Kindzelski Bogdan A, Li Ming, Mazilu Dumitru, Hunt Timothy, Horvath Keith A
Cardiothoracic Surgery Research Program, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
Cardiothoracic Surgery Research Program, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
Ann Thorac Surg. 2014 Dec;98(6):2194-9. doi: 10.1016/j.athoracsur.2014.09.017. Epub 2014 Dec 1.
New-generation stented bioprostheses coupled with better imaging modalities are expanding the clinical utility of transcatheter aortic valve replacement (TAVR). This study aimed at evaluating the feasibility of real-time cardiovascular magnetic resonance (rtCMR) -guided TAVR using the Medtronic Engager aortic valve system in a preclinical model.
The Engager delivery device was slightly modified to make it CMR-compatible. Ten Yucatan swine underwent rtCMR-guided transapical TAVR. Postplacement phase-contrast and first-pass perfusion CMR sequences were used to evaluate for aortic regurgitation and myocardial perfusion, respectively.
Real-time CMR provided excellent visualization of cardiac anatomy during TAVR. Nine of 10 animals had proper valve placement in the aortic annulus as determined by CMR and confirmed by necropsy inspection. Postplacement phase-contrast scans confirmed no intravalvular or paravalvular leaks. Perfusion scans demonstrated sufficient coronary flow. Roentgenographs confirmed proper placement of the prostheses.
The Engager valve can be implanted transapically under rtCMR guidance with a modified, CMR-compatible delivery device in a preclinical model. Cardiovascular magnetic resonance allowed for accurate preplacement evaluation, real-time guidance, and postplacement functional assessment.
新一代带支架生物假体与更好的成像方式相结合,正在扩大经导管主动脉瓣置换术(TAVR)的临床应用。本研究旨在评估在临床前模型中使用美敦力Engager主动脉瓣系统进行实时心血管磁共振(rtCMR)引导下TAVR的可行性。
对Engager输送装置进行了轻微改造,使其与CMR兼容。十只尤卡坦猪接受了rtCMR引导下的经心尖TAVR。放置后使用相位对比和首过灌注CMR序列分别评估主动脉瓣反流和心肌灌注。
实时CMR在TAVR期间能很好地显示心脏解剖结构。10只动物中有9只通过CMR确定瓣膜在主动脉瓣环中放置正确,并经尸检证实。放置后相位对比扫描证实无瓣内或瓣周漏血。灌注扫描显示冠状动脉血流充足。X线片证实假体放置正确。
在临床前模型中,使用经过改造且与CMR兼容的输送装置,Engager瓣膜可在rtCMR引导下经心尖植入。心血管磁共振可进行准确的放置前评估、实时引导和放置后功能评估。