Communicating versus Noncommunicating Acute Thoracic Aortic Dissection: Two Case Reports and Diagnostic Value of Transesophageal Echocardiography and Alternative Imaging Modalities

Abstract

Two patients, with communicating and noncommunicating Stanford type A acute aortic dissection each, are reported with anatomic and hemodynamic features diagnosed by single-plane transesophageal echocardiography (TEE) with color flow imaging. TEE demonstrated a communicating dissection, more in detail than aortography and computed tomography, with an intimai flap, the extent of dissection, the dissecting intimai flap prolapse through the aortic valve during diastole, flow patterns in the true and false lumina, presence and absence of aortic valvular regurgitation, and absence of pericardial effusion. TEE showed the presence of a noncommunicating (variant) dissection, which was nondiagnostic by magnetic resonance imaging and aortography before surgery, with intramural thrombus (hematoma) formation and its extent and location, accurate measurement of aortic wall thickness, and the presence of an intimai flap or intramural blood flow. In addition, TEE also permitted evaluation of global and regional systolic performance. Therefore, TEE can be recommended as the first-line modality of choice for an early diagnosis of an acute thoracic aortic dissection.