liver failure.
Others with with veno-occlusive disease have recurrent ascites,portal hypertension and eventually cirrhosis.
The diagnosis is suspected in patients particularly recipients of bone marrow transplantation with typical symptoms. Liver function tests, ultrasound and PT/INR .
Ultrasound shows retrograde flow in the portal vein. In patient with typical clinical, laboratory and ultrasound findings particularly in bone marrows transplant recipients, further testing may not be necessary. However if the diagnosis is not clear, liver biopsy or calculation of the difference between measured hepatic venous and portal venous pressure is necessary.
A Difference in pressure of > 10 mmHg suggests veno-occlusive disease
Treatment includes withdrawal of the causative agent, supportive therapy and transjugular intrahepatic stents for relief of portal hypertension. Liver transplantation is a last resort.
Ursodeoxycholic acid helps prevent graft-vs-host disease in bone marrow transplant recipients
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