Portal vein thrombosis means that there is a blood clot in the portal vein. This vein carries blood to the liver. A clot can fully or partially block the portal vein, as well as blood flow to the liver.
It can occur in people with liver disease, such as cirrhosis, sepsis, pancreatitis, lupus, and other medical conditions.
In many people, portal vein thrombosis does not cause symptoms. A doctor only notices it on an imaging scan while looking for something else.
Portal vein thrombosis can cause portal hypertension or high blood pressure in the portal vein. This can cause bleeding in the digestive tract.
Read on to learn more about portal vein thrombosis.
Thrombosis is the formation of a blood clot in a blood vessel. This can block blood flow. Portal vein thrombosis occurs when a blood clot causes the portal vein to become narrow or blocked. The portal vein carries blood to the liver.
Portal vein thrombosis may affect the body of the portal vein, its smaller branches in the liver, or the blood vessels of the portal vein that extend to the spleen.
Certain types of portal vein thrombosis can be immediately life threatening. For example, if the blood clot blocks the superior mesenteric veins, it can cause sepsis or a bowel infection.
Portal vein thrombosis can occur due to many reasons, such as infection or surgery. It may also occur as an acute or chronic condition.
The causes vary by age group.
Newborns and infants
- infection of the umbilical stump, which may spread to the portal vein from the umbilical vein
- congenital birth defects, which are present from birth
- JAK2 genetic mutation, which can cause portal vein thrombosis
Children
- congenital birth deficits, including JAK2 genetic mutation
- appendicitis that spreads to the portal vein
- sepsis
Adults
- recent surgery or injury
- liver cirrhosis
- cancer, especially liver cancer and pancreatic cancer
- conditions that increase the risk of blood clots, such as pregnancy, protein C or S deficiency, and clotting disorders
Most people with portal vein thrombosis do not have symptoms. When symptoms are present, the most common symptoms include:
- pain in the stomach, especially the upper right quadrant near the ribs
- fever
- swelling in the abdomen from the buildup of excess fluid
People with cirrhosis who develop new portal vein thrombosis usually develop sudden signs of liver health issues,
- jaundice, which can cause yellow eyes and skin and very dark urine
- bleeding in the digestive tract
- swelling in the abdomen
Liver function tests are typically normal in people with portal vein thrombosis, though people with cirrhosis typically show sudden liver enzyme elevations. Instead, doctors usually diagnose the condition using imaging scans that allow them to see a clot in the vein.
These scans may include the following:
Doppler ultrasounds measure blood flow through blood vessels. Because it is accessible and not invasive, doctors usually start with this test. Doppler ultrasounds can detect around
Learn more about Doppler ultrasounds.
If a person has portal vein thrombosis, a doctor will likely recommend an endoscopy. This uses a long, thin tube to visualize the digestive tract and look for bleeding.
A doctor may recommend further testing to assess for clotting disorders such as:
- antiphospholipid syndrome
- deficiencies in antithrombin III, protein C, and protein S
- factor V Leiden mutation
These conditions increase the risk of other types of blood clots.
Treatment begins by managing the underlying cause. In children and newborns, this may eliminate symptoms. For example, a child with appendicitis will need their appendix removed.
Treatment options include:
- Blood thinners or anticoagulants: These drugs can help shrink blood clots and prevent more clots from forming. However, blood thinners also increase the risk of bleeding, which can be dangerous if a person has bleeding in their digestive tract. Doctors typically recommend blood thinners if a person is awaiting a liver transplant.
- Thrombectomy: This is a procedure to surgically remove the clot. However, the clot may return, and trauma to the blood vessels may cause additional complications. Thrombectomy of the portal vein is a very high risk procedure that is only considered in the most life threatening circumstances.
- Thrombolysis: This uses medication or minimally invasive surgery to dissolve a clot. While there are several surgical ways to access the clot, the most practical thrombolysis access is when a doctor enters through the liver or from the jugular vein. However, these approaches do pose a risk of bleeding.
- Transvenous intrahepatic portosystemic shunt (TIPS): This nonsurgical procedure uses a tube to connect the portal vein to another blood vessel in the liver. This can improve blood flow. A person is usually awake for the procedure, and a doctor performs it by inserting a tube through another vein, usually in the neck.
Since the TIPS procedure can limit options for liver transplantation, people should consult with a liver transplant surgeon if that is an option prior to undergoing the treatment.
Portal hypertension — or high blood pressure in the portal vein — is the main complication of this diagnosis. Treatment options for portal hypertension
- variceal ligation, a procedure to treat enlarged veins in the esophagus and prevent bleeding
- antibiotics for people with an active, sudden bleed in the esophagus
- medication to lower blood pressure, usually beta blockers
Diet changes
A consultation with a dietitian can help with maintaining a healthy weight and choosing the right foods. For example, reducing sodium in the diet
The outlook for people with portal vein thrombosis not due to liver cirrhosis is generally good. However, the specific prognosis depends on the underlying cause.
Portal vein thrombosis can occur because of genetic mutations. However, in adults, it is usually a sign of an underlying medical condition, such as liver cirrhosis. The prognosis depends on the underlying cause, and on whether a person can safely undergo treatment.
People with portal vein thrombosis may not know they have it. However, those with other symptoms of liver disease should see a doctor since early treatment may improve life expectancy and reduce symptoms.