OBJECTIVE: To explore the clinical efficacy and characteristics of endoluminal repair for abdominal aortic aneurysm, and to summarize its indications, points and complications. METHODS: The clinical data of 23 patients with abdominal aortic aneurysm during the period from September 2006 to May 2011 in our hospital were retrospectively analyzed. RESULTS: Intraoperatively, 20 cases (87.0%) aneurysms disappeared with good sealing, and 3 cases (13.0%) developed endoleak; postoperatively, 20 cases (87.0%) were discharged from the hospital with clinical recovery, 1 case (4.3%) was transferred to a higher-level hospital for further treatment due to severe intrapulmonary infections, 1 case (4.3%) had a slight alleviation of clinical symptoms, and 1 case (4.3%) died, with the cause of death as multiple organ dysfunction syndrome ( MODS). CONCLUSION: Endoluminal repair for abdominal aortic aneurysm has the advantages of short operation time, less bleeding, fast recovery and minimally invasive. Abdominal aortic aneurysms (AAA) is one of the most common critical diseases in cardiovascular surgery. Its incidence is more common in men than in women, and 95% of patients are located below the plane of the renal artery, and rupture of the aneurysm is the most serious consequence of AAA.In 1991, Argentinean surgeons Parodi et al[1] reported for the first time that AAA was treated with endovascular aneurysm repair (EVAR) with success, and the aim of the clinical treatment was to rebuild the abdominal The aim of clinical treatment is to re-establish abdominal aortic blood flow, prevent the development of aneurysmal lesions, and improve their prognosis. Currently, EVAR has been accepted and widely practiced by vascular surgeons, and more than half of AAA patients are treated with EVAR [2-3]. In this study, the clinical efficacy of endoluminal repair for AAA was investigated, and its indications, points and complications were summarized. I. DATA AND METHODS 1. General data The clinical data of 23 cases of AAA patients in our hospital during the period from September 2005 to May 2011 were retrospectively analyzed. Among them, 17 cases were male and 6 cases were female, age 39.8-65.1 years old, average (51.3±7.2) years old; patients were found to have symptoms of abdominal pressure, abdominal pain, embolic symptoms or abdominal mass, and the duration of the disease ranged from 6h to 4.2 years, average (9.4±4.7) months; there was a history of coronary artery disease in 5 cases (21.7%), patients with a history of chronic obstructive pulmonary disease in 4 cases (17.4%), and history of diabetes mellitus in 3 Authors’ introduction : Wang Baocheng, male, (1970.12-), Yushi, postgraduate student, deputy chief physician, mainly engaged in cardiothoracic surgery clinical work. cases (13.4%), 5 cases (21.7%) with history of hypertension, 2 cases (8.7%) with history of arrhythmia patients, and 4 cases (17.4%) with history of smoking and drinking. Imaging showed that the aneurysm diameter ranged from 36.2 to 83.7 mm, with an average of 56.3±13.7 mm. 2. Surgical methods (1) Preoperative preparation CTA was performed in all cases before surgery, and all data were measured in detail according to the imaging examination: the diameter of bilateral renal arteries, the location, the length of the aneurysm in the abdominal aorta, the maximum diameter, the length and diameter of the aneurysm neck, the distance of the renal arteries to the neck of the aneurysm, and the distance of the renal arteries to the internal iliac arteries. Diameter of bilateral external iliac arteries, etc. The bilateral external iliac arteries and femoral arteries were observed for stenosis and curvature in order to consider the surgical access. According to the preoperative CTA examination, we chose the patients in our group whose tumor necks were below the level of bilateral renal arteries. (2) Stent selection 12 cases chose the aortic laminar stent produced by COOK in the United States, including 8 cases of bifurcation-type laminar stent, 8 cases chose the aortic laminar stent produced by Medtronic in the United States, including 7 cases of bifurcation-type laminar stent, and 3 cases chose the aortic laminar stent produced by the domestic Xianjian Company. All of them were bifurcation-type laminating stents. (3) Surgical methods The endoluminal repair of abdominal aortic aneurysm was carried out under the dynamic monitoring of digital subtraction angiography (DSA), and the whole group adopted oral or nasal endotracheal intubation, intravenous inhalation compound anesthesia, taking the supine position, routinely disinfecting and spreading the towel, taking the incision of bilateral inguinal area, incising the skin, subcutaneous