Comparison of Survival of Upper Arm Arteriovenous Fistulas and Grafts after Failed Forearm Fistula
Timmy Lee*,,
Jill Barker and
Michael Allon*
* Division of Nephrology, University of Alabama at Birmingham; Department of Veterans Affairs Medical Center, Birmingham, Alabama; and Department of Microbiology, Montana State University, Bozeman, Montana
Address correspondence to: Dr. Michael Allon, Division of Nephrology, 728 Richard Arrington Boulevard, Birmingham, AL 35294. Phone: 205-975-9676; Fax: 205-975-8879; mdallon{at}uab.edu
Received for publication October 16, 2006.
Accepted for publication March 28, 2007.
Although arteriovenous fistulas are considered superior to grafts,it is unknown whether that is true in the subset of patientswith a previous failed fistula. For investigation of this question,a prospective vascular access database was queried retrospectivelyto compare the outcomes of 59 fistulas and 51 grafts that wereplaced in the upper arm after primary failure of an initialforearm fistula. Primary access failure was higher for subsequentfistulas than for subsequent grafts (44 versus 20%; P = 0.006).Fistulas required more interventions than grafts before theirsuccessful use (0.42 versus 0.16 per patient; P = 0.04). Thetime to catheter-free dialysis was longer for fistulas thanfor grafts (131 versus 34 d; P < 0.0001) and was associatedwith more episodes of bacteremia before permanent access use(1.3 versus 0.4 per patient; P = 0.003). Cumulative survival(from placement to permanent failure) was higher for fistulasthan for grafts when primary failures were excluded (hazardratio 0.51; 95% confidence interval 0.27 to 0.94; P = 0.03),but similar when primary failures were included (hazard ratio0.99; 95% confidence interval 0.61 to 1.62; P = 0.97). Fistulasrequired fewer interventions to maintain long-term patency fordialysis after maturation (0.73 versus 2.38 per year; P <0.001). In conclusion, as compared with grafts, subsequent upperarm fistulas are associated with a higher primary failure rate,more interventions to achieve maturation, longer catheter dependence,and more frequent catheter-related bacteremia. However, oncethe access is usable for dialysis, fistulas have superior cumulativepatency than do grafts and require fewer interventions to maintainpatency.
The National Kidney Foundation Kidney Disease Outcomes QualityInitiative (KDOQI) guidelines for Vascular Access recommendincreasing the proportion of arteriovenous fistulas among hemodialysispatients (1). Adherence to these recommendations has increasedthe prevalence of fistulas in US hemodialysis patients from26 to 35% (2). A major hurdle to increasing further the proportionof fistula use is the high rate of primary fistula failures(fistulas never usable for dialysis) because of early thrombosisor failure to mature (3).
Given the high rate of primary fistula failure, a subsequentaccess will often need to be created in the upper arm. The subsetof patients who have a second fistula placed after failure ofan initial primary forearm fistula may differ from other patientsin that they may be at higher risk of failure of their secondfistula. In addition, they are more likely to already be receivingdialysis, such that they are dependent on catheters, with allof their attendant complications. Therefore, it is not clearwhether fistula outcomes are superior to those of grafts inthis high-risk patient subset.
The goal of this study was to compare the outcomes of upperarm fistulas and upper arm grafts that were placed in patientswhose initial forearm fistula had a primary failure. In addition,this study evaluated the clinical consequences of placing thetwo types of subsequent access, including the duration of catheterdependence and frequency of catheter-related complications.
Vascular Access Management
The University of Alabama at Birmingham oversees the medicalcare of 450 patients who receive in-center hemodialysis at fiveunits in metropolitan Birmingham. Ten full-time clinical nephrologists,all faculty members in the Division of Nephrology, provide medicalcare to these patients. Four experienced transplant surgeonsperform all vascular access procedures, and the Department ofRadiology performs diagnostic studies and interventions fordialysis access.
