Mesenteric venous thrombosis: clinical and therapeutical approach.

Mesenteric venous thrombosis (MVT), an unusual location of deep venous thrombosis, occurs especially on a predisposing terrain. Recently, hyperhomocysteinemia has been shown to be associated with venous thrombosis, often recurrent and located in an uncommon site. Hyperhomocysteinemia is mainly due to genetic causes (mutations 677C>T and 1298A>C of methylenetetrahydrofolate reductase) and vitamins B deficiencies. MVT may present as acute, subacute or chronic form. The clinical supposition of mesenteric thrombosis is based on the discrepancy between the abdominal pain and the physical examination. The nonspecific character of the pain, mimicking peptic ulceration in some cases, and the possibility of an initial normal clinical examination may delay the diagnosis. The occurrence of the fever, rebound tenderness and guarding suggests progression to bowel infarction. MVT leads to peritonitis in 1/3 to 2/3 of cases. Laboratory blood tests are not helpful in confirming the diagnosis of venous thrombosis. Leukocytosis and metabolic acidosis are considered to be the most specific laboratory findings in patients with mesenteric ischemia. Abdominal computed tomography is the test of choice for the diagnosis. However, most of the cases are diagnosed during laparotomy or autopsy. Anticoagulant therapy administrated early increases the survival rate. Surgery is indicated in cases with bowel infarction or peritonitis.