EVALUATION OF PROSTHETIC CARDIAC VALVE FAILURE IN AN ANIMAL MODEL STUDY

本项目的目的是开发一种动物模型， 评价体内心脏瓣膜。 该动物模型系统 以多学科方式加以利用，包括 外科学、生理学、病理学、工程学和技术 发展 我们已经证明植入的生物假体价值 在幼年绵羊中， 退化和钙化，如植入人体的那些; 然而，这些变化的发展是加速， 羊与人相比。 近600头猪主动脉或 来自14个来源的牛心包生物瓣膜， 超过30种不同的类型已经被植入 动物模型系统，以：1）评估 病理改变，2）比较不同类型的改变 3）比较不同类型瓣膜的变化; 4)比较在植入的瓣膜中发生的变化， 二尖瓣与三尖瓣位置，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，临床试验已经开始， 两种新型生物瓣膜 同样重要的是，如果 不仅如此，至少有七种阀门被拒绝 考虑临床使用。 的积极和 对这些过程的研究的负面结果增加了对 钙化、退化和功能障碍的机制 人工心脏瓣膜 此外，该模型正在 用于验证超声技术，包括彩色- 编码，二维多普勒，用于表征 生物、机械和合成瓣叶瓣膜速度 流动湍流轮廓和非侵入性检测 阀门故障。

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.