Two full-time access coordinators in the Division of Nephrologyscheduled all vascular access procedures and maintained a prospective,computerized access database of the procedures and their outcomes(4). Preoperative mapping was performed routinely to assistthe surgeons in the optimal planning of access surgery (3,5,6).The preoperative diameter criteria used for placement of anupper arm access included a minimum artery diameter of 2 mmand a minimum vein diameter of 2.5 mm for fistulas and 4.0 mmfor grafts. In addition, all draining veins were assessed forstenosis or thrombosis throughout their course. In selectedpatients, additional imaging was performed to exclude centralvein stenosis. Although our institutional consensus was to favorfistulas over grafts, the final decision about the type of accessto be placed in a given patient was at the discretion of thesurgeon. Fistulas were allowed to mature for 8 to 12 wk andgrafts for 2 to 3 wk before initial cannulation. Postoperativeultrasonography was performed to assess fistula maturation wheneverthere was clinical uncertainty (7). Fistulas that were deemedimmature by postoperative ultrasound were referred to Radiologyor Transplant Surgery for salvage procedures (8).
When a patient’s initial fistula failed to mature, thesurgeon typically placed a subsequent access in the upper arm.The decision on whether to place an upper arm fistula or graftwas determined on the basis of preoperative vascular mappingand clinical judgment. Patients who were already on dialysisused tunneled catheters until their permanent access had matured.All elective access procedures (creation of fistula or graft,angioplasty, thrombectomy, surgical revision, and placementor exchange of tunneled catheters) were performed in the outpatientsetting. Access-related hospitalizations were required onlyin the subset of patients who had catheter-related bacteremiaand were severely symptomatic.
Data Analysis
Approval was obtained from the University of Alabama at BirminghamInstitutional Review Board to review patients’ medicalrecords for research purposes. We retrospectively queried ourprospective vascular access database to identify all 769 newfistulas that were placed during a 5-yr period (January 1, 2000,to December 31, 2004). A fistula was deemed to have had a primaryfailure when it never matured adequately to be used successfullyfor dialysis. During the study period, 268 patients had an initialforearm fistula, 155 of whom had a primary fistula failure.Of these 155 patients, three received a subsequent contralateralforearm fistula, 13 received a forearm graft, six were switchedto peritoneal dialysis, and 23 had no subsequent access placed(i.e., remained catheter dependent). A subsequent upper armaccess (fistula or graft) was placed in the remaining 110 patients,and this last group constituted the study population.
Patient records were reviewed to determine demographic and clinicalinformation, including age, gender, race, diabetes, and peripheralvascular disease. We prospectively followed these patients fromthe time of access placement until cumulative access failureto determine (1) primary access failure, (2) primary (unassisted)access survival, (3) cumulative (assisted) access survival,(4) duration of catheter dependence from access placement toits use for dialysis, and (5) number of episodes of catheter-relatedbacteremia during access maturation.
The clinical outcome of each upper arm access (fistula or graft)was determined from the computerized access database. Primaryaccess failure was declared when the access was never usablefor dialysis. Primary (unassisted) access survival was calculatedfrom the time of access placement until the first access intervention(thrombectomy, angioplasty, or surgical revision) to maintainits patency for dialysis. For the purpose of this analysis,a fistulogram that was performed without a concurrent angioplastywas also considered to be an access intervention. Cumulative(secondary) access survival was calculated from access creationto permanent failure, regardless of the number of interventionsrequired to maintain long-term patency for dialysis.
The number of access interventions that were required beforethe access could be used for dialysis was calculated for eachpatient. The duration of catheter dependence was calculatedfor each patient as the time from upper arm access placementto the time of removal of the tunneled catheter after successfulcannulation of the access for dialysis. Patients whose accesswas placed before initiation of dialysis were excluded fromthis particular calculation. Catheter-related bacteremia wasdiagnosed in catheter-dependent patients with fever or chillsand positive blood cultures, in the absence of an alternativesource of infection (9).
