Abstract: To summarize the experience of endoluminal treatment of abdominal aortic aneurysm. METHODS: From September 2001 to December 2008, 84 cases of abdominal aortic aneurysm were treated by endoluminal treatment in vascular surgery, including 78 cases in men and 6 cases in women, with an average age of 70 years. RESULTS: All 84 cases of endoluminal repair of abdominal aortic aneurysms were or were successful (including 8 cases of emergency endoluminal repair of ruptured aneurysms). Bifurcated stents were applied in 77 cases and straight stents in 7 cases, including open-window stents in 2 cases. Two cases died within 30 days after surgery (mortality rate 2.4%), respectively, from acute myocardial infarction and infectious shock. Conclusion: Endoluminal repair of abdominal aortic aneurysm is a safe and effective method, and the mastery of aneurysm anatomical and morphological indications, operation techniques, management of complications and treatment of concomitant diseases are key. Surgical treatment of abdominal aortic aneurysms has changed dramatically from traditional surgery to endoluminal treatment, which has been rapidly developed nationwide with the advancement of endoluminal treatment techniques for abdominal aortic aneurysms and the continuous updating of peritoneal stent materials. From 2001.9 to 2008.12, 84 cases of abdominal aortic aneurysm were treated with endovascular repair, which are reported as follows: Clinical data 1. General data The group treated 84 cases of infrarenal abdominal aortic aneurysm with endovascular repair, 78 cases in men and 6 cases in women, with an average age of 70 years (28-83 years), including 65 cases of true aneurysm. Among the 19 cases of pseudoaneurysm, 11 cases were caused by leukoaraiosis, 2 cases by traumatic pseudoaneurysm, 3 cases by infected aneurysm, and 3 cases for unknown reasons. Among them, 8 cases were treated with emergency endoluminal therapy due to aneurysm rupture, including 4 cases of true aneurysm rupture and 4 cases of pseudoaneurysm rupture. 2. Endoluminal treatment: All 84 cases of endoluminal repair of aneurysms in this group were successful. The selected overlapping stents were: 77 cases of bifurcated aortic stents and 7 cases of straight stents. Bilateral iliac artery was covered in 5 cases (5.9%). Intraoperative endoleaks: 25 cases (29.7%) of immediate intraoperative endoleaks were found, including 18 cases of type I endoleaks (14 proximal cases, which disappeared after balloon expansion; 4 cases of distal iliac leg reflux, 2 cases disappeared after expansion and 2 cases were connected to extended iliac legs); 2 cases of type II endoleaks, which were not treated; 5 cases of type III endoleaks, which disappeared after expansion. 3. Postoperative complications: 1 case of postoperative iliac artery thrombosis (1.2%), blood flow was restored after embolization; 1 case of immediate postoperative paraplegia (1.2%), muscle strength of both lower limbs and defecation function were restored after treatment, but urinary dysfunction remained. Two cases (2.4%) had postoperative complications of intrapulmonary infection, one of which was cured and one died of infectious shock and multi-organ failure; two cases (2.4%) had complications of acute myocardial infarction, one of which was cured and one died of heart failure due to massive infarction; one case (1.2%) had postoperative contrast nephropathy requiring temporary hemofiltration, and renal function was restored after treatment. Postoperative wound hematoma was observed in 3 cases (3.6%), which improved after conservative treatment. Two cases died within 30 days after surgery (mortality rate 2.4%), respectively, from acute myocardial infarction and infectious shock. 4. Follow-up: In this group, 69 cases were effectively followed up after surgery by outpatient or telephone, with a follow-up rate of 84.1% (69/82), and the follow-up period ranged from 3 months to 5 years, with an average of 28 months. Among the 5 patients with bilateral internal iliac artery closure, 3 had intermittent hip claudication, 1 of which had internal iliac artery bypass reconstruction for severe symptoms, and 2 were relieved by conservative treatment; among the 3 cases of infected aneurysm, 2 died of recurrence and rupture of infected aneurysm with hemorrhage, and 1 was cured; among the 11 patients with leukoaraiosis, 1 Of the 11 patients with Leukocoria, 1 was lost to follow-up and 2 had recurrent pseudoaneurysms, of which 1 had a successful re-stenting and 1 died of a ruptured recurrent pseudoaneurysm. Discussion Abdominal aortic aneurysm is a major threat to human health, and the mortality rate is extremely high once it ruptures. Therefore, surgical treatment should be the mainstay for larger aneurysms (generally, aneurysm diameter greater than or equal to 5 cm is used as the standard for surgical treatment of aneurysm). At present, open surgery for abdominal aortic aneurysm has become a more mature technique, and the operative mortality rate can be reduced to less than 5% in experienced medical centers. However, since most patients with abdominal aortic aneurysm are elderly with systemic atherosclerotic disease and various