Resistance to Aortic Endograft Migration: Comparative Effectiveness of FDA Approv

描述(由申请人提供)： 本申请涉及广泛的挑战领域(05)比较有效性研究(CER)和特定挑战主题05-EB-105：医疗植入物的比较有效性。腹主动脉瘤(AAA)在美国人口中的患病率显著增加，60岁以上的美国人中有5%-7%受到影响。在过去的十年中，血管内动脉瘤修复术已成为动脉瘤疾病的主要治疗方法。目前，FDA批准的腹主动脉瘤内移植物有5种：美敦力AneuRx、Gore Excluer、Cook Zenith、Endologix Powerlink和美敦力Talent。每一种装置都有不同的设计和固定机制。血管内修复术是一种微创手术，与开放修补术相比，可降低围手术期的发病率和死亡率。然而，由于血流脉动力的作用，血管内移植物的长期位置稳定性(即移位性)丧失，血管内手术很容易在后期失败。植骨失败会导致昂贵的二次手术、转为开放修复、长期监测和死亡。了解体内移植物所经历的生物力学环境是确保该装置正确功能和长期耐用性的关键因素。这项工作的目标有两个：首先，我们将开发和应用一套工具来表征体内移植物的力学行为，总体目标是确定内移植物迁移的可能性。第二，我们将对5个AAA内移植物的移植进行比较有效性研究。我们将使用3D分割技术来生成植入内移植物的特定于患者的AAA的计算机模型。然后，我们将执行计算流体动力学(CFD)分析，以评估作用在设备上的血液动力。CFD分析将依赖于复杂的边界条件规范方法，以获得内植骨计算机模型中的流量和压力的真实分布。然后，我们将进行计算固体力学(CSM)分析，以评估内植骨在与血管壁的附着区中产生的固定力。对接受每种植骨治疗的患者的连续随访成像的纵向研究将提供必要的统计数据，以获得计算性研究的迁移可能性。我们组建的研究团队由领先的生物工程师、机械工程师、放射科医生和临床医生组成，将由斯坦福大学的Christopher K.Zarins博士领导，他是AAA疾病血管内治疗开发和临床应用的领先研究员。Zarins博士一直大力倡导使用成像和模拟工具来改进医疗设备设计，开发更安全、更有效的医疗产品。这项研究将是首次尝试使用一流的成像、CFD和计算固体力学工具来描述AAA内移植物的迁移问题。此外，这项工作将首次对FDA批准的5种AAA内移植物进行比较有效性研究。抗主动脉内移植物移植物：FDA批准的装置的比较效果。 公共卫生相关性： 腔内修复术已成为腹主动脉瘤(AAA)疾病的主要治疗方法。目前有5个FDA批准的用于AAA修复的植入物。人们对这些设备所经历的真实体内生物力学环境知之甚少。此外，目前还没有研究比较不同设备在长期位置稳定性(迁移)方面的性能。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (05) Comparative Effectiveness Research (CER) and specific Challenge Topic 05-EB-105: Comparative Effectiveness of Medical Implants. The prevalence of abdominal aortic aneurysms (AAA) has increased significantly in the American population, affecting 5-7% of Americans over age 60. During the past decade endovascular aneurysm repair has become the primary treatment for aneurysm disease. Currently, there are 5 FDA approved abdominal aortic aneurysm endografts: Medtronic AneuRx, Gore Excluder, Cook Zenith, Endologix Powerlink, and Medtronic Talent. Each of these devices presents different designs and fixation mechanisms. Endovascular repair is a minimally invasively procedure that reduces perioperative morbidity and mortality when compared to open repairs. However, endovascular procedures are prone to late failure due to the loss of long-term positional stability (i.e., migration) of the endograft as a result of the pulsatile forces of blood flow. Endograft failure results in costly secondary procedures, conversion to open repair, long-term surveillance, and death. Understanding the biomechanical environment experienced by endografts in vivo is a critical factor to ensure correct functioning and long term durability of the device. The goal of this work is two-fold: First, we will develop and apply a set of tools to characterize the mechanical behavior of endografts in vivo with the overall goal of determining the likelihood of migration of the endograft. Second, we will perform a comparative effectiveness study with regards to migration of the 5 AAA endografts. We will use 3D segmentation techniques to generate patient- specific computer models of AAAs with implanted endografts. Then, we will perform Computational Fluid Dynamics (CFD) analyses to evaluate the hemodynamic forces acting on the device. The CFD analysis will rely on sophisticated methods for boundary condition specification to obtain realistic distributions of flow and pressure in the computer model of the endograft. We will then perform a Computational Solid Mechanics (CSM) analysis to evaluate the fixation forces developed by the endograft in the attachment zones with the vessel wall. Longitudinal studies of serial follow-up imaging of patients treated with each endograft will provide the necessary statistical data to obtain a likelihood of migration for the computational studies. The research team we have assembled consists of leading bioengineers, mechanical engineers, radiologists, and clinicians and will be led by Dr Christopher K. Zarins at Stanford, a leading researcher in the development and clinical application of endovascular treatments for AAA disease. Dr. Zarins has been a strong advocate for using imaging and simulation tools to improve medical device design and develop safer and more effective medical products. This research will be the first attempt to characterize the problem of migration of AAA endografts using a combination of best-in-class imaging, CFD and Computational Solid Mechanics tools. Furthermore, this work will provide the first comparative effectiveness study of the 5 current FDA approved AAA endografts. Resistance to aortic endograft migration: comparative effectiveness of FDA approved devices. Public Health Relevance: Endovascular repair has become the primary treatment for abdominal aortic aneurysm (AAA) disease. There are currently 5 FDA approved endograft devices for AAA repair. The true in-vivo biomechanical environment experienced by these devices is poorly understood. Furthermore, there are currently no studies that compare the performance of the different devices with regards to their long term positional stability (migration).