soft tissues, revealing the bilateral femoral arteries for about 3cm, and then the abdominal aorta for about 3 hours. The bilateral femoral arteries were about 3cm, and after freeing, the upper and lower ends were covered with rubber strips to be used for blocking when bleeding, Seldinger technique was applied to puncture the bilateral femoral arteries, and a 5F pigtailed gold labeled catheter was inserted into the abdominal aorta at the thoracic 12 cone for abdominal aortography, to observe the structural and organizational features of the AAA, the levels of the bilateral renal arteries, the distance between the renal arteries and the necks of the tumors, and the neck diameter of the tumors, and to determine the strategy of endoluminal repair and feasibility, and to determine the strategy of endoluminal stenting. To determine the strategy and feasibility of endoluminal repair, determine the positioning of the abdominal aortic stent, and select the appropriate artificial overlay stent (the diameter of the stent is required to be larger than the diameter of the anchorage area by 10%-20%). Generally the right femoral artery catheter is replaced with an ultra-hard guidewire, an orbit is established, and the artificial overlay stent is delivered. The systolic blood pressure is controlled below 100 mmHg, the artificial overlay stent is positioned under X-ray fluoroscopy, and the body of the stent is released by imaging and positioning again. The bifurcated artificial overlay stent was placed due to surgical need, and the pigtail catheter was guided into the stent body through the ultra-smooth guidewire, exchanged with the ultra-rigid guidewire, and delivered into the straight single limb and released. After the stent was released, the blood flow patency was observed by imaging, and the closure of the aneurysm lumen was clarified, and the upper and lower ends of the stent were appropriately dilated by a low-pressure balloon. Necessary treatment and repair of bilateral femoral arteries are required for internal leakage. The operation time was 1.3~2.3h, mean (1.82±0.52)h. All patients’ aneurysms disappeared in 20 cases (87.0%) during the operation with good sealing, and endoleak was reduced in 3 cases (13.0%) after balloon dilatation and angiography; after the operation, 20 cases (87.0%) went back to the guardian room, and the respiratory machine was stopped after anesthesia awakening and the tracheal intubation was removed, and they were transferred to the general ward and went down to the ground in the second day. Three cases (13.0%) were admitted to the intensive care unit, of which one case (4.3%) underwent tracheotomy due to respiratory failure, which was cured after treatment, and one case (4.3%) was transferred to a higher level hospital for further treatment due to severe intrapulmonary infection (which was not cured), and there were three cases (13.0%) of incisional lymphatic leakage in the previous cases, which was cured after changing the medication. Postoperatively, 20 cases (87.0%) were discharged with clinical recovery, and the review of CTA imaging before discharge showed good stent fixation without displacement; endoleak disappeared in 3 cases; 1 case (4.3%) had a slight relief of clinical symptoms, and 1 case (4.3%) died, and the cause of death was multiple organ dysfunction syndrome (MODS). During the follow-up process, it was learned that 14 cases (60.9%) had a good survival, with stable vital signs, no signs of abdominal pain, self-conscious swelling, etc., and imaging showed that there was no dislocation of the endoluminal stent, thrombus and other formations. There were 4 (17.4%) deaths, including 2 (8.7%) short-term deaths, 1 (4.3%) acute myocardial infarction after 12 weeks and 1 (4.3%) malignant arrhythmia. The remaining patients were lost to follow-up. The follow-up period was from 1 month to 5 years. III.DISCUSSION 1.Purpose of EVAR treatment and complications The purpose of EVAR treatment for AAA is to isolate the tumor from the blood circulation, avoid tumor enlargement and rupture, and correct the disordered blood flow status to ensure blood supply to distal organs. It is not a radical surgery. Compared with traditional open surgery, the advantages of EVAR are obvious greatly reducing the degree of surgical trauma, shorter operative time, quicker recovery, less blood loss, and shorter hospital stay, which were also confirmed by M atsumura et al [6]. It also reduces the incidence of cardiac, pulmonary, renal and other vital organ complications that are common after conventional AAA resection. In our group, the follow-up time of endoluminal isolation was short, the number of cases was small, and no significant important complications