European Journal of Cardiovascular Medicine

The creation and maintenance of a functional arteriovenous hemodialysis access is a problem for the expanding population of patients with kidney failure. The original National Kidney Foundation’s Dialysis Outcome Quality Initiative recommended the autogenous arteriovenous fistula (AVF) over the prosthetic alternative (arteriovenous graft) and a tunneled dialysis catheter (TDC) based on its apparent benefits, which included improved patency, decreased morbidity, decreased mortality, and cost.¹ This increased emphasis on AVFs resulted in the unintended consequences of a higher rate of nonmaturation and TDC use.^2-6 Dember et al.⁷ reported a 61% rate of AVF nonmaturation from the Dialysis Access Consortium Fistula Trial (DAC), a multicenter National Institutes of Health National Institute of Diabetes and Diabetes and Kidney Diseases (NIH NIDDK) randomized trial that evaluated clopidogrel as an intervention to prevent early thrombosis of newly created AVFs. This study encompasses patients with chronic kidney disease (CKD), offers the opportunity to examine the short-term patency of AV Fistula created at our center. With the increasing emphasis in the recent National Kidney Foundation’s Dialysis Outcome Quality Initiative guideline on selecting the “right access, in the right patient, at the right time, forthe right reasons,”⁸ these findings may provide important insights to assist clinical decision-making for this challenging population.

The primary outcome measure was unassisted AVF maturation using predefined criteria. AV Fistulas created at our institute were included in the study. All patients underwent US Doppler preoperatively. Parameters looked for were Radial and Brachial artery size, arterial wall calcifications, vein size, vein thrombosis present or not. Those patients with patent cephalic vein with vein diameter of 2 mm were posted for AV fistula surgery at wrist. Those patients with thrombosed cephalic vein at wrist but patent median cubital or basilic vein at elbow were posted for AV fistula at elbow. Size of radial artery varied between 1.5 to 3 mm, and Brachial artery between 4 to 6 mm. a total of 32 patients were enrolled in study. They were followed up for 1 month, 3 months and 6 months and underwent US doppler and flow in the vein and size of the vein. Commencement of HD through AF fistula timing was noted. Patients who had either died, changed kidney replacement modality (e.g., peritoneal dialysis or transplant), or were lost to follow-up were excluded from study.

Out of patients evaluated (n = 32) were men (22 [68.75%]) and 10 were female. Mean (SD) age was 44.6 years. In 24 patients, AV fistula was created at wrist (Radio-Cephalic AV Fistula) and remaining 8 AV fistula was created at elbow (Brachio - Median Cuboital / Basilic AV Fistula). The AVF patency rates for CKD participants were 32 % at 1 month, 69 % at 3 months, and 81 % at 6 months. Most participants with kidney failure were undergoing dialysis through a Tunneled Dialysis Catheter (TDC) at the time of enrollment. As months passed the fistula got matured and the patency rates increased. The dialysis was initiated through AV fistula as soon as the fistula got matured. Even with dialysis the fistula remain patent in 81 % of patients after 6 months of AV Fistula creation.

Table 1: Age distribution

Table 2: Sex distribution

Table 3: Type of AV Fistula

Table 4: No. of patients with patent AV fistula

The results of this study help define functional patency rates. The AVF maturation rate at 6 months was 81% for participants with CKD which were reasonable with other studies. It may be helpful to put the current data in the context of similar studies. The AV Fistula patency rate for AVFs in our study was greater than those in the DAC.⁶ Notably, “failure to obtain suitability for dialysis” was the major secondary outcome measure in the DAC and was defined by the inability to meet specific dialysis criteria between 150 and 180 days after access placement. The AVF was not suitable for dialysis in 61% of the participants (clopidogrel, 61.8%; placebo, 59.5%) in the DAC. This finding corresponds to a 39% maturation rate at 6 months, which is markedly lower than the 69% rate reported in our study for the participants with CKD at the same time point

Our AVF maturation was consistent with those reported by Al-Jaishi et al.⁹ from their systematic review and meta-analysis examining AVF patency rates. They reported that the primary AVF failure rate (eg, immediate AVF failure within 72 hours, early dialysis suitability failure, and late dialysis suitability failure) was 23% (95% CI, 18%-28%; 37 cohorts; 7393 AVFs), although they stated that the estimate should be treated with caution owing to the high degree of heterogeneity within the studies.

