Idiopathic portal hypertension is a disease in which the pressure of the portal vein increases, despite there being no particular problems with the liver or portal vein. This causes symptoms such as gastric and esophageal varices, enlargement of the spleen, and anemia.
Between 640 and 1,070 people are affected each year. Approximately 18% of these patients are new annually. In Japan, the disease prevalence is estimated to be 7.3 per 1 million people, indicating a trend toward slightly higher numbers of patients in Japan than in Europe and the United States. There is also a trend toward higher numbers of patients in rural than urban areas.
There are three times as many male patients as females, and disease onset often occurs in people in their 40s and 50s.
Although the exact causes remain unknown, based on the fact that middle-aged females are prone to the disease and that blood tests show immune abnormalities in some cases, it is believed that some autoimmune disorder (i.e., the immune system attacks the body itself) is involved. Besides, recent research has found that some of the lymphocytes in the blood have abnormalities. Studies of these types of abnormalities of the immune system are currently underway, and the medical community is looking forward to their findings.
No data clearly indicates genetic involvement. However, since autoimmune disorders tend to occur multiple times within the same family, it is impossible to rule out the involvement of some genetic abnormality as the prime cause. This issue is currently being studied.
When the portal vein pressure rises, the spleen becomes enlarged, and ascites (accumulation of fluid in the abdomen) occurs. In addition, increased portal vein pressure causes some of the blood in the portal vein to flow away from the liver and find other routes. These alternate routes are referred to as "collateral circulation." Collateral circulation causes the veins in the abdominal wall to swell, which in turn leads to varices (abnormally dilated veins with a tortuous course; in the legs these are known as "varicose veins") in the esophagus and stomach. When the spleen becomes enlarged, a condition known as hypersplenism occurs, which causes anemia. In addition, the number of blood platelets decreases, and as a result, it becomes difficult for the body to stop bleeding. Also, when the pressure of the varices rises, the veins become unable to withstand this pressure, and they rupture, which causes bleeding. In such cases, symptoms such as bloody vomit or bloody diarrhea occur. In some cases, the bleeding leads to shock and death.
In cases of idiopathic portal hypertension, the gastric and esophageal varices that accompany portal hypertension, anemia (pancytopenia: low counts of all three types of blood cells: red blood cells, white blood cells, and platelets), and hypersplenism are treated.
When bleeding occurs from the varices, emergency treatment is required. If left untreated, the bleeding can cause the patient to go into shock, and in some cases, they may become critically ill or die. In such cases, the patient should immediately seek emergency treatment at the nearest emergency room. In addition to emergency measures such as IV and blood transfusion, the patient must also undergo an endoscopic procedure to stop the bleeding from the varices.
1) Hemostasis treatment (treatments to stop bleeding) for varices:
2) Treatments for hypersplenism:
Patients with idiopathic portal hypertension generally maintain normal liver functions, and therefore, if the bleeding from the gastric and esophageal varices can be sufficiently controlled, the course of this disease is good.