Budd-Chiari syndrome

Budd-Chiari syndrome is clotting of the hepatic vein, the major vein that leaves the liver. Patients with Budd-Chiari syndrome generally have an underlying condition that predisposes to blood clotting. About 10% have polycythemia vera, a condition in which abnormal amounts of red blood cells are. About 10% of patients with Budd-Chiari syndrome take birth control pills which also may predispose to blood clotting. Budd-Chiari syndrome is a condition caused by obstruction of the blood flow out of the liver, most often by blood clotting. Budd-Chiari syndrome most often occurs in individuals with underlying disorders that cause blood clotting, including antiphospholipid syndrome and myeloproliferative disorders such as polycythemia vera and paroxysmal nocturnal hemoglobinuria. Chronic disorders such as Behcet disease, inflammatory bowel disease, sarcoidosis, sjogren syndrome, or lupus may also cause Budd-Chiari syndrome.

It is known that Budd-Chiari syndrome is a rare disorder, but exactly how often it occurs is not really known. Budd-Chiari syndrome affects people of all ethnic backgrounds and affects men and women equally.

Symptoms

Classical Budd-Chiari syndrome refers to occlusion of the hepatic veins. Symptoms ususally include abdominal pain, hepatomegaly, jaundice, fever, and liver dysfunction. In about 50% of the patients the caudate lobe is markedly enlarged because drainage via the right hepatic vein is preserved. Liver histology shows centrilobular and sometimes midlobular involvement with sinusoidal congestion, hepatocyte atrophy, and fibrosis.

Most people who develop Budd-Chiari syndrome have 3 main symptoms:
* Ascites, in which fluid collects in the abdominal cavity, often making the abdomen distended
* An enlarged liver, known as hepatomegaly, because blood can flow into the liver but not out of it.
* Abdominal pain

Diagnosis

The usual symptoms of Budd-Chiari syndrome are not necessarily clues to its diagnosis, because those symptoms could be caused by any number of disorders. Budd-Chiari syndrome is most commonly diagnosed using ultrasound studies of the abdomen and retrograde angiography). Ultrasound may show obliteration of hepatic veins, thrombosis or stenosis, spiderweb vessels, large collateral vessels, or a hyperechoic cord replacing a normal vein. Computed tomography (CT) or magnetic resonance imaging (MRI) is sometimes employed although these methods are generally not as sensitive. Liver biopsy is nonspecific but sometimes necessary to differentiate between Budd-Chiari syndrome and other causes of hepatomegaly and ascites, such as galactosemia or Reye's syndrome

If an individual has a disorder that might cause Budd-Chiari syndrome, though, that can help with the diagnosis. The fluid that collects in the abdomen can be tested to help confirm the diagnosis. Ultrasound and magnetic resonance imaging (MRI) can help assess liver function and its blood flow. A sample (biopsy) of the liver can be taken to examine the cells under the microscope.

Treatment

If left untreated, Budd-Chiari syndrome can fatally damage the liver. Medications can be given to dissolve any existing blood clots in the liver and reduce the formation of new clots. A low-salt diet can help control ascites. Special surgical procedures can relieve the blood congestion in the liver Patients with Budd-Chiari syndrome who have deteriorating liver function and complications usually need to undergo liver transplantation. Other surgical procedures have been used with variable degrees of success. In some cases, the underlying condition that caused the syndrome excludes transplantation as a treatment option.

Note that, often, the patient is known to have a tendency towards thrombosis, although Budd-Chiari syndrome can also be the first symptom of such a tendency. Examples of genetic tendencies include Protein C deficiency, Protein S deficiency, and the Factor V Leiden mutation. An important non-genetic risk factor is the use of estrogen-containing (combined) forms of hormonal contraception. Other risk factors include the antiphospholipid syndrome, aspergillosis, Behcet's disease, dacarbazine, pregnancy, and trauma.
Many patients 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 39% develop venous thromboses and 12% may acquire Budd-Chiari.
A related condition is veno-occlusive disease, which occurs in recipients of bone marrow transplants as a complication of their medication. Although its mechanism is similar, it is not considered a form of Budd-Chiari syndrome.