Walther Thomas, Dewey Todd, Wimmer-Greinecker Gerhard, Doss Mirko, Hambrecht Rainer, Schuler Gerhard, Mohr Friedrich W, Mack Michael
Universität Leipzig, Herzzentrum, Klinik für Herzchirurgie, Strümpellstrasse 39, 04289 Leipzig, Germany.
Eur J Cardiothorac Surg. 2006 May;29(5):703-8. doi: 10.1016/j.ejcts.2006.01.062. Epub 2006 Apr 5.
Percutaneous aortic valve implantation has been performed in patients with severe aortic stenosis judged as nonsurgical candidates. We evaluated a facilitated transapical antegrade approach for potential use in surgical high-risk patients.
A pericardial xenograft fixed within a 23-mm stent (Cribier-Edwards aortic prosthesis, Edwards Inc., Irvine, CA, USA) was implanted using a transapical approach in fifteen 35-45 kg pigs. A limited or a full sternotomy was used to transapically introduce a crimped valve through a 24-F sheath. Deployments were performed on the beating heart either with ventricular unloading using femoro-femoral cardiopulmonary bypass (CPB) or rapid ventricular pacing (RVP), all under fluoroscopic and echocardiographic visualization.
All valves were successfully deployed at the target site with acceptable visualization of the noncalcified annulus. Valve migration occurred in six procedures (three distal and three retrograde) secondary to inadequate reduction of ventricular output, unfavorable annular anatomy, excessive crimping of the valve, and dislodgement by the delivery balloon. Exact positioning of the valve into the target area was confirmed by autopsy at the end of the procedures. Paravalvular leak was noted in five implants.
The transapical approach provides a safe, accurate, and effective route for facilitated antegrade delivery of a stent-fixed valve. Advanced stent design will lead to better stability of the implant and may minimize the risk of paravalvular leakage in future. Identifying the appropriate population for human feasibility trials remains a challenge.
已对被判定为非手术候选者的重度主动脉瓣狭窄患者实施经皮主动脉瓣植入术。我们评估了一种便于经心尖顺行的方法，用于手术高危患者的潜在应用。
使用经心尖方法，将固定在23毫米支架（美国加利福尼亚州欧文市爱德华兹公司的Cribier-Edwards主动脉瓣膜假体）内的心包异种移植物植入15头体重35 - 45千克的猪体内。采用有限胸骨切开术或全胸骨切开术，经心尖通过24F鞘管引入压接好的瓣膜。在透视和超声心动图可视化下，使用股-股体外循环（CPB）进行心室卸载或快速心室起搏（RVP），在跳动的心脏上进行瓣膜展开。
所有瓣膜均成功在目标部位展开，非钙化瓣环的可视化效果可接受。由于心室输出量减少不足、瓣环解剖结构不利、瓣膜过度压接以及输送球囊移位，6例手术（3例远端移位和3例逆行移位）中发生瓣膜移位。手术结束时通过尸检确认瓣膜准确置入目标区域。5例植入物中发现瓣周漏。
经心尖方法为便于顺行输送支架固定瓣膜提供了一条安全、准确且有效的途径。先进的支架设计将使植入物稳定性更好，并可能在未来将瓣周漏风险降至最低。确定适合人体可行性试验的人群仍然是一项挑战。
