1. Acute aortic syndrome (AAS): includes aortic dissection (AD), intramural aortic hematoma (IMH), and penetrating atherosclerotic aortic ulcer (PAU). Some people also include aneurysm dissection and traumatic aortic dissection.
2. Clinical manifestations of AAS: It is mostly seen in hypertensive patients with chest pain symptoms. Its chest pain is characterized by severe pain, rapid onset, tearing, tearing or stabbing, and the pain can gradually shift to other parts along the course of the lesion.
3.Transfer of AAS: IMH can be transformed into AD, and PAU can be transformed into IMH or AD.
(1) Aortic coarctation
Typical AD pathophysiology: The underlying pathological changes are degenerative lesions of collagen and elastic fibers in the middle layer of the artery. Cystic necrosis of the middle layer causes intimal tearing, and blood flow penetrates the middle layer of the lesion, and the separated layers of the aortic wall are filled with blood flow to become pseudoluminal, with traffic between the real and pseudoluminal “double lumens” existing, and a re-rupture may exist at the distal end. Once formed, the pseudolumen rapidly expands aneurysmatically and eventually hemorrhages and ruptures occur, the latter being the main cause of death. Compression of the true lumen leads to a reduction in the diameter of the duct, resulting in impaired blood supply to the organ.
(2) Intra-aortic wall hematoma.
IMH pathology is based on spontaneous rupture of trophoblastic vessels or rupture of atheromatous plaques leading to hematoma into the outer membrane of the artery without intimal tearing and without direct traffic between the middle layer and the arterial lumen.
(3) Penetrating atherosclerotic aortic ulcer.
PAU is an ulcer on an aortic atherosclerotic lesion that penetrates the elastic lamina and forms a hematoma in the middle layer of the artery.
The mid-layer hematoma formed by PAU is usually limited and may also promote IMH and may progress to aneurysm, pseudoaneurysm, aortic dissection and AD.
4.Imaging diagnosis
IMH is characterized by a thickened annular or crescentic area of high density within the aortic wall, the shape of which may change dynamically over time, with aortic wall thickening >7 mm, without intimal tears or pseudolumina. PAU may be combined with limited intermural hematoma or external penetration to form a pseudoaneurysm.
CT aortography (CTA) and magnetic resonance imaging (MRI) have high diagnostic sensitivity and specificity for AD, IMH, and PAU; CTA can clearly show the true and false lumen to identify and clarify the diagnosis; MRI is more suitable for those who are contraindicated to contrast. Esophageal ultrasound (TEE) can identify the intra-aortic luminal endoscopic oscillation sign and aortic valve closure insufficiency.
5. Treatment.
(1) AD treatment.
(1) Internal treatment: relieve pain, lower blood pressure, reduce the impact of blood pulsation on the aortic wall, and reduce ventricular contraction and heart rate.
(2) Surgical treatment: the main treatment for type A lesions to prevent and control aortic dissection. Vascular replacement and repair of the aortic root and aortic valve.
③Interventional treatment: mainly overlapping stent endoluminal repair (TSGP) is used.
The purpose of TSGP treatment: to close the primary rupture, enlarge the true lumen, improve distal and branch blood flow, eliminate aortic coarctation, and prevent rupture.
Acute indications: accumulation of blood in the pericardium, accumulation of blood in the chest cavity.
(2) IMH treatment.
Most people prefer that type A IMH should be treated immediately with surgery, while type B IMH can be treated with medication and followed up with a series of imaging examinations, and if the symptoms do not subside or the progression of the lesion is clearly confirmed, surgery or intervention should be performed immediately.
(3) Type A PAU has a higher likelihood of AD and aortic dissection and favors surgical treatment. In patients with uncomplicated type B PAU, pharmacological treatment is preferred and imaging is closely followed; if there is hemodynamic instability, progressive aortic aneurysmal dilatation, aneurysm formation or persistent or recurrent pain, surgical or interventional treatment should be performed.