Statistical Analyses
Primary (unassisted) and cumulative (assisted) access survivalwas plotted using Kaplan-Meier survival techniques, with patientfollow-up censored for death (n = 9), kidney transplant (n =1), transfer to a nonparticipating dialysis unit (n = 5), orend of the study follow-up (December 31, 2005). Fistulas andgrafts with primary failures were considered to have a survivalof 0 d because they were never usable for dialysis. Access survivalwas compared between the subsequent upper arm fistulas and graftsby the log rank test. Univariate Cox proportional hazard modelswere fit. Hazard ratios (HR) and their associated 95% confidenceintervals (CI) were computed. Finally, multiple variable survivalanalysis was used to model the association between the clinicalvariables and secondary access survival. To evaluate whetherthere was an interaction between time and access survival, wedefined a time-by-group interaction variable. We re-estimatedour Cox model after adding this covariate to the model. Otheraccess outcomes were compared between groups using unpairedt test or 2 test. P < 0.05 was considered statistically significant.
Patient Population Table 1 summarizes the demographic and clinical characteristicsof patients who received an upper arm access after the primaryfailure of their initial forearm fistula. Patients who receivedan upper arm fistula were more likely to be male than thosewho received an upper arm graft (P = 0.04). However, the twogroups were similar in terms of age, race, and frequency ofdiabetes and peripheral vascular disease. The majority of patientsin both groups were black, reflecting the demographics of ourhemodialysis population. Obesity (body mass index 30 kg/m2)was present in 38% of the study population but did not differsignificantly between the groups. The majority (80%) of patientswho received an upper arm access (fistula or graft) had alreadystarted dialysis.
Table 1. Baseline characteristics of patients who received an upper arm access after a failed forearm fistulaa
The preoperative vascular mapping that was obtained before accesscreation showed vasculature suitable for either an upper armfistula or an upper arm graft in the study population, usingour objective sonographic criteria. The mean preoperative diameterof the artery was slightly but significantly higher in the patientswho received an upper arm fistula than in those who receiveda graft (P = 0.04; Table 1). However, the arterial diametersin both groups were well above the minimum 2.0-mm diameter required.The preoperative vein diameters were similar in both groups(P = 0.63). Among the upper arm fistulas placed, 51 were brachiocephalicfistulas and eight were transposed brachiobasilic fistulas.
Frequency of Access Events
Primary access failure was twice as common in patients who receiveda subsequent upper arm fistula, as compared with those who receivedan upper arm graft (Table 2). Patients with upper arm fistulasrequired significantly more access interventions before successfulcannulation for dialysis, as compared with those with upperarm grafts (0.42 versus 0.16 interventions per patient; P =0.04). The duration of catheter dependence was evaluated forthe subset of patients who were already on maintenance dialysiswhen they received their upper arm access (43 fistulas and 45grafts). The median duration of catheter dependence until successfulcannulation of the upper arm access was significantly longerfor fistulas than for grafts (131 versus 34 d; P < 0.0001).During the catheter-dependent period (while awaiting accessmaturation), the patients with upper arm fistulas averaged 1.3episodes of catheter-related bacteremia, compared with 0.4 episodesin the patients with upper arm grafts (P = 0.003). The rateof catheter-related bacteremia normalized to 1000 catheter-dayswas similar in both groups (Table 2). There were seven hospitalizationsfor catheter-related bacteremia in the fistula group and threein the graft group. There were no deaths related to access-relatedinfections in the study population. There was one graft infection.
Table 2. Clinical outcomes of patients who received an upper arm access after a failed forearm fistulaa
Access Survival and Interventions
The mean duration of patient follow-up was 9.7 mo in the fistulagroup and 13.4 mo in the graft group. When primary access failureswere included in the analysis, the cumulative access survivaldid not differ significantly between the two groups (mediansurvival 231 versus 355 d; HR 0.99, 95% CI 0.61 to 1.62; P =0.97; Figure 1). However, when patients with a primary accessfailure were excluded, the cumulative access survival was significantlylonger for upper arm fistulas, as compared with grafts (mediansurvival 1524 versus 517 d; HR 0.51, 95% CI 0.27 to 0.94; P= 0.03; Figure 2).
Figure 1. Cumulative access survival (time from access creation to access failure), including primary access failures (P = 0.97). Sec fist, secondary upper arm fistula after primary failure of forearm fistula; Sec graft, secondary upper arm graft after primary failure of forearm fistula.
