Surveillance priorities and outcomes for Veterans treated with endovascular abdominal aortic aneurysm repair

背景：每年有8,000多名退伍军人接受腹主动脉瘤（AAA）修复术。近 70%的患者接受腹主动脉瘤腔内修复术（EVAR）治疗，其中使用覆膜支架 来加固受损的主动脉大多数国家指南和监管指令要求每年终身 腹主动脉瘤腔内修复术后的监测成像，通常通过每年一次的对比增强CT扫描提供。监控 成像评估血液围绕支架流入主动脉，称为“内漏”。虽然大多数 内漏是无害的，1-3%是高压“I型”内漏，其导致破裂并需要修复。 然而，可能会达到这样一个点，即持续的年度监测成像可能不是最佳选择， 腹主动脉瘤腔内修复术后的老年退伍军人。成像相关风险包括使用造影剂导致的急性肾损伤 在CT扫描期间（3-10%），识别不需要治疗的无害内漏（10-20%），以及 偶然发现，如肺或肾结节，引发进一步的侵入性测试或治疗（10-15%）。 我们在这个项目中的科学原理集中在更好地理解知识的一个关键差距：权衡 成像相关风险和识别危险形式内漏的机会（1-3%）之间的关系可能是 困难，特别是对于患有多种合并症的老年退伍军人。 意义：围绕何时停止监视的证据缺口对退伍军人尤为重要， 比非退伍军人腹主动脉瘤腔内修复术人群更虚弱、老年和农村。我们估计， 退伍军人目前还活着，腹主动脉瘤腔内修复术已就位。这意味着将有超过10，000次扫描 根据我们的初步队列集会，每年进行，500多名退伍军人将有 肾毒性等并发症。因为它影响了我们最古老的退伍军人中的慢性疾病， 研究与HRD&D主题类别“慢性病管理”和HSR&D保持一致 具体优先领域“长期护理和老龄化”。 创新和影响：缺乏指导方针来帮助退伍军人和他们的临床医生决定何时 监视成像应该发生，当它的效用可能受到限制。发展和传播这一 证据将带来一种创新方法，限制老年人不必要的检测和伤害 老兵 具体目标：我们提出了一个具有两个具体目标的混合方法研究。目标1将定性评估 退伍军人，家庭和医疗保健团队成员对监视成像的态度和信念， EVAR。目标2将定量描述观测数据源，以了解监视成像 腹主动脉瘤腔内修复术后结局。我们的传播计划将整合这些发现，为何时 监视成像应继续下去，并在其效用可能有限的情况下继续下去。我们假设成像 相关的风险可能超过对老年退伍军人进行持续监测的益处， 合并症。 方法：我们的研究设计利用了一种平行的方法：对利益相关者的信念进行定性评估 关于停止成像监测（目标1）和对回顾性临床数据进行定量分析， 评估影像监测的使用、结果和风险（目标2）。 下一步/实施：我们的项目涉及来自VA的国家VA等组织的领导人 外科咨询委员会，血管外科学会，一个全国公认的基于网络的论坛， 老年护理和其他组织，以确保有效传播我们的证据。证据 在我们的建议中产生的将使用创新的途径，如播客，以确保我们的项目的共享 可交付成果和影响得以持续。

Background: More than 8,000 Veterans undergo abdominal aortic aneurysm (AAA) repair each year. Nearly 70% are treated with endovascular abdominal aortic aneurysm repair (EVAR), where a covered stent is used to reinforce the weakened aorta. Most national guidelines and regulatory directives mandate annual life-long surveillance imaging after EVAR, typically provided via a once-yearly contrast-enhanced CT scan. Surveillance imaging evaluates for blood flowing around the stent into the aorta, called an “endoleak”. While most endoleaks are harmless, 1-3% are high-pressure “Type I” endoleaks, which lead to rupture and require repair. However, a point may be reached where continued annual surveillance imaging may not be the best choice for elderly Veterans after EVAR. Imaging-associated risks include acute kidney injury from contrast dye used during the CT scan (3-10%), the identification of harmless endoleaks which require no treatment (10-20%), and incidental findings such as lung or kidney nodules which trigger further invasive testing or treatment (10-15%). Our scientific rationale in this project centers on better understanding a key gap in knowledge: the tradeoffs between imaging-associated risks and the chance of identifying a dangerous form of endoleak (1-3%) can be difficult, especially for aging Veterans with multiple co-morbidities. Significance: This evidence gap surrounding when to stop surveillance is especially important for Veterans, who are more frail, elderly, and rural than non-Veteran EVAR populations. We estimate that more than 10,000 Veterans are currently alive with an EVAR in place. This suggests that more than 10,000 scans will be performed each year based on our preliminary cohort assembly, and more than 500 Veterans will have complications such as nephrotoxicity. Because it affects a chronic condition among our oldest Veterans, our study is aligned with the HRD&D Topic Category “Management of Chronic Conditions” and the HSR&D Specific Priority Area “Long-term Care and Aging”. Innovation and Impact: There is an absence of guidelines to help Veterans and their clinicians decide when surveillance imaging should occur, and when its utility may be limited. Developing and disseminating this evidence would bring an innovative approach towards limiting unnecessary testing and harms among elderly Veterans. Specific Aims: We propose a mixed-methods study with two Specific Aims. Aim 1 will qualitatively assess Veteran, family, and health care team members’ attitudes and beliefs surrounding surveillance imaging after EVAR. Aim 2 will quantitatively characterize observational data sources to understand surveillance imaging outcomes after EVAR. Our Dissemination Plan will integrate these findings to create evidence for when surveillance imaging should continue, and when it may have limited utility. We hypothesize that imaging associated risks may outweigh the benefits of ongoing surveillance in older Veterans with significant comorbidities. Methodology: Our study design leverages a parallel approach: qualitative assessment of stakeholder beliefs about cessation of imaging surveillance (Aim 1) and quantitative analysis of retrospective clinical data to evaluate the use, outcomes, and risks of imaging surveillance (Aim 2). Next Steps/Implementation: Our project involves leaders from organizations such as the VA’s national VA Surgery Advisory Board, the Society for Vascular Surgery, a nationally recognized web-based forum for geriatric care, and other organizations to ensure effective dissemination of our evidence. The evidence generated in our proposal will be shared using innovative pathways, such as podcasts, to ensure our project’s deliverables and impact are sustained.