二尖瓣成型环, 钛镍合金, 超弹性, 动物实验, 生物相容性

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