BIOMECHANICAL FACTORS IN ANASTOMOTIC INTIMAL HYPERPLASIA

吻合口内膜增生的生物力学因素

• 批准号: 3358914
• 负责人: CHRISTOPHER K ZARINS
• 金额: $ 23.11万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1993-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3358914
• 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

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.

内膜增厚是正常愈合反应的一个特征 移植物吻合。 然而，在外周动脉移植物中，内膜 远端吻合口增生是造成该病的主要原因 人工血管移植失败。 药理学努力 最大限度地减少小血管吻合中的内膜增生 到目前为止还没有成功。 这种方法并不直接 解决远端普遍存在的生物力学因素 吻合小血管或改变的性质 吻合口处的流场。 相关血流动力学因素 与分支几何形状和机械性能 动脉壁与内膜的定位密切相关 增厚和动脉粥样硬化。 血管吻合影响 通过改变几何形状、壁柔度来实现近壁流动特性 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 内膜增厚或增生对应分布 作用在流体-壁界面处的壁上的剪应力和 主要发生在低剪切和振荡剪切区域 应力，即局部颗粒停留时间增加。 我们 因此建议在狗身上构建血管旁路移植物 在不同吻合几何形状的条件下，流量 条件墙壁特性，例如发生在 接受下肢动脉搭桥手术的患者 评估相关机械和 结构因素对定位和程度的影响 愈合过程中吻合口内膜增厚 过程。 为了实现这一目标，我们将量化空间 使用计算机计算吻合口内膜增厚的分布 辅助三维重建技术和 将这些发现与规模的空间分布相关联 壁面剪切应力与颗粒停留时间关系的模型 几何形状、移植物与动脉顺应性以及 吻合口周围血管的流速分布。 这 预计调查结果将明确和定量地定义， 首次实现肛周吻合口的实际定位 内膜增厚和相应的流场条件， 并确定最佳的生物力学条件 最大限度地减少吻合口内膜增生。