EVALUATION OF PROSTHETIC CARDIAC VALVE FAILURE IN AN ANIMAL MODEL STUDY

这个项目的目的是开发一种动物模型来 活体评估心脏瓣膜。这个动物模型系统是 以多学科方式利用，包括以下领域 外科、生理学、病理学、工程学和技术 发展。我们已经证明了植入的生物假体价值 在幼年绵羊身上表现出相同的病理变化 退化和钙化，与植入人体的一样； 然而，这些变化的发展在 绵羊与人类相比。近600个猪主动脉或 来自14个来源的牛心包生物瓣膜和 已经有30多种不同类型的人被植入了 动物模型系统：1)评估动物的特性 病理改变，2)比较不同类型的改变 在阀门方面，3)比较不同类型阀门的变化； 4)比较植入的瓣膜的变化。 二尖瓣和三尖瓣位置，以及4)评估瓣膜 在植入前进行处理以延缓或 消除钙化和退化过程。由于 这些类型的观察、临床试验已经启动 有两种新型的生物瓣膜。同样重要的，如果 更糟的是，至少有七种阀门被拒绝了 从临床使用的考虑。积极的一面和积极的一面 对这些过程研究的负面结果增加了洞察力 关于钙化、退变和功能障碍的机制 人工心脏瓣膜。此外，该模型正在被 用来验证超声波技术，包括彩色- 编码的二维多普勒，用于表征 生物瓣膜、机械瓣膜和合成瓣膜的速度 流动湍流型线及其非侵入性检测 阀门失灵。

The purpose of this project is to develop an animal model to evaluate cardiac valves in vivo. This animal model system is utilized in a multidisciplinary manner, including the fields of surgery, physiology, pathology, engineering and technology development. We have shown that bioprosthetic values implanted in juvenile sheep demonstrate the same pathologic alterations of degeneration and calcification as those implanted in humans; however, the development of these alterations is accelerated in sheep as compared to humans. Nearly 600 porcine aortic or bovine pericardial bioprosthetic valves from fourteen sources and of more than thirty different types have been implanted in the animal model system to: 1) assess the characteristics of the pathologic changes, 2) compare the alterations in different types of valves, 3) compare the alterations in different types of valves; 4) compare the alterations occurring in valves implanted in the mitral versus the tricuspid positions, and 4) evaluate valves treated prior to implantation with processes to retard or to eliminate the calcification and degeneration processes. Due to these types of observations, clinical trials have been initiated with two new types of bioprosthetic valves. Equally important, if not more so, at least seven types of valves have been rejected from consideration for clinical use. Both the positive and negative results of studies of these processes have added insight to the mechanisms of calcification, degeneration and malfunction of prosthetic cardiac valves. Additionally, the model is being utilized to validate ultrasonic techniques, including color- encoded, two-dimensional Doppler, for the characterization of bioprosthetic, mechanical, and synthetic leaflet valve velocity flow turbulence profiles and for the noninvasive detection of valve failure.