Medical progress. Diagnostic imaging in the evaluation of suspected aortic dissection: Old standards and new directions

Abstract

Acute aortic dissection is a life-threatening condition, and its prompt diagnosis remains essential for successful management. Although early mortality may be as high as 1 percent per hour [1] among untreated patients, survival can be improved by the rapid institution of appropriate medical or surgical therapy (or both). The Stanford classification system [2] divides aortic dissections anatomically into two types on the basis of location. A dissection in which there is involvement of the ascending aorta, regardless of the site of entry, is defined as type A (this includes De Bakey [3] types I and II and is often described as a proximal dissection). All aortic dissections that do not involve the ascending aorta are defined as type B (these include De Bakey type III and may be referred to as distal dissections). Over the past several decades it has become clear that most patients with type A dissections require urgent surgical repair, whereas those with uncomplicated type B dissections can be treated successfully with medical therapy alone. The optimal care of patients with aortic dissection requires that the diagnosis be made promptly and that its site of origin and extent be identified as rapidly as possible. Furthermore, in the age of thrombolytic therapy for acute myocardial infarction it is crucial to exclude aortic dissection among patients presenting with syndromes involving chest pain, since the administration of such agents to patients with aortic dissection can be catastrophic.