The 2004 Fistula First Initiative and 2006 Kidney Disease Outcomes Quality Initiative (KDOQI) vascular access guidelines were developed in response to the low prevalence (24%) of arteriovenous (AV) fistulas in the United States in the 1990s. In that select population, only 10% of AV fistulas failed to mature, and AV fistulas were superior to grafts in terms of their prolonged secondary patency and a low frequency of interventions to maintain it. By contrast, AV grafts had a shorter secondary patency, frequent thrombosis, and required frequent interventions to maintain their patency.1 These observations led to the belief that maximizing AV fistulas placement would reduce the burden of access procedures and lower the cost of vascular access management.

Several strategies were implemented to maximize AV fistula placement and maturation in hemodialysis patients. First, routine preoperative vascular mapping was introduced to select adequately sized vessels.2 With preoperative mapping, an AV fistula was feasible in 75% of dialysis patients, but upper arm fistulas increased substantially (from 30% to 70%).3 A high rate of AV fistula nonmaturation persisted despite preoperative mapping, leading to prolonged catheter dependence. AV fistula nonmaturation was consistently higher in women, older patients, patients with peripheral vascular disease, and forearm (as opposed to upper arm) fistulas.4 Second, concerted efforts were introduced to identify nonmaturing AV fistulas and to intervene to promote their maturation. The postoperative ultrasound frequently identified specific anatomic abnormalities in immature AV fistulas, including anastomotic stenosis, large collateral veins, or fistulas too deep to be safely cannulated. Targeted percutaneous or surgical interventions to remedy these anatomic abnormalities often promoted AV fistula maturation (assisted maturation).5

A recent single-center study quantified vascular access outcomes among patients initiating hemodialysis with a central venous catheter (CVC) in 2004–2012, who underwent placement of an AV fistula or graft.6 During this period, an AV fistula was placed preferentially if the preoperative mapping identified suitable vasculature, without considering patient characteristics. There were two major findings. First, patients with an initial AV fistula required more vascular access procedures annually, as compared with those with an initial AV graft. Second, the median annual cost of access management per patient was almost $4000 greater in those receiving an AV fistula versus a graft. Notably, the annual cost of access management was twice as high in the patients with AV fistula nonmaturation (36% of the total) than in those with successful maturation. The cost of access management was substantially higher in patients who never received an AV fistula or graft.

In summary, when AV fistulas are placed aggressively in hemodialysis patients, 30%–40% fail to mature, particularly in female and older patients or those with severe vascular disease, leading to prolonged catheter dependence. These observations led to the updated 2019 KDOQI Vascular Access guidelines to “place the right access in the right patient at the right time for the right reason.”7 This phrasing is too vague to be helpful to clinicians. What is missing are more granular recommendations on how to implement this goal. Unfortunately, prospective multicenter vascular access studies are sparse, but recent retrospective single-center studies suggest strategies to improve vascular access outcomes.

We assessed the impact of a change from a less selective vascular access strategy to a more selective approach (placing an AV graft in patients in whom an AV fistula is unlikely to mature) on the frequency of vascular access procedures and the cost of vascular access management in a single-center study.8 In the less selective period, patients receiving an AV graft and fistula were similar in age and frequency of peripheral vascular disease, whereas in the more selective period, patients receiving an AV graft were older and more likely to have peripheral vascular disease. The annual frequency of access procedures in patients receiving an initial AV fistula versus a graft was 14% higher in the period with a less selective AV fistula strategy, but 22% lower in the period with a more selective strategy. The median annual cost of access management in patients receiving an initial AV fistula versus a graft was $3832 higher during the period with the less selective strategy, but $2772 lower during the period with a more selective strategy. CVC exposure among all patients in the cohort was similar with both AVF strategies (18.6 versus 19.2 years per 100 patient-years).

There has also been growing interest in improving vascular access management in patients with advanced CKD. Ideally, AV fistula creation should occur early enough to ensure that it is ready to use at hemodialysis initiation and that central venous catheter use is minimized. Unfortunately, we are far from achieving this goal. In 2020, only 25% of US patients initiating hemodialysis had undergone predialysis AV fistula placement, only 14% used an AV fistula, and 71% initiated with a central venous catheter only.9,10 Incident dialysis patients with longer predialysis nephrology care were more likely to initiate dialysis with an AV fistula and less likely to initiate with a central venous catheter only. However, even among patients with over 1 year of predialysis nephrology care, 55% initiated dialysis with a central venous catheter only.

The 2019 KDOQI Vascular Access guidelines recommend AV fistula placement in patients with CKD when their eGFR is 15–20 ml/min to ensure adequate time for fistula maturation, as well as interventions to assist maturation, when indicated.7 They do not address the preferred access in patients with a lower eGFR. We analyzed a cohort of 380 patients undergoing pre-ESKD access surgery at a single center.11 The median time from access placement to dialysis initiation was 69, 156, and 429 days in patients with an eGFR <10, 10–14, and ≥15 ml/min per 1.73 m2, respectively. Among those with AV fistula placement, the likelihood of catheter-free hemodialysis initiation was progressively higher (43%, 54%, and 75%) when the eGFR at the time of surgery was <10, 10–14, and ≥15 ml/min per 1.73 m2, respectively. By contrast, among patients undergoing pre-ESKD AV graft placement, the proportion initiating dialysis without a CVC was similarly high (88%–90%) at all eGFR ranges. Confirmatory studies are needed to assess whether increased placement of AV grafts in patients with advanced CKD reduces dialysis initiation with a central venous catheter.

In summary, the updated 2019 KDOQI guidelines recognize the need to customize vascular access management in patients with advanced CKD or kidney failure but provide little guidance on how to achieve this goal. We propose the following strategies to optimize vascular access outcomes (Figure 1). First, nephrologists and surgeons should tailor their approach after consideration of individual surgeons' outcomes, patient characteristics affecting AV fistula maturation, different fistula locations (upper arm versus forearm) and fistula configurations (brachiobasilic versus brachiocephalic), and the local success of interventions to salvage immature fistulas. Second, arteriovenous fistulae should be placed preferentially in the upper arm, rather than the forearm, when a forearm fistula is unlikely to mature. Third, in patients initiating hemodialysis with a central venous catheter and who are at high risk for AV fistula nonmaturation, an AV graft should be placed preferentially. Prospective studies from additional centers are needed to validate and refine these recommendations. It is also possible that newer vascular access technologies, such as bioengineered vessels or endovascular AV fistulas, may lead to future changes in vascular access strategies.

Figure 1:

The arteriovenous fistula pendulum, summarizing vascular access strategies during three time periods.

Disclosures

Disclosure forms, as provided by each author, are available with the online version of the article at https://links.lww.com/JSN/E602.

Funding

M. Allon: NIMHD (R01 MD013818).

Acknowledgments

The content of this article reflects the personal experience and views of the author(s) and should not be considered medical advice or recommendation. The content does not reflect the views or opinions of the American Society of Nephrology (ASN) or JASN. Responsibility for the information and views expressed herein lies entirely with the author(s).

Author Contributions

Conceptualization: Michael Allon.

Writing – original draft: Michael Allon.

Writing – review & editing: Timmy Lee.

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