经导管镍钛合金自膨式主动脉人工瓣膜支架植入的实验研究

Transcatheter aortic valve implantation with self-expandable nitinol valved stent: an experimental study in sheep

目的验证国产镍钛合金自膨式主动脉人工瓣膜经导管原位置换实验羊主动脉瓣的有效性和安全性。方法将新鲜猪心包在0.01%胰蛋白酶溶液中震荡脱细胞处理24 h后,置磷酸盐溶液调定pH值为7.4的0.625%戊二醛溶液中浸泡36h,再在2%L-谷氨酸溶液中浸泡24 h去除戊二醛毒性,然后将其缝合固定在镍钛形状记忆合金制成的自膨胀支架上,制成人工瓣膜支架。选择10只健康山羊,通过锁骨下动脉和腹主动脉下段途径经导管原位置换主动脉瓣,术后随访3个月。结果 2只羊因支架过大、定位过深导致大量反流,1只羊因右冠开口堵塞突发室颤,1只羊死于血管并发症,其余6只羊即时成功。随访3个月,心脏彩色多普勒超检查证实带瓣膜支架无移位,瓣膜功能、心脏功能与术前比较无变化。结论国产镍钛合金自膨式主动脉人工瓣膜支架可以通过经导管植入,植入3个月后人工瓣膜功能良好,瓣膜支架结构完整。

Objective To determine the feasibility and safety of transcatheter aortic valve implantation with domestic self-expandable nitinol va]ved stent in experimental sheep. Methods A fresh pig pericardium was cross-linked with a 0.6% glutaraldehyde solution for 36 hours and then sutured on a nitinol self-expandable stent. Ten healthy sheep of （46.00 ± 2.60） kg body weight were chosen for the stusdy. Under general anesthesia, the device was delivered through catheter into the native aortic valve of the sheep via the femoral artery or abdominal aorta. The animals were followed up for three months. Results Six devices were successfully delivered at the desired position in six sheep with no occurrence of complications. Angiographic and hemodynamic studies confirmed that the stents were fixed at correct position with competent valve function immediately and 90 days after the procedure. Technical failure or fatal complications occurred in the remaining four sheep. Conclusion Implantation of a domestic nitinol self-expandable stent at the aortic valve position through a transcatheter approach is feasible in experimental sheep.