Because multiplane TEE probe was not available in all patients in protocol A, the additional diagnostic value of various tomographic planes for accurate identification of reverberation images was not specifically studied. However, most of the proposed diagnostic criteria may also be used in other TEE planes, as shown in Figure 7. In addition, because of the inability of monoplane TEE probes to adequately image the distal ascending aorta, the aortic arch was not studied. Because linear artifacts may be confounding images only when interpreted as aortic flaps, patients sustaining acute aortic condition without associated intraluminal flaps were not studied. Therefore, the reported diagnostic capability of TEE for the diagnosis of spontaneous AD and TDA did not take into account certain clinical presentations (eg, thrombosed false lumen, intramural hematoma, traumatic intimal tear) for which a diagnosis may be challenging.
Although the learning curve could have influenced TEE diagnostic accuracy in protocol B, the systematic application of predefined diagnostic criteria to intra-aortic linear images probably minimized this potential bias. In addition, both the retrospective and prospective series were comparable in terms of frequency of intra-aortic linear artifacts and true flaps (data not shown). The comparison of TEE diagnostic accuracy between these two cohorts of patients is therefore clinically relevant.
Other types of multiple-path artifacts, such as mirror artifacts, are frequently encountered during TEE examination of the descending thoracic aorta. We did not study these reverberation images because they are rarely misleading and visualized only if the field of view is expanded to accommodate a second signal. health and care mall
In the present study, misleading intraluminal linear artifacts within the ascending aorta were observed in one fourth of the patients undergoing a TEE examination for a suspicion of AD or TDA. These multiple-path artifacts that originate in the left atrium of the right pulmonary artery were encountered when the ascending aorta exceeded the size of the adjacent posterior anatomic structure, and were less frequent within the descending thoracic aorta. The use of differential echocardiographic diagnostic criteria that allowed reliable identification of reverberation images resulted in improved TEE specificity for the diagnosis of AD or TDA. Routine use of these diagnostic criteria promises to further improve the diagnostic accuracy of TEE for accurate identification of acute aortic conditions in the setting of severely ill patients with potential need for rapid surgery.
Figure 7. Example of linear images (arrows) observed in the longitudinal view of the descending thoracic aorta. Color Doppler TEE discloses the overimposition of a laminar blood flow on both sides of the linear artifact (left, A), whereas it has opposite directions in the two lumina of the AD (right, B).