concomitant diseases, the operative risk is greater, and the open surgery is more traumatic and the postoperative recovery is relatively slow. Endoluminal abdominal aortic aneurysm repair (EVAR) is a relatively new treatment technique with less trauma and faster recovery compared with traditional surgical treatment. In a clinical study of EVAR, 1082 patients with abdominal aortic aneurysms (diameter >5.5 cm) were randomly divided into the endoluminal treatment group and the traditional open surgery group, and the results showed that the 30-day mortality rates in the endoluminal treatment group and the surgical treatment group were Patients with 1.7% and 4.7% (p5cm) were randomly assigned to undergo open and stenting groups, and it was found that the 30-day mortality and serious complication rates were 4.7% in the stenting group and 9.8% in the surgical group, while the overall 2-year mortality rates were 10.3% and 10.4%, respectively, and the two studies came to the consistent conclusion that the benefits of EVAR for patients are more in the perioperative period, resulting in less pain for patients However, there was no significant difference in the long-term mortality and complication rates. This is mainly related to the patient’s own atherosclerotic disease and various concomitant diseases. EVAR technology has developed rapidly in recent years and is now a more mature treatment technology, and the update of overlapping stent products is also an important factor in promoting the rapid development of EVAR technology. According to the author’s experience, the treatment of the following aspects is the key to ensure the success of EVAR treatment: 1. Suitable stent anchorage zone It is generally believed that the length of the anchorage zone of the proximal tumor neck should be at least R1.5 cm and the length of the distal anchorage zone should be at least R1.0 cm, which is the key to ensure the success of the surgery and. A suitable anchorage zone allows the overlying stent to fit firmly in the aortic wall, avoiding the occurrence of recent or distant type I endoleaks and achieving the purpose of trans-luminal repair. In recent years, for aneurysms with a short proximal aneurysm neck and involving the renal or visceral arteries, the open-window technique, or endoluminal repair using a stent with branches, or the combined (hybrid) technique of endoluminal repair combined with arterial bypass can be adopted, but they are all in the clinical exploration stage. In our group, there were 2 cases of aortic pseudoaneurysm with very short aneurysm neck involving the renal artery, which were successfully treated with one-sided and bilateral open-window techniques, respectively. It has been reported in the literature that for small aneurysms of 4-5.5 cm in diameter, which usually have better anatomical morphology, intracavitary repair can achieve ideal therapeutic results. Intracavitary treatment should be implemented as early as possible under the premise of reasonable systemic assessment of the patient, which can receive ideal therapeutic results and can avoid losing the opportunity of intracavitary treatment due to the expansion of the aneurysm and shortening of the aneurysm neck. The influence of the angle of the neck and calcification The angle of the neck will affect the stability of the stent and lead to the failure of the endoluminal repair, especially when the neck has both calcification and a large angle, it is not suitable for the endoluminal repair. In general, it is considered inappropriate to perform intraluminal repair when the proximal neck angle is R60 degrees. In a few cases where the angulation is greater than 60 degrees or even close to 90 degrees, endoluminal repair may be attempted as long as there is a sufficient length of the neck, but a reversal surgery is required as a back-up measure. In addition, the irregular shape of the neck, calcification, tapered shape, attached thrombus, etc. are also the reasons that affect the stability of the overlapping stent and cause endoleaks, which need to be fully considered when selecting cases for comprehensive judgment. Prevention and treatment of endoleaks Endoleaks in aortic endoluminal therapy are usually divided into four types: type I endoleaks: leakage of blood from the proximal or distal end of the overlapping stent; type II endoleaks: reflux of blood through the inferior mesenteric artery, lumbar artery and other side branches; type III endoleaks: leakage of blood from the stent connection; type IV endoleaks: leakage of blood from the stent overlapping membrane itself or leakage of blood from the overlapping membrane pores, etc. Type I and III endoleaks usually lead to failure of intraluminal repair and require active treatment, while most type II endoleaks can heal spontaneously; for type IV endoleaks, they can be closed quickly with the pressure balance in the lumen and the aggregation of platelets in the lamina cribrosa. In our group, the incidence of endoleaks was found to be 29.7% at the time of stent placement. The proximal endoleaks were related to factors such as calcification of the tumor neck, irregular morphology and poor fitting of the overlying stent, which disappeared after balloon expansion and fitting; the distal endoleaks were related to factors such as short tumor neck, intraoperative vascular blockage and high reflux pressure, which disappeared after balloon expansion and access to the extension leg to the external iliac floor. 