REVIEW URRENT C OPINION
Strategies for planning the optimal dialysis access for an individual patient David A. Drew a and Charmaine E. Lok b
Purpose of review Achieving functioning vascular access in hemodialysis patients remains challenging. Current guidelines recommend creating arteriovenous fistulas (AVFs) as the initial form of vascular access and are primarily based on outdated, observational data. Determining the optimal access for each individual patient is, therefore, of great interest. Recent findings Multiple recent studies suggest that certain subgroups of patients may benefit from alternative forms of vascular access. In particular, the elderly and patients with limited life-expectancy may be less likely to benefit from an AVF first approach. These patients may be more likely to die before benefiting from an AVF and are more likely to experience primary failure of an AVF. If these factors are considered, arteriovenous grafts, and in some cases central venous catheters, become a valid alternative form of vascular access. Patients may also have strong opinions about each type of vascular access, leading to a preference for alternative forms of access. Summary A patient-centered approach to the choice of dialysis access that incorporates a balance between recent evidence from the literature and patient preferences may be preferred to the current fistula first focus in vascular access choice. Keywords arteriovenous fistula, arteriovenous graft, elderly, patient-centered, vascular access
INTRODUCTION Access planning for end-stage renal disease (ESRD) patients continues to be challenging. Current recommendations push for the creation of arteriovenous fistulas (AVFs) in most, if not all, patients starting hemodialysis. In contrast, patient-centered care, with a focus on individual patient preferences, is increasingly the goal of appropriate medical care. The inherent tension that can sometimes exist between practice guidelines and individualized patient care increases the need for well-designed studies assessing important clinical outcomes. In the case of hemodialysis vascular access, this means exploring how patient preferences, co-existing medical conditions, social and support situations, and the competing risk of mortality or change in renal replacement modality intersect with the type of dialysis access. This review attempts to describe the potential strategies for choosing the optimum dialysis access in an individual patient. For the last decade, the Fistula First Breakthrough Initiative [1] has largely been successful www.co-nephrolhypertens.com
in increasing the number of prevalent hemodialysis patients receiving dialysis via an AVF. This recommendation is based on the data showing lower rates of infection, cost, and mortality in comparison to central venous catheters (CVCs), and, to a lesser degree, in comparison to arteriovenous grafts. To incentivize higher AVF rates, the Centers for Medicare and Medicaid Services will soon financially penalize dialysis centers that do not meet the set benchmark rates for AVF use [2]. Underlying these recommendations is a body of evidence based largely on now outdated, observational studies, potentially making findings susceptible to selection a
Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, Massachusetts, USA and bDivision of Nephrology, Department of Medicine, Toronto General Hospital, Toronto, Ontario, Canada Correspondence to Dr Charmaine E. Lok, MD, MSc, 8N-844, 200 Elizabeth Street, Toronto, ON, Canada M5G-2C4. Tel: +1 416 340 4140; e-mail: [email protected] Curr Opin Nephrol Hypertens 2014, 23:314–320 DOI:10.1097/01.mnh.0000444815.49755.d9 Volume 23 Number 3 May 2014
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Planning for the optimal dialysis access Drew and Lok
KEY POINTS
appropriate referral of these patients to surgeons for vascular access assessment and creation.
Many, if not all, professional nephrology societies currently recommend an arteriovenous fistula as the first and preferred form of hemodialysis vascular access.
Recommendations
Elderly patients and patients with significant comorbidity may derive less benefit from the creation of an arteriovenous fistula because of both high mortality and low fistula patency. Consideration of the individual patient and their preferences regarding dialysis and vascular access, both before and after dialysis initiation, may be important in improving patient satisfaction and clinical outcomes.
or indication bias and not applicable to the currentday dialysis patients and practices. In an attempt to provide a more informed view, recent additional attention has been paid to how patient characteristics and preferences may affect the choice of dialysis access; in this review, we will focus specifically on hemodialysis vascular access. In addition, we will identify several key factors that a dialysis patient and provider should keep in mind while navigating from predialysis vascular access planning to maintenance dialysis.
Current recommendations encourage prompt referral of patients with established CKD to nephrologists. Early access planning forms the basis of much of these recommendations, as it is hoped that such referrals may increase the number of patients that initiate hemodialysis with a functioning AVF. Internationally, many professional societies and organizations have issued guidelines explicitly promoting the use of an AVF as the first form of hemodialysis access (Table 1).
Evidence Although there is apparent agreement on the choice of the AVF as the preferred form of access, this recommendation is not based on the top-level evidence. No randomized trials have been conducted comparing vascular access choices, and evidence suggests that patient heterogeneity may have a substantial impact on vascular access outcomes. Proper planning, therefore, requires consideration of each individual patient. Evidence suggests that older age may lead to the consideration of an alternative to an AVF [8 ]. Older patients with kidney disease have a significantly higher mortality rate compared with younger patients. Importantly, this trend continues across the spectrum of older ages, with patients of age 90 and above having one quarter the median lifeexpectancy of those aged 65–69 years [9]. This &&
REFERRAL FOR VASCULAR ACCESS Timely referral for hemodialysis vascular access creation first requires awareness of chronic kidney disease (CKD) by primary care providers and appropriate referral to nephrologists, followed by the Table 1. Current international vascular access guidelines Organization
Country
Recommendation
National Kidney Foundation Kidney Disease Outcomes Quality Initiative
United States
‘Options for fistula placement should be considered first, followed by prosthetic grafts if fistula placement is not possible. Catheters should be avoided for HD and used only when other options listed are not available’ [3]
Canadian Society of Nephrology
Canada
‘Establish AV fistulae when the patient has an estimated GFR of 15 to 20 ml/min and progressive kidney disease’ [4].
The Renal Association
United Kingdom
‘We recommend that any individual who commences haemodialysis should do so with an arteriovenous fistula as first choice, an arteriovenous graft as second choice, a tunnelled venous catheter as third choice and a nontunnelled catheter as an option of necessity’ [5].
National Health and Medical Research Council
Australia
‘The AV fistula is the haemodialysis vascular access of first choice’ [6].
Japanese Society for Dialysis Therapy
Japan
‘The first (vascular access) choice is an AVF’ [7].
AVF, arteriovenous fistula; AV, arteriovenous; GFR, glomerular filtration rate; HD, hemodialysis. Adapted with permission [3–7]. Adaptations are themselves works protected by copyright. In order to publish this adaptation, authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation.