have been seen. However, it has been reported in the literature that after endoluminal isolation, there is a certain incidence of graft displacement, distortion, internal leakage, tumor rupture, renal failure, arterial embolism and infection, and the durability of the device also needs to be further investigated. Postoperative complications include: (1) endoleak. This is the phenomenon of persistent blood flow associated with endoluminal vascular grafts outside the lumen of the graft and in the lumen of the aneurysm and neighboring vessels treated by the graft [4], which is a major complication after EVAR. In our group, three cases of endoleak occurred, and after balloon dilatation, imaging showed that the endoleak was alleviated, and all of them disappeared on review of CTA before discharge. (2) Displacement. The stent was disconnected and dislodged due to insecure stent or unstable suture with artificial blood vessels. (3) Embolization. During the implantation of grafts, atheromatous plaque or arterial thrombus dislodgement may be caused; (4) stent implantation syndrome, the patient appeared to manifest as leukocytosis, fever and other symptoms and signs, can not be treated, and can be relieved within 1 week. (5) Incisional lymphatic leakage. This is related to the suture incision is not close, and later we changed the suture method continuous suture disappeared. This is helpful for departments that are just starting to perform the surgery. There are also reports in the literature of inaccurate stent placement, easy rupture or difficult expansion of the balloon, and the possibility of insertion and extraction difficulties during the operation, thrombosis, occurrence of endoleak, stent displacement and fracture, and rupture of the aneurysm [5]. 2, Surgical indications for the treatment of AAA by EVAR We appreciate that the use of endoluminal repair for the treatment of AAA is firstly free of allergic reactions to contrast media. Secondly, the morphological requirements of the lesion are more rigorous, and the main indicators for consideration are proximal tumor neck length >1.5 cm, total tumor diameter >5 cm (asymptomatic AAA patients), calcification, twisting and angulation, etc., which are not serious, tend to rupture of AAA patients, bilateral iliac artery occlusion and stenosis are not serious, and so on. Endoluminal repair is more suitable for AAA patients with severe comorbidities,. EVAR is especially suitable for patients with advanced age and AAA patients with comorbidities such as cardiac, hepatic, renal, pulmonary and other vital organ insufficiency, who have received surgical treatment for malignant tumors in the last 5 years, or patients with a history of previous surgery resulting in intra-abdominal adhesions that make it difficult for them to tolerate an open laparotomy [7]. At the same time, endoluminal repair treatment also reduces the important organ complications that are common in traditional open surgical treatment, which is one of the main factors for active endoluminal repair treatment in recent years. 3, EVAR treatment of AAA key points (1) Preoperative CTA examination is required, detailed measurement of various data according to imaging, if necessary, in the CT room workstation measurement data, repeated observation of the structure and tissue characteristics of AAA. (2) Select the appropriate artificial overlay stent, the diameter of the stent is required to be larger than the diameter of the anchorage area by 10%-20%. (3) Positioning the artificial overlay stent requires imaging and positioning again. (4) When releasing the main body of the stent with the membrane stent, the upper end of the bare stent can cross the renal artery, while the membrane stent must be located below the opening of the renal artery. (5) This can be determined by femoral artery angiography before and after stent release. (6) Intraoperative release of the stent requires lowering the systolic blood pressure to below 100 mmHg. (7) Final imaging is performed to observe the patency of blood flow after stent release, as well as to clarify the closure of the aneurysm lumen, and low-pressure balloons are used to appropriately dilate the upper and lower ends of the stent. Necessary treatment is needed for internal leakage. (8) The preoperative and postoperative treatment of this group of patients, preoperative mainly for patients with other diseases, such as hypertension, diabetes mellitus and cardiac arrhythmia, etc., need to stabilize blood pressure, blood glucose, and correct cardiac arrhythmia, etc., to make adequate preparation for surgery. Postoperative prophylactic use of anti-inflammatory for 48-72 hours does not advocate the application of anticoagulation.