Technology helps put the AVF in a new light
Fifteen years ago, CMS launched the Fistula First Breakthrough Initiative to encourage greater use of the arteriovenous fistula among patients with end-stage renal disease. The natural anastomosis created by using the vein and the artery was considered the “gold standard” in nephrology care – both in the United States and abroad – for its longevity, superior delivery of high blood flows and fewer infections compared to the use of the synthetic arteriovenous graft and the central venous catheter.
At the time, the number of patients in the United States on dialysis with an AVF was around 32% — lower than the 60% to 90% used in other countries. CMS set a goal for dialysis providers: 40% of patients should have a working fistula. By 2009, the renal community achieved that goal ahead of the deadline, and CMS took it to the next level with a goal of 66%. The National Kidney Foundation developed practice guidelines in 2006 that encouraged greater use of fistulas and CMS developed the Quality Incentive Program that penalized clinics if they did not reach certain performance scores indicating that prevalent patients were using AVFs.
Successes and failures
While most dialysis clinics reached 60% AVF use by 2011, studies were noting a significant variation across the country in successes and failures.
“AVF performances differ vastly in geographically contiguous networks,” Lynch and colleagues wrote. in the Journal of Vascular Surgery after examining fistula placement in more than 4,000 dialysis facilities from January 2007 to April 2010. “AVF use was lower in facilities with higher percentages of women, patients with peripheral vascular disease starting hemodialysis and with older populations.”
The authors likewise made a pitch for careful decision- making over AVF use. “Finally, it needs to be emphasized that ‘fistula first’ does not mean ‘fistula only.’ Patients with poor likelihood of maturation of a fistula; or a life expectancy, may be better candidates for a graft.”1
That notation was made in 2011. If there is such a thing as a 7-year itch in vascular access literature, we are hearing much the same in 2018. This month’s Cover Story asks CMS to recognize that avoiding placement of an AVF in a patient is not showing indifference about quality; it means there may be better choices. Lee and colleagues looked at the likely success rate of an AVF placed in elderly patients.2 Thamer and colleagues looked at the costs of AVFs when they do not mature compared to other access options.3 “Permanent AVF failure within the first year after surgical creation is reported to occur in up to 40% of patients and can result in prolonged [central venous catheter] dependence and subsequent morbidity, as well as the need for additional access surgery,” they wrote.
Help on the way
The increased use of AVFs – an almost doubling since 2003 – has lead to a high rate of failures and ultimately undermines the value of the access, as Thamer and colleagues noted. Is there a way to make the AVF itself a better product? At least three companies are suggesting there is, two with recent FDA approval to launch new products.
- Avenu Medical, a venture capital funded group focused on medical devices, recently received FDA approval for its Ellipsys Vascular Access System. The device uses a catheter inserted into a blood vessel in the arm and is guided to the site of the planned AV fistula. The devices then deliver energy to form a connection between an upper forearm artery and an adjacent vein.
- The everlinQ endoAVF System, which will be marketed by TVA Medical Inc., uses two 6Fr magnetic catheters and a radiofrequency energy generator to create a consistent, hemodynamic fistula.
- Earlier this year, Fresenius Medical Care announced it would invest $150 million in the company Humacyte, which is working on a new bioengineered fistula.
These devices still rely on the basic approach of access via the fistula – a natural bridge for connecting artery and vein to allow dialysis to take place. Without an access, there is no treatment.
- 1. Lynch JR, et al. Jrnl of Vas Surg, 2011;doi:10.1016/j.jvs.2011.04.014.
- 2. Lee T, et al. Am J Kidney Dis. 2018;doi:10.1053/j.ajkd.2018.03.023.
- 3. Thamer M, et al. Am Kidney Dis.2018;doi:10.1053/j.ajkd.2018.01.034.
- For more information
- Mark E. Neumann is Editor-in-Chief of Nephrology News & Issues.