Patients in their study who received intervention had a higher risk of both primary access loss and need for postmaturation interventions. The average AV Fistula maturation time in our study (CKD 81 days) was not consistent with findings from the US Renal Data System that documented a median time of 111 days between AVF creation and usability.¹⁰ This maturation period typically mandates dialysis through a TDC for patients with kidney failure and places them at risk for the spectrum of catheter-related complications, including sepsis, hospitalization, and death. Not unexpectedly, delayed AVF maturation or the need for remedial interventions is associated with additional catheter-dependent dialysis time.¹¹

The Dialysis Outcomes and Practice Patterns Study reported that AVFs not used within the first 6 months after placement were associated with a 53% higher mortality rate within the ensuing 6 months.¹² The appropriate duration for AVF maturation and number of remedial interventions remains undefined; however, the maturation rate increased from 69% at 3 months to 81% at 6 months among participants with kidney failure in the present study. From a practical standpoint, it seems worthwhile to begin investigating the next access option at 6 months if the AVF has not matured. There is clearly a substantial financial cost associated with AVF maturation that is increased with remedial interventions and/or complications, although these data were not collected in the present study. In addition, there is a substantial psychological cost to the patient associated with delayed maturation that should not be underestimated.

It is generally accepted that a mature AVF is the optimal dialysis access. Approximately 65% of the patients dialyze through an AVF.¹³ However, access care has evolved over the past 3 decades since the publication of the original National Kidney Foundation’s Dialysis Outcome Quality Initiative guidelines,¹ shifting from an emphasis on AVFs to an emphasis on access functionality and the appreciation that the access choice should be tailored to the individual patient’s need. The present study was singularly focused on the process of AVF patency and did not include a comparison arteriovenous graft or TDC group, so it is impossible to comment on their relative risks or benefits. The remaining challenge is to select the ideal access type and configuration, optimizing the likelihood of success while reducing the number of remedial interventions and the duration of catheter dependence.

The findings of this study suggest that the AVF remains a reasonable option for patients who require access for hemodialysis access. The AV Fistula patency rates in our study were comparable to other studies.

1. ational Kidney Foundation–Dialysis Outcomes Quality Initiative. NKF-DOQI clinical practice guidelines for vascular access.  Am J Kidney Dis. 1997;30(4)(suppl 3):S150-S191.
2. Huijbregts HJ, Bots ML, Moll FL, Blankestijn PJ; CIMINO members. Hospital specific aspects predominantly determine primary failure of hemodialysis arteriovenous fistulas.  J Vasc Surg. 2007;45(5):962-967.
3. Lok CE, Allon M, Moist L, Oliver MJ, Shah H, Zimmerman D. Risk equation determining unsuccessful cannulation events and failure to maturation in arteriovenous fistulas (REDUCE FTM I).  J Am Soc Nephrol. 2006;17(11):3204-3212.
4. McLafferty RB, Pryor RW III, Johnson CM, Ramsey DE, Hodgson KJ. Outcome of a comprehensive follow-up program to enhance maturation of autogenous arteriovenous hemodialysis access.  J Vasc Surg. 2007;45(5):981-985.
5. Danese MD, Liu Z, Griffiths RI, et al. Catheter use is high even among hemodialysis patients with a fistula or graft.  Kidney Int. 2006;70(8):1482-1485.
6. Lacson E Jr, Lazarus JM, Himmelfarb J, Ikizler TA, Hakim RM. Balancing fistula first with catheters last.  Am J Kidney Dis. 2007;50(3):379-395.
7. Dember LM, Beck GJ, Allon M, et al.; Dialysis Access Consortium Study Group. Effect of clopidogrel on early failure of arteriovenous fistulas for hemodialysis: a randomized controlled trial.  JAMA. 2008;299(18):2164-2171.
8. Lok CE, Huber TS, Lee T, et al.; National Kidney Foundation. 2019 Update.  Am J Kidney Dis. 2020;75(4)(suppl 2):S1-S164.
9. Al-Jaishi AA, Oliver MJ, Thomas SM, et al. Patency rates of the arteriovenous fistula for hemodialysis: a systematic review and meta-analysis.  Am J Kidney Dis. 2014;63(3):464-478.
10. Woodside KJ, Bell S, Mukhopadhyay P, et al. Arteriovenous fistula maturation in prevalent hemodialysis patients in the United States: a national study.  Am J Kidney Dis. 2018;71(6):793-801.
11. Harms JC, Rangarajan S, Young CJ, Barker-Finkel J, Allon M. Outcomes of arteriovenous fistulas and grafts with or without intervention before successful use.  J Vasc Surg. 2016;64(1):155-162.
12. Pisoni RL, Zepel L, Zhao J, et al. international comparisons of native arteriovenous fistula patency and time to becoming catheter-free: findings from the Dialysis Outcomes and Practice Patterns Study (DOPPS).  Am J Kidney Dis. 2021;77(2):245-254.
13. Saran R, Li Y, Robinson B, et al. US Renal Data System 2015 annual data report: epidemiology of kidney disease in the United States.  Am J Kidney Dis. 2016;67(3 suppl 1):S1-S305.