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Epidemiology and prevention
finding alone has several important implications for the referral for vascular access. First, elderly patients who have an AVF placed prior to reaching ESRD have a high likelihood of dying prior to initiating dialysis [10], negating any potential benefit from an AVF. Complicating the picture is the inherent difficulty in accurately predicting the time frame until start of renal replacement therapy. Estimation of kidney function may be more difficult in the elderly and the rates of decline may be slower [11,12], both of which may increase the chance of mortality prior to start of dialysis. At the other extreme are pediatric patients who may have renal limited causes of ESRD and are not otherwise burdened with any comorbidity. In such cases, they may have a high likelihood of receiving a kidney transplant before needing to use their AVF, highlighting the need for individualized consideration in vascular access choice [13].
looking at the first access placed, essentially an intention-to-treat analysis, the authors provide a better comparison between AVFs and arteriovenous grafts. Stratifying by age, those with AVFs had marginally improved survival for the 67–79 year age group, but not for patients 80 and above. A reasonable conclusion from this study, echoed by others [15], is that arteriovenous grafts may be an option for patients 80 and above. Finally, patient preference and choice regarding dialysis modality impacts the type of dialysis access and should be considered prior to referring for vascular access creation. Patients who are independent and have an active lifestyle may choose to pursue peritoneal dialysis. Similarly, peritoneal dialysis may be the modality of choice for patients who cannot tolerate large hemodynamic shifts or those with unfavorable vascular anatomy (e.g. substantial central vein stenosis).
Patient preference
ACCESS CREATION
Patient preferences are also important when deciding to refer for AVF creation. A recent study showed that elderly patients who have an AVF placed prior to ESRD appear more likely to forgo or delay dialysis [14 ]. In this analysis, patients 85 years old and older were nearly half as likely to start dialysis when compared to those 54 years old and younger, even after considering the competing risk of death. In these particular cases, patients underwent a surgical procedure, with the potential for complications, sometimes referred to as an ‘unnecessary procedure’. One interpretation of this study is that elderly patients could benefit from earlier discussion of the potential benefits and risks of forgoing AVF surgery, particularly if there is hesitation about starting hemodialysis. In an elderly patient with advanced CKD with multiple comorbidities, it may be reasonable to take a ‘watch-and-wait’ approach. If dialysis becomes necessary and is desired by such a patient, an arteriovenous graft, with a shorter maturation time and higher likelihood of primary patency, may be the preferred choice. Additionally, elderly patients are at high risk of death once they have begun hemodialysis, resulting in less time on dialysis and less potential to benefit from the placement of an AVF. A recent study by DeSilva et al. [8 ] explores this possibility using the United States Renal Data System (USRDS) database linked to Medicare claims data. When examining the risk for mortality associated with the first reported access placed, they found no difference between AVFs and arteriovenous grafts, in contrast to a higher risk for mortality in the CVC group. By
Once a decision has been made to create an arteriovenous access, individual patient factors can determine whether a certain type of access will be successful.
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Recommendations The 2006 National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines recommend creation of an AVF with a distal-toproximal anatomical approach, prior to consideration of other forms of vascular access [3].
Evidence The rationale for the above guideline recommended approach emphasizes the preservation of access sites to allow for future sites should the prior one fail. However, the evidence for such an approach varies based on several factors, including patient age, sex, ethnicity, comorbidities such as diabetes, vessel characteristics, surgical experience, and a patient’s life and clinical circumstances. In older patients, preservation of future sites may be less important than achieving a quickly usable access that allows for dialysis without access complications to ensure quality of the remaining life. Older age has a strong influence on the probability that an AVF will mature, with those in the 65 and over age group experiencing more than twice the risk of failure compared with younger patients [16]. In a similar study, older age, particular those older than 85, was associated with a 25% lower odds of having a mature AVF at the start of hemodialysis Volume 23 Number 3 May 2014
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[17]. The site of AVF creation and its probability for success may also be modified by age; in one metaanalysis, older patients were more likely to experience maturation failure in proximal AVFs [18], perhaps because of poorer vessel quality. Female sex has also been associated with lower rates of AVF use and AVF failure [17,19]. It is currently unknown whether this association is because of presurgical anatomic differences (such as smaller vein caliber), postsurgical differences in maturation, or selection bias. Vascular disease and its risk factors have also been shown to be associated with AVF failure [16]. Diabetes, because of its impact on vascular health, has also been thought to modify the probability of successful AVF maturation. A recent decision analysis explored how age, sex, and diabetes status modify the impact of vascular access type on subsequent mortality [20]. For younger patients (under 60 years old), an AVF attempt strategy yielded consistently superior survival. For patients over 60, the results were more complex. Older male, nondiabetic patients had similar results to younger patients and did best with an AVF attempt strategy. However, for men with diabetes, and for women with or without diabetes (all scenarios where AVF success may be less likely), the difference in survival between AVF and arteriovenous graft strategies was minimal. Anatomical and functional differences in blood vessels also influence the chance of AVF creation success. Favorable vascular anatomy, defined by blood vessel size and responsiveness and determined by duplex ultrasound, has been associated with improved AVF primary patency [21–23]. The presence of stenosis and thrombosis, either peripherally or centrally, may significantly modify the chance vascular access success [24]. The presence of either small vessels or existing disease (e.g. arteriosclerosis) may also compel a surgeon or provider to recommend an arteriovenous graft as an alternative [24]. Additional consideration should be taken if a patient has experienced prior access failure. In addition to compromising or altering the existing vascular anatomy, prior access failure may be more likely to be associated with other risk factors for access failure, described above [25]. In these cases, a careful review of the current vascular anatomy will be necessary to determine what type of access has a reasonable likelihood of success.
Patient preference A high risk of maturation failure in some patients may lead them to suffer from ‘surgical fatigue’ – a desire to avoid the repeated procedures that are
sometimes necessary to obtain and maintain fistula patency [26]. For elderly dialysis patients, who may have a short life-expectancy anyway, an arteriovenous graft, with a higher rate of primary patency, may be the preferred access type [27 ]. Additionally, for some patients, the desire to avoid cannulation with needles may be strong, leading to a request for a long-term CVC [26,28]. Young patients on hemodialysis, who are expected to be on dialysis for years or are awaiting a kidney transplant, should be strongly encouraged to avoid catheter use. With elderly patients who are not transplant candidates, have serious comorbid conditions or are palliative, and who are strongly opposed to needle cannulation, tunneled catheter use may be considered, as long as a discussion on the risks of catheter use and informed consent for its use has occurred [15,29]. &&
LONG-TERM USE The long-term use of one or more vascular access types must consider their associated short and long term risks and benefits.
Recommendations Ultimately, the most important vascular access goal for all hemodialysis patients is an uncomplicated, stable form of useable vascular access to achieve the prescribed dialysis. On the basis of a high rate of infectious and noninfectious complications, CVCs are consistently recommended as the least preferred option for long-term access [3].
