EVALUATION OF BIOPROSTHETIC CARDIAC VALVE FAILURE IN AN ANIMAL MODEL

本项目的目的是研制生物假体的动物模型 心脏瓣膜衰竭，并利用该动物模型系统来评估 病理改变和血流动力学功能障碍， 价值观 我们已经证明，在青少年中植入生物瓣膜 绵羊表现出相同的变性病理变化， 与植入人体的钙化物一样， 与人类相比，这些变化在绵羊中加速。 近 500个猪主动脉或牛心包生物瓣膜值来自9个 将不同的源植入动物模型系统中以评估 病理改变的特点，比较 在不同类型的价值观，比较发生在阀门的变化 植入二尖瓣与三尖瓣位置，并评价 在植入前对瓣膜进行处理，以延迟或消除 钙化过程。 由于这些类型的观察，临床 已经开始了对一种新型生物假体瓣膜的试验。 同样重要的是，如果不是更重要的话，至少有五种类型的阀门已经被开发出来。 拒绝考虑临床使用。 该模型还 用于验证超声波技术，包括彩色编码 二维多普勒，用于生物假体、机械和 合成瓣叶瓣膜速度/流量曲线和非侵入性 检测阀门故障。

The purpose of this project is to develop animal model of bioprosthetic cardiac valve failure and to utilize this animal model system to evaluate the pathologic alterations and hemodynamic dysfunction which develops in the values. We have shown that bioprosthetic valves implanted in juvenile sheep demonstrate the same pathologic alternations of degeneration and calcification as those implanted in humans; however, the development of these alterations is accelerated in sheep as compared to humans. Nearly 500 procine aortic or bovine pericardial bioprosthetic values from nine different sources have been implanted in the animal model system to assess the characteristics of the pathologic changes, to compare the alterations in different types of values, to compare the alterations ocurring in valves implanted in the mitral versus the tricuspid positions, and to evaluate valves treated prior to implantation with processes to retard or eliminate the calcification process. Due to these types of observations, clinical trials have been initiated with one new type of bioprosthetic valve. Equally important, if not more so, at least five types of valves have been rejected from consideration for clinical use. The model is additionally being utilized to validate ultrasonic techniques, including color encoded 2-D Doppler, for the characterization of bioprosthetic, mechanical, and synthetic leaflet valve velocity/flow profiles and for the noninvasive detection of valve failure.