Portal Vein Thrombosis

What is portal vein thrombosis?

Portal vein thrombosis (PVT) is the formation of a blood clot (thrombus) that narrows or blocks your portal vein. This vein carries blood to your liver from organs in your abdomen (belly). Clots can also develop in your portal vein’s branches (inside your liver) or the blood vessels that drain into your portal vein (superior mesenteric vein and splenic vein).

Portal vein thrombosis is a serious condition, but it often causes no symptoms. So, you may not know you have a blood clot until a healthcare provider finds it through testing or you develop complications, like portal hypertension. Such complications are serious and life-threatening without treatment. Common symptoms include vomiting blood and rectal bleeding (blood in your poop). If you have these symptoms, seek medical care immediately.

People with cirrhosis face a higher risk of portal vein thrombosis and its complications. Many other medical conditions, like certain blood clotting disorders, can also raise your risk. It’s important to talk to a healthcare provider if you have risk factors for portal vein thrombosis. Your provider will make sure you receive appropriate screenings to diagnose and treat issues as early as possible.

Types of portal vein thrombosis

Healthcare providers classify PVT into two main types based on who’s affected:

• Cirrhotic portal vein thrombosis: This is the formation of a portal vein thrombus in people who have cirrhosis (scarring of the liver). This type is more common.
• Non-cirrhotic portal vein thrombosis: This is the formation of a portal vein thrombus in people who don’t have cirrhosis.

This distinction is important in managing the condition. For example, providers often make treatment decisions based on whether or not you have cirrhosis.

Cirrhosis can also affect your prognosis (outlook) by raising your risk for complications. However, providers continue to learn more about both types of portal vein thrombosis and how to lower your risk for complications. Talk to your provider about your treatment options and what you can expect.

How common is this condition?

Portal venous thrombosis is relatively uncommon in people without liver disease. But the risk is higher among certain groups, including people with cirrhosis. As many as 1 in 4 people with cirrhosis develop PVT. This is because scar tissue in your liver slows down your blood flow, and slow blood flow raises your risk of a blood clot.

What are the complications of portal vein thrombosis?

Complications depend on the exact location of the clot and any underlying conditions you have. Possible complications include:

• Esophageal varices.
• Gastrointestinal (GI) bleeding.
• Mesenteric ischemia.
• Portal hypertension.
• Splenomegaly (enlarged spleen).

What are the symptoms of portal vein thrombosis?

Many people have no symptoms. Healthcare providers often diagnose this condition through imaging tests ordered for other purposes.

However, you may have symptoms if complications develop. Symptoms can include:

• Vomit that contains blood.
• Rectal bleeding (blood in your poop).
• Bloated stomach.
• Swelling (edema) in your legs and feet.
• Cramping in your belly.

What causes thrombosis of the portal vein?

Healthcare providers call this condition “multifactorial.” That means two or more factors usually interact to cause it.

A blood clot may form in your portal vein due to:

• Blood that’s prone to clotting (hypercoagulable state).
• Slow blood flow through your liver.
• Damage to the lining (endothelium) of your portal vein.

What are the risk factors for this condition?

Many different medical conditions can make your blood more likely to clot and/or slow down blood flow through your liver. These include:

• Abdominal tumors.
• Antiphospholipid syndrome.
• Antithrombin deficiency.
• Cirrhosis.
• Factor V Leiden.
• Infection in your belly (like pancreatitis).
• Myeloproliferative neoplasms.
• Portal hypertension (advanced stage).
• Pregnancy.
• Protein C deficiency.
• Protein S deficiency.
• Prothrombin gene mutation.

In addition, certain abdominal surgeries (like splenectomy) can raise your risk by injuring the lining of your vein.

How is portal vein thrombosis diagnosed?

Healthcare providers diagnose this condition through a comprehensive physical exam and testing. They’ll also ask about your medical history to learn if you have risk factors for portal vein thrombosis.

What tests will be done to diagnose this condition?

Your provider may order tests to diagnose portal vein thrombosis and check for complications. Possible tests you may need include:

• Computed tomography (CT) scan.
• Doppler ultrasound.
• Liver function tests.
• Magnetic resonance imaging (MRI).

The results of these tests will guide your treatment plan.

How do healthcare providers treat portal vein thrombosis?

Healthcare providers decide treatment on an individual basis. They tailor treatment to your needs based on many factors, including:

• The location of the blood clot.
• The cause of the blood clot.
• Your underlying medical conditions (like cirrhosis).
• The presence of complications.
• Your medical history.

Treatment options include:

• Anticoagulants. These medications can help stop blood clot growth and prevent new clots from forming. But healthcare providers use these with caution in people with cirrhosis, who may face an increased risk of internal bleeding.
• Thrombolytic therapy. This IV- or catheter-based treatment can dissolve the clot if anticoagulants aren’t adequate. Providers may also use this method if your intestines aren’t receiving enough blood flow.
• Transjugular intrahepatic portosystemic shunt (TIPS). This catheter-based procedure manages complications of portal vein thrombosis, including GI bleeding. It creates a tunnel through your liver to connect your portal vein to one of your hepatic veins. This new route allows blood from your intestines to avoid your liver. It reduces pressure in your liver’s veins and lowers your risk of bleeding. But as your liver normally filters toxins (poisons) from your blood, you now have unfiltered blood circulating through your body. So, a risk of this treatment is that toxins can reach your brain and affect brain function (hepatic encephalopathy).

Talk to your provider about the benefits and risks of treatment in your individual situation.

Can portal vein thrombosis be prevented?

You can’t always prevent blood clots, including those in your portal vein. But here are some actions you can take to lower your risk:

• Visit a healthcare provider for yearly checkups, and go to all of your follow-up appointments.
• Work with your provider to manage underlying conditions.
• Take all of your medications as prescribed.
• Tell your provider right away about any new or changing symptoms.

What is the outlook for this condition?

Your healthcare provider is the best person to ask about your prognosis. They’ll tell you what you can expect based on your individual situation. The survival rate and life expectancy for portal vein thrombosis can vary based on:

• The cause of the blood clot.
• Whether or not you have cirrhosis.
• Other underlying conditions you may have.
• Complications that arise.
• The condition of your liver.

In general, prompt diagnosis and treatment can help improve your outcome.

When should I see my healthcare provider?

See your provider for yearly checkups. Contact them sooner if you have any new or unexplained symptoms.

If you have one or more risk factors for portal vein thrombosis, it’s a good idea to discuss these with your provider. Ask about your individual level of risk and what you can do to lower it.

When should I go to the ER?

Acute gastrointestinal (GI) bleeding can be a complication of portal vein thrombosis. Symptoms are often sudden and severe. Call 911 or your local emergency number if you have:

• Dizziness or faintness (syncope).
• Black or red stool or blood in your vomit
• Fast pulse.

What questions should I ask my healthcare provider?

Some questions that may help you learn more about your condition include:

• What caused the blood clot to develop?
• What’s the best treatment plan for me?
• Do I need to take any medications, and if so, for how long?
• What are the benefits and risks of treatment?
• What can I expect as I recover?
• What is my long-term outlook?