1.What is abdominal aortic aneurysm? The abdominal aorta is the continuation of the aorta in the abdomen and is mainly responsible for the blood supply to the abdominal viscera, abdominal wall and lower extremities. Abdominal aortic aneurysm is formed when a segment of the abdominal aorta becomes dilated and its diameter exceeds more than 1.5 times the diameter of the normal abdominal aorta. Abdominal aortic aneurysm is actually an arterial dilatation disease caused by degeneration of the arterial blood vessel wall, not a “tumor” in the usual sense, but it is no less threatening to human health than any kind of malignant tumor. 2.What is the danger of abdominal aortic aneurysm? Abdominal aortic aneurysm is like an untimely bomb in human body, which is very dangerous. Once an abdominal aortic aneurysm ruptures, high speed and high pressure arterial blood is immediately ejected into the abdominal cavity, and the patient loses thousands of milliliters of blood in just a few minutes, followed by shock, hemorrhage and death. As long as the rupture appears in the abdominal cavity, any resuscitation and blood transfusion is futile, so clinicians call this dangerous disease “untimely bomb”, which means that as soon as abdominal aortic aneurysm is found, it is equivalent to bringing an untimely bomb, which may rupture anytime and anywhere. 3. What is the incidence of abdominal aortic aneurysm? In recent years, the incidence of abdominal aortic aneurysms has been on the rise worldwide. In the United States, the incidence of abdominal aortic aneurysm has increased 7 times compared to 30 years ago, and about 15,000 people die from it every year, accounting for the 13th cause of death. In China, the incidence of abdominal aortic aneurysm is increasing year by year with the continuous improvement of people’s living standard and the aging of population. 4.What are the causes of abdominal aortic aneurysm? The cause of abdominal aortic aneurysm is complex, and is currently considered to be most closely related to atherosclerosis, as well as congenital factors, genetic factors and metabolic factors. Degradation, disruption and calcification of elastic fibers in the aortic wall, excessive fat intake and atherosclerotic plaque formation in the arterial wall in the elderly can all contribute to the occurrence and development of abdominal aortic aneurysms. Many common diseases are also high-risk factors for abdominal aortic aneurysm: hypertension promotes the hardening of the arterial wall and makes it more prone to dilatation; diabetes reduces the ability of the arterial wall tissue to repair and rebuild, making it difficult to resist the attack of various pathogenic factors. In addition, many tissue lesions that are under tension in the human body have been found to be closely related to abdominal aortic aneurysm after investigation and statistics, such as emphysema, chronic bronchitis, and abdominal hernia. In conclusion, the causes of abdominal aortic aneurysm can be summarized as “eight high and one low”: high blood lipid, high blood sugar, high uric acid, high weight, high blood pressure, high (blood) viscosity, high age, high (mental) stress, and reduced exercise. 5.What are the clinical manifestations of abdominal aortic aneurysm? Most patients do not feel any symptoms. Occasionally, patients find a pulsating mass around the umbilicus or in the middle and upper abdomen by themselves or by physicians. Some patients only feel a throbbing sensation and mild discomfort in the abdomen. A small number of patients complain of abdominal pain or distending discomfort. When abdominal pain is significant and involves the low back, it suggests that the aneurysm has compressed or eroded adjacent tissues (e.g., lumbar vertebral body) or that the posterior wall of the aneurysm has ruptured and is bleeding to form a hematoma. A sudden increase in abdominal pain is often a precursor to aneurysm rupture. Most aneurysms rupture into the abdominal cavity, resulting in intra-abdominal hemorrhage with shock. Very rarely, aneurysms penetrate into the duodenum or jejunum and cause upper gastrointestinal bleeding. Partial intestinal obstruction may occur as the aneurysm enlarges forward, compressing or displacing the duodenum and upper jejunum located anterior to it. Sclerotic plaque debris or attached thrombus dislodged from the aneurysm can cause arterial embolism of the lower limbs, resulting in acute or chronic ischemic symptoms of the lower limbs. 6.What are the characteristic findings of abdominal aortic aneurysm on physical examination? Most patients with abdominal aortic aneurysm have almost no symptoms before the rupture of the vessel, except for a portion of patients with wasting who can palpate a pulsating mass in the abdomen with a frequency consistent with the heart rate, and a few other patients who have vague pain in the abdomen and lower back, in which case early diagnosis and early treatment are particularly important. There are many clinical methods used to examine blood vessels, such as ultrasound, CT, MRI, and arteriography. Among these examinations, vascular ultrasound has become an important tool for screening abdominal aortic aneurysm by virtue of its non-invasive, inexpensive and easy operation. It can not only detect aortic aneurysm quickly, but also provide many important information about the aneurysm, such as the diameter and length of the aneurysm, the size of the sclerotic plaque and the thrombus condition. 