Figure 2. Cumulative access survival (time from access creation to access failure), excluding primary access failures (P = 0.03).
Similarly, when primary access failures were included in theanalysis, the unassisted survival did not differ between upperarm fistulas and grafts (median survival 100 versus 91 d; HR0.88, 95% CI 0.56 to 1.32; P = 0.50; Figure 3). However, whenprimary access failures were excluded, the primary (unassisted)survival of upper arm fistulas was superior to that of upperarm grafts (median survival 392 versus 146 d; HR 0.54, 95% CI0.32 to 0.87; P = 0.01; Figure 4). After access maturation,patients with fistulas required significantly fewer interventions(fistulogram, angioplasty, thrombectomy, or surgical revisions)than did those with grafts to maintain long-term access patencyfor dialysis (0.73 versus 2.38 per year; P < 0.001). Thetotal rate of interventions for the life of the access (fromits creation to permanent failure) was also significantly lowerfor fistulas than for grafts (1.28 versus 2.66 per year; P =0.005).
Figure 4. Primary access survival (time from access creation to first access intervention), excluding primary access failures (P = 0.01).
On multiple variable survival analysis with access type, age,gender, diabetes, peripheral vascular disease, obesity, andpreoperative artery and vein diameters in the model, accesstype was the only significant factor associated with cumulativeaccess survival excluding primary failures (HR for graft versusfistula failure 2.01; 95% CI 1.05 to 3.82; P = 0.03). None ofthe factors was significant in the multiple variable survivalanalysis of cumulative access including primary failure, primaryaccess survival excluding primary failure, or primary accesssurvival including primary failures.
There was a significant interaction between time and accesssurvival (P = 0.01) for unassisted survival excluding primaryfailure, indicating that unassisted survival was better forfistulas in the early period but better for grafts in the lateperiod. There was no significant interaction between time andaccess survival for the other three models (cumulative survivalincluding primary failures, cumulative survival excluding primaryfailures, and unassisted survival including primary failures).
The KDOQI recommendations to place a fistula in preference toa graft are predicated on the evidence that fistulas have superiorcumulative survival than do grafts and require fewer interventionsto maintain their long-term patency for dialysis (5,10–16).In patients with a primary failure of their initial forearmfistula, the current recommendations are to place a new fistulain the upper arm. The decision in this case differs from thatregarding the initial access placement in two important respects.First, patients whose initial forearm fistula failed may beat increased risk for failure of their subsequent fistula, ascompared with those who receive their initial fistula. Second,patients are much more likely to have already initiated hemodialysisby the time their second access is placed. This means that theyare catheter dependent until the access is ready to cannulate.
This study documents in quantitative terms the trade-offs thatare involved in placing an upper arm fistula after a primaryfailure of the initial forearm fistula. As compared with a subsequentupper arm graft, fistulas had a two-fold higher risk for primaryfailure and required substantially more interventions to promotefistula maturation. Moreover, patients who received an upperarm fistula were catheter dependent for 3 mo longer than thosewho received a graft. This longer period of catheter dependencetranslated into a more than three-fold higher frequency of catheter-relatedbacteremia until the permanent access could be used. Althoughnot documented in this study, we previously observed that catheter-dependentpatients are three times as likely to receive an inadequatedosage of dialysis, as compared with patients who undergo dialysiswith a fistula or a graft (17). However, both primary and cumulativeaccess survival were significantly longer for fistulas thanfor grafts, when one excludes patients with primary failureof their access. In addition, maintenance of the long-term patencyof the access for dialysis entailed a three-fold lower frequencyof intervention (fistulogram, angioplasty, thrombectomy, orsurgical revision) for upper arm fistulas as compared with grafts.However, when primary access failures were included in the survivalanalysis, the superior survival of fistulas over grafts wasno longer evident.
