What Is Mesenteric Venous Thrombosis?
Mesenteric venous thrombosis occurs when a blood clot forms in one or more of the major veins that drain blood from your intestines.
There are three veins that carry blood from the intestines: the superior mesenteric vein, the inferior mesenteric vein, and the splenic vein. These veins deliver nutrient-rich blood to the liver via the hepatic portal vein. A clot in any of these veins blocks blood flow to the intestines, which can lead to damage and tissue death.
This condition is rare, but can lead to life-threatening complications without prompt treatment.
Symptoms typically include abdominal pain, bloating, and diarrhea. Certain digestive diseases that cause swelling of the tissues surrounding the intestines can increase your risk of developing this condition. It can also be caused by trauma to the abdomen or cancers of the digestive system.
Your doctor will normally prescribe blood thinners to treat this condition. In some cases however, surgery is necessary to remove the clot. Life-threatening complications include death of part of the intestine. If this happens, the dead portion of the intestine must also be surgically removed.
Your outlook will depend on many factors, including any underlying health conditions and how quickly treatment is begun.
Causes of Mesenteric Venous Thrombosis
Certain conditions can cause swelling around your veins, which can lead to mesenteric venous thrombosis. These conditions include:
- injury to your abdomen
- genetic disorders that make your blood more prone to clotting, such as Factor V Leiden thrombophilia—an inherited clotting disorder
- abdominal infections, such as appendicitis
- inflammatory bowel diseases, such as diverticulitis, ulcerative colitis, and Crohn’s disease
- inflammation of the pancreas, (pancreatitis)
- liver disease and cirrhosis (scarring of the liver)
- cancers of the digestive system
You are also at an increased risk for developing blood clots if you use hormone therapies or take birth control pills. Smoking also increases your risk of blood clots.
Symptoms of Mesenteric Venous Thrombosis
Symptoms of this condition include:
- abdominal pain, especially after eating
- bloody stools
Make an appointment with your doctor if you repeatedly experience abdominal pain or any of these symptoms. Delaying treatment can lead to serious complications.
Diagnosing Mesenteric Venous Thrombosis
Diagnosis is usually based on your symptoms and several imaging tests. A computed tomography (CT) scan is typically used to diagnose this condition. This test uses X-ray pictures to create cross-sectional images of the abdomen. Other imaging tests may include an ultrasound or magnetic resonance imaging (MRI) scan of the abdomen. This test utilizes high-powered magnets and radio waves to create images of the abdomen.
An arteriogram may be performed to see how blood is moving through your arteries and to help determine the location of a blood clot. For this test, a doctor will inject a special dye into your arteries and then take X-rays of your abdomen. The dye will appear in the images, allowing your doctor to identify any areas with damage or blockages.
Treating Mesenteric Venous Thrombosis
Blood thinners are the main treatment for this condition. If you have a blood clotting disorder, you may need to take blood thinners indefinitely.
In some cases, such as when a blood clot is discovered in the portal or mesenteric veins, blood thinners can be delivered directly to the clot through a procedure called thrombolysis. This process uses a catheter, or a flexible tube, that is inserted into your vein. Your doctor will use X-ray images to position the catheter within the clot and then inject a blood-thinning medication to dissolve it.
In rare cases, the clot is removed in a surgical procedure called thrombectomy. This is similar to a thrombolysis, but instead of injecting a blood thinner, the catheter is used to pull the clot from the vein.
If you have symptoms of peritonitis (a severe infection of the peritoneum — the thin membrane that lines the abdominal wall and covers the organs inside the abdomen), you will need surgery to remove the affected areas of your intestine. Surgery usually requires resection of the affected bowel. Afterward, your body’s waste products will be collected in an ileostomy (a bag placed on the skin over an opening from the small intestine), or a colostomy (a bag placed on the skin over an opening from the colon).
Mesenteric venous thrombosis can decrease the supply of blood to the tissues and cells of your digestive system. This condition, called ischemia or infarction, causes your intestines to be damaged and is life threatening. It requires emergency medical attention. Always contact your doctor if you experience severe stomach pain along with fever, diarrhea, and vomiting.