7.How to prevent abdominal aortic aneurysm in early stage? (1) Strengthen health education, raise people’s health awareness and develop good health and hygiene habits. Older people over 55 years old should strictly control fat intake and avoid overeating. Frequent consumption of low-fat, low-sugar, high-fiber, high-protein foods and fresh vegetables and fruits can help reduce the incidence of atherosclerosis. (2) Pay attention to behavior regulation, quit smoking and alcohol, for long-term smoking in more than 20 cigarettes per day should be strictly controlled, and those who have difficulty in quitting smoking should be patiently persuaded, explain the advantages and disadvantages, and gradually reduce, in order to help reduce the damage of harmful gases to the blood vessel wall. (3) Maintain adequate sleep, emotional stability and relaxation, and avoid excessive tension and emotional excitement. Participate actively in social activities within your ability and appropriate physical activities to improve the body’s ability to resist disease. Avoid forceful bowel movements and violent coughing. (4) Strictly control obesity, hyperlipidemia, and actively treat diabetes and hypertension. (5) Once abdominal aortic aneurysm is diagnosed, blood pressure should be strictly controlled and trauma, forceful defecation and violent coughing should be avoided. All activities that increase abdominal pressure should be avoided, and abdominal pain should be closely observed. Prevent rupture of abdominal aortic aneurysm. 8.What are the treatment options for abdominal aortic aneurysm? In recent years, the surgical treatment of abdominal aortic aneurysm has been improved with the development of vascular surgery technology, from the initial ligation, embolization and wrapping to the classic transabdominal surgical aneurysm removal and artificial vessel replacement, as well as the recently emerging endovascular repair and laparoscopic aneurysm removal and artificial vessel replacement. 9.How is endoluminal treatment of abdominal aortic aneurysm performed? After anesthesia, the patient is placed in a lying position, an incision is made in the inguinal ligament on one side, the femoral artery is dissected, the femoral artery is punctured, a sheath of about 2 mm in diameter is inserted, a guide wire of about 1 mm in diameter is fed through the sheath, the geometric parameters of the aneurysm are measured through the monitoring screen of the DSA, a graft of appropriate caliber and length is selected, and a pre-stored graft is fed along the guide wire. When the graft reaches the appropriate position, the graft is released from the introducer system and the stent with memory alloy automatically opens and adheres to the normal arterial wall, completely repairing the aneurysm. The repaired aneurysm lumen is thrombosed and blood flows through the graft. This minimally invasive procedure has a rapid recovery and is adapted to many patients who cannot tolerate traditional open surgery, bringing a boon to every patient with abdominal aortic aneurysm. 10.What are the advantages of the endoluminal approach to abdominal aortic aneurysm? Endoluminal repair is a minimally invasive surgery with the advantages of less trauma and faster recovery. Numerous clinical reports and evidence-based studies have confirmed that the perioperative safety of endoluminal repair is higher than that of open surgery. Randomized controlled trials in recent years, such as the EVAR1 trial in the United Kingdom and the DREAM trial in the Netherlands, have also shown that the 30-day postoperative death and serious complication rates for endoluminal repair are lower than those for open surgery, and the survival rate at 5 years of follow-up is better for patients with endoluminal repair than for those with traditional open surgery. 11. Patients are concerned about the high risk of surgery or endoluminal treatment, is this true? If the traditional open surgery for abdominal aortic aneurysm is heavy-handed and massively invasive, which many patients cannot tolerate, resulting in high mortality during the operative period, then endoluminal repair for abdominal aortic aneurysm can be considered light and minimally invasive, which can be tolerated by almost all high-risk patients, and the recent use of various organ-protective drugs and contrast agents that have less impact on kidney function has further reduced the riskiness of endoluminal repair. Most patients can be out of bed by day 2 after endoluminal repair and can be discharged from the hospital in 3-5 days. 12.What do I need to pay attention to after abdominal aortic aneurysm surgery? Patients should be followed up regularly after endoluminal repair to assess the degree and location of graft patency. In addition, the presence or absence of endoleaks is an important indicator of whether the aneurysm has been completely repaired after surgery, usually at 3 months, 6 months, 12 months and annually. A CTA is usually done to know the medium and long-term outcome of endoluminal repair. After endoluminal repair, patients can continue to exercise as before, including walking, riding in a car, swimming and cycling.