Evidence Comparing AVFs and arteriovenous grafts, recent studies have questioned whether there is a true difference in the long-term patency between these two access types. By looking at the time from access creation until permanent failure, several studies have compared AVF and arteriovenous graft cumulative patency, finding similar access survival durations until complete failure [25,30 ,31,32]. AVFs appear to have twice the primary failure rate of arteriovenous grafts, which explains the similar cumulative patency times. Several factors may create a false impression of AVF superiority. First, nephrologists and surgeon preferences may influence who is referred for AVF creation, in selecting those who are most likely to have a successful AVF. Second, although AVFs may require fewer overall interventions, as shown, the primary failure rate can be much higher than with arteriovenous grafts. Patients with primary AVF failure are also likely to be dependent on catheters for much of the time
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Epidemiology and prevention
before or after an AVF fails, in contrast to the arteriovenous grafts that require less time to mature and are less likely to experience primary failure [8 ,31]. However, when an uncomplicated functional fistula can be quickly achieved to provide prescribed dialysis, then, indeed, it is an ideal access. The finding that AVF rates differ between countries, regions, and even individual centers [33,34] demonstrates that improvement in functional fistula rates is possible. As individual patient characteristics, including age, sex, and comorbidity, as well as vessel size and quality, may influence the chance of fistula failure, preoperative screening and planning may improve the primary maturation rates [35]. Furthermore, once a patient has been referred for AVF creation, the skill of the surgeon has been demonstrated in several studies to be a good marker of subsequent function [36–38]. Finally, once an AVF has been placed, the type of subsequent interventions [39 ] and routine monitoring [40] may be helpful in maintaining a working fistula. &&
&
Patient preference Patient preferences regarding long-term access use are similar to those mentioned as part of initial
vascular access creation. Some patients may wish to avoid repeated interventions or routine cannulation, leading them to choose alternative access types [28]. If young patients with few comorbid diseases bring up these concerns, discussion should occur about the benefits of AVFs for long-term use.
OVERALL STRATEGY On the basis of the available literature, we would recommend the following approach to determining the appropriate vascular access in an individual approach (Fig. 1). First, assess the dialysis needs of the patient; is hemodialysis needed currently or is it needed in the future? Second, assess the anticipated life-expectancy of the patient; age and comorbidity will factor heavily into this determination. If survival is expected to be poor, an AVF may not be the optimal access for either current or future hemodialysis. A patient may benefit more from either a watch-and-wait approach (if there is no current need for hemodialysis), an arteriovenous graft, or, in select cases, from a CVC. Finally, if the patient has a reasonable life-expectancy, an assessment should be made as to whether an AVF
Need for hemodialysis
Current
Future
Likelihood of long-term survival Consider age, comorbidity
Likelihood of long-term survival Consider age, comorbidity
Poor
Good
Good
Consider AV graft, CVC if strong patient preference
Assess for AV fistula Consider age, comorbidity, site, prior access failure and vessel suitability
Poor AVF candidate
Good AVF candidate
Consider alternative access: AV graft +/– secondary AV fistula
Proceed with AV fistula creation
Poor Watch and wait approach Consider AV graft if HD needed, CVC if strong patient preference
FIGURE 1. Flow diagram for choosing vascular access in an individual patient. AVF, arteriovenous fistula; AV, arteriovenous; CVC, central venous catheter; HD, hemodialysis. 318
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Planning for the optimal dialysis access Drew and Lok
can be successfully created. Factors which can lead to AVF failure such as age, comorbidity, vessel size and quality, access location, and a history of prior access failure should be considered. Those patients with a reasonable chance of AVF success (i.e. with few negative factors) should be referred for AVF creation. In patients with a high probability of primary fistula failure, consideration should be given to alternative approaches such as arteriovenous graft placement.
CONCLUSION The goal for every nephrologist and surgeon should be helping to achieve the right access for the right patient at the right time. In order to do so, the patient’s clinical and life circumstances, comorbidities, likelihood of access success, and their preferences should be considered. Overall, the AVF remains the access of choice for many patients on hemodialysis. However, multiple studies currently suggest that certain subgroups of patients may benefit from alternative forms of vascular access. In particular, the elderly and patients with limited life-expectancy may be less likely to benefit from an AVF for all approaches. When the nephrologist or surgeon is challenged by the discordance between policy and new evidence as it applies to an individual patient, the decision about the optimal access for a truly informed patient can often be elucidated by asking the patient their preference. Acknowledgements Funding was provided by the American Society of Nephrology Fellowship Grant to D.A.D. Conflicts of interest There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. Fistula first breakthrough initiative. 2013. www.fistulafirst.org. [Accessed 2 December 2013]. 2. Medicare program; end-stage renal disease prospective payment system and quality incentive program; ambulance fee schedule; durable medical equipment; and competitive acquisition of certain durable medical equipment prosthetics, orthotics and supplies. Final rule. Fed Regist 2011; 76:70228–70316. 3. NKF/KDOQI. Clinical practice guidelines for vascular access. Am J Kidney Dis 2006; 48 (Suppl. 1):S176–S247. 4. Vascular access for haemodialysis. The Renal Association; 2011. http:// www.renal.org/clinical/guidelinessection/vascularaccess.aspx#Summary1. [Accessed 25 November 2013]. 5. Commencing haemodialysis with appropriate vascular access. National Institute of Clinical Studies; 2005. http://www.nhmrc.gov.au/_files_nhmrc/file/ nics/material_resources/haemodialysis_vascular_access.pdf. [Accessed 25 November 2013]. 6. Ohira S, Naito H, Amano I, et al. 2005 Japanese Society for Dialysis Therapy guidelines for vascular access construction and repair for chronic hemodialysis. Ther Apher Dial 2006; 10:449–462.
