Aortic intramural hematoma

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Overview

 * It may occur as a primary event in hypertensive patients in whom there is spontaneous bleeding from vasa vasorum into the media or may be caused by a penetrating atherosclerotic ulcer.


 * Intramural hematoma may also develop as a result of blunt chest trauma with aortic wall injury.


 * Thought to begin with the rupture of the vasa vasorum, the blood vessels that penetrate the outer half of the aortic media from the adventitia and arborize within the media to supply the aortic wall.


 * The hematoma propagates along the media layer of the aorta.


 * Consequently, intramural hematoma weakens the aorta and may progress either to outward rupture of the aortic wall or to inward disruption of the intima, the latter leading to communicating aortic dissection.


 * Unlike aortic dissection, no intimal flap is present.


 * If it involves the ascending aorta, treatment is surgical to prevent rupture or progression to a classic aortic dissection.


 * Conservative management is indicated for aortic intramural hematomas of the descending aorta.

Diagnostic Findings

 * On unenhanced CT, intramural hematoma is hyperdense.
 * Intramural hematoma can be distinguished from mural thrombus by identification of the intima:
 * Mural thrombus lies on top of the intima (which is frequently calcified)
 * Intramural hematoma is subintimal.

Examples
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