Choice of vascular access and patient outcomes among older hemodialysis patients

 描述（由申请人提供）：Allon博士对透析血管通路有着长期的研究兴趣，在过去15年中发表了100多篇同行评议的出版物，并获得了NIH关于该主题的几项赠款。他的短期目标是提高我们对接受动静脉内瘘（AVF）和移植物（AVG）的患者的临床结局的理解。他的长期目标是开发新的方法来改善这些临床结果。大约80%的美国ESRD患者开始使用中心静脉导管（CVC）进行血液透析（HD）。一旦开始HD，患者将被转诊给外科医生，以创建永久性血管通路，AVF或AVG。目前的共识指南强烈建议放置AVF，而不是AVG。然而，几项小型观察性研究表明，AVG可能是老年HD患者中比AVF更好的选择，因为AVF失败率更高，患者生存期相对较短。主要入路失败导致CVC依赖性延长，伴随并发症，直到放置另一个功能正常的血管入路并适合HD。我们假设，在使用CVC开始HD的老年HD患者中，放置AVG而不是AVF将导致CVC依赖性缩短、CRB发作减少、住院次数减少和患者生存期延长。我们提出了一项回顾性队列研究，重点关注年龄>65岁的新发ESRD患者，这些患者开始使用CVC进行HD，没有二级血管通路（AVF或AVG），并且在开始HD后6个月内接受了后续AVF或AVG。我们将比较2个患者队列（AVF vs. AVG）的主要入路失败率、入路置入后CVC依赖的持续时间、CRB频率、感染相关住院和全因住院的频率以及总患者生存率。本观察性研究的结果将用于B：（1）提供关于开始HD后接受AVF与AVG的老年HD患者的临床结局的有价值信息;（2）提供设计和执行本研究人群中AVF与AVG的确定性随机临床试验的把握度分析所需的可靠信息。

 DESCRIPTION (provided by applicant): Dr. Allon has had a long-standing research interest in vascular access for dialysis, culminating in over 100 peer-reviewed publications during the past 15 years, as well as several funded NIH grants on this topic. His short-term goal is to improve our understanding of the clinical outcomes of patients receiving arteriovenous fistulas (AVF) and grafts (AVG). His long-term goal is to develop novel approaches to improve these clinical outcomes. Approximately 80% of U.S. ESRD patients initiate hemodialysis (HD) with a central vein catheter (CVC). Once HD has been started the patient is referred to a surgeon for creation of a permanent vascular access, either an AVF or an AVG. The current consensus guidelines strongly recommend placing an AVF, rather than an AVG. However, several small observational studies have suggested that AVG may be a better choice than an AVF in elderly HD patients, due to the higher AVF failure rate and relatively short patient survival. Primary access failure leads to prolonged CVC-dependence, with its attendant complications, until another functioning vascular access is placed and suitable for HD. We hypothesize that in older HD patients who initiate HD with a CVC, placement of an AVG rather than an AVF will result in shorter CVC-dependence, fewer episodes of CRB, fewer hospitalizations and longer patient survival. We propose a retrospective cohort study focused on new ESRD patients age >65 years who initiate HD with a CVC and no secondary vascular access (AVF or AVG), and who receive a subsequent AVF or AVG within 6 months of initiating HD. We will compare the 2 patient cohorts (AVF vs. AVG) in terms of primary access failure rate, duration of CVC-dependence after access placement, frequency of CRB, frequency of infection-related hospitalization and all cause hospitalization, and overall patient survival. The results of this observational study will b used to (1) provide valuable information about clinical outcomes in elderly HD patients receiving an AVF vs. an AVG after initiation of HD, and (2) provide robust information necessary to design and perform a power analysis for a definitive randomized clinical trial of AVF vs AVG in this study population.