Mesenteric Ischemia

Posted by • March 11th, 2016

2016-03-10_9-18-19Although mesenteric ischemia is an uncommon cause of abdominal pain, accounting for less than 1 of every 1000 hospital admissions, an inaccurate or delayed diagnosis can result in catastrophic complications; mortality among patients in whom this condition is acute is 60 to 80%.

Although mesenteric ischemia is uncommon, it can be life-threatening, and its recognition is therefore crucial. This review article explains the pathophysiology, diagnosis, and treatment of intestinal ischemic syndromes.

Clinical Pearl

• What is the clinical presentation of mesenteric ischemia?

Patients with acute mesenteric ischemia may initially present with classic “pain out of proportion to examination,” with an epigastric bruit; many, however, do not. Other patients may have tenderness with palpation on examination owing to peritoneal irritation caused by full-thickness bowel injury. This finding may lead the physician to consider diagnoses other than acute mesenteric ischemia. Differentiation between arterial and venous obstruction is not always simple; however, patients with mesenteric venous thrombosis, as compared with those with acute arterial occlusion, tend to present with a less abrupt onset of abdominal pain. Patients with chronic mesenteric ischemia can present with a variety of symptoms, including abdominal pain, postprandial pain, nausea or vomiting (or both), early satiety, diarrhea or constipation (or both), and weight loss. Abdominal pain 30 to 60 minutes after eating is common and is often self-treated with food restriction, resulting in weight loss and, in extreme situations, fear of eating, or “food fear.”

Clinical Pearl

• What are the imaging modalities used in the diagnosis and management of mesenteric ischemia?

Given its 95 to 100% accuracy, computed tomographic angiography (CTA) has become the recommended method of imaging for the diagnosis of visceral ischemic syndromes. Magnetic resonance angiography (MRA) is an attractive option that may provide information about flow and avoid the risks of radiation and use of contrast material that are associated with CTA. However, this test takes longer to perform than CTA, lacks the necessary resolution, and can overestimate the degree of stenosis. Although MRA techniques are evolving, currently CTA imaging is almost always the preferred choice, and the advantages of CTA outweigh any risks associated with the use of this form of imaging among patients with acute mesenteric ischemia. Catheter angiography, which was previously considered to be the standard method of diagnosis of mesenteric ischemia, has become a component of initial therapy. Angiography can also be used to confirm the diagnosis before open abdominal exploration is undertaken. The value of ultrasonographic testing is extremely dependent on the skill of the technologist. In addition, adequate ultrasonographic imaging can be difficult to obtain in patients with obesity, bowel gas, and heavy calcification in the vessels. Adequate ultrasonographic assessment is often impossible in patients with acute mesenteric ischemia because of the length of the study and the abdominal pressure required; it is therefore best reserved for the evaluation of patients with chronic mesenteric ischemia and for monitoring after intervention.

Figure 1. Computed Tomographic Angiography (CTA) in a Patient with Acute Mesenteric Ischemia Caused by an Embolism in the Superior Mesenteric Artery.

Morning Report Questions

Q: What are current trends regarding open repair versus endovascular revascularization for the treatment of mesenteric ischemia?

A: Endovascular strategies can theoretically restore perfusion more rapidly than can open repair and may thus prevent progression of mesenteric ischemia to bowel necrosis. Although the use of endovascular techniques is becoming more common, the comparative data on the results with the two approaches in patients with acute mesenteric ischemia are insufficient to show a clear advantage of one approach over the other. Available data suggest that the use of endovascular procedures for acute mesenteric ischemia is becoming more common; the use of these procedures increased from 12% of cases in 2005 to 30% of cases in 2009. These data also show that this strategy may be most appropriate for patients with ischemia that is not severe and those who have severe coexisting conditions that place them at high risk for complications and death associated with open surgery. Revascularization is indicated for all patients with symptoms of chronic mesenteric ischemia in whom symptoms of this disease develop. Open repair, which was formerly considered to be the standard in such cases, has been surpassed in recent years by endovascular repair, which is now used in 70 to 80% of initial procedures. Open repair for chronic mesenteric ischemia is associated with slower recovery and longer hospital stays. Data on mortality are inconsistent; however, patients treated with open repair have improved rates of symptom relief at 5 years and of primary patency (both rates as high as 92%), and lower rates of reintervention.

Q: What are some of the components of long-term care in patients diagnosed with mesenteric ischemia?

A: The long-term care of patients with mesenteric ischemia is focused on managing coexisting conditions and risk factors. Therefore, aggressive smoking-cessation measures, blood-pressure control, and statin therapy are recommended. Lifelong preventive treatment with aspirin is recommended in all patients who undergo endovascular or open repair. Patients who undergo endovascular repair should also receive clopidogrel for 1 to 3 months after the procedure. Because the recurrence of symptoms is common in patients with a history of mesenteric ischemia, lifelong repeated assessment of vascular patency is indicated. Duplex ultrasonography should be performed every 6 months for the first year after repair, then yearly thereafter. All patients should be informed about the risks and warning signs of stenosis, occlusion, and repeated episodes of ischemia.

2 Responses to “Mesenteric Ischemia”

  1. Renzo says:

    Regarding the etiology of mesenteric ischemia, what are the most common causes of this clinical issue? Are the thromboembolic events more often? Do chronic pathologies have a preponderant role?

  2. MJ.Motamedi says: