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BIOMECHANICAL FACTORS IN ANASTOMOTIC INTIMAL HYPERPLASIA

吻合口内膜增生的生物力学因素

基本信息

批准号：
3358918
负责人：
SEYMOUR GLAGOV
金额：
$ 25.11万
依托单位：
UNIVERSITY OF CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-07-01 至 1994-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3358918
关键词：
atherosclerosis biomaterial interface interaction biomechanics blood vessel prosthesis blood vessels dogs hemodynamics heterodyning hyperplasia imaging /visualization /scanning mechanical stress oscillatory blood flow physical model surgical wound wound healing

项目摘要

Intimal thickening is a feature of the normal healing response at graft anastomoses. Yet, in grafts to peripheral arteries, intimal hyperplasia at the distal anastomosis is the major cause of prosthetic vascular graft failure. Pharmacologic efforts to minimize intimal hyperplasia in small vessel anastomoses have thus far been unsuccesful. This approach does not directly address the biomechanical factors which prevail at distal anastomoses to small vessels or the nature of the changes in the flow field at anastomotic sites. Hemodynamic factors associated with branch geometry and with the mechanical properties of the artery wall correlate closely with the localization of intimal thickening and atherosclerosis. Vascular anastomoses affect near-wall flow properties by altering geometry, wall compliance and motion, and flow velocities about the anastomotic junction. It is our working hypothesis that the distribution of anastomotic intimal thickening or hyperplasia corresponds to the distribution of shear stress acting on the wall at the fluid-wall interface and occurs principally in regions of lowered and oscillartory shear stress, i.e., where local particle residence time is increased. We therefore propose to construct vascular bypass grafts in dogs under conditions of differing anastomotic geometry, flow conditions an wall characteristics such as those which occur in patients undergoing lower extremity arterial bypass surgery and to assess the effects of the associated mechanical and configurational factors on the localization and degree of anastomotic intimal thickening during the course of the healing process. To accomplish this we will quantify the spatial distribution of anastomotic intimal thickening using computer- assisted three dimensional reconstruction techniques and correlate these findings with the spatial distribution in scale models of wall shear stress and particle residence time in relation to geometry, to graft versus artery compliance and to the distribution of flow velocities in the perianastomatic vessels. The findings would be expected to define clearly and quantitatively, for the first time, the actual localization of perianastomotic intimal thickening and the corresponding flow field conditions, and to identify the optimal biomechanical conditions for minimizing anastomotic intimal hyperplasia.

动脉内膜增厚是正常愈合反应的一个特征移植物吻合。然而，在移植到外周动脉时，内膜吻合口远端的增生是主要原因。人造血管移植失败。药理学上的努力最大限度地减少小血管吻合口内膜增生到目前为止，这一举措并不成功。这种方法不会直接解决在远端占优势的生物力学因素小血管的吻合术或血管内病变的性质吻合口的流场。与血流动力学相关的因素具有树枝几何形状，并具有动脉壁与血管内膜的定位密切相关增厚和动脉粥样硬化。血管吻合影响改变几何形状、壁面顺应性的近壁流动特性以及吻合口周围的运动和流速。我们的工作假设是吻合口的分布血管内膜增厚或增生的分布与作用在流体-壁界面处的壁上的剪应力主要发生在低切变和振荡切变区域应力，即局部颗粒停留时间增加的情况。我们因此建议在犬体内建立血管搭桥术。在不同吻合口几何条件下，血流调整墙特征，例如出现在接受下肢动脉搭桥术的患者以评估相关机械和机械设备的效果构型因素对本土化程度的影响愈合过程中吻合口内膜增厚进程。为了实现这一点，我们将量化空间用计算机检测吻合口内膜增厚的分布辅助三维重建技术和将这些发现与尺度上的空间分布联系起来壁面剪应力与颗粒滞留时间的关系模型到几何学，移植物对动脉顺应性和吻合口周围血管的血流速度分布。这个预计调查结果将明确和定量地定义，第一次对吻合口周围的实际定位血管内膜增厚和相应的流场条件，并确定最佳的生物力学条件最大限度减少吻合口内膜增生。