非体外循环下经心尖二尖瓣成形环内带瓣膜支架植入的研究

Transapical stent -valve implantation into mitral annuloplasty ring off bypass

目的验证无体外循环支持下心尖径路成形环内二尖瓣支架植入的可能性，评价自制自扩张支架瓣膜功能。方法7头成年猪，体质量（58．3±5．55）kg，体外循环下植入26mm二尖瓣成形环，撤除体外循环，导管下经心尖植入30mm自制二尖瓣带瓣膜自扩张支架，评价血流动力学及瓣膜功能。结果非体外循环导管下经心尖成形环内二尖瓣支架植入成功率为100％，植入时间为（21．6±5．3）min，整个过程血流动力学平稳，植入前后各项指标差异无统计学意义（P〉0．05）。植入的自扩张瓣膜支架平均瓣环直径、瓣膜功能面积和跨瓣压差分别为（2．58±0．03）cm、（4．22±0．44）em。和（4．6±4．7）mmHg（1mmHg：0．133kPa）。心内超声下探及微量或少量返流。术后大体标本检查支架均良好地固定在成形环上。结论非体外循环导管下经心尖成形环内植入-二尖瓣支架瓣膜是可行、安全的。对于一些成形后二尖瓣返流复发的高危患者，进行导管下成形环内二尖瓣置换，心尖径路或许是一个理想的路径。自制的自扩张支架瓣膜有着接近于正常瓣膜的功能面积。

Objective To evaluate the feasibihty of off - pump transapical mitral valve - in - ring implantation and to test the performance of a custom - made self - expandable stent valve. Methods Sev- en pigs, mean weight （58. 3 ±5.5） kg, underwent mitral valve annuloplasties under cardiopulmonary by- pass using 26 mm rings （ SJMTM ）. Then, a 30 mm custom - made self - expandable stent valve was deployed within the annuloplasty rings through a transapical access under fluoroscopic guidance and off pump. Results 100% （7 of 7 ） success was in the procedural of transapical mitral valve - in - ring implantation. Mean transapical procedure time was （21.6 ± 5. 3 ） min. Hacmedynamic status during transapical implan- tation remained stable, and differences in data collected before and after the stent - valve deployment were not statistically significant. Mean mitral annulus diameter and mean mitral orifice area were （ 2. 58 ± 0. 03） cm and （4. 22 ±0. 44） cm2. Trace or mild regurgitation was detected. Mean gradients were （4. 6 ± 4. 7） mmHg （1 mmHg =0. 133 kPa） across the self- expandable stent valves. Postmortem examination confirmed adequate positioning of the self - expandable valves within the annuloplasty ring. Conclusion Transapical mitral valve - in - ring implantation without cardiopulmonary bypass is safe and feasible. Transapical access may represent the ideal option for valve - in - ring procedures in cases of recurrent mitral regurgitation after mitral valve repair, in high - risk patients. Owing to the supra - annular profile of the valve components, our custom - made nitinol stent valve provides nearer to normal functional area. ]