Development of nitinol-based stent-graft for the treatment of aortic aneurysms : with special reference to a thin and flexible stent-graft system.

点击翻译按钮获取中文摘要

The purpose of this study was to develop a thin and flexible stent-graft system with homogeneous attachment to the entire aortic wall. According to our previous experimental study, we constructed a new type of nitinol based mesh type stent made of one nitinol (0.30mm wire, distances between each wires was 4-5mm in 20-30mm diameter stent) wire covered with thin polyester membrane (0.1mm thickness, porosity 500-1000, woven type). This stent-graft was examined in vivo and it was well tolerated by strength and vibration tests (almost the same radial force as that of Z stent, slight erosion of the wires was seen in vibration test comparable to more than 8 years heart beats counts). In vitro examination in aorta of the dogs revealed good patency of the aorta and blockade of its branches. After these basic tests, this new type of stent- graft was used for the inoperable emergent cases of aortic aneurysms after intense informed consent. Until March 2001, around 30 cases of inonerable emergent cases of aortic aneurysm were treated by this system. No definite system-related complications were seen. This flexible stent-graft system well fitted the tortuous aortas. Final exclusion of the aortic aneurysm was seen around 90% of cases. Further evaluation of these cases is now undergoing. In addition, the basic evaluation of this system in vivo and in animals is also being performed for further improvement of this system and for the development of more advanced system.