Two previous studies compared the outcomes of upper arm fistulasand grafts (10,14). Both documented a higher primary failurerate of fistulas over grafts. In addition, Oliver et al. (14)documented longer catheter dependence after placement of a fistula,as compared with a graft. Both observed a lower frequency ofinterventions in fistulas than in grafts to maintain their long-termpatency for dialysis. In agreement with this study, Oliver etal. (14) demonstrated a superior primary and cumulative survivalof fistulas over grafts when primary failures were excludedbut a comparable survival when primary failures were included.There was also a trend of higher rates of catheter-related bacteremiain patients who received a fistula, as compared with those whoreceived a graft. Our study was restricted to patients who receiveda subsequent upper arm access after primary failure of theirinitial forearm fistula, whereas the study by Oliver et al.(14) included many patients in whom the upper arm access wastheir first vascular access. Notwithstanding some differencesin the dialysis populations enrolled in these three studies,they all illustrate similar trade-offs between upper arm fistulasand grafts.
Published data demonstrate that US nephrologists have been heedingthe Fistula First recommendations. The proportion of US hemodialysispatients who undergo dialysis with fistulas increased from 26to 35% in the 5-yr period between 1998 and 2003 (2). Duringthe same time period, catheter use increased from 19 to 27%.Therefore, it seems that each 1% increase in fistula prevalenceis associated with a corresponding 1% increase in catheter prevalence.This is most likely due to increased numbers of primary fistulafailures. If this trend continues, then achieving fistula usein 50% of US hemodialysis patients may entail accepting catheteruse in 40%, a scenario that closely mirrors the Canadian numbers(18). This creates a dilemma, in that adhering to one desirableguideline (increasing fistulas) has the unintended consequenceof worsening adherence with another desirable guideline (reducingcatheters). Achieving the optimal balance between these twocompeting goals requires an individualized approach. In a subsetof patients who are at high risk for failure of maturation offistulas, it may be preferable to place a graft instead, soas to minimize the duration of catheter dependence. The trade-offsare particularly pronounced in patients who are already on dialysiswhen they receive their upper arm access. In this patient subset,delays in achieving a working vascular access directly translateinto prolonged catheter dependence and more episodes of catheter-relatedbacteremia. Certainly, concerted efforts to optimize fistulaoutcomes are indicated, including early referral to surgeonsfor fistula creation, preoperative vascular mapping, improvementsof surgical technique, aggressive attempts to salvage immaturefistulas, and education of staff in cannulation techniques.At the same time, there is a growing body of evidence showingthat some dialysis patients are at high risk for primary fistulafailure despite optimal vascular access management. This subsetof patients may be better served by having a graft placed, ratherthan by subjecting them to prolonged catheter dependence withits risks of recurrent bacteremia and suboptimal dialysis.
This study has some limitations. First, it was a single-centerstudy and the results may not generalize to all hemodialysisunits in the United States. In our study population, it seemsthat patients who had a primary failure of their initial forearmfistula and whose expected survival was <2 yr may have beenbetter off receiving a graft rather than a fistula. However,the trade-offs between placement of subsequent fistulas andgrafts that were observed in our investigation may be more clearlyin favor of fistulas in dialysis centers with a lower rate ofprimary fistula failure, shorter time to fistula maturation,or lower rate of catheter-related bacteremia. Second, this studywas retrospective. However, the vast majority of access procedureswere performed at a single hospital by one group of surgeonsand one group of radiologists, and all access procedures weremaintained in a prospective, computerized database. Therefore,we are confident that the study included a comprehensive listof patients who fulfilled the study criteria and an accurateaccount of the outcome of each vascular access. Finally, incommon with previous publications (10,14), this was not a randomizedclinical trial, and there may have been undocumented differencesbetween patients who received upper arm fistulas and those whoreceived grafts.
