FLOW TURBULENCE INDUCED BY CORONARY STENTS

冠状动脉支架引起的血流湍流

• 批准号: 3899257
• 负责人: M B LEON
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3899257
• 关键词: antithrombogenic surface; atherosclerosis; blood vessel prosthesis; coronary disorder; implant; model design /development; peripheral blood vessel disorder; ultrasound blood flow measurement

Although metallic intravascular stents have been placed in patients with peripheral and coronary artery disease, there are no data describing fluid mechanics changes which would predict for favorable or adverse clinical responses. We have hypothetical concerns that placement of multiple stents (either in tandem or non-tandem fashion) may affect flow and large side-branches especially in the setting of either proximal or distal disease. To define quantitative parameters examining flow turbulence and wall sheer stress across stented endovascular surfaces would be helpful in predicting future design modifications and in anticipating potential adverse anatomic or clinical stent placement variables. Therefore, an in vitro pulse duplicator system was developed which reproduces coronary flow waveforms using a glycerin and water mixture equivalent to blood viscosity as the test fluid. Hot film probes and laser doppler techniques were used to assess turbulence and wall shear stress in these artificially constructed vascular tree models before and after stent implantation. These studies demonstrated that multiple stents and especially disease in a vessel segment proximal to the site of stent placement results in significance flow instability which might correlate with adverse short-term responses, including increase thrombogenicity and deleterious chronic affects such as intimal proliferation which might result in chronic restenosis. Further modeling techniques are being used to expand upon this design concept such that we can make more definite analyses and predictions of flow turbulence after stent implantation.

尽管金属血管内支架已经被放置在患有 外周和冠状动脉疾病，没有数据描述液体 力学变化，这将预测有利或不利的临床 应答我们有一个假设性的担忧， （以串联或非串联方式）可能会影响流量， 侧支，特别是在近端或远端的设置 疾病定义定量参数，检查流动湍流， 穿过支架血管内表面的壁剪切应力将有助于 预测未来的设计修改和预测潜在的 不良解剖学或临床支架置入变量。因此，在 研制了一种体外脉冲复制系统， 使用甘油和水的混合物的波形相当于血液粘度 作为测试流体。采用热膜探头和激光多普勒技术 为了评估湍流和壁面剪切应力， 构建支架植入前后的血管树模型。这些 研究表明，多个支架，特别是疾病， 支架置入部位近端的血管节段导致 显著流动不稳定性，可能与不利的短期 反应，包括增加血栓形成和有害的慢性 影响，如内膜增生，这可能导致慢性 再狭窄进一步的建模技术正在被用来扩展这一点 设计概念，以便我们可以做出更明确的分析和预测 支架植入后的流动湍流。