Aortic pathology: aortic trauma, debris, dissection, and aneurysm

The aorta is a conduit from the left ventricle that delivers pulsatile blood distally in either a compliant or stiffened vessel to organs and tissue beds. Only recently, since the advent of transesophageal echocardiographic imaging, did its presence and associated pathologies become more profound and more prominent for the intensivist. Angiography, the "gold standard" for diagnostic imaging, now seems to be in question since the advent of ultrasound (transesophageal echocardiography), improvements in magnetic resonance imaging, and particularly the advancement to 64-slice computed tomography. It is now a revelation of how revealing these newer imaging tools have expanded our knowledge potential of pathologies that involve the aorta. The latter three imaging modalities are continuing to improve, with established efficacy, particularly in the critically ill and injured patient. This article will enlighten the intensivist and others of their potential and contrast each imaging device in several prominent pathologies common to the critical care physician. The disadvantages of all will be brought forth. Evidence will be presented revealing the dynamic nature of imaging technologies that will continue to affect the outcome of our patients. The most common indications for interrogation of the aorta are in traumatic events in which there might be a catastrophic transection, intimal tear or flap, or subadventitial tear. The identification of hematomas (by these imaging devices) in the mediastinum might be associated with significant physical forces, and this article will show the relevance. The significance of atherosclerotic plaques, ulcers, and debris will also be debated. Finally, imaging of a patient with aortic dissection or aneurysm will be discussed, as its pathology and pathogenic process are well known, and the changing nature or paradigm shift in the imaging of this life-threatening disease will be addressed.