Given the strong "fistula first" recommendations in the KDOQIguidelines, it may seem heretical to recommend placing a graft,rather than a fistula, in some dialysis patients. However, earlyfistula failure is more common in certain patient subsets, includingwomen, nonwhite individuals, older patients, and obese individuals(8,19,20). Used in combination, such clinical factors may beuseful in stratifying the risk for primary fistula failure (20).Moreover, accelerated neointimal hyperplasia that leads to primaryfistula failure has been associated with pathophysiologic conditionsthat favor hemodynamic stress, vasoconstriction, platelet aggregation,and endothelial dysfunction (21,22). It is likely that the variabilityin vascular access outcomes is affected by individual variationsin the expression of vasoactive substances that modulate neointimalhyperplasia. In this regard, recent retrospective studies haveimplicated genetic polymorphisms in differences in fistula failurerates (23–25). Using clinical and genetic prognostic factorsgleaned from such observations, it should be possible to identifya subset of hemodialysis patients who are at high risk for earlyfistula failure. A randomized, multicenter clinical trial thatallocates high-risk patients to placement of a fistula or agraft should be performed. Such a study would help to quantifythe trade-offs between fistulas and grafts and to identify whichpatients are best suited for each type of vascular access. Itwould also provide meaningful economic comparisons of all access-relatedprocedures and hospitalizations in patients who are randomlyassigned to each access type, akin to a recent economic analysisperformed on a nonrandomized cohort (26).
Our findings have important clinical implications for the unbiasedpresentation of vascular access options to dialysis patients.If patients are simply informed that fistulas have better long-termsurvival than grafts, then they are likely to prefer a fistula.However, if they are also informed that they also have a highrisk for primary fistula failure and prolonged catheter dependencewith its associated risks, then they may prefer a graft. Thismay be particularly true for patients who return to the surgeonafter a primary failure of their initial fistula or patientswith a relatively short life expectancy.
Clinical trade-offs are involved in the decision about placingan upper arm access in patients whose initial forearm fistulahas failed. As compared with a graft, placement of a fistulaincreases the risk for primary failure and requires more interventionsto achieve maturation. If the patient is already on dialysis,then fistula placement also entails longer catheter dependenceand a higher risk for catheter-related bacteremia. However,for the subset of accesses that are usable for dialysis, fistulashave longer cumulative patency and require fewer interventions.
This research was supported in part by grant 1 K24 DK59818-01from the National Institute of Diabetes and Digestive and KidneyDiseases to M.A. and the National Kidney Foundation ResearchFellowship and the University of Alabama at Birmingham ClinicalInvestigator Research Fellowship to T.L.
Portions of this manuscript were presented in abstract format the annual meeting of the American Society of Nephrology;November 14 through 19, 2006; San Diego, CA.
Footnotes
Published online ahead of print. Publication date availableat www.jasn.org.
Clinical practice guidelines for vascular access.
Am J Kidney Dis 48
: S176
–S273, 2006[CrossRef][Medline]
Centers for Medicare and Medicaid Services: 2004 Annual Report: End-Stage Renal Disease Clinical Performance Measures Project.
Am J Kidney Dis 46
: 1
–100, 2005[Medline]
Allon M, Robbin ML: Increasing arteriovenous fistulas in hemodialysis patients: Problems and solutions.
Kidney Int 62
: 1109
–1124, 2002[CrossRef][Medline]
Allon M, Bailey R, Ballard R, Deierhoi MH, Hamrick K, Oser R, Rhynes VK, Robbin ML, Saddekni S, Zeigler ST: A multidisciplinary approach to hemodialysis access: Prospective evaluation.
Kidney Int 53
: 473
–479, 1998[CrossRef][Medline]
Allon M, Lockhart ME, Lilly RZ, Gallichio MH, Young CJ, Barker J, Deierhoi MH, Robbin ML: Effect of preoperative sonographic mapping on vascular access outcomes in hemodialysis patients.
Kidney Int 60
: 2013
–2020, 2001[CrossRef][Medline]
Robbin ML, Gallichio MH, Deierhoi MH, Young CJ, Weber TM, Allon M: US vascular mapping before hemodialysis access placement.
Radiology 217
: 83
–88, 2000[Abstract/Free Full Text]
Robbin ML, Chamberlain NE, Lockhart ME, Gallichio MH, Young CJ, Deierhoi MH, Allon M: Hemodialysis arteriovenous fistula maturity: US evaluation.
Radiology 225
: 59
–64, 2002[Abstract/Free Full Text]
Miller CD, Robbin ML, Allon M: Gender differences in outcomes of arteriovenous fistulas in hemodialysis patients.
