Portal hypertension is characterized by abnormally high pressure in the portal vein (vein in the digestive tract) and its branches. It is a major complication of cirrhosis (diffuse, chronic and irreversible disease of the liver).

Definition of portal hypertension

Portal hypertension is defined as an abnormal increase in pressure in the portal vein and its branches. The portal vein is a large diameter blood vessel that carries blood from the intestines, spleen, pancreas, and gallbladder to the liver. After entering the liver, the vein divides into two branches which then branch out into multiple small intrahepatic vessels.

Portal hypertension disrupts the portal venous network. It causes the formation of new vessels which will bypass the liver. Instead of passing through the liver, the blood conveyed by the portal vein will be returned directly to the general circulation. However, the passage of blood through the liver is essential since this organ acts as a filter. In particular, the liver helps rid the blood of substances potentially harmful to the body.

Newly formed vessels can have another drawback. Some of them are very fragile. They can bleed or even rupture. Bleeding with serious complications can occur.

Causes of portal hypertension

In France, as in all Western countries, the main cause of portal hypertension is cirrhosis. It is a liver disease that leads to the loss of organ functions and is accompanied by multiple complications.

Liver vascular abnormalities can also be the cause of portal hypertension.

Risk factors

The risk factors for portal hypertension are those of its underlying causes, and in particular those for cirrhosis:

• alcohol consumption, which is the main risk factor for cirrhosis;
• contamination with hepatitis B virus (transmitted through blood, saliva and sexual intercourse) or hepatitis C virus (transmitted through blood);
• the metabolic syndrome which combines different disorders such as type 2 diabetes, hyperlipemia and overweight.

Diagnosis of portal hypertension

The diagnosis of portal hypertension is initially based on a clinical examination. The doctor notices certain signs suggestive of the disease, such as:

• swelling of the abdominal wall;
• the presence of a dull sound during percussion at the abdominal level;
• an increase in the volume of the spleen by abdominal palpation.

Depending on the signs observed, the diagnosis can be confirmed and / or deepened by additional examinations such as:

• blood tests;
• a cognitive function test;
• medical imaging tests such as an ultrasound or a CT scan.

Portal hypertension is asymptomatic (without clinical manifestation). The symptoms are due to its complications.

Risk of digestive bleeding

The most serious consequence of portal hypertension is the occurrence of digestive hemorrhage (significant loss of blood in the digestive system). Emergency management of bleeding is necessary.

Other possible complications

Other consequences of portal hypertension can be observed:

• ascites, or intra-abdominal fluid effusion (accumulation of fluid within the abdomen);
• splenomegaly (enlargement of the spleen);
• leukopenia (low number of white blood cells);
• thrombocytopenia (decrease in the number of blood platelets);
• hepatic encephalopathy (brain dysfunction caused by the build-up of toxic substances in the blood which are normally eliminated by the liver).

The management of portal hypertension essentially consists of treating its complications, and in particular any bleeding that may occur.

Several treatments can be considered:

• prescribing medications to slow bleeding;
• prescribing drugs to lower portal pressure;
• blood transfusions to compensate for blood loss;
• endoscopic ligation to tie the veins;
• portosystemic intrahepatic shunt, a surgical procedure aimed at diverting blood flow.

Management of the underlying disease is also essential in the treatment of portal hypertension. In the case of cirrhosis, the underlying cause must be treated and the aggravating factors limited. Alcohol withdrawal is essential in the event of alcoholic cirrhosis. Antiviral treatments are given for viral hepatitis. In the most severe cases when the prognosis is threatened, a liver transplant may be considered.

Prevention of portal hypertension involves preventing its underlying causes, especially the risk of cirrhosis. To do this, it is possible to act on certain avoidable risk factors:

• limit alcohol consumption;
• get the hepatitis B vaccine.