The hepatic veins that drain blood from the liver or the sub-hepatic vena cava that leads to the heart become occluded or narrowed, which has a negative effect on the flow of blood from the liver. This, in turn, causes the portal vein pressure to rise, which causes symptoms such as portal hypertension.
Each year around 300 people are either outpatients or inpatients for this disease. The incidence of this disease is estimated to be 2.4 per 1 million people.
There are slightly more male patients, as the male-to-female ratio is 1.6:1. The mean age at onset is 36 years for males and 47 years for females. Thus, onset tends to occur at a younger age in males.
The causes are thought to be congenital angiodysplasia and acquired thrombus (blood clot) of the hepatic vein or sub-hepatic vena cava. However, approximately 70% of patients develop the disease due to unknown causes. It is still not known why the blood vessels in this region are prone to blockage. There are also many cases of Budd-Chiari Syndrome comorbidity in patients who suffer from underlying conditions such as hematologic (blood) diseases, oral contraceptive use, pregnancy and childbirth, intra-abdominal infection, vasculitis, and blood coagulation disorders.
Recently, attention has been placed on whether or not genetic abnormalities contribute to blood coagulation disorders. This issue is currently the focus of academic study.
Although it is generally thought that this disease is not hereditary, since there is a great deal of attention on genetic abnormalities, there is suspicion that a congenital factor may be involved in some patients. This issue is currently being studied.
When portal vein pressure increases, some of the blood in the portal vein is unable to flow toward the liver and instead finds different routes. These new blood flow routes are known collectively as "collateral circulation." The presence of collateral circulation causes the spleen to enlarge, causes dilation of the abdominal wall veins, causes varices to form in the esophagus and stomach and causes ascites. Once the spleen becomes enlarged, it leads to a condition known as hypersplenism, which causes anemia and reduced numbers of platelets and white blood cells. In addition, when the pressure of varices increases, the veins become unable to withstand the pressure and rupture, causing bleeding. This then causes symptoms such as bloody vomit and bloody diarrhea.
The major symptoms of Budd-Chiari Syndrome are ascites, lower extremity edema (swelling), varicose veins in the lower extremities, and swelling of the abdominal wall veins. The symptoms of portal hypertension include gastric and esophageal varices, enlarged spleen, and anemia.
In cases of Budd-Chiari Syndrome, the symptoms caused by occlusion (blockage) or narrowing of the hepatic veins and sub-hepatic vena cava and the symptoms caused by portal hypertension are treated as indicated below:
1) For occlusion (blockage) or narrowing of the veins:
If test results indicate a blood clot, anticoagulant treatment is performed to remove the clot. Depending upon the disease condition, stenosis dilation using a balloon catheter on the narrowed portions of the veins or direct release of occluded or narrowed portions of veins are among the treatment options.
2) For portal hypertension:
Emergency treatment is required when gastric or esophageal varices rupture and bleed. If left untreated, the bleeding can cause the patient to go into shock, and in some cases, the patient's life may be in danger. In such cases, the patient should immediately seek medical treatment at the nearest medical facility. IV and blood transfusion are used to prevent shock. The patient will then have to undergo endoscopic hemostasis treatment to stop the bleeding from the varices.
3) Hemostasis treatments for varices:
Balloon tamponade therapy
Endoscopic treatments: sclerotherapy, ligation
Surgical treatments: esophageal transection, Hassab's operation
Budd-Chiari Syndrome is either acute or chronic, depending upon how the symptoms appear. Acute cases are severe, and patients experience abdominal pain, vomiting, sudden enlargement of the liver, and ascites. In many cases, death occurs within one month. However, this type is extremely rare in Japan, as many cases are chronic patients. Chronic cases progress without the appearance of any symptoms in many cases, and eventually, edema (swelling) of the lower extremities, ascites, and dilation of the abdominal wall veins occur. In the case of chronic Budd-Chiari Syndrome, if bleeding from gastric and esophageal varices can be sufficiently controlled, the course of the disease is good.