(See also Overview of Vascular Disorders of the Liver Overview of Vascular Disorders of the Liver The liver has a dual blood supply. The portal vein (which is rich in nutrients and relatively high in oxygen) provides two thirds of blood flow to the liver. The hepatic artery (which is oxygen-rich)... read more .)
Venous congestion causes portal hypertension Portal Hypertension Portal hypertension is elevated pressure in the portal vein. It is caused most often by cirrhosis (in North America), schistosomiasis (in endemic areas), or hepatic vascular abnormalities. Consequences... read more and ischemic necrosis (which leads to cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic fibrosis that has resulted in widespread distortion of normal hepatic architecture. Cirrhosis is characterized by regenerative nodules surrounded by dense... read more ).
Etiology of Sinusoidal Obstruction Syndrome
Common causes include
Irradiation
Graft-vs-host disease Graft rejection and graft-vs-host disease Transplants may be The patient’s own tissue (autografts; eg, bone, bone marrow, and skin grafts) Genetically identical (syngeneic [between monozygotic twins]) donor tissue (isografts) Genetically... read more resulting from bone marrow or hematopoietic cell transplantation
Pyrrolizidine alkaloids in crotalaria and senecio plants (eg, medicinal bush teas) and other herbs (eg, comfrey)
Other hepatotoxins (eg, dimethylnitrosamine, aflatoxin, azathioprine, some anticancer drugs)
Symptoms and Signs of Sinusoidal Obstruction Syndrome
Initial manifestations include sudden jaundice, ascites, and tender, smooth hepatomegaly. Onset is within the first 3 weeks of transplantation in bone marrow or hematopoietic cell recipients, who either recover spontaneously within a few weeks (or sometimes, with mild cases, after an increase in immunosuppressant therapy) or die of fulminant liver failure Acute Liver Failure Acute liver failure is caused most often by drugs and hepatitis viruses. Cardinal manifestations are jaundice, coagulopathy, and encephalopathy. Diagnosis is clinical. Treatment is mainly supportive... read more . Other patients have recurrent ascites, portal hypertension Portal Hypertension Portal hypertension is elevated pressure in the portal vein. It is caused most often by cirrhosis (in North America), schistosomiasis (in endemic areas), or hepatic vascular abnormalities. Consequences... read more , splenomegaly, and, eventually, cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic fibrosis that has resulted in widespread distortion of normal hepatic architecture. Cirrhosis is characterized by regenerative nodules surrounded by dense... read more .
Diagnosis of Sinusoidal Obstruction Syndrome
Clinical evaluation and liver tests
Ultrasonography
Sometimes invasive tests (eg, liver biopsy, measurement of portal-hepatic venous pressure gradient)
The diagnosis is suspected in patients with unexplained clinical or laboratory evidence of liver disease, particularly in those with known risk factors, such as bone marrow or hematopoietic cell transplantation.
Laboratory results are nonspecific: elevated aminotransferase and conjugated bilirubin levels. Prothrombin time/international normalized ratio (PT/INR) becomes abnormal when disease is severe. Ultrasonography shows retrograde flow in the portal vein.
If the diagnosis is unclear, liver biopsy Liver Biopsy Liver biopsy provides histologic information about liver structure and evidence of liver injury (type and degree, any fibrosis); this information can be essential not only to diagnosis but also... read more and measurement of the portal-hepatic venous pressure gradient is definitive (a pressure gradient > 10 mm Hg is consistent with sinusoidal obstruction syndrome). Measuring the pressure across the liver entails inserting a catheter percutaneously into a hepatic vein and then wedging it into the liver. This wedged pressure reflects portal vein pressure. (An exception is portal vein thrombosis Portal Vein Thrombosis Portal vein thrombosis causes portal hypertension and consequent gastrointestinal bleeding from varices, usually in the lower esophagus or stomach. Diagnosis is based on ultrasonography. Treatment... read more ; in this case, the pressure is normal despite portal hypertension Portal Hypertension Portal hypertension is elevated pressure in the portal vein. It is caused most often by cirrhosis (in North America), schistosomiasis (in endemic areas), or hepatic vascular abnormalities. Consequences... read more .)
Treatment of Sinusoidal Obstruction Syndrome
Supportive care
Treatment of cause
For progressive disease, transjugular intrahepatic portosystemic shunting or transplantation
Ursodeoxycholic acid helps prevent graft-vs-host disease Complications Hematopoietic stem cell (HSC) transplantation is a rapidly evolving technique that offers a potential cure for hematologic cancers ( leukemias, lymphomas, myeloma) and other hematologic disorders... read more in bone marrow or hematopoietic stem cell transplant recipients.
Management includes withdrawing the causative agent (such as herbal teas) and providing supportive therapy. Defibrotide, a sodium salt of single-stranded oligodeoxyribonucleotide, has been demonstrated to protect endothelial cells from further activation, and may be considered in patients with sinusoidal obstruction syndrome that complicates hematopoietic stem cell transplantation (1 Treatment reference Hepatic sinusoidal obstruction syndrome is caused by endothelial injury, leading to nonthrombotic occlusion of the terminal hepatic venules and hepatic sinusoids, rather than of the hepatic... read more ).
Most patients have mild to moderate disease and do quite well. Transjugular intrahepatic portosystemic shunting (TIPS) can be tried for relief of portal hypertension Treatment Portal hypertension is elevated pressure in the portal vein. It is caused most often by cirrhosis (in North America), schistosomiasis (in endemic areas), or hepatic vascular abnormalities. Consequences... read more , but has not yet been shown to prolong survival, particularly when sinusoidal obstruction syndrome is severe. In 25%, sinusoidal obstruction syndrome is severe, accompanied by fulminant liver failure Acute Liver Failure Acute liver failure is caused most often by drugs and hepatitis viruses. Cardinal manifestations are jaundice, coagulopathy, and encephalopathy. Diagnosis is clinical. Treatment is mainly supportive... read more . Liver transplantation Liver Transplantation Liver transplantation is the 2nd most common type of solid organ transplantation. (See also Overview of Transplantation.) Indications for liver transplantation include Cirrhosis (70% of transplantations... read more is a last resort in highly selected patients.
Treatment reference
1. Richardson PG, Riches ML, Kernan NA, et al: Phase 3 trial of defibrotide for the treatment of severe veno-occlusive disease and multi-organ failure. Blood 27(13):1656-1665, 2016. doi: 10.1182/blood-2015-10-676924
Drugs Mentioned In This Article
Drug Name | Select Trade |
---|---|
azathioprine |
Azasan, Imuran |
ursodeoxycholic acid |
Actigall, Reltone, Urso 250, Urso Forte |
defibrotide |
Defitelio |