QUANTIFICATION OF FACTORS LEADING TO VEIN GRAFT FAILURE

描述：各种形式的干预措施失败的最常见原因 在循环的动脉和静脉一侧是肌内膜 增生症。它代表了血管壁对损伤的反应。 损伤是一种复杂的现象，涉及内皮和光滑 媒体的肌肉。当启动时，平滑的肌肉生长与 基质的沉积导致血管变窄，这可能会在 极端情况下，会导致血栓形成和失败。 最常见的部位发生在外周动脉 已放置旁路的隐静脉移植物中有循环。 遮挡区域。这种情况的发生率在20%-40%之间。这个 这项建议的目的是开发灵敏的定量方法 移植物监测，目的是在手术失败之前发现病变 管道的发生和干预何时将保留长期的功能 移植物。 该提案旨在开发和评估能够 用于生成三维模型，以及高分辨率 病变本身的图像。此外，通过使用高 分辨率超声，建议测试内膜-中膜的作用 静脉移植物在防止血管平滑肌增殖方面的作用。 目标人群将是那些接受过隐匿术的患者 静脉移植以及谁可以在第一次手术中频繁地随访 一年，这是这些问题发展的时间。每次来访， 泥石流的流速、几何及三维重建研究 将进行静脉移植。对于所有检测到的损伤，其 进展/倒退将通过这些技术进行监控。干预 只有当移植物内的病变导致发展时才会这样做 压力梯度或症状重现。此外，还有可能 监测流入动脉和流出动脉的动脉硬化状态 评估其在移植物功能和预后中的作用。 这是第一项旨在提供这方面的自然历史数据的研究。 损伤，这是动脉系统衰竭的常见原因。

DESCRIPTION: The most common cause of failure of all forms of intervention on the arterial and venous side of the circulation is myointimal hyperplasia. It represents the response of the vascular wall to injury. The injury is a complex phenomenon involving the endothelium and smooth muscle of the media. when initiated, smooth muscle growth along with the deposition of matrix leads to narrowing of the vessel, which may in the extreme case, lead to thrombosis and failure. The most common site for this to occur in the peripheral arterial circulation is in saphenous vein grafts that have been placed to bypass areas of occlusion. The incidence of this is in the range of 20-40%. the purpose of this proposal is to develop sensitive quantitative methods for graft surveillance with the goal of detecting lesions before failure of the conduit occurs and when intervention will preserve the long-term function of the graft. The proposal is designed to develop and evaluate ultrasonic methods that can be used to generate three dimensional models, as well as high resolution images of the lesions themselves. In addition, by the use of high resolution ultrasound, it is proposed to test the role of the intima-media of the vein graft in preventing proliferation of the smooth muscle. The target population will be those patients who have undergone saphenous vein grafting and who can be followed at frequent intervals during the first year, which is the time in which these problems develop. At each visit, studies of flow velocity, geometry and three dimensional reconstruction of the vein graft will be carried out. for all detected lesions, their progression/regression will be monitored by these techniques. Intervention will only be done when the lesions within the graft lead to the development of a pressure gradient or symptoms return. In addition, it will be possible to monitor the status of atherosclerosis in the inflow and outflow arteries to assess its role in graft function and outcome. This is the first study designed to provide natural history data on this lesion, which is such a common cause of failure in the arterial system.