Medicare Costs Associated With Arteriovenous Fistulas Among US Hemodialysis Patients.

BACKGROUND: An arteriovenous fistula (AVF) is the recommended vascular access for hemodialysis (HD). Previous studies have not examined the resources and costs associated with creating and maintaining AVFs. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: Elderly US Medicare patients initiating hemodialysis therapy during 2010 to 2011. PREDICTOR: AVF primary and secondary patency and nonuse in the first year following AVF creation. OUTCOMES: Annualized vascular access costs per patient per year. RESULTS: Among patients with only a catheter at HD therapy initiation, only 54% of AVFs were successfully used for HD, 10% were used but experienced secondary patency loss within 1 year of creation, and 83% experienced primary patency loss within 1 year of creation. Mean vascular access costs per patient per year in the 2.5 years after AVF creation were $7,871 for AVFs that maintained primary patency in year 1, $13,282 for AVFs that experienced primary patency loss in year 1, $17,808 for AVFs that experienced secondary patency loss in year 1, and $31,630 for AVFs that were not used. Similar patterns were seen among patients with a mature AVF at HD therapy initiation and patients with a catheter and maturing AVF at HD therapy initiation. Overall, in 2013, fee-for-service Medicare paid $2.8 billion for dialysis vascular access-related services, ∼12% of all end-stage renal disease payments. LIMITATIONS: Lack of granularity with certain billing codes. CONCLUSIONS: AVF failure in the first year after creation is common and results in substantially higher health care costs. Compared with patients whose AVFs maintained primary patency, vascular access costs were 2 to 3 times higher for patients whose AVFs experienced primary or secondary patency loss and 4 times higher for patients who never used their AVFs. There is a need to improve AVF outcomes and reduce costs after AVF creation.

Definitions and End Points for Interventional Studies for Arteriovenous Dialysis Access.

This paper is part of the Clinical Trial Endpoints for Dialysis Vascular Access Project of the American Society of Nephrology Kidney Health Initiative. The purpose of this project is to promote research in vascular access by clarifying trial end points which would be best suited to inform decisions in those situations in which supportive clinical data are required. The focus of a portion of the project is directed toward arteriovenous access. There is a potential for interventional studies to be directed toward any of the events that may be associated with an arteriovenous access' evolution throughout its life cycle, which has been divided into five distinct phases. Each one of these has the potential for relatively unique problems. The first three of these correspond to three distinct stages of arteriovenous access development, each one of which has been characterized by objective direct and/or indirect criteria. These are characterized as: stage 1-patent arteriovenous access, stage 2-physiologically mature arteriovenous access, and stage 3-clinically functional arteriovenous access. Once the requirements of a stage 3-clinically functional arteriovenous access have been met, the fourth phase of its life cycle begins. This is the phase of sustained clinical use from which the arteriovenous access may move back and forth between it and the fifth phase, dysfunction. From this phase of its life cycle, the arteriovenous access requires a maintenance procedure to preserve or restore sustained clinical use. Using these definitions, clinical trial end points appropriate to the various phases that characterize the evolution of the arteriovenous access life cycle have been identified. It is anticipated that by using these definitions and potential end points, clinical trials can be designed that more closely correlate with the goals of the intervention and provide appropriate supportive data for clinical, regulatory, and coverage decisions.

Elderly patients with CKD--dilemmas in dialysis therapy and vascular access.

The population of elderly patients with end-stage renal disease (ESRD) is growing rapidly worldwide. The high prevalence of comorbidities, limited life expectancy and complex quality of life issues associated with this population pose substantial challenges for clinicians in terms of clinical decision-making and providing optimal care. The first dilemma encountered in the management of an elderly patient with ESRD is deciding whether to initiate renal replacement therapy and, if so, selecting the most-suitable dialysis modality. Planning vascular access for haemodialysis is associated with additional challenges. Several clinical practice guidelines recommend an arteriovenous fistula, rather than a central venous catheter or arteriovenous graft, as the preferred access for maintenance haemodialysis therapy. However, whether this recommendation is applicable to elderly patients with ESRD and a limited life expectancy is unclear. Selection and planning of the most appropriate vascular access for an elderly patient with ESRD requires careful consideration of several factors and ultimately should lead to an improvement in the patient's quality of life.

Predicting dialysis vascular access blood flow and diameter: too much, too little, or just right.

Arteriovenous fistula (AVF) maturation continues to cause significant morbidity and mortality. Despite the magnitude of the clinical problem, however, there are no effective clinical or biological predictors of AVF success or failure. Caroli et al. describe an innovative technology that may be successful in predicting AVF flow and diameter using standard-of-care preoperative inputs. Pending additional longer-term validation, the use of this technology could help us get the right access into the right patient at the right time.

Understanding surgical preference and practice in hemodialysis vascular access creation.

Understanding healthcare providers' preferences, values, and beliefs around AVF eligibility is important to explain variability in practice. We conducted a survey of international surgeons, using hypothetical patient scenarios, to assess resources used, variables, perceived barriers, and absolute contraindications to access creation. A total of 134 surgeons completed the survey. Venous duplex ultrasound mapping (VDUM) was offered to all patients by 90% of US, 68% Canadian, and 63% European respondents. VDUM altered clinical decision less than 25% of the time for 33% American, 48% Canadian, and 85% European surgeons. Increased comorbidities and previous failed access were deterrents to AVF creation as was vessel size. Second choice access was the AV graft in the US and Europe and the catheter in Canada. Absolute contraindications to AVF creation included patient life expectancy <1 year, left ventricular ejection fraction (LVEF) <15%, and a history of dementia, while 42% surgeons reported no absolute contraindications. Perceived barriers included patient preferences, long wait times for surgery, and late referral to a Nephrologist. Significant variability exists in the surgical preoperative assessment of patients, and the eligibility criteria used for fistula creation. Understanding surgeons' preferences can aid in establishing standardization for VA access eligibility, including surgical assessment.

