An Experimental Study Using Domestic Made Stent-graft For The Endovascular Repairment Of Aortic Aneurysm And The Influence Of Oversize For The Abdominal Aortic

Objective:1. Manufacture the models of thoracic aortic aneurysm(TAA) and abdominal aortic aneurysm(AAA) in canines use the posterior sheath. To test the effectiveness of domestic made stent-graft for the endovascular repairment of aortic aneurysm and to investigate the postoperative pathology in a canine experiment.2. To elucidate the histological changes after stent graft oversizing in abdominal aortic using an experimental canine model.Methods:1. The stent-grafts and delivery system were formulated. This stent-graft was sutured with Ni-Ti thread and PET graft. The system was manufactured by Wei Xin Corporation (Weihai).2. Twelve male hybrid canines were divided into four groups and every group has three canines. Group A:without building the TAA in the descending aorta; Group B: without building the AAA in the abdominal aorta; Group C:building the TAA in the descending aorta; Group D:building the AAA in the abdominal aorta. Every canine was investigated the postoperative pathology after the endovascular repairment at 30、60 and 90 days.3. Fifteen male hybrid canines were divided into three groups and every group has five canines. Group 1:the ovsize is 10-20%; Group 2:the ovsize is 20-30%; Group 3: the ovsize is> 30%. Every canine was investigated the postoperative pathology after the endovascular repairment at 30 days.Results:1. The total of 12 experimental canines undergoing surgery and survived. All aortic aneurysms were made successfully, and all case were successful repaired by stent-graft.Angiographic:stent-graft attached to the vessel wall is good, and the aneurysm disappear, and no obvious endoleak. Visually observed no nitinol wire and PET breakage.2. The total of 15 experimental canines undergoing surgery. All cases survived. Visually observed no nitinol wire and PET breakage.Conclusions:1. It’s a better method to use the posterior sheath of rectus made the aneurysm model, because of the facile material, simple procedure, no leakage and unusual material reaction. The design of domestic made stent-graft is reasonable, Its manufacture technology is mature and manipulation is practicable.2. Histologic studies confirmed the structural disarrangement of the aortic wall after insertion of a self-expanding stent-graft, including reduced number of muscle fibers and became thin of the artery wall, which may lead to the expansion of artery, and this trend is positively correlated with oversize.