Abstract
Acute aortic dissection (AAD) is a life-threatening disease with an incidence of about 2.6–3.6 cases per 100,000/year. Depending on the site of rupture, AAD is classified as Stanford-A when the ascending aortic thoracic tract and/or the arch are involved, and Stanford-B when the descending thoracic aorta and/or aortic abdominal tract are targeted. It was recently shown that inflammatory pathways underlie aortic rupture in both type A and type B Stanford AAD. An immune infiltrate has been found within the middle and outer tunics of dissected aortic specimens. It has also been observed that the recall and activation of macrophages inside the middle tunic are key events in the early phases of AAD. Macrophages are able to release metalloproteinases (MMPs) and pro-inflammatory cytokines which, in turn, give rise to matrix degradation and neoangiogenesis. An imbalance between the production of MMPs and MMP tissue inhibitors is pivotal in the extracellular matrix degradation underlying aortic wall remodelling in dissections occurring both in inherited conditions and in atherosclerosis. Among MMPs, MMP-12 is considered a specific marker of aortic wall disease, whatever the genetic predisposition may be. The aim of this review is, therefore, to take a close look at the immune-inflammatory mechanisms underlying Stanford-A AAD.
Funding: No funding has been received.
Declaration of interest: The authors have no conflict of interest to declare, including specific financial interest or any relationship with pharmaceutical companies, biomedical device manufacturers, or other corporation whose products or services are related to the subject matter of the article. Such relationships include employment by and industrial concern, ownership of stock, membership of a standing advisory council or committee, being on the board of directors or being publicly associated with a company or its products. Moreover the authors declare that they have not received honoraria, fees, grants, or funds from such corporations or individuals representing such corporations.