4. Prevention and management of thrombosis Intraluminal aortic repair usually rarely occurs with in-stent thrombosis. When the iliac artery is angled or twisted severely, and the structural design of the iliac leg of the stent lacks lateral anti-fracture support, the iliac leg of the stent is prone to fracture resulting in slow or interrupted blood flow and secondary thrombosis. In one case in this group, due to angulation of the common iliac artery, during the stent release angiography, due to the temporary support of the super-rigid guidewire in the stent, the folding of the iliac leg was not obvious and the blood flow was unobstructed, but when the guidewire was withdrawn, the iliac leg of the stent was designed without lateral anti-folding design (commonly known as no back tendon), and the iliac leg of the stent quickly fractured causing occlusion of the iliac artery. Stenting was successful. Therefore, in cases with significant twisting or angulation of the iliac artery, the iliac leg with dorsal tendon should be selected to avoid stenosis or occlusion caused by folding of the iliac leg. In principle, at least one side of the internal iliac artery should be preserved to avoid ischemia in the hip and pelvis. However, when the aneurysm involves bilateral iliac arteries and the patient can hardly afford open aneurysm surgery, one side of the internal iliac artery can be reconstructed at the same time as the internal iliac artery is closed. In this group, there were 5 cases of phase I internal iliac artery coverage, and there was no acute pelvic or intestinal ischemia after surgery, 3 cases had intermittent hip rows, 1 of which had more severe symptoms and underwent phase II internal iliac ground reconstruction, and the rest had gradual symptom relief with conservative treatment. Some literature reported that no acute intestinal or pelvic ischemic necrosis occurred after phase I coverage of bilateral internal iliac arteries, and the incidence of intermittent gluteal claudication was 31%. For patients who must undergo phase I coverage of bilateral internal iliac arteries, symptoms should be closely observed after surgery, and phase II internal iliac artery reconstruction should be performed if necessary. Pseudoaneurysms are rare but dangerous, and patients have obvious painful symptoms and are prone to rupture if not treated in time. Among the 19 cases of pseudoaneurysm in this group, 11 cases were caused by Leukocerebrosis. Pseudoaneurysm of leukoaraiosis is not common clinically and has been a clinical treatment problem due to easy recurrence. The key to the treatment of leukoaraiosis pseudoaneurysm lies not only in the intraluminal repair technique, but also in the immunotherapy of leukoaraiosis. In this group, 11 cases were treated with immunotherapy at the same time, and 2 cases had recurrence of pseudoaneurysm due to discontinuation of medication by themselves, among which 1 case was repaired by second intraluminal repair, 1 case died due to aneurysm rupture, and 1 case was lost to visit. The two cases of infected pseudoaneurysm that died in this group were all emergency surgeries without effective antimicrobial treatment before surgery. Although the patient’s life was saved by overlapping stent implantation, the postoperative anti-infection time was insufficient, and both died of aneurysm rupture due to recurrence of infection 2-3 months after surgery. For the other case of infected aneurysm, we made strict preparations and adopted a special treatment method, i.e., strict preoperative antimicrobial therapy after 6 weeks (antimicrobial selection based on blood culture); intraoperative injection of antimicrobial soak into the sheath of the overlapping stent delivery; intraoperative intubation through the brachial artery, placement of a single curved catheter in the aneurysm lumen, and implantation of the abdominal aortic overlapping stent through the femoral artery, when the overlapping stent closed the After the closure of the aneurysm lumen, a highly concentrated sensitive antimicrobial agent was injected into the aneurysm lumen via the catheter; postoperative anti-infective treatment was maintained for 4 weeks followed by oral antimicrobial agent, and the patient has been followed for 8 months with good recovery and no recurrence. Therefore, individualized measures are often required in the management of infected aneurysms, which require aggressive treatment for the primary disease. In conclusion, endoluminal repair of abdominal aortic aneurysms is a safe and effective treatment technique, especially for high-risk patients who cannot tolerate traditional open surgery, and has now become one of the main treatment methods for abdominal aortic aneurysms. The key to its successful treatment mainly lies in the mastery of indications, operational techniques and skills, management of complications, and treatment of concomitant diseases.