Transcatheter Valve Underexpansion Limits Leaflet Durability: Implications for Valve-in-Valve Procedures
Transcatheter Valve Underexpansion Limits Leaflet Durability: Implications for Valve-in-Valve Procedures
复制标题
DOI：
10.1007/s10439-016-1738-8
复制
发表时间：
2017-02-01
影响因子：
3.8
通讯作者：
Sun, Wei
中科院分区：
文献类型：
--
作者：
Martin, Caitlin;Sun, Wei
经导管主动脉瓣（TAV）植入失败的人工生物瓣膜内是高风险患者的一种增长趋势。先前假体的非顺应性支架可能会阻止TAV的完全扩张，这已被证明会扭曲瓣叶构型，并被假设会对耐久性产生不利影响。在本研究中，使用有限元分析模拟在支架膨胀不足0（完全膨胀）、1、2和3 mm的情况下循环加压下TAV瓣叶疲劳损伤，以检验该假设。在2 mm和3 mm膨胀不足器械中，瓣膜闭合期间TAV瓣叶出现严重的针轮现象，这显著增加了瓣叶应力，并导致瓣叶加速疲劳损伤。1 mm膨胀不足情况下的瓣叶疲劳损伤与完全膨胀情况相似。在临床上，10-15%的膨胀不足通常被认为是可接受的;但是，在本研究中观察到，ae 2 mm（ae9.1%）的膨胀不足将显著影响器械耐用性。需要进一步研究以确定各种展开条件（即非均匀和非圆形展开以及不同植入高度）对不同TAV器械的影响，但很明显，必须保留正常TAV瓣叶构型以保持耐久性。
Transcatheter aortic valve (TAV) implantation within a failed bioprosthetic valve is a growing trend for high-risk patients. The non-compliant stent of the previous prosthesis may prevent full expansion of the TAV, which has been shown to distort the leaflet configuration, and has been hypothesized to adversely affect durability. In this study, TAV leaflet fatigue damage under cyclic pressurization in the setting of stent underexpansion by 0 (fully expanded), 1, 2 and 3 mm was simulated using finite element analysis to test this hypothesis. In the 2 and 3 mm underexpanded devices, the TAV leaflets exhibited severe pin-wheeling during valve closure, which increased leaflet stresses dramatically, and resulted in accelerated fatigue damage of the leaflets. The leaflet fatigue damage in the 1 mm underexpanded case was similar to that in the fully expanded case. Clinically a range of 10-15% underexpansion is generally considered acceptable; however, it was observed in this study that ae2 mm (ae9.1%) underexpansion, will significantly impact device durability. Further study is necessary to determine the impact of various deployment conditions, i.e. non-uniform and non-circular deployments and different implantation heights, on differing TAV devices, but it is clear that the normal TAV leaflet configuration must be preserved in order to preserve durability.