Acute Aortic Syndrome (AAS) and Traumatic Aortic Injury (TAI)

Conventionally, the term acute aortic syndrome (AAS) identifies a series of clinical signs and symptoms embracing the distinct clinical entities of intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU) and aortic dissection. Some recent reviews (Vilacosta et al., J Am Coll Cardiol 78:2106–2125, 2021) have added another intermediate pathogenic condition, defined incomplete dissection (ID), which identifies an AAS with discrete damage to intimal and subjacent medial layer of the vessel wall, without the development of significant intra-medial hematoma or associated false lumen. AAS has a reported incidence of 7.7 per 100,000 people per year and can be classified, depending on the anatomic location of the lesion, into three subtypes. Type-A refers to the involvement of the ascending aorta and aortic arch, type-B to the involvement of the descending aorta distal to the left subclavian artery origin, whereas non-A–non-B-type is an unusual condition with isolated involvement of the aortic arch or with retrograde involvement of the arch from an initially type-B AAS. This classification also reflects the different prognosis of the patients and guides the clinical vs. surgical management (Vilacosta et al., J Am Coll Cardiol 78:2106–2125, 2021).