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Three Part Question

[In patients with suspected aortic dissection] is [transesophageal echocardiography as accurate as computed tomography] in the [diagnosis of dissection]?

Clinical Scenario

A 60 year old female presents to the emergency department with severe sudden onset chest pain that radiates to her back. Her exam, 12-EKG and initial cardiac enzymes are normal. The patient has an elevated creatinine at 2.0. You are concerned about an aortic dissection and wonder which test would be the best to evaluate for this suspected diagnosis.

Search Strategy

MEDLINE(R) 1950 to April Week 4 2008 using the OVID interface.
([exp Aneurysm, Dissecting/ or Aortic Aneurysm, Thoracic/ or aortic dissection.mp] AND [exp Echocardiography, Transesophageal/] AND [exp Tomography, X-Ray Computed/ or exp Tomography, Spiral Computed/ or computed tomography.mp]) LIMIT to human AND English language.

Search Outcome

Overall, 167 papers were found. There was one recent systemic review and metanalysis.

Comment(s)

Helical CT is currently recommended as the test of choice in the evaluation in a patient with chest pain and a suspected aortic dissection; although, a patient with an elevated creatinine limits the use of this test secondary to the need for contrast. Therefore, a viable alternative to this is transesophageal echocardiography and current evidence indicates that this test is an equally reliable diagnostic test as helical CT. The metanalysis noted above also addressed MRI as a reliable test; however, this is not discussed here. TEE can be a rapid bedside test, which is non-invasive, does not use radiation, and may give additional information about cardiac function which can be very important in making further treatment decisions. TEE does have limitations when evaluating the aortic arch and its branches. It also has limited value if the trachea and left main stem bronchus produce a blind zone. These limitations must be considered when using this test. TEE can also have variable interobserver reliability and be dependent on the performer's experience. Also, it may not be readily available at some institutions.

Clinical Bottom Line

When an aortic dissection is clinically suspected and the patient has an elevated creatinine, a transesophageal echocardiogram is a useful alternative to either rule in or rule out a diagnosis of aortic dissection. TEE has a few limitations that still need to be considered.