7. Culleton BF. Vascular access – Canadian Society of Nephrology. J Am Soc Nephrol 2006; 17 (3 Suppl 1):S1–S3. 8. DeSilva RN, Patibandla BK, Vin Y, et al. Fistula first is not always the best && strategy for the elderly. J Am Soc Nephrol 2013; 24:1297–1304. Using USRDS data, this study demonstrates that mortality does not differ by access type in older adults. 9. Tamura MK, Tan JC, O’Hare AM. Optimizing renal replacement therapy in older adults: a framework for making individualized decisions. Kidney Int 2011; 82:261–269. 10. O’Hare AM, Choi AI, Bertenthal D, et al. Age affects outcomes in chronic kidney disease. J Am Soc Nephrol 2007; 18:2758–2765. 11. Glassock RJ, Rule AD. The implications of anatomical and functional changes of the aging kidney: with an emphasis on the glomeruli. Kidney Int 2012; 82:270–277. 12. Eriksen BO, Ingebretsen OC. The progression of chronic kidney disease: a 10-year population-based study of the effects of gender and age. Kidney Int 2006; 69:375–382. 13. Chand D, Valentini R, Kamil E. Hemodialysis vascular access options in pediatrics: considerations for patients and practitioners. Pediatr Nephrol 2009; 24:1121–1128. 14. Oliver MJ, Quinn RR, Garg AX, et al. Likelihood of starting dialysis after & incident fistula creation. Clin J Am Soc Nephrol 2012; 7:466–471. In focusing on patient preferences, this study highlights that many older patients with kidney disease may delay or forgo dialysis, potentially impacting the vascular access choice. 15. Vachharajani TJ. Dialysis vascular access selection in elderly patients. European Nephrol 2011; 5:152–154. 16. Lok CE, Allon M, Moist L, et al. Risk equation determining unsuccessful cannulation events and failure to maturation in arteriovenous fistulas (REDUCE FTM I). J Am Soc Nephrol 2006; 17:3204–3212. 17. Lilly MP, Lynch JR, Wish JB, et al. Prevalence of arteriovenous fistulas in incident hemodialysis patients: correlation with patient factors that may be associated with maturation failure. Am J Kidney Dis 2012; 59:541–549. 18. Lazarides MK, Georgiadis GS, Antoniou GA, Staramos DN. A meta-analysis of dialysis access outcome in elderly patients. J Vasc Surg 2007; 45:420.e2 – 426.e2. 19. Peterson WJ, Barker J, Allon M. Disparities in fistula maturation persist despite preoperative vascular mapping. Clin J Am Soc Nephrol 2008; 3:437–441. 20. Drew DA, Cohen J, Tangri N, et al. Vascular access choice in incident hemodialysis patients: a decision analysis. Kidney Week 2012. San Diego, CA: American Society of Nephrology; 2013. 21. Allon M, Lockhart ME, Lilly RZ, et al. Effect of preoperative sonographic mapping on vascular access outcomes in hemodialysis patients. Kidney Int 2001; 60:2013–2020. 22. Robbin ML, Chamberlain NE, Lockhart ME, et al. Hemodialysis arteriovenous fistula maturity: U.S. evaluation. Radiology 2002; 225:59–64. 23. Malovrh M. Approach to patients with end-stage renal disease who need an arteriovenous fistula. Nephrol Dial Transplant 2003; 18 (Suppl. 5):v50–v52. 24. Sidawy AN, Spergel LM, Besarab A, et al. The Society for Vascular Surgery: clinical practice guidelines for the surgical placement and maintenance of arteriovenous hemodialysis access. J Vasc Surg 2008; 48 (5 Suppl.):S2– S25. 25. Lee T, Ullah A, Allon M, et al. Decreased cumulative access survival in arteriovenous fistulas requiring interventions to promote maturation. Clin J Am Soc Nephrol 2011; 6:575–581. 26. Chaudhry M, Bhola C, Joarder M, et al. Seeing eye to eye: the key to reducing catheter use. J Vasc Access 2011; 12:120–126. 27. O’Hare AM. Vascular access for hemodialysis in older adults: a ‘patient first’ && approach. J Am Soc Nephrol 2013; 24:1187–1190. This editorial comprehensively discusses the ways in which elderly dialysis patients may benefit less from arteriovenous fistulas when compared with younger patients. 28. Xi W, Harwood L, Diamant MJ, et al. Patient attitudes towards the arteriovenous fistula: a qualitative study on vascular access decision making. Nephrol Dial Transplant 2011; 26:3302–3308. 29. Rehman R, Schmidt RJ, Moss AH. Ethical and legal obligation to avoid longterm tunneled catheter access. Clin J Am Soc Nephrol 2009; 4:456– 460. 30. Lok CE, Sontrop JM, Tomlinson G, et al. Cumulative patency of contemporary && fistulas versus grafts (2000–2010). Clin J Am Soc Nephrol 2013; 8:810– 818. Current data are used to compare the cumulative patency of arteriovenous fistulas versus arteriovenous grafts, showing little difference between the two types of vascular access. 31. Lee T, Barker J, Allon M. Comparison of survival of upper arm arteriovenous fistulas and grafts after failed forearm fistula. J Am Soc Nephrol 2007; 18:1936–1941. 32. Disbrow DE, Cull DL, Carsten CG 3rd, et al. Comparison of arteriovenous fistulas and arteriovenous grafts in patients with favorable vascular anatomy and equivalent access to healthcare: is a reappraisal of the fistula first initiative indicated? J Am Coll Surg 2013; 216:679–685. 33. Allon M, Ornt DB, Schwab SJ, et al. Factors associated with the prevalence of arteriovenous fistulas in hemodialysis patients in the HEMO Study. Kidney Int 2000; 58:2178–2185.
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Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Epidemiology and prevention 34. Pisoni RL, Arrington CJ, Albert JM, et al. Facility hemodialysis vascular access use and mortality in countries participating in DOPPS: an instrumental variable analysis. Am J Kidney Dis 2009; 53:475–491. 35. Allon M, Robbin ML. Increasing arteriovenous fistulas in hemodialysis patients: problems and solutions. Kidney Int 2002; 62:1109–1124. 36. Goodkin DA, Pisoni RL, Locatelli F, et al. Hemodialysis vascular access training and practices are key to improved access outcomes. Am J Kidney Dis 2010; 56:1032–1042. 37. Prischl FC, Kirchgatterer A, Brandsta¨tter E, et al. Parameters of prognostic relevance to the patency of vascular access in hemodialysis patients. J Am Soc Nephrol 1995; 6:1613–1618.
320
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38. Saran R, Elder SJ, Goodkin DA, et al. Enhanced training in vascular access creation predicts arteriovenous fistula placement and patency in hemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study. Ann Surg 2008; 247:885–891. 39. Lee T, Tindni A, Roy-Chaudhury P. Improved cumulative survival in fistulas & requiring surgical interventions to promote fistula maturation compared with endovascular interventions. Semin Dial 2013; 26:85–89. This study finds that surgical intervention is superior to endovascular techniques for aiding arteriovenous fistula maturation. 40. Allon M, Robbin ML. Hemodialysis vascular access monitoring: current concepts. Hemodial Int 2009; 13:153–162.
