应用新型介入瓣膜行经导管主动脉瓣置入术的实验研究

Initial experience of transcatheter implantation with a new aortic valve in sheep

目的探讨应用新型介入瓣膜在实验动物体内行经导管主动脉瓣置入术（TAVI）的可行性，并观察新型介入瓣膜置入后的短期效果。方法选取健康成年绵羊20只，在全身麻醉及成像造影设备的辅助下，经绵羊一侧颈总动脉置入输送鞘管，于主动脉瓣环处释放新型介入瓣膜。以左心室和主动脉造影及经胸超声心动图观察介入瓣膜的位置和作用。记录术后30d实验动物的存活情况。结果所有实验绵羊均置入新型介入瓣膜。15只（75％）存活绵羊的术后造影显示介入瓣膜位置良好，无移位，未影响二尖瓣；冠状动脉开口显影良好，冠状动脉通畅。经胸超声心动图显示5例绵羊存在轻度瓣周漏。术后存活绵羊主动脉瓣反流百分比由术前（1．25±0．46）％增加至（4．52±3．56）％（P〈0．05）。术后主动脉瓣有效瓣口面积、主动脉收缩压、主动脉舒张压、平均主动脉压、左心室收缩压、左心室舒张末压、心率与术前比较差异均无统计学意义（P〉0．05）。5只（25％）绵羊于TAVI后30d内死亡，其中介入瓣膜释放展开后即刻，因左冠状动脉开口堵塞发生心室颤动而死亡1只，术后20min死于急性心肌梗死1只，术后8和12h死于二尖瓣反流2只，术后26d死于感染性心内膜炎1只。结论采用新型介入瓣膜在实验动物体内行TAVI是可行的。短期内安全、有效。

Objective To evaluate the feasibility and short-term results of transcatheter aortic valve implantation （TAVI） using a new transcatheter valve. Methods Twenty healthy adult sheep received general anesthesia. Under the guidance of X-ray and transthoracic echocardiography （3TE） , the new anticalcification transcatheter valve was released from delivery system and implanted at the level of native aortic annulus via left common carotid artery. Position and function of the new anti-calcification transcatheter valve were evaluated by angiography and ＂[TE immediately after intervention. Thirty day survival rate of animals was obtained. Results New transcatheter valves were inplanted in all sheep. Fifteen sheep（75% ） survived up to 30 days and post-operative examination showed that the transcatheter valve was in optimal position without migration and mitral valve impingement. The native coronary artery was patent in these animals. There was a slight paravalvular leak in 5 sheep. Postoperative eehoeardiography showed reflux percentage was significantly increased （P 〈 0. 05 ） compared pre-intervention. Effective orifice area, aortic systolic pressure, diastolic aortic pressure, mean aortic pressure, left ventricular systolic pressure, left ventricular end diastolic pressure and heart rate were similar between post and pre-intervention （ all P 〈 0.05 ）. Five sheep died after TAVI within 30 days, including one fatal ventricular fibrillation occurred immediately after releasing the transcatheter valve and another sheep died of acute myocardial infarction due to left main coronary artery occlusion evidenced by angiography. Two sheep died of severe mitral regurgitation at 8 and 12 hours post-operation and one died of infective endocarditis at 26 days after intervention. Conclusion Our favorable preliminary results showed that it was feasible to perform TAVI using the new transeatheter valve.