Kidney Int 63
: 346
–352, 2003[CrossRef][Medline]
Krishnasami Z, Carlton D, Bimbo L, Taylor ME, Balkovetz DF, Barker J, Allon M: Management of hemodialysis catheter-related bacteremia with an adjunctive antibiotic lock solution.
Kidney Int 61
: 1136
–1142, 2002[CrossRef][Medline]
Miller A, Holzenbein TJ, Gottlieb MN, Sacks BA, Lavin PT, Goodman WS, Gupta SK: Strategies to increase the use of autogenous arteriovenous fistula in end-stage renal disease.
Ann Vasc Surg 11
: 397
–405, 1997[CrossRef][Medline]
Oliver MJ, McCann RL, Indridason OS, Butterly DW, Schwab SJ: Comparison of transposed brachiobasilic fistulas to upper arm grafts and brachiocephalic fistulas.
Kidney Int 60
: 1532
–1539, 2001[CrossRef][Medline]
Rocco MV, Bleyer AJ, Burkart JM: Utilization of inpatient and outpatient resources for the management of hemodialysis access complications.
Am J Kidney Dis 28
: 250
–256, 1996[Medline]
Winsett OE, Wolma FJ: Complications of vascular access for hemodialysis.
South Med J 78
: 513
–517, 1985[CrossRef][Medline]
Lee T, Barker J, Allon M: Tunneled catheters in hemodialysis patients: Reasons and subsequent outcomes.
Am J Kidney Dis 46
: 501
–508, 2005[CrossRef][Medline]
Mendelssohn DC, Ethier J, Elder SJ, Saran R, Port FK, Pisoni RL: Haemodialysis vascular access problems in Canada: Results from the Dialysis Outcomes and Practice Patterns Study (DOPPS II).
Nephrol Dial Transplant 21
: 721
–728, 2006[Abstract/Free Full Text]
Kats M, Hawxby AM, Barker J, Allon M: Impact of obesity on arteriovenous fistula outcomes in dialysis patients.
Kidney Int 71
: 39
–43, 2007[CrossRef][Medline]
Lok CE, Allon M, Moist L, Oliver MJ, Shah H, Zimmerman D: Risk equation determining unsuccessful cannulation events and failure to mature in arteriovenous fistulas (REDUCE FTM I).
J Am Soc Nephrol 17
: 3204
–3212, 2006[Abstract/Free Full Text]
Roy-Chaudhury P, Sukhatme VP, Cheung AK: Hemodialysis vascular access dysfunction: A cellular and molecular viewpoint.
J Am Soc Nephrol 17
: 1112
–1127, 2006[Abstract/Free Full Text]
Heine GH, Ulrich C, Sester U, Sester M, Kohler H, Girndt M: Transforming growth factor beta1 genotype polymorphisms determine AV fistula patency in hemodialysis patients.
Kidney Int 64
: 1101
–1107, 2003[CrossRef][Medline]
Lin CC, Yang WC, Lin SJ, Chen TW, Lee WS, Chang CF, Lee PC, Lee SD, Su TS, Fann CS, Chung MY: Length polymorphism in heme oxygenase-1 is associated with arteriovenous fistula patency in hemodialysis patients.
Kidney Int 69
: 165
–172, 2006[CrossRef][Medline]
Heine GH, Ulrich C, Kohler H, Girndt M: Is AV fistula patency associated with angiotensin-converting enzyme (ACE) polymorphism and ACE inhibitor intake?
Am J Nephrol 24
: 461
–468, 2004[CrossRef][Medline]
Manns B, Tonelli M, Yilmaz S, Lee H, Laupland K, Klarenbach S, Radkevich V, Murphy B: Establishment and maintenance of vascular access in incident hemodialysis patients: A prospective cost analysis.
J Am Soc Nephrol 16
: 201
–209, 2005[Abstract/Free Full Text]
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Top
Abstract
Introduction
2 test. P < 0.05 was considered statistically significant. 
30 kg/m2) was present in 38% of the study population but did not differ significantly between the groups. The majority (80%) of patients who received an upper arm access (fistula or graft) had already started dialysis. 
