Splenic vein thrombosis is a blockage in the splenic vein due to a blood clot. The splenic vein carries blood away from the spleen and parts of the stomach and pancreas.

The spleen is an organ that filters and stores blood and produces white blood cells. A blood clot — also called a thrombus — in the splenic vein can cause blood to back up into the spleen, leading to various serious complications.

This article discusses further details of splenic vein thrombosis, including symptoms, possible causes, and treatments.

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Certain triggers can cause blood to clot inside a vein, leading to a blockage that stops blood from passing through the blood vessel as it usually would. When this happens in the splenic vein, it is called splenic vein thrombosis.

A clot in the splenic vein can lead to a buildup of blood and pressure in the spleen. This can also affect nearby connected veins and other parts of the body, including the stomach, liver, and pancreas.

Splenic vein thrombosis is relatively uncommon and most often affects individuals with pancreatitis or other conditions involving the pancreas.

In most cases, splenic vein thrombosis does not cause any noticeable symptoms.

However, possible symptoms include:

The severity of symptoms may depend on the size of the blockage in the splenic vein and whether complications have occurred.

According to a 2022 case series, chronic pancreatitis is the most common cause of splenic vein thrombosis, affecting between 5% and 22% of those with the condition. Pancreatitis is inflammation of the pancreas.

In fact, splenic vein thrombosis is a common complication of pancreatitis. This is because the splenic vein sits very close to the pancreas, and repeated inflammation can damage or compress the blood vessels, leading to thrombosis.

Still, splenic vein thrombosis can occur without pancreatic inflammation. It can happen whenever there is damage or pressure on the splenic vein.

Other possible causes include:

  • traumatic injury
  • complications from surgery
  • abdominal cancers
  • certain inflammatory conditions
  • severe infection
  • cirrhosis or liver scarring
  • conditions that increase the risk of blood clots

Diagnosing splenic vein thrombosis may involve physical exams, laboratory tests, and imaging tests.

A medical history can help a diagnostic team determine whether splenic vein thrombosis is a likely diagnosis.

However, as many people with splenic vein thrombosis do not present with obvious symptoms, imaging tests may be essential for diagnosis. They allow a healthcare professional to look for blockages in the splenic vein. Tests include:

Indications or test results that may mean a person has splenic vein thrombosis include:

The treatment for splenic vein thrombosis may depend on the underlying cause or if an individual has developed further complications.

Possible treatments include:

Thrombolysis

This treatment targets blood clots to help break them down and clear blockages in the vein.

Thrombolysis can involve either medications that target the whole body or catheter-directed thrombolysis. The latter delivers medication directly to the clot through a small tube inside the vein.

Anticoagulation

Anticoagulant drugs help prevent further thrombosis by stopping blood from clotting. They can also help reduce the risk of splenic vein thrombosis recurring or becoming more severe.

In some cases, a doctor may not use anticoagulants to treat splenic vein thrombosis, as this can increase the risk of internal bleeding.

Splenectomy

This is the surgical removal of the spleen.

A person may need to have their spleen removed if they have internal bleeding within the gastrointestinal (GI) tract, which can be a complication relating to splenic vein thrombosis.

While splenectomy is an effective treatment for GI bleeding, it may not be suitable for all individuals.

In many cases, treating the underlying condition may help manage splenic vein thrombosis and prevent recurrence.

There are many complications associated with splenic vein thrombosis. The splenic vein is an important part of the portal venous system, which is responsible for carrying blood in certain organs to the liver for filtering.

When this system is not functioning properly, many parts of the GI system and related organs may be affected.

Gastric varices are a known complication of splenic vein thrombosis. It refers to unusually dilated blood vessels in the stomach that can rupture and cause significant bleeding in the upper GI tract. In some cases, gastric varices can be life threatening.

Other possible complications of splenic vein thrombosis include:

  • ascites (fluid buildup in the abdomen)
  • intestinal ischemia, which means that not enough oxygen is reaching the tissue in the abdomen
  • infection
  • organ damage

The outlook for individuals with splenic vein thrombosis can vary and depends on the following:

  • underlying causes
  • the severity of their condition
  • if complications are present

Many individuals with splenic vein thrombosis do not experience symptoms. According to a 2022 case report, nearly 1 in 3 individuals with splenic vein thrombosis due to chronic pancreatitis saw their blood clot resolve with or without anticoagulation.

Going forward, individuals should make certain lifestyle adjustments to help prevent the issue from recurring or continue to take anticoagulants on a long-term basis.

Certain complications, such as severe GI bleeding, can be severe and, in some cases, fatal.

How serious is splenic vein thrombosis?

Splenic vein thrombosis is a serious condition and can sometimes lead to life threatening complications. The seriousness of splenic vein thrombosis can vary depending on the underlying cause, how quickly a person receives treatment, and whether complications develop.

How long do you need to be on anticoagulation for splenic vein thrombosis?

How long a person needs to take anticoagulation medication for splenic vein thrombosis can change on a case-to-case basis. However, experts note that this treatment should probably last at least 3 months.

A doctor can best advise on whether a person needs anticoagulation therapy and how long they will need to take it.

What happens when the splenic vein is occluded?

When the splenic vein is occluded, it means a blood clot is blocking the vessel. Several things can occur as a result, including spleen enlargement, as not enough blood is flowing out of the organ.

Splenic vein occlusion can also lead to a buildup of pressure in the portal vein system and other complications, such as GI bleeding.

Splenic vein thrombosis is a blood clot in the splenic vein, which carries blood away from the spleen and toward the liver. This can lead to issues in the spleen, liver, stomach, and other parts of the GI tract. In some cases, complications can be serious.

It is important for people with splenic vein thrombosis to receive treatment as soon as possible to reduce the chance of complications occurring. Several treatment options can target blood clots and reduce the risk of clots recurring.