Volume 23 Number 3 May 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Strategies for planning the optimal dialysis access for an individual patient David A. Drew a and Charmaine E. Lok b
Purpose of review Achieving functioning vascular access in hemodialysis patients remains challenging. Current guidelines recommend creating arteriovenous fistulas (AVFs) as the initial form of vascular access and are primarily based on outdated, observational data. Determining the optimal access for each individual patient is, therefore, of great interest. Recent findings Multiple recent studies suggest that certain subgroups of patients may benefit from alternative forms of vascular access. In particular, the elderly and patients with limited life-expectancy may be less likely to benefit from an AVF first approach. These patients may be more likely to die before benefiting from an AVF and are more likely to experience primary failure of an AVF. If these factors are considered, arteriovenous grafts, and in some cases central venous catheters, become a valid alternative form of vascular access. Patients may also have strong opinions about each type of vascular access, leading to a preference for alternative forms of access. Summary A patient-centered approach to the choice of dialysis access that incorporates a balance between recent evidence from the literature and patient preferences may be preferred to the current fistula first focus in vascular access choice. Keywords arteriovenous fistula, arteriovenous graft, elderly, patient-centered, vascular access
INTRODUCTION Access planning for end-stage renal disease (ESRD) patients continues to be challenging. Current recommendations push for the creation of arteriovenous fistulas (AVFs) in most, if not all, patients starting hemodialysis. In contrast, patient-centered care, with a focus on individual patient preferences, is increasingly the goal of appropriate medical care. The inherent tension that can sometimes exist between practice guidelines and individualized patient care increases the need for well-designed studies assessing important clinical outcomes. In the case of hemodialysis vascular access, this means exploring how patient preferences, co-existing medical conditions, social and support situations, and the competing risk of mortality or change in renal replacement modality intersect with the type of dialysis access. This review attempts to describe the potential strategies for choosing the optimum dialysis access in an individual patient. For the last decade, the Fistula First Breakthrough Initiative [1] has largely been successful www.co-nephrolhypertens.com
in increasing the number of prevalent hemodialysis patients receiving dialysis via an AVF. This recommendation is based on the data showing lower rates of infection, cost, and mortality in comparison to central venous catheters (CVCs), and, to a lesser degree, in comparison to arteriovenous grafts. To incentivize higher AVF rates, the Centers for Medicare and Medicaid Services will soon financially penalize dialysis centers that do not meet the set benchmark rates for AVF use [2]. Underlying these recommendations is a body of evidence based largely on now outdated, observational studies, potentially making findings susceptible to selection a
Division of Nephrology, Department of Medicine, Tufts Medical Center, Boston, Massachusetts, USA and bDivision of Nephrology, Department of Medicine, Toronto General Hospital, Toronto, Ontario, Canada Correspondence to Dr Charmaine E. Lok, MD, MSc, 8N-844, 200 Elizabeth Street, Toronto, ON, Canada M5G-2C4. Tel: +1 416 340 4140; e-mail: [email protected] Curr Opin Nephrol Hypertens 2014, 23:314–320 DOI:10.1097/01.mnh.0000444815.49755.d9 Volume 23 Number 3 May 2014
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Planning for the optimal dialysis access Drew and Lok
KEY POINTS
appropriate referral of these patients to surgeons for vascular access assessment and creation.
Many, if not all, professional nephrology societies currently recommend an arteriovenous fistula as the first and preferred form of hemodialysis vascular access.
Recommendations
Elderly patients and patients with significant comorbidity may derive less benefit from the creation of an arteriovenous fistula because of both high mortality and low fistula patency. Consideration of the individual patient and their preferences regarding dialysis and vascular access, both before and after dialysis initiation, may be important in improving patient satisfaction and clinical outcomes.
or indication bias and not applicable to the currentday dialysis patients and practices. In an attempt to provide a more informed view, recent additional attention has been paid to how patient characteristics and preferences may affect the choice of dialysis access; in this review, we will focus specifically on hemodialysis vascular access. In addition, we will identify several key factors that a dialysis patient and provider should keep in mind while navigating from predialysis vascular access planning to maintenance dialysis.
Current recommendations encourage prompt referral of patients with established CKD to nephrologists. Early access planning forms the basis of much of these recommendations, as it is hoped that such referrals may increase the number of patients that initiate hemodialysis with a functioning AVF. Internationally, many professional societies and organizations have issued guidelines explicitly promoting the use of an AVF as the first form of hemodialysis access (Table 1).
Evidence Although there is apparent agreement on the choice of the AVF as the preferred form of access, this recommendation is not based on the top-level evidence. No randomized trials have been conducted comparing vascular access choices, and evidence suggests that patient heterogeneity may have a substantial impact on vascular access outcomes. Proper planning, therefore, requires consideration of each individual patient. Evidence suggests that older age may lead to the consideration of an alternative to an AVF [8 ]. Older patients with kidney disease have a significantly higher mortality rate compared with younger patients. Importantly, this trend continues across the spectrum of older ages, with patients of age 90 and above having one quarter the median lifeexpectancy of those aged 65–69 years [9]. This &&
REFERRAL FOR VASCULAR ACCESS Timely referral for hemodialysis vascular access creation first requires awareness of chronic kidney disease (CKD) by primary care providers and appropriate referral to nephrologists, followed by the Table 1. Current international vascular access guidelines Organization
Country
Recommendation
National Kidney Foundation Kidney Disease Outcomes Quality Initiative
United States
‘Options for fistula placement should be considered first, followed by prosthetic grafts if fistula placement is not possible. Catheters should be avoided for HD and used only when other options listed are not available’ [3]
Canadian Society of Nephrology
Canada
‘Establish AV fistulae when the patient has an estimated GFR of 15 to 20 ml/min and progressive kidney disease’ [4].
The Renal Association
United Kingdom
‘We recommend that any individual who commences haemodialysis should do so with an arteriovenous fistula as first choice, an arteriovenous graft as second choice, a tunnelled venous catheter as third choice and a nontunnelled catheter as an option of necessity’ [5].
National Health and Medical Research Council
Australia
‘The AV fistula is the haemodialysis vascular access of first choice’ [6].
Japanese Society for Dialysis Therapy
Japan
‘The first (vascular access) choice is an AVF’ [7].
AVF, arteriovenous fistula; AV, arteriovenous; GFR, glomerular filtration rate; HD, hemodialysis. Adapted with permission [3–7]. Adaptations are themselves works protected by copyright. In order to publish this adaptation, authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation.
