Diagnosis of Arteriovenous Fistula Dysfunction Tushar J. Vachharajani Nephrology Section, Department of Medicine, W. G. (Bill) Hefner VA Medical Center, Salisbury, North Carolina ABSTRACT Arteriovenous fistula (AVF) dysfunction remains a major con- tributor to the morbidity and mortality of hemodialysis patients. The failure of a newly created AVF to mature and development of stenosis in an established AVF are two com- mon clinical predicaments. The goal is to identify a dysfunc- tional AVF early enough to intervene in a timely manner to either assist with the maturation process or to prevent throm- bosis. The currently available tools in our armamentarium include clinical evaluation, physical examination of the AVF, and surveillance tests. Physical examination has been recog- nized as a simple and cost-effective tool, but is often not imple- mented either because of lack of training or time constraints. Surveillance tests include measurement of access flow or pres- sure as a surrogate marker of AVF dysfunction. Surveillance tests often require expensive equipment, additional personnel, and are controversial. Currently, there are guidelines and rec- ommendations to include all of these measures while evaluat- ing an AVF. Implementing judicious use of these tools in clinical practice can facilitate early diagnosis for timely inter- vention in the appropriate population. Furthermore, this strat- egy may avoid unnecessary interventions and assist with healthcare cost containment. The creation and maintenance of a well-functioning dialysis vascular access remains a major contributor to the morbidity and mortality seen in patients with end- stage renal disease (ESRD) (1–5). The three types of vas- cular access commonly used for maintenance hemodial- ysis are arteriovenous fistula (AVF), arteriovenous graft (AVG), and central venous catheter (CVC). A well-func- tioning AVF has been recognized as a preferred access by the renal community because of its lower incidence of stenosis and thrombosis resulting in prolonged patency rates, lower incidence of infection, and lower overall maintenance costs compared with an AVG (6–10). The Fistula First Breakthrough Initiative (FFBI) established by Centers for Medicare and Medicaid (CMS), the National Kidney Foundation guidelines for Vascular Access, and other major renal societies across the globe recommends AVF as the preferred choice of hemodialy- sis access (11–15). In spite of these recommendations, 82% of ESRD patients in the United States initiate dialysis with a CVC (16). Globally, AVF use for dialysis initiation var- ies between 15% and 83% as reported by the Dialysis Outcomes and Practice Pattern Study (17). The discon- nect between the clinical practice guidelines and the real- ity of successfully creating AVF and early identification of its dysfunction remains a major hurdle in providing optimal vascular access care (5,18). Several factors such as early referral to the nephrologist (19), proper preop- erative strategies (20–22), selecting a skilled surgeon (23,24), adequately training and educating the dialysis staff (25,26), and proper monitoring and surveillance techniques (10) have been shown to improve the overall success of vascular access care. However, the changing demographics of the dialysis population, mainly advanced age and multiple co-morbidities, continue to pose challenges to creating a functioning AVF (27,28). Defining Functional AVF The definition of a functioning access in the literature remains author-dependent and is often controversial, making it difficult to draw concrete conclusions. Recently, the North American Vascular Access Consor- tium has proposed several standardized definitions as relevant to vascular access care (29). In the absence of consensus on standardized definition of a functioning AVF, a broad working definition of a functioning AVF, as accepted by most clinicians, includes repeated success- ful cannulations with two needles to provide adequate dialysis as per the prescribed dialysis prescription. The definition is certainly not enough for scientific reporting, but helps with the three basic clinical needs of an opti- mally functioning access: ease of repeated cannulation, provision of blood flow for adequate dialysis, and mini- mal need for intervention to keep the access patent. The clinical working definition helps with the education and training process of everyone involved in the care of ESRD patients. Multidisciplinary Approach for AVF Care A multidisciplinary vascular team approach is essential for the creation, maintenance, and salvage of a Address correspondence to: Tushar J. Vachharajani, MD, FASN, FACP, Chief, Nephrology Section, W. G. (Bill) Hefner VA Medical Center, 1601 Brenner Avenue, Salisbury, NC 28144, or e-mail: tvachh@gmail.com. Seminars in Dialysis—Vol 25, No 4 (July–August) 2012 pp. 445–450 DOI: 10.1111/j.1525-139X.2012.01094.x Published 2011. This article is a U.S. Government work and it is in the public domain in the USA. DIAGNOSTIC CHALLENGES IN HEMODIALYSIS PATIENTS 445