Aortic dissection aneurysm vs dissection

Associate Editor-In-Chief:

Aneurysm vs Dissection:
An aortic aneurysm is not synonymous with aortic dissection. Aneurysms are defined as a localized permanent dilation of the aorta to a diameter > 50% of normal. Cystic medial necrosis is the most common risk factor for the development of ascending aneurysms, and atherosclerosis is the most common risk factor for descending aneurysms.
 * The natural history of thoracic aneurysms depends on the size. Rupture is the most common cause of death, and the frequency of rupture is much higher in dissecting aneurysms than in non-dissecting ones.
 * Thoracic aneurysms enlarge at a more rapid rate than abdominal aneurysms (0.42 vs. 0.28 cm/yr), with aneurysms of the aortic arch growing at ~ 0.56 cm/yr. Aneurysms that are 5-6cm in diameter have a faster rate of growth and a greater tendency to rupture than smaller ones.

Acknowledgements
The content on this page was first contributed by: David Feller-Kopman, MD and C. Michael Gibson M.S., M.D.