Aortic aneurysms of the thoracic aorta include aortic root, ascending aorta, aortic arch, descending aorta, and subdiaphragmatic thoracoabdominal aortic aneurysms. Clinically, “aneurysmal” masses are formed by localized or multiple irreversible outward dilatation or bulging of the normal aorta due to various causes. It is called an aneurysm. It is often referred to as an aneurysm when the diameter or bulge of the artery is more than 1.5 times its normal diameter. Pang Yunfeng, Department of Cardiac Surgery, Qinghai Cardiovascular Disease Hospital, China Etiology1 Cystic necrosis or degeneration of the middle layer of the arterial wall, 2 hereditary disease, 3 atherosclerosis, 4 aortic coarctation, 5 trauma, 6 bacterial or fungal infection, 7 congenital classification1 Classification according to anatomical site1) root aneurysm, 2) ascending aortic aneurysm, 3) aortic arch aneurysm, 4) thoracic descending aortic aneurysm, 5) abdominal thoracic descending aortic aneurysm2 Classification according to etiology 1) atherosclerotic aneurysm, 2) congenital aneurysm, 3) hereditary aneurysm, 4) infected aneurysm, 5) traumatic aneurysm3 Classification according to morphology 1) cystic aneurysm, 2) spindle aneurysm, 3) mixed aneurysm Diagnosis clinically, patients with thoracic aortic aneurysm do not have characteristic clinical manifestations, and most of the X-ray chest plain films have negative results or cannot be diagnosed clearly. Non-invasive imaging including echocardiography, CTA and MRI (magnetic resonance imaging) and aortography are the most common and main methods for its diagnosis. Aortic aneurysms are diagnosed on imaging when the aorta is locally or diffusely dilated more than 1.5 times its normal diameter. Treatment Once diagnosed, thoracic aortic aneurysms should, in principle, be treated with surgery as soon as possible. Simple ascending aortic aneurysm The aneurysm is confined to the ascending aorta without involvement of the aortic root. For coronary artery openings and cephalobrachial artery openings, ascending aortic replacement is performed. Aortic root aneurysm Aortic aneurysm involving the aortic sinus, annulus and part of the ascending aorta, often combined with upward shift of the coronary opening and incomplete aortic valve closure. 1. Bentall procedure Aortic valve removal, aortic root replacement with a prosthetic valve and a valved conduit made of artificial blood vessels, and coronary artery grafting. 2. Davld procedure For aortic disorders not originating from the aortic leaflets and annulus, such as If the aortic valve leaflets are normal, aortic root replacement with preservation of the normal structure and function of the aortic valve can be performed. Aortic arch aneurysm Descending aortic aneurysm Descending aortic replacement Patients with untreated aortic aneurysms are prone to rupture or aortic coarctation and have a poor prognosis, but if treated with timely surgery, their natural life expectancy can reach that of a normal person.