新型带瓣膜主动脉瓣球囊扩张支架的研制及测试

A novel balloon-expandable valved stents for transcatheter aortic valve implantation: preparation and testing

目的通过体外测试评价新型带瓣膜主动脉瓣球囊扩张支架及输送装置的各项性能,为下一步动物体内实验提供依据。方法支架材料采用钴基合金,设计成圆柱形网状结构。人工瓣膜取材于经处理的新鲜牛心包,将人工瓣膜缝合在支架上制成带瓣膜主动脉支架。使用人工心脏瓣膜脉动流测试仪和人工心脏瓣膜加速疲劳测试仪,分别对带瓣膜支架瓣叶材料脉动流和人工瓣膜耐疲劳情况进行测试。将带瓣膜支架压缩至自行研制的输送装置的球囊上,取离体羊心脏标本,经升主动脉将支架直视下置入羊主动脉瓣位置,扩张球囊释放支架,注水观察瓣膜功能。结果人工瓣膜瓣叶脉动流测试结果表明人工瓣膜启闭良好,无明显反流,符合生理需求。人工瓣膜耐疲劳测试结果表明瓣膜耐疲劳性能良好。带瓣膜支架经压缩后可通过输送鞘管送入离体羊主动脉瓣,支架释放后可牢固地置于羊主动脉瓣位置,人工瓣膜启闭功能良好。结论带瓣膜支架设计合理,性能良好,可用于动物经导管主动脉瓣置入实验。

Objective To evaluate the functions of a new balloon-expandable valved stent for transcatheter aortic valve implantation and the delivery system, so as to provide evidence for future animal study. Methods A new tube-like balloon- expandable valved stent was designed and made of cobalt-base alloys. Bovine pericardium was sutured by hand into the stent to prepare valved aortic stent, which was placed on the instrument to test the pulsating flow and fatigue property of prosthetic valve. The valved stent, which was compressed on a balloon catheter and pulled into a delivery sheath, was placed in the native aortic valve of isolated goat heart via the ascending aorta, and water was injected into the ascending aorta by a silicon tube to evaluate the competence of the prosthetic heart valves. Results Plusating flow examination showed that the artificial valve opened and closed well, without noticeable reflow, and accorded with human physiology. The prosthetic heart valves also performed well in the testing of fatigue property. The valved stent could be stably placed in the native valves of goat heart by delivery sheath, and the prosthetic heart valves showed satisfactory function. Conclusion The aortic valved stent is well- designed and has satisfactory function. It can be used for animal study of transcatheter aortic valve implantation.