Education in vascular access.

The successful creation and use of an arteriovenous vascular access (VA) requires a coordinated, educated multidisciplinary team to ensure an optimal VA for each patient. Patient education programs on VA are associated with increased arteriovenous VA use at dialysis initiation. Education should be tailored to patient goals and preferences with the understanding that experiential education from patient to patient is far more influential than that provided by the healthcare professional. VA education for the nephrologist should focus on addressing the systematic and patient-level barriers in achieving a functional VA, with specific components relating to VA creation, maturation, and cannulation that consider patient goals and preferences. A deficit in nursing skills in the area of assessment and cannulation can have devastating consequences for hemodialysis patients. Delivery of an integrated education program increases nurses' knowledge of VA and development of simulation programs or constructs to assist in cannulation of the VA will greatly facilitate the much needed skill transfer. Adequate VA surgical training and experience are critical to the creation and outcomes of VA. Simulations can benefit nephrologists, dialysis nurses surgeons, and interventionalists though aiding in surgical creation, understanding of the physiology and anatomy of a dysfunctional VA, and practicing cannulation techniques. All future educational initiatives must emphasize the importance of multidisciplinary care to attain successful VA outcomes.

Optimal hemodialysis vascular access in the elderly patient.

The optimal vascular access for elderly patients remains a challenge due to the difficulty balancing the benefits and risks in a population with increased comorbidity and decreased survival. Age is commonly associated with failure to mature in fistula and decreased rates of primary and secondary patency in both fistula and grafts. In the elderly, at 1 and 2 years, primary patency rates range from 43% to 74% and from 29% to 67%, respectively. Secondary patency rates at 1 and 2 years range from 56% to 82% and 44% to 67%, respectively. Cumulative fistula survival is no better than grafts survival when primary failures are included. Several observational studies consistently demonstrate a lower adjusted mortality among those using a fistula compared with a catheter; however, catheter use in the elderly is increasing in most countries with the exception of Japan. Both guidelines and quality initiatives do not acknowledge the trade-offs involved in managing the elderly patients with multiple chronic conditions and limited life expectancy or the value that patients place on achieving these outcomes. The framework for choice of vascular access presented in this article considers: (1) likelihood of disease progression before death, (2) patient life expectancy, (3) risks and benefits by vascular access type, and (4) patient preference. Future studies evaluating the timing and type of vascular access with careful assessments of complications, functionality, cost benefit, and patients' preference will provide relevant information to individualize and optimize care to improve morbidity, mortality, and quality of life in the elderly patient.

Who should be referred for a fistula? A survey of nephrologists.

BACKGROUND: There is marked variation in the use of the arteriovenous fistula (AVF) across programmes, regions and countries not explained by differences in patient demographics or comorbidities. The lack of clear criteria of who should or should not get a fistula may contribute to this, as well as barriers to creating AVFs. METHODS: We conducted a survey of Canadian and American nephrologists to assess the patient variables considered to determine the timing and type of access requested. Perceived barriers and absolute contraindications to access were also collected. RESULTS: An immediate referral for a fistula was more highly preferred when patients are <65 years old, have minimal comorbidities or have no history of failed accesses. In older patients, and in those with increased comorbidities or a previously failed fistula, US nephrologists selected arteriovenous grafts as an alternative to the fistula, while Canadian nephrologists selected primarily catheters. Referral for vascular mapping was more common in the USA than in Canada. Gender did not influence the timing or the type of access. Perceived barriers to establishing a mature fistula included patient refusal for creation (77%) or cannulation (58%), delay in decision regarding dialysis modality (71%), wait time for surgical creation (55%) and high failure-to-mature rate (52%). We found that 27% of Canadian and 43% of American nephrologists indicated no absolute contraindications for permanent vascular access. CONCLUSIONS: This study demonstrated marked variability in timing and criteria used to select patients for referral for a vascular access between nephrologists practicing within Canada and the USA. Establishing minimal eligibility criteria for fistulae is an important area of future research.

Vascular stenosis: biology and interventions.

PURPOSE OF REVIEW: The aim of this review will be to summarize recent concepts pertaining to the pathophysiology of dialysis access stenosis and to then use this information to highlight novel interventions (both diagnostic and therapeutic) for dialysis access dysfunction. The studies covered in this review will include experimental and observational studies in addition to clinical trials. RECENT FINDINGS: An important biological focus of this review will be an emphasis on the role of the adventitia and progenitor cells in the pathogenesis of dialysis access dysfunction. The main interventional focus will be on access surveillance, local drug delivery and other novel therapeutic interventions. An important underlying theme throughout this review will be an emphasis on arteriovenous fistulae and on the many advantages of local therapeutic interventions in the specific clinical setting of dialysis access dysfunction. SUMMARY: Vascular access dysfunction remains a significant cause of morbidity and mortality for hemodialysis patients. We believe that a better understanding of the biological mechanisms of vascular access stenosis will help guide the development of novel therapies to prevent and treat dialysis access stenosis.