Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Enterprise Park, Suite 200, 387 Technology Circle, Atlanta, GA, 30313-2412, USA.
Exponent, Inc., Philadelphia, PA, USA.
Ann Biomed Eng. 2020 Jan;48(1):169-180. doi: 10.1007/s10439-019-02324-y. Epub 2019 Jul 16.
Transcatheter heart valve (THV) leaflet thrombosis in the neo-sinus and associated reduced leaflet motion is of clinical concern due to risks of embolism and worsened valve hemodynamics. Flow stasis in the neo-sinus (the space between the native and THV leaflets) is a known risk factor, but the role of proximal coronary flow is yet to be investigated. We tested two replicas of FDA approved commercial THVs-intra-annular and supra-annular (similar to the SAPIEN 3 and CoreValve families)-in a left heart simulator with coronary flow. Velocity fields in the left coronary cusp (LCC) and non (NCC) neo-sinus were quantified using high speed particle image velocimetry and particle residence times (PRT) were computed to evaluate flow stasis in the region. The supra-annular THV LCC neo-sinus had shorter PRT than its NCC neo-sinus (0.66 ± 0.00 vs. 0.76 ± 0.04, p = 0.038), while the intra-annular THV LCC neo-sinus had similar PRT to its NCC neo-sinus (1.93 ± 0.05 vs. 1.92 ± 0.03 cycles, p = 0.889). The supra-annular valve LCC and NCC neo-sinuses had shorter PRT than their intra-annular valve counterparts (p < 0.001). These results showed that coronary flow reduces flow stasis in the supra-annular THV neo-sinus and, ostensibly, thrombosis risk in the region. This effect was not significant in the intra-annular valve.
经导管心脏瓣膜（THV）瓣叶在新窦内血栓形成和相关的瓣叶活动度降低是临床关注的问题，因为存在栓塞和瓣膜血液动力学恶化的风险。新窦（原生和 THV 瓣叶之间的空间）内的血流停滞是一个已知的危险因素，但近端冠状动脉血流的作用尚未得到研究。我们在带有冠状动脉血流的左心模拟器中测试了两种经过 FDA 批准的商业 THV 复制品-环形内和环形上（类似于 SAPIEN 3 和 CoreValve 系列）-的效果。使用高速粒子图像测速法量化了左冠状动脉瓣（LCC）和非（NCC）新窦中的速度场，并计算了粒子停留时间（PRT）以评估该区域的血流停滞情况。环形上 THV 的 LCC 新窦的 PRT 比其 NCC 新窦短（0.66±0.00 比 0.76±0.04，p=0.038），而环形内 THV 的 LCC 新窦与 NCC 新窦的 PRT 相似（1.93±0.05 比 1.92±0.03 个周期，p=0.889）。环形上 THV 的 LCC 和 NCC 新窦的 PRT 比其环形内 THV 的新窦短（p<0.001）。这些结果表明，冠状动脉血流减少了环形上 THV 新窦内的血流停滞，显然也降低了该区域的血栓形成风险。这种效果在环形内瓣膜中并不显著。
