Abdominal aortic aneurysms are most commonly seen in older men, with a male to female ratio of approximately 4:1 and an incidence of 2,5% in men over 60 years of age. The incidence of abdominal aortic aneurysms has increased over the years, with two reports from Mayo Hospital showing a threefold increase from 12,2/100,000 to 36,2/100,000 from 1951 to 1980, with the increasing age of the population playing a role in the increase in incidence. The ninth leading cause of death. 1. Is there value in screening programs for abdominal aortic aneurysms? Screening for abdominal aortic aneurysms in the general population is impractical, and most aneurysms detected by screening are small. Conversely, selective screening is feasible and has a particularly high incidence in patients with peripheral vascular disease, heavy smokers, and those with a family history of aneurysm. 2. What causes abdominal aortic aneurysms? Because most patients with aneurysms have atherosclerosis in the arterial wall, abdominal aortic aneurysms used to be called atherosclerotic aneurysms. Atherosclerosis is thought to be the cause of atheroma-like degeneration. Smoking and hypertension are common risk factors for abdominal aortic aneurysms and obstructive vascular disease, but it is uncommon for abdominal aortic aneurysms to be combined with obstruction of the main-iliac aorta; therefore, it is more appropriate to call atherosclerotic aneurysms degenerative and nonspecific aortic aneurysms. 3.Can abdominal aortic aneurysms be inherited? The high incidence of abdominal aortic aneurysms in members of some large families suggests that genetic factors are involved in the pathogenesis, and abnormalities in the long arm of chromosome 16 have been found in some familial aneurysms. in Ehler-Danlos syndrome, a rare genetic deletion of collagen type III, which forms the main structure of the arterial wall, occurs, resulting in multiple aneurysms. in Mafan syndrome Patients present with dilated arteries and whole aortic coarctation due to mutations in the protofibrillin-Ⅰ gene on chromosome 15. In the 1980s, several studies showed a familial predisposition to abdominal aortic aneurysms, with at least 18% of patients with abdominal aortic aneurysms having close relatives involved. 4. What are the other causes of abdominal aortic aneurysms? Degenerative aneurysms account for 90% of infrarenal aortic aneurysms. Other causes include cystic mesangial necrosis, arteritis, injury, hereditary connective tissue disease, disruption of anatomical structures, and infection can also lead to abdominal aortic aneurysms. Infected aneurysms originate from local infection of the arterial wall. Most infected aneurysms develop from bacteraemia caused by distant lesions and are the most common type of aortic aneurysm in children. 5. What are the clinical manifestations of abdominal aortic aneurysms? Aneurysms are often diagnosed during routine physical examination when an asymptomatic pulsatile mass in the upper abdomen is found. 6. Do all patients with abdominal aortic aneurysms present with symptoms? The most common symptom of an abdominal aortic aneurysm is unspecified abdominal pain in the patient. Rapid expansion of the aneurysm may produce more widespread pain, probably due to straining of the peritoneum on the surface of the aneurysm. The typical pain is a persistent or throbbing pain confined to the upper abdomen. Aneurysm invasion of different adjacent structures may produce corresponding symptoms. Large aneurysms often erode the vertebral body and cause severe back pain; early gastrointestinal symptoms of anorexia, nausea, and weight loss indicate gastrointestinal tract compression; ureteral compression may result in hydronephrosis. Ureteral obstruction may produce pain radiating to the groin, occasionally accompanied by pyelonephritis. Appendage thrombus in the lining of the aneurysm may cause embolism and lead to acute lower extremity ischemia. Rare manifestations include thrombosis that worsens lower extremity ischemia, acute congestive heart failure due to aortic vena cava disease, and primary aortoenteric fistula due to aortic aneurysm erosion of the third segment of the duodenum. 7.Why is surgery necessary for abdominal aortic aneurysm? Rupture of abdominal aortic aneurysm is the most dangerous complication. Most patients do not have a priori symptoms and are not diagnosed until the aneurysm ruptures suddenly causing definite signs and symptoms. A ruptured aneurysm indicates advanced disease, and despite prompt surgery, the mortality rate is greater than 50%.