Mitral regurgitation (MR) due to annular dilation occurs in a variety of mitral valve diseases and is observed in many patients with heart failure due to mitral regurgitation. To understand the biomechanics of MR and ultimately design an optimized annuloplasty ring, a representative disease model with asymmetric dilation of the mitral annulus is needed. This work shows the design and implementation of a 3D-printed valve dilation device to preferentially dilate the posterior mitral valve annulus. Porcine mitral valves (n = 3) were sewn into the device and mounted within a left heart simulator that generates physiologic pressures and flows through the valves, while chordal forces were measured. The valves were incrementally dilated, inducing MR, while hemodynamic and force data were collected. Flow analysis demonstrated that MR increased linearly with respect to percent annular dilation when dilation was greater than a 25.6% dilation threshold (p < 0.01). Pre-threshold, dilation did not cause significant increases in regurgitant fraction. Forces on the chordae tendineae increased as dilation increased prior to the identified threshold (p < 0.01); post-threshold, the MR resulted in highly variable forces. Ultimately, this novel dilation device can be used to more accurately model a wide range of MR disease states and their corresponding repair techniques using ex vivo experimentation. In particular, this annular dilation device provides the means to investigate the design and optimization of novel annuloplasty rings.

中文翻译：

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一种新型 3D 打印优先后二尖瓣环扩张装置在体外心脏模拟器中描绘了反流起始阈值。

由于瓣环扩张导致的二尖瓣关闭不全 (MR) 发生在多种二尖瓣疾病中，并且在许多因二尖瓣关闭不全导致的心力衰竭患者中观察到。为了了解 MR 的生物力学并最终设计出优化的瓣环成形术环，需要一个具有二尖瓣环不对称扩张的代表性疾病模型。这项工作展示了 3D 打印瓣膜扩张装置的设计和实施，以优先扩张后二尖瓣环。猪二尖瓣（n = 3）被缝入装置并安装在左心模拟器中，该模拟器产生生理压力并流经瓣膜，同时测量弦力。瓣膜逐渐扩张，诱发 MR，同时收集血流动力学和力数据。血流分析表明，当扩张大于 25.6% 扩张阈值（p < 0.01）时，MR 相对于环状扩张百分比呈线性增加。阈值前，扩张不会导致反流分数显着增加。在确定阈值之前，随着扩张增加，腱索上的力增加（p < 0.01）；阈值后，MR 导致高度可变的力。最终，这种新型扩张装置可用于使用离体实验更准确地模拟各种 MR 疾病状态及其相应的修复技术。特别是，这种环形扩张装置提供了研究新型瓣环成形术环的设计和优化的手段。阈值前，扩张不会导致反流分数显着增加。在确定阈值之前，随着扩张增加，腱索上的力增加（p < 0.01）；阈值后，MR 导致高度可变的力。最终，这种新型扩张装置可用于使用离体实验更准确地模拟各种 MR 疾病状态及其相应的修复技术。特别是，这种环形扩张装置提供了研究新型瓣环成形术环的设计和优化的手段。阈值前，扩张不会导致反流分数显着增加。在确定阈值之前，随着扩张增加，腱索上的力增加（p < 0.01）；阈值后，MR 导致高度可变的力。最终，这种新型扩张装置可用于使用离体实验更准确地模拟各种 MR 疾病状态及其相应的修复技术。特别是，这种环形扩张装置提供了研究新型瓣环成形术环的设计和优化的手段。这种新型扩张装置可用于更准确地模拟各种 MR 疾病状态及其使用离体实验的相应修复技术。特别是，这种环形扩张装置提供了研究新型瓣环成形术环的设计和优化的手段。这种新型扩张装置可用于更准确地模拟各种 MR 疾病状态及其使用离体实验的相应修复技术。特别是，这种环形扩张装置提供了研究新型瓣环成形术环的设计和优化的手段。