Mesenteric Ischemia

Mesenteric ischemia refers to the lack of blood flow to one or more of the mesenteric arteries (arteries that supply the intestines) causing pain and possibly placing the affected portion of the intestine in jeopardy of dying. The cause is often sudden thrombosis (occlusion from blood clot formation) at a chronic stenosis (narrowing) that develops from progressively worsening atherosclerotic (cholesterol) plaque build-up within that artery.

Other possible causes are embolization and dissection. Embolization is when thrombus (blood clot) or plaque from higher up in the aorta or heart breaks loose and lodges itself into a mesenteric artery further downstream. Dissection is when the inner wall of an artery tears and blood flows between 2 layers of the artery wall in 2 lumens (channels) known as the ‘false’ lumen (newly created channel within the wall of the artery), and the ‘true’ lumen (the proper lumen that has always existed). The ‘false’ lumen can often cause collapse and occlusion of the ‘true’ lumen and thus lack of blood flow to the associated portion of the intestine. One final cause may be chronic stenosis itself, which causes only limited blood flow to the intestines and a more chronic form of the condition.

The symptoms that can occur with mesenteric ischemia include sudden and severe abdominal pain, which is usually associated with acute thrombosis of chronic stenosis/disease, embolization, or dissection, and abdominal pain after eating that leads to weight loss, which is usually associated with chronic stenosis/disease.

Complications from mesenteric ischemia include severe weight loss from avoidance of eating due to the associated pain, and infarction (injury or death) of the affected intestine, which often requires surgery to remove that portion of the intestine.

Diagnosis of mesenteric ischemia requires a thorough history and physical exam by a vascular surgeon and an imaging study such as a computed tomography (CT) scan, magnetic resonance imaging (MRI) study, or arteriogram (injection of contrast dye into the arteries).

Treatment of mesenteric ischemia requires a procedure, sometimes emergent, to restore blood flow to the affected portion of the intestine. This may include a minimally invasive (endovascular) treatment with thrombolysis (removal of thrombus with medicine through a catheter), thrombectomy (mechanical disruption and removal of thrombus through a catheter), and possibly also balloon angioplasty and/or stenting. If the patient or circumstances do not allow for this technique, then it requires open surgical removal of thrombus or embolus and subsequent open surgical treatment of the cause.