THROMBOGENESIS IN BLOOD PUMPING DEVICES

器械相关血栓栓塞是血液接触中的主要问题 假体装置（例如氧合器、全人工心脏、心室 辅助设备、肾脏、肺等）并导致严重的并发症 试图用药物控制血栓栓塞并不总是成功的， 主要是因为血栓栓塞的过程开始了， 由许多因素维持，其中许多因素尚未得到很好的理解。 该装置的设计和产生的流动模式，性质和 所用材料的组成，以及 接受装置的人，都参与了血栓形成的过程。 本建议是一项研究血栓形成的血泵（心室 辅助设备，体外循环）的帮助下，一个独特的 研究人员和新技术。 生物医学研究人员 和工程背景将调查事件的顺序， 导致血栓栓塞。 体外小牛模型 具有光散射检测器的透明左心室辅助装置 安装在流出导管中，并且将使用换位的肾脏。 一 光散射检测器不仅可以检测到微栓子通过 通过探测器，它也会测量它们的大小和频率。 过滤模型将确定这些微栓子的可能性， 阻塞较小的血管，换位的肾脏将表明 肾脏中微栓子的百分比。 这三种方法 将相互补充，提供有关 血栓栓塞现象的发生及其随时间的进展。 的 将分析流量的贡献及其对血栓栓塞的影响。 同样，所提出的定量方法可能证明是理想的， 确定药物治疗方案在控制 血栓栓塞 肝素和阿司匹林这两种药物的作用 仔细检查。 在研究过程中，一些 将监测血液学参数，以帮助确定早期标志物， 循环血液中的血栓形成。 这些努力应该有助于我们更好地 了解血栓形成的过程，提供线索， 血栓形成开始，流变学因素的作用，以及 生物材料，并可能有助于消除不良反应铺平道路 通过设计修改、改进材料表面或适当的 治疗剂的组合。

Device-associated thromboembolism is a major problem in blood-contacting prosthetic devices (e.g. oxygenators, total artificial hearts, ventricular assist devices, kidneys, lungs, etc.) and cause severe complications. ATtempts to control thromboembolism with drugs are not always successful, primarily because the process of thromboembolization is initiated and sustained by a number of factors, many of which are not well understood. The design of the device and resulting flow patterns, the nature and composition of the materials used, and the coagulation state of the recipient of the device, all contribute in the process of thrombogenesis. This proposal is a study of thrombogenesis in blood pumps (ventricular assist devices, extracorporeal circulations) with the help of an unique team of investigators and novel techniques. Researchers with biomedical and engineering background will investigate the sequence of events that lead to thromboembolization. An ex-vivo calf model with externalized transparent left ventricular assist device with a light scattering detector installed in the outflow conduit and a transposed kidney will be used. A light scattering detector will detect not only the microemboli passing through the detector cell, it will also measure their size and frequency. A filtration model will determine the potential of these microemboli to occlude smaller blood vessels, the transposed kidney will indicate the percentage of the microemboli lodged in the kidney. These three methods will complement each other in providing useful information concerning the onset of the thromboembolic phenomena and its progress over the time. The contribution of flow and its impact on thromboembolism will be analyzed. Similarly, the proposed quantitation methods may prove ideal in establishing the effectiveness of drug regimen in controlling the thromboembolism. The effect of 2 drugs, heparin and aspirin, will be carefully examined. During the course of this study, a number of hematologic parameters will be monitored to help identify early markers of thrombogenesis in circulating blood. These efforts should help us better understand the process of thrombogenesis, provide clues as to where thrombogenesis is initiated, the role of rheological factors, and the biomaterials, and may help pave the way for elimination of adverse effects by design modifications, improved material surfaces, or appropriate combination of therapeutic agents.