Mesenteric venous thrombosis occurs when a blood clot forms in one or more of the major veins that drain blood from your intestines. This condition is rare, but it can lead to life-threatening complications without prompt treatment.
There are three veins that carry blood from the intestines:
- the superior mesenteric vein
- the inferior mesenteric vein
- the splenic vein
These veins deliver nutrient-rich blood to the liver through 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.
The symptoms of mesenteric venous thrombosis typically include abdominal pain (especially after eating), bloating, and diarrhea. Additional symptoms include:
- 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.
Certain digestive diseases that cause swelling of the tissues surrounding the intestines can increase your risk of developing 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, which is 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, which is called pancreatitis
- liver disease and cirrhosis, which is scarring of the liver
- cancers of the digestive system
It can also be caused by trauma to the abdomen or cancers of the digestive system. You’re 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.
Diagnosis is usually based on your symptoms and imaging tests. Typically, a CT scan is used. This test uses X-rays to create cross-sectional images of the abdomen. Other imaging tests may include an ultrasound or MRI scan of the abdomen. This test utilizes high-powered magnets and radio waves to create images of the abdomen.
An arteriogram, which is an X-ray of the arteries, may be done to see how blood is moving through your arteries. It may also 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.
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 involves using a flexible tube called a catheter that’s 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 the catheter isn’t used to inject blood thinner. Instead, it’s used to pull the clot from the vein.
Mesenteric venous thrombosis can decrease the supply of blood to the tissues and cells of your digestive system. This is called ischemia. It causes intestinal damage or the death of intestinal tissue, which is called infarction. It can be life-threatening, and it requires emergency medical attention. If death of part of the intestine occurs, the dead portion of the intestine must be surgically removed.
Peritonitis is a severe infection of the peritoneum that can result from a mesenteric venous thrombosis. The peritoneum is the thin membrane that lines the abdominal wall and covers the organs inside the abdomen. If this occurs, you’ll need surgery to remove the affected areas of your intestine. Surgery may require resection of the affected bowel. If that’s the case, your body’s waste products will be collected in an ileostomy or a colostomy afterward. An ileostomy is a bag placed on the skin over an opening from the small intestine. A colostomy is a bag placed on the skin over an opening from the colon.
Your outlook will depend on many factors, including any underlying health conditions and how quickly you start treatment.
Always contact your doctor if you have severe stomach pain along with fever, diarrhea, and vomiting.