Abstract 13989: Detection of Micro Intimal Tear at a Very Early Stage in Patients With Acute Aortic Intramural Hematoma
Background: Although rupture of the vasa vasorum is thought to be the main cause of acute aortic intramural hematoma (IMH), previous studies have suggested the existence of micro intimal tear at the onset, which supported a common pathophysiologic mechanism of aortic dissection (AD) and IMH. A better understanding of the pathophysiology of IMH may lead to successful identification of high-risk patients and appropriate management. The purpose of this study was to investigate the prevalence and clinical outcome of micro intimal tear detected by multi-detector computed tomography (MDCT) in patients with IMH at a very early stage.
Methods and Result: We retrospectively analyzed 50 patients with IMH who underwent 64-row MDCT at admission: 34 patients underwent MDCT within 3 hours (early scan group) and 16 patients more than 3 hours after the onset (late scan group). Micro intimal tear was defined as continuity disruption of the inner layer of thrombosed false lumen with tiny inflow of contrast medium, which suggested small flow communication. Localized contrast pooling in aortic wall, which is considered as a pseudoaneurysm of branch artery, was not regarded as micro intimal tear and excluded from the analysis. In early scan group, 18 (52%) patients had 27 micro intimal tears. Of these, 12 tears were located in aortic arch, 2 in proximal descending aorta (PD), 1 in mid descending aorta (MD), 9 in distal descending aorta (DD) and 3 in abdominal aorta (AA). In late scan group, 5 (31%) patients had 6 micro intimal tears; 1 in arch, 4 in DD and 1 in AA. Micro intimal tear observed in aortic arch was significantly more frequent (12/34) in early scan group than late scan group (1/16, p=0.03). During initial hospitalization, progression of micro intimal tears was observed in 11 of 18 patients (61%) in early group and 4 of 5 patients (80%) in late group (p=0.41). On the other hand, 2 micro intimal tears observed in arch regressed in early scan group.
Conclusion: Early MDCT scan within 3 hours after the onset detected micro intimal tear in a considerable portion of patients with IMH, most frequently in aortic arch. These findings may suggest common pathophysiologic mechanism of AD and IMH.
Author Disclosures: M. Nakashima: None. S. Kaji: None. R. Murai: None. Y. Sasaki: None. M. Ota: None. K. Kim: None. T. Yamane: None. T. Kitai: None. A. Kobori: None. N. Ehara: None. M. Kinoshita: None. Y. Furukawa: None.
- © 2016 by American Heart Association, Inc.