Objective We aim to evaluate the effectiveness and safety of a " new-style " cut-out mitral annuloplasty ring made of a hyperelastic nitinol through long-term in vivo animal experiments. Methods These " new-style" annuloplasty rings and Edward annuloplasty ring as control were implanted into healthy Small Tailed Han sheep, the cardiac function, the mitral valve and the heart morphology, the integrity, the local inflammation, the endothelialization and the thrombus of these " rings" , the hematolysis, the infection and the liver and kidney function were detected at post implantation day 90 and 180 through  echocardiography, pathology, complete blood count and blood chemistry. Results Echocardiography showed that there were similar effects these two-type rings on the cardiac structure and function, and the mitral valve shape. Autopsy, revealed that all rings tightly coupled with the mitral ring of receptors without breaking, cracking, or deformation, the circumferential fiber around the rings were thin and full, but without thrombus.Histopathology found revealed that both types of formed rings had complete fibrous capsules, with only mild local inflammatory reactions around them.Scanning electron microscope discovered endothelialization was complete. The blood tests showed that there were no significant changes in the blood routine and liver and kidney functions of all individuals compared to before the operation.Conclusion This" new-style " mitral annuloplasty ring made of a hyperelastic nitinol continued functioning post implanting in Small Tailed Han sheep, it is in no way inferior to Edward annuloplasty ring.

mitral annuloplasty ring, nitinol, hyperelastic, animal experiments, biocompatibility

目的 通过长期动物在体实验对比评价新型镍钛合金超弹性二尖瓣成型环的有效性和安全性。 方法 将普惠二尖瓣成型环(实验品)和爱德华二尖瓣成型环(对照品) 植入健康小尾寒羊体内,在植入后 90 和 180 d 时采用经胸超声心动图、病理学和血液学方法检测心脏结构及血液流体力学改变、瓣膜成型环结构完整性、成型环局部炎症反应和内皮化程度以及血常规和肝肾功能改变情况。 结果 超声检测发现两种成型环的植入对二尖瓣结构及血流动力学的影响相同,剖检发现两种成型环均与受体二尖瓣环紧密贴合、未发生折断、开裂和变形,组织病理发现两种成型环均形成完整的纤维囊、周围局部炎症反应轻微、内皮化完整,血液检查发现所有个体血常规、肝肾功能与术前相比无显著变化。 结论 该新型镍钛合金超弹性二尖瓣成型环植入小尾寒羊体内后可以长期有效工作,在有效性和安全性上与爱德华二尖瓣成型环相当。

二尖瓣成型环, 钛镍合金, 超弹性, 动物实验, 生物相容性