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finding alone has several important implications for the referral for vascular access. First, elderly patients who have an AVF placed prior to reaching ESRD have a high likelihood of dying prior to initiating dialysis [10], negating any potential benefit from an AVF. Complicating the picture is the inherent difficulty in accurately predicting the time frame until start of renal replacement therapy. Estimation of kidney function may be more difficult in the elderly and the rates of decline may be slower [11,12], both of which may increase the chance of mortality prior to start of dialysis. At the other extreme are pediatric patients who may have renal limited causes of ESRD and are not otherwise burdened with any comorbidity. In such cases, they may have a high likelihood of receiving a kidney transplant before needing to use their AVF, highlighting the need for individualized consideration in vascular access choice [13].
looking at the first access placed, essentially an intention-to-treat analysis, the authors provide a better comparison between AVFs and arteriovenous grafts. Stratifying by age, those with AVFs had marginally improved survival for the 67–79 year age group, but not for patients 80 and above. A reasonable conclusion from this study, echoed by others [15], is that arteriovenous grafts may be an option for patients 80 and above. Finally, patient preference and choice regarding dialysis modality impacts the type of dialysis access and should be considered prior to referring for vascular access creation. Patients who are independent and have an active lifestyle may choose to pursue peritoneal dialysis. Similarly, peritoneal dialysis may be the modality of choice for patients who cannot tolerate large hemodynamic shifts or those with unfavorable vascular anatomy (e.g. substantial central vein stenosis).
Patient preference
ACCESS CREATION
Patient preferences are also important when deciding to refer for AVF creation. A recent study showed that elderly patients who have an AVF placed prior to ESRD appear more likely to forgo or delay dialysis [14 ]. In this analysis, patients 85 years old and older were nearly half as likely to start dialysis when compared to those 54 years old and younger, even after considering the competing risk of death. In these particular cases, patients underwent a surgical procedure, with the potential for complications, sometimes referred to as an ‘unnecessary procedure’. One interpretation of this study is that elderly patients could benefit from earlier discussion of the potential benefits and risks of forgoing AVF surgery, particularly if there is hesitation about starting hemodialysis. In an elderly patient with advanced CKD with multiple comorbidities, it may be reasonable to take a ‘watch-and-wait’ approach. If dialysis becomes necessary and is desired by such a patient, an arteriovenous graft, with a shorter maturation time and higher likelihood of primary patency, may be the preferred choice. Additionally, elderly patients are at high risk of death once they have begun hemodialysis, resulting in less time on dialysis and less potential to benefit from the placement of an AVF. A recent study by DeSilva et al. [8 ] explores this possibility using the United States Renal Data System (USRDS) database linked to Medicare claims data. When examining the risk for mortality associated with the first reported access placed, they found no difference between AVFs and arteriovenous grafts, in contrast to a higher risk for mortality in the CVC group. By
Once a decision has been made to create an arteriovenous access, individual patient factors can determine whether a certain type of access will be successful.
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Recommendations The 2006 National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines recommend creation of an AVF with a distal-toproximal anatomical approach, prior to consideration of other forms of vascular access [3].
Evidence The rationale for the above guideline recommended approach emphasizes the preservation of access sites to allow for future sites should the prior one fail. However, the evidence for such an approach varies based on several factors, including patient age, sex, ethnicity, comorbidities such as diabetes, vessel characteristics, surgical experience, and a patient’s life and clinical circumstances. In older patients, preservation of future sites may be less important than achieving a quickly usable access that allows for dialysis without access complications to ensure quality of the remaining life. Older age has a strong influence on the probability that an AVF will mature, with those in the 65 and over age group experiencing more than twice the risk of failure compared with younger patients [16]. In a similar study, older age, particular those older than 85, was associated with a 25% lower odds of having a mature AVF at the start of hemodialysis Volume 23 Number 3 May 2014
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Planning for the optimal dialysis access Drew and Lok
[17]. The site of AVF creation and its probability for success may also be modified by age; in one metaanalysis, older patients were more likely to experience maturation failure in proximal AVFs [18], perhaps because of poorer vessel quality. Female sex has also been associated with lower rates of AVF use and AVF failure [17,19]. It is currently unknown whether this association is because of presurgical anatomic differences (such as smaller vein caliber), postsurgical differences in maturation, or selection bias. Vascular disease and its risk factors have also been shown to be associated with AVF failure [16]. Diabetes, because of its impact on vascular health, has also been thought to modify the probability of successful AVF maturation. A recent decision analysis explored how age, sex, and diabetes status modify the impact of vascular access type on subsequent mortality [20]. For younger patients (under 60 years old), an AVF attempt strategy yielded consistently superior survival. For patients over 60, the results were more complex. Older male, nondiabetic patients had similar results to younger patients and did best with an AVF attempt strategy. However, for men with diabetes, and for women with or without diabetes (all scenarios where AVF success may be less likely), the difference in survival between AVF and arteriovenous graft strategies was minimal. Anatomical and functional differences in blood vessels also influence the chance of AVF creation success. Favorable vascular anatomy, defined by blood vessel size and responsiveness and determined by duplex ultrasound, has been associated with improved AVF primary patency [21–23]. The presence of stenosis and thrombosis, either peripherally or centrally, may significantly modify the chance vascular access success [24]. The presence of either small vessels or existing disease (e.g. arteriosclerosis) may also compel a surgeon or provider to recommend an arteriovenous graft as an alternative [24]. Additional consideration should be taken if a patient has experienced prior access failure. In addition to compromising or altering the existing vascular anatomy, prior access failure may be more likely to be associated with other risk factors for access failure, described above [25]. In these cases, a careful review of the current vascular anatomy will be necessary to determine what type of access has a reasonable likelihood of success.
Patient preference A high risk of maturation failure in some patients may lead them to suffer from ‘surgical fatigue’ – a desire to avoid the repeated procedures that are
sometimes necessary to obtain and maintain fistula patency [26]. For elderly dialysis patients, who may have a short life-expectancy anyway, an arteriovenous graft, with a higher rate of primary patency, may be the preferred access type [27 ]. Additionally, for some patients, the desire to avoid cannulation with needles may be strong, leading to a request for a long-term CVC [26,28]. Young patients on hemodialysis, who are expected to be on dialysis for years or are awaiting a kidney transplant, should be strongly encouraged to avoid catheter use. With elderly patients who are not transplant candidates, have serious comorbid conditions or are palliative, and who are strongly opposed to needle cannulation, tunneled catheter use may be considered, as long as a discussion on the risks of catheter use and informed consent for its use has occurred [15,29]. &&
LONG-TERM USE The long-term use of one or more vascular access types must consider their associated short and long term risks and benefits.
Recommendations Ultimately, the most important vascular access goal for all hemodialysis patients is an uncomplicated, stable form of useable vascular access to achieve the prescribed dialysis. On the basis of a high rate of infectious and noninfectious complications, CVCs are consistently recommended as the least preferred option for long-term access [3].
