Novel Simulation Technologies for BHV Long-Term Durability

摘要：最流行的心脏瓣膜置换设计(所谓的生物假体 心脏瓣膜“或BHV)继续由异种生物材料制造，用于 当前和新颖的瓣膜设计(例如标准支架瓣膜、经皮给药)。 失效仍然是疲劳导致的传单结构恶化的结果 和/或组织矿化，耐久性限制为10-15年。这样的限制 结果来自阀门设计和发动机的固有疲劳响应。 组成异种移植生物材料。因此，提高耐用性仍然是一个重要的问题 临床目标，并代表了一个独特的心血管工程挑战 与血液接触时产生的极端瓣膜机械需求。然而， 当前的BHV评估完全依赖于设备级评估，这些评估是 被同时和高度耦合的生物材料力学行为和 疲劳、瓣膜设计、血流动力学和钙化。因此，尽管几十年来 BHV的临床应用和日益流行，目前还没有可以接受的方法来治疗 在设备和部件上模拟替换阀门的功能和耐用性 生物材料水平。这种情况导致了BHV目前的停滞 开发，限制合理开发的人工心脏瓣膜的改进 耐用性。因此我们假设，通过使用先进的生物固体力学 新型异种生物材料疲劳响应的模拟 流固耦合(FSI)方法，一种严格的生物力学和生理学方法 可以开发出预测BHV性能的现实方法。我们将发展 这些耦合的计算目标首先并行，然后在 最后的项目阶段。

Summary: The most popular replacement heart valve designs (so called “bioprosthetic heart valves” or BHV) continue to be fabricated from xenograft biomaterials for both current and novel valve designs (e.g. standard stented valve, percutaneous delivery). Failure continues to be the result of leaflet structural deterioration mediated by fatigue and/or tissue mineralization, with durability limited to 10-15 years. Such limitations results from a combination of valve design and the intrinsic fatigue response of the constituent xenograft biomaterials. Thus, improved durability remains an important clinical goal and represents a unique cardiovascular engineering challenge resulting from the extreme valvular mechanical demands that occur with blood contact. Yet, current BHV assessment relies exclusively on device-level evaluations, which are confounded by simultaneous and highly coupled biomaterial mechanical behaviors and fatigue, valve design, hemodynamics, and calcification. Thus, despite decades of clinical BHV usage and growing popularity, there exists no acceptable method for simulating replacement valve function and durability at both the device and component biomaterial levels. This situation has contributed to the current stagnation in BHV development, limiting rationally developed improvements in prosthetic heart valve durability. We thus hypothesize that with the use of advanced biosolid mechanics simulations of the fatigue response of xenograft biomaterials coupled to state-of-the-art fluid-structure interaction (FSI) methods, a biomechanically rigorous and physiologically realistic approach to predict BHV performance can be developed. We will develop these coupled computational goals first in parallel, then combine and validate them in a final project stage.