Portal hypertension

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 28, 2016
StartDiseasesPortal hypertension

Portal hypertension is any sort of hypertension that occurs in the portal venous system. The portal venous system is responsible for draining capillaries from the gastrointestinal tract into the liver. This helps the body to process nutrients and remove toxins from the bloodstream. If the portal venous system starts having difficulty functioning, it can lead to many problems.

Contents

Definition & Facts

Portal hypertension is essentially high blood pressure that happens specifically in the veins that take blood from the gastrointestinal tract to the liver. The highest points of blood pressure typically happen in the main portal vein, where all of the smaller veins from the stomach, pancreas, spleen, and intestines join together.

Patients with portal hypertension often appear to have normal blood pressure overall because the pressure in the portal venous system is not normally measured. However, the portal venous system can have intensely high pressure even if the rest of the veins have normal pressure. Portal hypertension is often associated with a liver blockage that prevents adequate blood flow from reaching the liver. 

Symptoms & Complaints

In the early stages of portal hypertension, patients might not notice any significant symptoms. However, as more and more blood flow to the liver is cut off, more symptoms appear.

Many develop varices which are veins that become enlarged due to abnormal blood flow. They can show up in the stomach, intestine, or esophagus. If they rupture, a patient can face life threatening internal bleeding. Even minimal amounts of internal bleeding will result in blood in stool or blood in vomit. Stool may appear tarry and black due to stomach bleeding.

Abnormal amounts of fluid may build up in the abdominal cavity, so patients can experience a very swollen, fluid filled torso. If waste products build up in the liver due to a lack of proper circulation, people with portal hypertension can start to feel groggy and confused constantly.

The spleen can also become enlarged (splenomegaly) due to a backup of blood, causing more inflammation in the abdomen. The enlarged spleen also tends to trap blood cells in certain areas. This can lead to anemia from a low red blood cell count and increased infection risks from a low white blood cell count.

Causes

There are a few different causes of portal hypertension, but the most common cause is liver damage. Liver cells can normally regenerate, but when they face excessive amounts of damage from alcohol, hepatitis, or other sources, the liver becomes scarred.

This scar tissue prevents blood from flowing into all of the areas of the liver. All of the blood from gastrointestinal system then has to squeeze through just a few small veins into the liver. This increases blood pressure and causes portal hypertension.

Conditions that can cause enough liver damage to lead to portal hypertension include alcohol abuse, hepatitis infections, non-alcoholic fatty liver disease, cystic fibrosis, and Wilson's disease.

Portal hypertension may also occur as a rare complication of a parasitic infection called schistosomiasis. These parasites can form cysts that block blood flow in some parts of the portal venous system.

Another cause of portal hypertension is blood clots. Any sort of clot that is large enough to block blood flow can increase blood pressure, especially if they occur in the veins going from the liver to the heart.

Diagnosis & Tests

Portal hypertension is not normally diagnosed until it causes more severe symptoms. It is normally only diagnosed at early stages if a patient is experiencing liver failure. Because liver failure often causes portal hypertension, doctors may regularly check patients with liver issues to see if they have the condition. Otherwise, portal hypertension is typically diagnosed once a patient gets ascites or extremely noticeable gastrointestinal bleeding.

A physical examination can often reveal many of the telltale signs associated with portal hypertension.If portal hypertension is a possibility, it will need to be confirmed through certain tests. A blood test can reveal the low blood cell counts often associated with the condition.

Imaging tests like computed tomography (CT) scans and magnetic resonance imaging (MRI) scans can reveal the signature enlarged veins that occur around the portal venous system. Some doctors may recommend a test where contrast dye is injected into the veins before an X-ray is taken. This can show any specific blockages or areas of particularly high blood pressure.

Treatment & Therapy

Treatments for portal hypertension will vary based on the reason for the high blood pressure. If a patient has a treatable condition, like a parasitic infection, then the portal hypertension will often resolve itself after the condition is treated.

Treatment for most cases of portal hypertension will rely on managing the symptoms and making lifestyle changes to reduce overall blood pressure. If a patient has bleeding from the varices, procedures may be needed to stop the gastrointestinal bleeding. This treatment can be either banding to block off blood vessels or sclerotherapy to clot the blood around the bleeding area.

Other options, like the TIPS procedure (transjugular intrahepatic portosystemic shunt) or the DSRS procedure (distal splenorenal shunt procedure), include placing a shunt in certain areas to redirect blood and relieve pressure.

To reduce overall pressure, doctors may recommend that patients avoid excessive sodium, stress, alcohol, and certain medications. Beta blockers may be prescribed to reduce pressure in the area. Ascites can be temporarily relieved by draining the excessive fluid in the abdomen, but it may recur if the high blood pressure continues. In cases with extreme liver damage, a liver transplant may be necessary.

Prevention & Prophylaxis

It may be possible to prevent portal hypertension. Preventative approaches focus on living an overall healthy lifestyle. Patients should try to stay within recommended weight guidelines and avoid eating excessive sodium or sugar.

Alcohol abuse, drug abuse, and unsafe sexual practices should also be avoided to prevent the conditions that can cause liver failure. To avoid the schistosomiasis parasitic infection, one should avoid swimming in or drinking dirty water.