Evidence Comparing AVFs and arteriovenous grafts, recent studies have questioned whether there is a true difference in the long-term patency between these two access types. By looking at the time from access creation until permanent failure, several studies have compared AVF and arteriovenous graft cumulative patency, finding similar access survival durations until complete failure [25,30 ,31,32]. AVFs appear to have twice the primary failure rate of arteriovenous grafts, which explains the similar cumulative patency times. Several factors may create a false impression of AVF superiority. First, nephrologists and surgeon preferences may influence who is referred for AVF creation, in selecting those who are most likely to have a successful AVF. Second, although AVFs may require fewer overall interventions, as shown, the primary failure rate can be much higher than with arteriovenous grafts. Patients with primary AVF failure are also likely to be dependent on catheters for much of the time
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Epidemiology and prevention
before or after an AVF fails, in contrast to the arteriovenous grafts that require less time to mature and are less likely to experience primary failure [8 ,31]. However, when an uncomplicated functional fistula can be quickly achieved to provide prescribed dialysis, then, indeed, it is an ideal access. The finding that AVF rates differ between countries, regions, and even individual centers [33,34] demonstrates that improvement in functional fistula rates is possible. As individual patient characteristics, including age, sex, and comorbidity, as well as vessel size and quality, may influence the chance of fistula failure, preoperative screening and planning may improve the primary maturation rates [35]. Furthermore, once a patient has been referred for AVF creation, the skill of the surgeon has been demonstrated in several studies to be a good marker of subsequent function [36–38]. Finally, once an AVF has been placed, the type of subsequent interventions [39 ] and routine monitoring [40] may be helpful in maintaining a working fistula. &&
&
Patient preference Patient preferences regarding long-term access use are similar to those mentioned as part of initial
vascular access creation. Some patients may wish to avoid repeated interventions or routine cannulation, leading them to choose alternative access types [28]. If young patients with few comorbid diseases bring up these concerns, discussion should occur about the benefits of AVFs for long-term use.
OVERALL STRATEGY On the basis of the available literature, we would recommend the following approach to determining the appropriate vascular access in an individual approach (Fig. 1). First, assess the dialysis needs of the patient; is hemodialysis needed currently or is it needed in the future? Second, assess the anticipated life-expectancy of the patient; age and comorbidity will factor heavily into this determination. If survival is expected to be poor, an AVF may not be the optimal access for either current or future hemodialysis. A patient may benefit more from either a watch-and-wait approach (if there is no current need for hemodialysis), an arteriovenous graft, or, in select cases, from a CVC. Finally, if the patient has a reasonable life-expectancy, an assessment should be made as to whether an AVF
Need for hemodialysis
Current
Future
Likelihood of long-term survival Consider age, comorbidity
Likelihood of long-term survival Consider age, comorbidity
Poor
Good
Good
Consider AV graft, CVC if strong patient preference
Assess for AV fistula Consider age, comorbidity, site, prior access failure and vessel suitability
Poor AVF candidate
Good AVF candidate
Consider alternative access: AV graft +/– secondary AV fistula
Proceed with AV fistula creation
Poor Watch and wait approach Consider AV graft if HD needed, CVC if strong patient preference
FIGURE 1. Flow diagram for choosing vascular access in an individual patient. AVF, arteriovenous fistula; AV, arteriovenous; CVC, central venous catheter; HD, hemodialysis. 318
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Planning for the optimal dialysis access Drew and Lok
can be successfully created. Factors which can lead to AVF failure such as age, comorbidity, vessel size and quality, access location, and a history of prior access failure should be considered. Those patients with a reasonable chance of AVF success (i.e. with few negative factors) should be referred for AVF creation. In patients with a high probability of primary fistula failure, consideration should be given to alternative approaches such as arteriovenous graft placement.
CONCLUSION The goal for every nephrologist and surgeon should be helping to achieve the right access for the right patient at the right time. In order to do so, the patient’s clinical and life circumstances, comorbidities, likelihood of access success, and their preferences should be considered. Overall, the AVF remains the access of choice for many patients on hemodialysis. However, multiple studies currently suggest that certain subgroups of patients may benefit from alternative forms of vascular access. In particular, the elderly and patients with limited life-expectancy may be less likely to benefit from an AVF for all approaches. When the nephrologist or surgeon is challenged by the discordance between policy and new evidence as it applies to an individual patient, the decision about the optimal access for a truly informed patient can often be elucidated by asking the patient their preference. Acknowledgements Funding was provided by the American Society of Nephrology Fellowship Grant to D.A.D. Conflicts of interest There are no conflicts of interest.
REFERENCES AND RECOMMENDED READING Papers of particular interest, published within the annual period of review, have been highlighted as: & of special interest && of outstanding interest 1. Fistula first breakthrough initiative. 2013. www.fistulafirst.org. [Accessed 2 December 2013]. 2. Medicare program; end-stage renal disease prospective payment system and quality incentive program; ambulance fee schedule; durable medical equipment; and competitive acquisition of certain durable medical equipment prosthetics, orthotics and supplies. Final rule. Fed Regist 2011; 76:70228–70316. 3. NKF/KDOQI. Clinical practice guidelines for vascular access. Am J Kidney Dis 2006; 48 (Suppl. 1):S176–S247. 4. Vascular access for haemodialysis. The Renal Association; 2011. http:// www.renal.org/clinical/guidelinessection/vascularaccess.aspx#Summary1. [Accessed 25 November 2013]. 5. Commencing haemodialysis with appropriate vascular access. National Institute of Clinical Studies; 2005. http://www.nhmrc.gov.au/_files_nhmrc/file/ nics/material_resources/haemodialysis_vascular_access.pdf. [Accessed 25 November 2013]. 6. Ohira S, Naito H, Amano I, et al. 2005 Japanese Society for Dialysis Therapy guidelines for vascular access construction and repair for chronic hemodialysis. Ther Apher Dial 2006; 10:449–462.
