With the continuous improvement of the comprehensive capability of cardiovascular surgery in China, the level of diagnosis and treatment of aortic diseases has also made great progress. In order to deepen the medical workers’ understanding of aortic diseases and to keep abreast of the latest progress in the diagnosis and treatment of aortic diseases, Circulation Weekly has opened a column called “Focus on Aorta” starting from this issue to provide you with a detailed description of the progress in the diagnosis and treatment of various aortic diseases one by one.
Congenital aortic disease
Aortic stenosis
Aortic constriction refers to congenital narrowing of the aortic isthmus, occasionally between the left common carotid artery and the left subclavian artery, or in the thoracic or abdominal aorta. It is a relatively common congenital aortic malformation, accounting for approximately 6.5% of congenital heart disease (CHD).
Aortic constriction has been classified into two categories, simple and complex, based on whether it is combined with other cardiovascular malformations (other than ductus arteriosus).
The Bonnet typology of 1903 is currently used clinically (although with significant limitations).
(1) Pre-catheter type (infant type), where the constriction is located between the ductus arteriosus and the left subclavian artery;
(ii) Post-ductal type (adult type), in which the constriction is located distal to the arterial duct or the arterial ligament attachment.
Interruption of the aortic arch
Interruption of the aortic arch is diagnosed when there is an anatomic discontinuity between any two segments or when the lumen is completely inaccessible, including the proximal arch, the distal arch, and three segments of the aortic isthmus. Autopsy shows that it accounts for 1% to 4% of precordial disease, while clinical data indicate that it accounts for 1.3% of severe pediatric precordial disease.
There are 3 types of aortic arch disruption.
①Type A, the aortic arch interruption is located in the isthmus, accounting for about 40%;
②Type B, the aortic arch interruption is located between the left subclavian artery and the left common carotid artery, accounting for about 55%;
③Type C: interruption of the aortic arch is located between the left common carotid artery and the unnamed artery, accounting for about 5%.
Congenital vascular ring
Congenital vascular rings refer to the complete or partial encirclement and compression of the esophagus and/or trachea by the aortic arch and its branch vessels, and mainly include complete and incomplete vascular rings. The disease accounts for 1% to 2% of the composition ratio of precordial disease.
Table 1 Anatomic classification of vascular rings
Vascular suspensory band
Vascular suspensory band refers to the left pulmonary artery starting from the right pulmonary artery outside the pericardium, bifurcating left posteriorly through the trachea, and entering the left hilar in front of the esophagus, forming a suspensory band around the trachea. The disease is rare, with the largest reported case being only 15 (accumulated over 45 years).
Supra-aortic stenosis
Supra-aortic stenosis refers to a restrictive or diffuse stenosis of the aorta occurring over the aortic valve and has three main clinical manifestations: as one of the phenotypes of Williams syndrome (about half of cases), disseminated, or familial.
Most supra-aortic stenoses are limited stenoses, caused by an annular protrusion of the inner wall of the aorta above the aortic valve junctional stop into the aortic lumen, often with an hourglass appearance. Diffuse supra-aortic stenosis usually presents with abnormal thickening of the aortic intima and wall, which may extend to the origin of the innominate artery.
The disease is a complex lesion of the aortic root and the aortic sinus proximal to the stenosis may be dysplastic. The coronary opening may be obstructed not only by thickened aortic tissue but also by the aortic valve. aortic valve thickening is present in 30% of patients with supra-aortic stenosis, but aortic valve stenosis due to leaflet fusion is rare.
Acquired aortic disease
Aortic aneurysm
The English word for aneurysm (aneurysm) is of Greek origin and originally meant dilatation. A true aortic aneurysm is an aortic lesion that is more than 1.5 times the diameter of the normal aorta at the site of the lesion, with all layers of the structure intact. A pseudoaneurysm is a limited periaortic hematoma caused by infection, trauma, surgery, or ulcer rupture. The difference between the two is that the arterial wall structure of a pseudoaneurysm is incomplete.
Aortic aneurysms are classified as ascending aortic aneurysms, aortic arch aneurysms and thoracic and abdominal aortic aneurysms (descending aortic aneurysms) depending on the site of occurrence.
Crawford (Crawford) has typed thoracic and abdominal aortic aneurysms into 4 types.
① Type I, thoracic aorta and/or partial abdominal aorta involvement;
②Type II, total descending aorta involvement (including all thoracic and abdominal aorta, may involve iliac artery);
(iii) Type III, involvement of the distal thoracic aorta and abdominal aorta;
Type IV, involvement of the abdominal aorta.
Aortic coarctation
Aortic coarctation refers to the entry of blood in the aortic lumen through an endothelial breach into the middle layer of the aortic wall and tearing the middle layer of the aortic wall to form a false lumen. However, aortic coarctation can also occur in the absence of an endothelial rupture. The nomenclature of aortic coarctation is confusing, such as aortic coarctation, aortic coarctation formation, aortic coarctation dissection (separation) and coarctation aneurysm. In recent years, foreign scholars have increasingly applied the term aortic coarctation, which is also recognized by many domestic scholars. Therefore, it is suggested that the term “aortic dissection” be used uniformly in China to facilitate standardization and communication.
Aortic interstitial hematoma refers to the overflow of blood from the arterial lumen into the aortic wall without rupture of the outer membrane of the artery.
Depending on the time of onset, aortic coarctation is divided into two categories: acute (<14 days) and chronic (>14 days).
There are two internationally accepted staging methods for aortic coarctation. DeBakey (DeBakey) typing.
①DeBakey type I, aortic coarctation starts from the ascending aorta (or the root of the aorta) and involves most or all of the aorta;
②DeBakey type II, aortic coarctation involving only the ascending aorta;
③DeBakey type III, aortic coarctation involving only the descending aorta (IIIa, involving only the thoracic descending aorta; IIIb, involving the thoracic and abdominal aorta).
Stanford (Stanford) typing, proposed by Daily and others in the 1970s, is divided into 2 types.
①Stanford type A, aortic coarctation involving the ascending aorta (including the aortic root);
(2) Stanford type B, in which the aortic coarctation involves the descending aorta.
There is also a less commonly used Kirklin typing method, which is not described here. The author has unique insights into the staging of aortic coarctation, which will be described in detail in a later series.
Other Acquired Aortic Diseases
Non-infectious aortic disease
Multiple aortitis (Takayasu arteritis), leukoaraiosis, cutaneous mucosal lymph node syndrome (Kawasaki disease), and giant cell arteritis may develop into aneurysms, especially multiple aortitis, which more often involves the aortic arch and head and arm trunks and often requires surgical intervention. Other immune diseases, such as ankylosing spondylitis, Wright’s syndrome, and nodular polyarteritis, may also develop aortic root aneurysms and aortic valve closure insufficiency, requiring surgical treatment.
Aortic trauma
Among aortic trauma, acute traumatic aortic dissection is more common and is defined as a total or partial dissection of the aortic wall that occurs within 14 days of injury. Chronic aortic trauma may result in aortic aneurysm.