NN&I - June 2010

Vascular Access 32 Nephrology News & Issues June 2010Subscribe to our free eNewsletter at www.nephronline.com Medical Officer Barry Straube, MD, explaining why we believe a surveil-lance requirement is not supported by the best available evidence. Here is an excerpt from that letter: "More than 10 years ago, propos-als were made that access thrombo -sis could be reduced and access life prolonged by surveillance of access blood flow or dialysis venous pres-sure combined with preemptive angioplasty to correct stenosis," we wrote. "This soon became a recom-mendation of the KDOQI [Kidney Disease Outcomes Quality Initiative] Guidelines. Unfortunately, claims of improved outcomes were not based upon randomized controlled trials. Also, claims that surveillance could be used to predict thrombosis were not based upon proper statistical testing, such as receiver operating characteris -tic curves."These deficiencies have resulted in persistent controversy in the neph -rology community and have stimulat -ed much research. Most subsequent randomized trials have not found that surveillance prolongs synthetic graft life or reduces thrombosis. Also, ran-domized trials have not found that surveillance prolongs native fistula life, but there are limited data sup-porting a reduction in thrombosis. Moreover, angioplasty causes an injury that can stimulate progression of stenosis."It is possible that the failure of surveillance to prolong access life in randomized trials has been caused by false positive referrals for angioplasty of stable stenotic lesions. Thus, many nephrologists and researchers in this field consider surveillance with pre -emptive intervention to be an unprov -en therapy that may adversely affect access survival." Our concern about a surveillance requirement is based upon these considerations: 1. Surveillance does not prolong graft or fistula life. 2. Surveillance does not reduce graft thrombosis. There is limited evidence that surveillance may reduce fistula thrombosis, but the proper role of fis-tula surveillance awaits the results of further research. 3. Surveillance leads to many unnec-essary and expensive radiocontrast procedures. 4. Interventions based upon sur -veillance may adversely affect access survival. KDOQI has defined surveillance as measurement of access blood flow, static or derived-static dialysis venous pressure, or duplex ultrasound stud-ies, followed by an intervention pro -cedure if these tests meet certain cri-teria. Thus, surveillance does not refer to any of the other activities involved in maintaining vascular accesses. For example, in flow surveillance of grafts, monthly measurements are taken and if flow is less than 600 ml/min, or if flow decreases by more than 25% and falls below 1,000 ml/min, then the patient is referred for an intervention proce -dure. Thus, surveillance is a knee-jerk response to a measurement rather than a process that considers all available clinical information combined with clinical judgment. To our knowledge, CMS has not yet responded to our "Access Surveillance Statement." Moreover, the surveillance controversy has recently spread be- yond the medical community. Senator Charles E. Schumer, D-N.Y., and U.S. Representative Michael A. Arcuri of New York have encouraged CMS to con-sider promoting the ultrasound dilu-tion device manufactured by Ithaca, N.Y.-based Transonic Systems Inc. for flow surveillance of vascular accesses.4 They are hopeful that the device will save lives and money while creating jobs for New Yorkers.Thus, we believe that it has become more urgent to resolve the surveil-lance controversy. We hope this posi -tion paper promotes a dialogue with- in the nephrology community on the proper role of surveillance. We should emphasize, however, that although a surveillance requirement is not evi-dence-based,3,5-9 there is a consensus that physical examination combined with good clinical judgment is essen -tial to the management of vascular accesses. Unfortunately, regular physi -cal examination of accesses is typically not practiced in most dialysis centers. We would certainly support a strong emphasis by CMS on physical exami -nation of accesses. References1. Medicare and Medicaid Programs: Conditions for Coverage for End-Stage Renal Disease Facilities; Final Rule: Rules and Regulations, Part II, Department of Health and Human Services, Federal Register, vol 73, April 15, 2008 2. Center for Medicaid and State Operations/ Survey & Certification Group: ESRD Interpretive Guidance Update, Oct 3, 20083. Paulson WD, Work J. Controversial vascular access surveillance mandate. Sem Dial 23: 92- 94, 20104. Schumer, Arcuri urge Feds to examine new tech- nology to help save lives of dialysis patients and cut unnecessary costsTechnology is produced by Ithaca-based Transonic Systems and others, March 2, 2010. Web address: http://schumer.senate.gov/new_website/record. cfm?id=322675 5. Allon M. Do we really need periodic monitoring of vascular access for hemodialysis? NephSAP 6: 111-116, 20076. Tonelli M, James M, Wiebe N, Jindal K, Hemmelgarn B. Ultrasound monitoring to detect access stenosis in hemodialysis patients: A systematic review. Am J Kidney Dis 51: 630- 640, 20087. Paulson WD, White JJ. Should arteriovenous fistulas and synthetic grafts undergo surveillance with pre-emptive correction of stenosis? Nature Clin Practice Nephrol 4: 480-481, 2008 8. Ram SJ, Nassar R, Work J, Abreo K, Dossabhoy NR, Paulson WD. Risk of hemodialysis graft throm-bosis: Analysis of monthly flow surveillance. Am J Kidney Dis 52: 930-938, 2008 9. Allon M, Robbin ML: Hemodialysis vascular access monitoring: Current concepts. Hemodialysis Int 13:153-162, 2009 VascAccess_NNI0610_6.indd 32 5/14/10 5:26:53 PM