7. Culleton BF. Vascular access – Canadian Society of Nephrology. J Am Soc Nephrol 2006; 17 (3 Suppl 1):S1–S3. 8. DeSilva RN, Patibandla BK, Vin Y, et al. Fistula first is not always the best && strategy for the elderly. J Am Soc Nephrol 2013; 24:1297–1304. Using USRDS data, this study demonstrates that mortality does not differ by access type in older adults. 9. Tamura MK, Tan JC, O’Hare AM. Optimizing renal replacement therapy in older adults: a framework for making individualized decisions. Kidney Int 2011; 82:261–269. 10. O’Hare AM, Choi AI, Bertenthal D, et al. Age affects outcomes in chronic kidney disease. J Am Soc Nephrol 2007; 18:2758–2765. 11. Glassock RJ, Rule AD. The implications of anatomical and functional changes of the aging kidney: with an emphasis on the glomeruli. Kidney Int 2012; 82:270–277. 12. Eriksen BO, Ingebretsen OC. The progression of chronic kidney disease: a 10-year population-based study of the effects of gender and age. Kidney Int 2006; 69:375–382. 13. Chand D, Valentini R, Kamil E. Hemodialysis vascular access options in pediatrics: considerations for patients and practitioners. Pediatr Nephrol 2009; 24:1121–1128. 14. Oliver MJ, Quinn RR, Garg AX, et al. Likelihood of starting dialysis after & incident fistula creation. Clin J Am Soc Nephrol 2012; 7:466–471. In focusing on patient preferences, this study highlights that many older patients with kidney disease may delay or forgo dialysis, potentially impacting the vascular access choice. 15. Vachharajani TJ. Dialysis vascular access selection in elderly patients. European Nephrol 2011; 5:152–154. 16. Lok CE, Allon M, Moist L, et al. Risk equation determining unsuccessful cannulation events and failure to maturation in arteriovenous fistulas (REDUCE FTM I). J Am Soc Nephrol 2006; 17:3204–3212. 17. Lilly MP, Lynch JR, Wish JB, et al. Prevalence of arteriovenous fistulas in incident hemodialysis patients: correlation with patient factors that may be associated with maturation failure. Am J Kidney Dis 2012; 59:541–549. 18. Lazarides MK, Georgiadis GS, Antoniou GA, Staramos DN. A meta-analysis of dialysis access outcome in elderly patients. J Vasc Surg 2007; 45:420.e2 – 426.e2. 19. Peterson WJ, Barker J, Allon M. Disparities in fistula maturation persist despite preoperative vascular mapping. Clin J Am Soc Nephrol 2008; 3:437–441. 20. Drew DA, Cohen J, Tangri N, et al. Vascular access choice in incident hemodialysis patients: a decision analysis. Kidney Week 2012. San Diego, CA: American Society of Nephrology; 2013. 21. Allon M, Lockhart ME, Lilly RZ, et al. Effect of preoperative sonographic mapping on vascular access outcomes in hemodialysis patients. Kidney Int 2001; 60:2013–2020. 22. Robbin ML, Chamberlain NE, Lockhart ME, et al. Hemodialysis arteriovenous fistula maturity: U.S. evaluation. Radiology 2002; 225:59–64. 23. Malovrh M. Approach to patients with end-stage renal disease who need an arteriovenous fistula. Nephrol Dial Transplant 2003; 18 (Suppl. 5):v50–v52. 24. Sidawy AN, Spergel LM, Besarab A, et al. The Society for Vascular Surgery: clinical practice guidelines for the surgical placement and maintenance of arteriovenous hemodialysis access. J Vasc Surg 2008; 48 (5 Suppl.):S2– S25. 25. Lee T, Ullah A, Allon M, et al. Decreased cumulative access survival in arteriovenous fistulas requiring interventions to promote maturation. Clin J Am Soc Nephrol 2011; 6:575–581. 26. Chaudhry M, Bhola C, Joarder M, et al. Seeing eye to eye: the key to reducing catheter use. J Vasc Access 2011; 12:120–126. 27. O’Hare AM. Vascular access for hemodialysis in older adults: a ‘patient first’ && approach. J Am Soc Nephrol 2013; 24:1187–1190. This editorial comprehensively discusses the ways in which elderly dialysis patients may benefit less from arteriovenous fistulas when compared with younger patients. 28. Xi W, Harwood L, Diamant MJ, et al. Patient attitudes towards the arteriovenous fistula: a qualitative study on vascular access decision making. Nephrol Dial Transplant 2011; 26:3302–3308. 29. Rehman R, Schmidt RJ, Moss AH. Ethical and legal obligation to avoid longterm tunneled catheter access. Clin J Am Soc Nephrol 2009; 4:456– 460. 30. Lok CE, Sontrop JM, Tomlinson G, et al. Cumulative patency of contemporary && fistulas versus grafts (2000–2010). Clin J Am Soc Nephrol 2013; 8:810– 818. Current data are used to compare the cumulative patency of arteriovenous fistulas versus arteriovenous grafts, showing little difference between the two types of vascular access. 31. Lee T, Barker J, Allon M. Comparison of survival of upper arm arteriovenous fistulas and grafts after failed forearm fistula. J Am Soc Nephrol 2007; 18:1936–1941. 32. Disbrow DE, Cull DL, Carsten CG 3rd, et al. Comparison of arteriovenous fistulas and arteriovenous grafts in patients with favorable vascular anatomy and equivalent access to healthcare: is a reappraisal of the fistula first initiative indicated? J Am Coll Surg 2013; 216:679–685. 33. Allon M, Ornt DB, Schwab SJ, et al. Factors associated with the prevalence of arteriovenous fistulas in hemodialysis patients in the HEMO Study. Kidney Int 2000; 58:2178–2185.
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Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Epidemiology and prevention 34. Pisoni RL, Arrington CJ, Albert JM, et al. Facility hemodialysis vascular access use and mortality in countries participating in DOPPS: an instrumental variable analysis. Am J Kidney Dis 2009; 53:475–491. 35. Allon M, Robbin ML. Increasing arteriovenous fistulas in hemodialysis patients: problems and solutions. Kidney Int 2002; 62:1109–1124. 36. Goodkin DA, Pisoni RL, Locatelli F, et al. Hemodialysis vascular access training and practices are key to improved access outcomes. Am J Kidney Dis 2010; 56:1032–1042. 37. Prischl FC, Kirchgatterer A, Brandsta¨tter E, et al. Parameters of prognostic relevance to the patency of vascular access in hemodialysis patients. J Am Soc Nephrol 1995; 6:1613–1618.
320
www.co-nephrolhypertens.com
38. Saran R, Elder SJ, Goodkin DA, et al. Enhanced training in vascular access creation predicts arteriovenous fistula placement and patency in hemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study. Ann Surg 2008; 247:885–891. 39. Lee T, Tindni A, Roy-Chaudhury P. Improved cumulative survival in fistulas & requiring surgical interventions to promote fistula maturation compared with endovascular interventions. Semin Dial 2013; 26:85–89. This study finds that surgical intervention is superior to endovascular techniques for aiding arteriovenous fistula maturation. 40. Allon M, Robbin ML. Hemodialysis vascular access monitoring: current concepts. Hemodial Int 2009; 13:153–162.
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