Fluid Dynamic Characterization of Transcatheter Aortic Valves Using Particle Image Velocimetry
Fluid Dynamic Characterization of Transcatheter Aortic Valves Using Particle Image Velocimetry
复制标题
DOI：
10.1111/aor.13290
复制
发表时间：
2018-11-01
影响因子：
2.4
通讯作者：
Azadani, Ali N.
中科院分区：
文献类型：
--
作者：
Barakat, Mohammed;Dvir, Danny;Azadani, Ali N.
与同等大小的外科生物瓣膜相比，经导管主动脉瓣在瓣膜压力梯度和有效瓣口面积方面具有更好的收缩血流动力学性能。然而，对流场结构的深入研究对于检验流场特性并为计算模型的验证提供必要的实验证据是有意义的。本研究的目的是使用锁相粒子图像测速仪(PIV)比较三种最常用的经导管瓣膜和外科瓣膜的流场特性。26 mm Edwards SAPIEN 3、26 mm美敦力CoreValve和25 mm Carpentier-Edwards PERIMOUNT Magna在脉搏复印机上进行检查，输入参数符合ISO-5840，即心率70次/分，心输出量5 L/分，平均主动脉压100毫米汞柱。使用二维PIV系统获得整个心动周期的血流速度场和粘性剪切应力场。体外测试显示，SAPIEN 3的平均跨瓣膜压力梯度最低，其次是CoreValve和PERIMOUNT Magna外科生物假体。此外，PERIMOUNT MAGNA射流边界层内的粘性剪切应力值高于CoreValve和SAPIEN 3。然而，测量的剪切应力值低于已知的血小板激活和红细胞损伤的阈值。因此，三种生物瓣膜在收缩过程中不太可能发生剪切诱导的血小板激活。PIV测量结果可用于验证和验证计算模拟。
Transcatheter aortic valves provide superior systolic hemodynamic performance in terms of valvular pressure gradient and effective orifice area compared with equivalent size surgical bioprostheses. However, in depth investigation of the flow field structures is of interest to examine the flow field characteristics and provide experimental evidence necessary for validation of computational models. The goal of this study was to compare flow field characteristics of the three most commonly used transcatheter and surgical valves using phase-locked particle image velocimetry (PIV). 26-mm Edwards SAPIEN 3, 26-mm Medtronic CoreValve, and 25-mm Carpentier-Edwards PERIMOUNT Magna were examined in a pulse duplicator with input parameters matching ISO-5840, that is, heart rate of 70 beats/min, cardiac output of 5 L/min, and mean aortic pressure of 100 mm Hg. A 2D PIV system was used to obtain flow velocity and viscous shear stress fields during the entire cardiac cycle. In vitro testing showed that the mean transvalvular pressure gradient was lowest for SAPIEN 3, followed by CoreValve, and PERIMOUNT Magna surgical bioprosthesis. In addition, the viscous shear stress magnitude within the jet boundary layer was higher in PERIMOUNT Magna than CoreValve and SAPIEN 3 at the peak of the flow. However, the measured shear stress values were below the known threshold for platelet activation and red blood damage. Therefore, shear-induced platelet activation is unlikely to take place during systole in the three bioprosthetic heart valves. The PIV measurements can be used for verification and validation of computational simulations.