Recently, an elderly patient was admitted to our hospital, who was usually in good health and had no obvious discomfort in eating, sleeping and recreation, but one day in the early morning suddenly developed abdominal pain, radiating to the lower back, with severe pain, panic, pallor, weakness of the limbs and decreased blood pressure. What is abdominal aortic aneurysm? In fact, it is not really a “tumor”, but a dilated disease of the abdominal segment of the aorta, which is the result of abnormal local expansion and enlargement of the arterial wall, and when the diameter of the dilated abdominal aorta exceeds 1.5 times the normal value, it is called “abdominal aortic aneurysm”. It is the most common type of aneurysm with a serious life-threatening effect, and once ruptured, the mortality rate is extremely high. With the advent of an aging society and the improvement of various new detection devices and methods, its incidence is increasing year by year. Therefore, the disease should be given full attention. The normal aortic wall of human body consists of three membranes: outer, middle and inner. Among them, pathological changes of the middle membrane play a very important role in the occurrence of aneurysm, which is composed of many elastic thin layers and smooth muscle cells between the thin layers. At the same time, there are many factors that lead to the destruction of the elastic lamina, which activates matrix metalloproteinases, causing the destruction and degradation of the elastic and collagen fibers of the elastic lamina, while smooth muscle cells have difficulty synthesizing and replenishing enough elastic and collagen fibers, resulting in a decrease in the elastic lamina and a decrease in its strength, which eventually leads to the development of abdominal aortic aneurysms. Abdominal aortic aneurysms are mostly seen in men, with an incidence ratio of 4:1 between men and women, at the age of 60 years or older. Some patients find pulsating abdominal masses on their own, and most of them appear without any symptoms, but are occasionally detected during general examination as well as during abdominal surgery. Therefore, for early detection and timely treatment of the disease, middle-aged and elderly patients should be alert when the following symptoms appear: 1. Upper abdominal discomfort aneurysms compressing the intestine can produce a feeling of fullness, decreased appetite, nausea, vomiting, and even intestinal obstruction; compression of the urinary system can lead to ureteral obstruction and pelvic effusion; aneurysm penetration into the duodenum can lead to vomiting blood, black stool, etc. 2. 2, Some have obvious abdominal pain when the pain shifts to the lower back, maybe the aneurysm compresses the adjacent tissues or there is a small amount of blood leakage to form a hematoma in the retroperitoneum. It is worth noting that sudden and severe abdominal pain is often a characteristic manifestation of abdominal aortic aneurysm rupture or acute dilatation, which is regarded as the most dangerous signal. 3, acute lower limb pain atheroma within the hardened plaque debris off with blood flow caused by lower limb artery embolism when the abdominal pulsating mass and the above symptoms are found, due to timely hospital consultation, after ultrasound, abdominal X-ray, CT, magnetic resonance imaging (MRI) and other examinations can confirm the diagnosis. Once the diagnosis of abdominal aortic aneurysm is confirmed, surgical treatment is the only effective treatment method. The mortality rate of surgical treatment for unruptured abdominal aortic aneurysm is 3-5%, while some patients die in time for resuscitation in case of rupture, and the mortality rate of emergency surgery is still very high. Surgical treatment includes traditional open surgery – abdominal aortic aneurysm resection, artificial vessel replacement, and minimally invasive intervention – abdominal aortic endoluminal isolation. The former is highly invasive and carries high surgical risks; the latter is less invasive but more expensive to treat.