Real-time magnetic resonance imaging-guided transcatheter aortic valve replacement.
Real-time magnetic resonance imaging-guided transcatheter aortic valve replacement.
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DOI：
10.1016/j.jtcvs.2015.11.024
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发表时间：
2016-05
期刊：
影响因子：
--
通讯作者：
Horvath KA
中科院分区：
文献类型：
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作者：
Miller JG;Li M;Mazilu D;Hunt T;Horvath KA
经导管主动脉瓣置换术（TAVR）已成为无法手术或高风险患者的治疗选择。目前，TAVR是结合荧光透视和经食管超声心动图进行的，其具有视觉限制，包括二维视图和软组织对比度差。实时磁共振成像（rtMRI）引导通过解剖结构的三维视图克服了这些限制，改善了软组织对比度，并允许器械输送的精确度。迄今为止，美国临床上可用的器械尚未用于rtMRI TAVR。我们展示了使用CoreValve®器械的结果。研究者对Medtronic CoreValve®输送导管系统进行了最小程度的改良，通过将不锈钢组件替换为氟塑料树脂和高密度聚乙烯组件，使其与MRI兼容。8只体重在60 - 90 kg之间的猪通过左锁骨下入路使用有源导丝进行rtMRI引导的TAVR。在植入过程中同时使用两个成像平面（长轴视图和短轴视图）进行实时成像。在没有快速心室起搏或心肺转流的情况下成功展开。采集展开后图像以评价最终瓣膜位置以及瓣膜和心脏功能。我们的研究结果表明，通过rtMRI引导、最小改良的瓣膜输送导管系统和有源导丝，CoreValve®可从左锁骨下入路轻松有效地展开。该方法允许在展开之前实现上级可视化，从而允许以精确的精度展开瓣膜。rtMRI的额外受益是能够进行术后即刻功能评估，同时消除辐射暴露、快速心室起搏、造影剂肾毒性和更具侵入性手术的发病率。市售器械的使用使rtMRI引导方法更接近临床现实。
Transcatheter aortic valve replacement (TAVR) has become a treatment option for otherwise inoperable or high risk patients. Currently TAVR is performed with a combination of fluoroscopy and transesophageal echocardiography, which has visual limitations including a two dimensional view and poor soft tissue contrast. Real-time magnetic resonance imaging (rtMRI) guidance overcomes these limitations with a three dimensional view of anatomical structures, improved soft tissue contrast, and allows pinpoint accuracy of device delivery. To date a device clinically available in the US has not been used for rtMRI TAVR. We present our results using the CoreValve® device. The Medtronic CoreValve® delivery catheter system was minimally modified by the investigators to be MRI compatible by replacing the stainless steel components with fluoroplastic resin and high density polyethylene components. Eight swine ranging between 60 and 90 kg underwent rtMRI guided TAVR with an active guidewire via a left subclavian approach. Two imaging planes (long axis view and short axis view) were utilized simultaneously for real-time imaging during implantation. Successful deployment was performed without rapid ventricular pacing or cardiopulmonary bypass. Post-deployment images were acquired to evaluate the final valve position in addition to valvular and cardiac function. Our results show that the CoreValve® can be easily and effectively deployed from the left subclavian approach by utilizing rtMRI guidance, a minimally modified valve delivery catheter system, and an active guidewire. This method allows superior visualization prior to deployment, thereby allowing deployment of the valve with pinpoint accuracy. rtMRI has the added benefit of the ability to perform immediate post-procedural functional assessment, while eliminating the morbidity of radiation exposure, rapid ventricular pacing, contrast media renal toxicity, and a more invasive procedure. Use of a commercially available device brings this rtMRI guided approach closer to a clinical reality.