Mesenteric venous thrombosis
Mesenteric venous thrombosis (MVT) is a blood clot in one or more of the major veins that drain blood from the intestine. The superior mesenteric vein is most commonly involved.
MVT is a clot that blocks blood flow in a mesenteric vein. There are two such veins through which blood leaves the intestine. The condition stops the blood circulation of the intestine and can result in damage to the intestine.
The exact cause of MVT is unknown. However, there are many diseases that can lead to MVT. Many of the diseases cause swelling (inflammation) of the tissues surrounding the veins, and include:
- Cancer of the abdomen
- Liver disease with cirrhosis
- High blood pressure in the blood vessels of the liver
- Abdominal surgery or trauma
- Inflammatory bowel disorders
- Heart failure
- Protein C or S deficiencies
- Polycythemia vera
- Essential thrombocythemia
People who have disorders that make the blood more likely to stick together (clot) have a higher risk for MVT. Birth control pills and estrogen medicines also increase risk.
MVT is more common in men than women. It mainly affects middle aged or older adults.
Symptoms may include any of the following:
- Abdominal pain, which may get worse after eating and over time
- Bloody diarrhea
- Septic shock
- Lower gastrointestinal bleeding
- Vomiting and nausea
Exams and Tests
A CT scan is the main test used to diagnose MVT.
Other tests may include:
- Angiogram (studying the blood flow to the intestine)
- MRI of the abdomen
- Ultrasound of the abdomen and mesenteric veins
Blood thinners (most commonly heparin or related medicines) are used to treat MVT when there is no associated bleeding. In some cases, medicine can be delivered directly into the clot to dissolve it. This procedure is called thrombolysis.
Less often, the clot is removed with a type of surgery called thrombectomy.
If there are signs and symptoms of a severe infection called peritonitis, surgery to remove the intestine is done. After surgery, an ileostomy (opening from the small intestine into a bag on the skin) or colostomy (an opening from the colon into the skin) may be needed.
Outlook depends on the cause of the thrombosis and any damage to the intestine. Getting treatment for the cause before the intestine has died can result in a good recovery.
Intestinal ischemia is a serious complication of MVT. Part or all of the intestine dies because of poor blood supply.
When to Contact a Medical Professional
Contact your health care provider if you have severe or repeated episodes of abdominal pain.
Cloud A, Dussel JN, Webster-Lake C, Indes J. Mesenteric ischemia. In: Yeo CJ, ed. Shackelford's Surgery of the Alimentary Tract. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 87.
Feuerstadt P, Brandt LJ. Intestinal ischemia. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 118.
Roline CE, Reardon RF. Disorders of the small intestine. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 82.