Why Does the U.S. Still Use Steel Needles for Hemodialysis?

Many years ago at a Dialysis Outcomes and Practice Patterns Study (DOPPS) meeting at ASN, the brilliant epidemiologist Ron Pisoni, PhD, MS, reported on differences in vascular access practices between Japan, the U.S., and a number of other countries. I can’t quote his actual words, but the gist of his message was that Japan did very early cannulation of fistulas.* Perhaps we should do that here? he mused. “Nooo!” I commented (I remember my part). “Japan runs at blood flow rates of 250-300. We run patients at 450-500. If we try to do that to new fistulas here, we will destroy them!”

*DOPPS found that median time to successful AVF use was 10 days in Japan, 46 days in Europe, Australia, and New Zealand, and 82 days in the U.S. (1)

I wasn’t wrong. But, I wasn’t fully informed, either. You see, Japan had a secret they still have not published about to this day: they weren’t using steel needles for hemodialysis. They have been using plastic cannulas for 30 years.

Plastic Cannulas

Let’s start with the basics. Veins bend, but steel needles are rigid. In what universe does it make sense to make people sit with large gauge, inch-plus long steel needles in their arms for hours at a time? None. In fact, 74 years ago, in 1950, it was observed that metal needles are dangerous to blood vessels (2). Yet, the authors noted, “the design of metal needles has remained relatively unchanged over the years.”

Some patients are allergic to the nickel in steel (3). Some are pediatric (3). Some have deep or tortuous accesses (3). Some are restless and can’t sit still (3). Some do nocturnal hemo (3), and if 3 ½ or 4 hours of steel needles is a lot, try to imagine 7-8 hours. Even an IV—which is a plastic cannula—is uncomfortable after a while. Plastic cannulas are also ideally suited to endovascular AVFs, which are especially challenging to cannulate with steel needles (3).

A plastic dialysis cannula is essentially a larger gauge IV. It has a metal introducer, which is withdrawn, and a soft, fluoroplastic catheter segment that stays in a fistula or graft (3).

In a 2015 study of 20 patients using plastic cannulas and 19 historic controls using steel needles, there were three times fewer hematomas with plastic cannulas, and primary fistula survival was better as well: 95% at 3 months (vs. 79% with steel), 90% at 6 months (vs. 67% with steel), and 74% at 12 months (vs. 60% with steel) (4).

Further, plastic cannulas offer more stable pressures inside fistulas, with more gentle jetting of blood against the vessel walls than with steel (5).

Avoiding Central Venous Catheters (CVCs)

A good part of the Fistula First, Catheter Last initiative is…keeping catheters last. Using plastic cannulas allows early cannulation of fistulas—so some patients can avoid starting hemodialysis with a CVC. In a study of 122 patients with new fistulas, half were cannulated early (<10 days) with plastic cannulas and half late (>10 days) (1). Of the group, just eight required a CVC—and there was no difference in access patency between the early or late-cannulated patients. Avoiding CVCs also means reducing rates of bloodstream infections, venous stenosis, and thrombosis.

Downsides to Plastic Cannulas?

Plastic cannulas do not have wings, and the cannulation technique is a bit different. This caused some challenges for nurses cannulating patients, until they got used to the change (5).

Cost is, as always, a consideration. In Europe, Canada, Australia, and New Zealand—along with Japan—some form of globally capitated care aligns fiscal incentives in favor of improving patient outcomes, and all of these countries use plastic cannulas. In Canada, there is an estimated 42.8% savings for plastic cannulas, considering the device and procedure cost (6). In Italy, authors noted, “In making decisions, hospital administration, and payer should take into consideration, not just the price of devices, but the entire patient’s pathway. The use of plastic cannulae in hemodialysis patients shows improved outcomes compared to traditional metal needles. Furthermore, combining it with accurate and efficient cannulation techniques reduces complication rates, improves patients’ quality of life, and reduces healthcare resource consumption.” (7)

Yet, in the U.S.—which has the highest rate of dialysis mortality in the developed world—the artificial “wall” between Medicare Part A (hospitalization) and Part B (outpatient services, including dialysis) is nearly insurmountable for small device innovations. No company has yet submitted a plastic cannula for FDA review and approval (though reportedly several are close) because plastic cannulas cost more up front. Since no hospital-side savings accrue to dialysis clinics, there is little incentive to spend, say $2 each on plastic cannulas when steel needles only cost about fifty cents.

We can—and we need to—do better.

References

1. Shi K, Jiang H, Wakabayashi M. Effect of early cannulation with plastic cannula on arteriovenous fistula patency in hemodialysis patients. Blood Purif. 2020;49(1-2):79-84

2. Nardinocci MD, Manocchi K, Traini T. The appropriateness of cannulation devices in the management AVF. Giorn Ital Nefrol. 2020 Jun 10; 37(3):2020-vol3

3. Kumbar L, Ramani K, Brouwer-Maier D. Considerations in access cannulation: traditional and evolving approaches. 2020 May;27(3):199-207

4. Letachowicz K, Kusztal M, Golebiowski T, Letachowicz W, Weyde W, Klinger M. Use of plastic needles for early arteriovenous fistula cannulation. Blood Purif. 2015;40(2):155-9

5. Choi SR, Park P, Han S, Kim C, Joo N, Kim JK, Song YR, Kim HJ, Kim SG, Lee HS. Comparison of dynamic arterial and venous pressure between metal needles and plastic cannulas in incident hemodialysis patients with arteriovenous graft. J Vasc Access. 2021 Jan;22(1):42-47

6. Marticorena RM, Dacouris N, Donnelly SM. Randomized pilot study to compare metal needles versus plastic cannulae in the development of complications in hemodialysis access. J Vasc Access. 2018;19(3):272-282

7. Tito F, Davidson-Peck D, Roettger AD, Borghetti F, Corbo M, Tozzi M. Hemodialysis patients and complications management costs in Italy: Plastic cannule a potentially cost-effective strategy. J Vasc Access. 2024 Mar;25(2):599-606