With the advent of an aging population and a change in diet, the incidence of aneurysms, especially abdominal aortic aneurysms, is on the rise in China. Statistical data show that the incidence of abdominal aortic aneurysm is about 8.8% among people over 65 years old. Many patients suddenly rupture their aneurysms without any symptoms and die of hemorrhage, with a mortality rate of over 90%. Therefore, the medical profession refers to aneurysm as a “time bomb” in the body. China’s famous geologist Li Siguang and the great physicist Albert Einstein were both killed by ruptured abdominal aortic aneurysms. What kind of disease is abdominal aortic aneurysm? Why is it so dangerous? Is there any way to detect it early? Aneurysms are caused by atherosclerosis, infection, necrosis of the middle layer of the artery, or congenital factors that cause the arterial wall to lose its normal integrity and to expand and deform locally under the action of intra-arterial blood pressure, to the point of rupture, resulting in instantaneous hemorrhage and death. Abdominal aortic aneurysm is the largest artery in the body, and it is not a tumor in the usual sense, as it is a limited bulge caused by lesion and damage to the arterial wall. Abdominal aortic aneurysm can be classified according to its etiology — ① True aneurysm: atherosclerosis is the main factor, due to the deposition of lipids in the arterial wall, forming atheromatous plaque and calcium deposits, causing the artery to lose elasticity, and under the impact of blood pressure, the aneurysm body is progressively enlarged. (ii) Clamped aneurysm: cystic necrosis or progressive degenerative lesion in the middle layer of artery, which may be related to old age, specific inflammation and metabolic abnormalities, etc. It is a systemic lesion. (iii) Pseudoaneurysm: The origin is due to trauma, direct or indirect violence (e.g. shrapnel, stabbing), penetrating trauma that ruptures and disconnects the artery, surrounded by surrounding soft tissue and forming a pulsatile hematoma. What are the clinical manifestations of abdominal aortic aneurysm? Abdominal aortic aneurysm is unlikely to heal on its own, and if left untreated, it often ruptures and bleeds easily, leading to the patient’s death. Therefore, clarifying the clinical manifestations of abdominal aortic aneurysm is the key to early diagnosis of the disease. The clinical manifestations of the disease are mainly — ① A pulsatile mass in the abdomen. Most patients can find a pulsating mass around the umbilicus and in the left mid-upper abdomen, accompanied by tremor and vascular murmurs. ② Pain. Most patients have only mild discomfort or distension in the abdomen, but when the tumor compresses the spinal nerve root, significant low back pain may occur. If severe abdominal pain or low back pain suddenly appears, it is a sign that the tumor has involved the blood supplying arteries in the abdominal cavity or caused rupture and bleeding of the retroperitoneal vessels. ③ Compression of adjacent organs. If the tumor compresses the duodenum and proximal jejunum, it may cause gastrointestinal symptoms; if it compresses the ureter, it may lead to urinary tract obstruction; and a few patients may develop obstructive jaundice due to the tumor compressing the common bile duct. ④Arterial embolism. If the thrombus inside the aneurysm cavity is dislodged, it may cause acute embolism of abdominal aortic branches, such as mesenteric artery embolism and lower limb artery embolism, or even ischemic necrosis of the corresponding parts. (5) Aneurysm rupture. This is the most dangerous symptom in patients with abdominal aortic aneurysm. Rupture of the aneurysm leads to massive bleeding, and such patients often die of hemorrhagic shock within a short period of time. The irregular geometry and thickness of the vessel wall within the aneurysm lumen slow blood flow and are often accompanied by thrombosis, where the thrombus adheres to the vessel wall. The adherent thrombus is sometimes dislodged to produce an arterial embolism. In addition, aneurysms can become infected. Once infection occurs, the symptoms worsen, making the aneurysm more likely to rupture. How to rule out “time bomb” early When a suspected aneurysm is detected, a color Doppler ultrasound should be done in time to detect the size of the aneurysm and whether there is atherosclerosis and thrombus in the wall. This test is particularly useful for early detection of abdominal aortic aneurysms below the renal artery. Abdominal aortography or digital subtraction angiography (DSA) and CT examinations can help diagnose and determine the size and extent of the aneurysm. Abdominal aortic aneurysms are not curable with medications and surgery is the only effective way to treat aneurysms. When is the best time to operate? Domestic literature reports that the percentage of ruptures occurring when the maximum diameter of the aneurysm is greater than 4 cm is significantly higher. Therefore, the current standard for surgical intervention is 5 cm. However, even in small aneurysms, there is a possibility of acute rupture. The rupture of abdominal aortic aneurysms is directly related to the size of the aneurysm diameter. Studies have shown that the incidence of rupture is 10% for diameters less than 4 cm, 30%-50% for diameters greater than 5 cm, and 80% for diameters greater than 10 cm. If thrombosis is detected, thrombolytic drugs should be used early to achieve the reduction of complications caused by thrombus dislodgement. Traditional abdominal aortic aneurysm surgery uses general anesthesia and a large incision in the middle of the abdomen, which is a very traumatic and risky surgical method with a long recovery time. In our hospital, we have the technique of transvascular internal placement of abdominal aortic aneurysm stent, which requires only a small incision at the root of the thigh, and under local or semi-body anesthesia, a stent is implanted into the blood vessel to block the diseased aneurysm from the normal blood vessel for treatment purposes. The patient does not need to be admitted to the intensive care unit (ICU) and can eat or get out of bed on the day of surgery.