NN&I - April 2010
Vascular Accesswww.nephronline.comApril 2010 Nephrology News & Issues 39 and Canada, every country partic -ipating in the international Dialysis Outcomes and Practice Patters Study (DOPPS)including all of western Europe, Japan, Australia, and New Zealandhas a prevalent AVF rate greater than 66%.1 After evaluating the evidence, the workgroup for the NKF-KDOQI vascular access guidelines rec- ommended a prevalent AVF rate of > 65%.2 During the 2009 American Society of Nephrology (ASN) Renal Week, the FFBI presented a poster3 which demonstrated the proportion of facilities with 66% or more of their patients using an AVF increased from 6.2% (during January 2007) to 12.7% (during March 2009). There is significant unexplained geographic variation in the proportion of treatment facilities attaining a 66% AVF rate in March 2009, varying by ESRD Network from a low of 6.2% to a high of 40.8% of facilities. This suggests that best practices for AVF placement and maintenance have been exported within regions and can potentially be exported between regions. The NKF-KDOQI vascular access guidelines acknowledge that about 10% of prevalent HD patients can be expected to have long-term catheters, including those who have exhausted permanent vascular access sites and those who are not medical or surgi-cal candidates for permanent vascular access placement. Perhaps 15% to 20% of HD patients will not have suitable vessels for AVF creation and, despite the "AVF only" change concept, will undergo placement of an arteriovenous graft (AVG). This leaves room for only 4% to 9% of patients in the remaining category, namely incident HD patients with catheters who are waiting for per -manent vascular access placement or maturation. As of December 2008, 52% of prevalent HD patients had an AVF, 7% had a catheter with an AVF matur -ing, and 7% had a catheter less than 90 days. With better pre-ESRD AVF place-ment, the 66% prevalent AVF goal could readily be achieved (see Myth No. 5). Myth No. 3: The Fistula First program has caused dialysis catheter prevalence to rise Fact: This is clearly not supported by the evidence presented in another FFBI poster at the 2009 ASN Renal Week,4 which showed that despite an increase in the prevalent AVF rate from 45.2% in Jan. 2007 to 52.2% in March 2009, the catheter > 90 days rate decreased from 12% to 10.9%, the catheter <90 days rate decreased from 6.9% to 5.9%, the cath-eter with AVF rate decreased from 7.8% to 7.5%, and the catheter with AVG rate decreased from 2.2% to 1.9%. Between July 2003 and November 2009, as the prevalent AVF rate has increased from 32.2% to 54.4%, the prevalent catheter rate has decreased from 26.9% to 24.4% (see Figure 1). Myth No. 4: The Fistula First program has resulted in many unnecessary surgeries in patients who shouldn't receive fistulas Fact: This is the most controversial of the myths and its credibility depends upon whether one is examining indi -viduals or populations. A cornerstone of medical practice is that evidence is based on populations, not individuals. For example, if an individual dies of a complication of an influenza vaccine which saves thousands of lives, it is unfortunate but it does not mean the deceased individual should not have received the vaccine. The 2006 NKF-KDOQI vascular access guidelines state that "a 70% AV 'working' fistula access rate can be achieved, even in patients who have diabetes and are women." Did the other 30% undergo unnecessary surgery? Not if it were not known in advance that 30% would fail, as all patients deserve a chance at a working AVF. Some authors have proposed a risk stratification system weighing patients' age, race, and presence of cardiovas-cular disease and peripheral vascular disease. The FFBI leadership applied the formula proposed by Lok et al.5 to 346,291 new start HD patients from July 2005 to December 2008. Using the Lok formula along with patient demo -graphic and comorbidity data from the 2728 Medical Evidence Report, 66% of these patients are categorized as low to moderate risk for AVF failure. However, the risk score did not predict which patients actually started dialysis with an AVF: 13.8% of low risk patients, 13.3% of moderate risk patients, 13.2% of high risk patients, and 11.4% of very high risk patients started HD with an Table 2. Original change concepts for increasing AV fistulas Change Concept 1: Routine CQI review of vascular access Change Concept 2: Timely referral to nephrologist Change Concept 3: Early referral to surgeon for "AVF only" evaluation and timely placement Change Concept 4: Surgeon selec-tion based on best outcomes, willingness, and ability to provide access services Change Concept 5: Full range of surgical approaches to AV fistula evaluation and placement Change Concept 6: Secondary AV fistula placement in patients with AV grafts Change Concept 7: AV fistula place-ment in patients with catheters where indicated Change Concept 8: AV fistula can-nulation training Change Concept 9: Monitoring and maintenance to ensure adequate access function Change Concept 10: Education for caregivers and patients Change Concept 11: Outcomes feedback to guide practice VascAccess_NNI0410_5.indd 39 3/18/10 5:20:10 PM
You must have JavaScript enabled to view digital editions.
