The 40-year lack of progress in haemodialysis access cannulation

Deborah J Brouwer-Maier is the vascular access marketing manager for Transonic (Ithaca, USA) and a haemodialysis nurse of 40 years. In this opinion piece, she explores how her experience has shaped her views on access, outlines its problems, and argues for longoverdue remedies.

In the spring of 2023, I will be celebrating my 40th anniversary as a nephrology nurse. I have focused most of my career on haemodialysis vascular access, including cannulation, which captured my interest during my orientation as a haemodialysis nurse for a large US dialysis provider. The vascular access education and training was on-the-job training with limited theory and skills practice. I learned cannulation with a preceptor showing me how to cannulate several arteriovenous (AV) accesses, before I was then handed the needles and expected to successfully cannulate the subsequent AV accesses. The lack of a proper fake arm for initial cannulation training led to a different training model: individuals requiring haemodialysis. I found this unacceptable, and have worked for years to help innovate cannulation training methods, techniques, and devices to improve the cannulation experience for both dialysis staff and the individuals requiring cannulation of their vascular access to receive haemodialysis.

There are a number of areas that show promise for yielding this improvement, but need more effort to bring innovation to all individuals requiring haemodialysis. Improved fake arms and simulators to help train staff on cannulation would be an excellent start, as would providing meaningful assessment and feedback on the specific element of their cannulation method to adjust to improve outcomes. This includes elements such as the angle of entry of the needle into the skin and vessel to successfully reach the centre of the target vessel without infiltration, as well as measurement of the pressure exerted on the needle, and adjustment of the needle angle to advance the needle into the vessel. The simulator devices need to be low-cost to allow utilisation by global dialysis facilities to train new staff as well as ongoing skills assessments to further the capabilities of experienced dialysis staff. Ideally, the simulators could also be utilised to train any individual requiring haemodialysis that wants to learn self-cannulation for in-centre or home haemodialysis.

We also need a standardised cannulation training programme that includes both theory and skills practice. The recent work by the Managing Access by Generating Improvements in Cannulation (MAGIC) group is supported by the UK Kidney Quality Improvement Partnership and can serve as a template for a global training process. The training also needs to expand to any individual that wants to learn self-cannulation.

Point of Care Ultrasound (POCUS) for cannulation mapping and ultrasound-guided cannulation availability globally for initial and difficult cannulation procedures by dialysis staff are also required. The POCUS allows the cannulator to measure the vessel depth from the skin to determine the proper cannulation angle, selection of the appropriate cannulation sites, improve needle site rotation for the rope ladder cannulation method, and needle advancement without infiltration. The POCUS usability has reached a level that allows any trained cannulator to use the devices for cannulation mapping and with skills training for ultrasound-guided cannulation.

We need to see advancements in the needle or cannula designs. Safety needles and buttonhole needles have been the two major innovations in the standard metal AV fistula needle design, while plastic cannula utilisation has been standard practice in Japan for many years. More recently, the utilisation of plastic cannulas has spread in Europe.

The cost and the training required for staff to adjust to the plastic cannula have limited the adoption. Currently, no device is cleared by the US Food and Drug Administration (FDA) for use. This is a promising area that needs more focus by the kidney community for the adoption of an innovative needle design to become the standard of care.

Cannulation research needs to continue to advance. The various elements of the actual cannulation procedure need more clinical research, including the arterial needle direction (antegrade or retrograde), bevel orientation (up or down), angle of entry based on vessel depth, advancement of the needle, and needle design impacting the cannulation procedure. In addition, studies have investigated general cannulation methods such as area puncture (not to be used but still commonly practised), rope ladder, and buttonhole cannulation. A cannulation simulator could allow for the various elements of cannulation to be documented and then used to analyse the clinical cannulation outcomes of the same cannulator.

I served on the 1997, 2000, and 2006 National Kidney Foundation (NKF) Kidney for future research

Test the safety, efficacy, and impact on health care resources and patient outcomes of ultrasoundguided cannulation in busy, operating dialysis units

Assess impact of manual compression versus mechanical clamp use after needle withdrawal on access patency/stenosis (AV access flow dysfunction)

Test effectiveness of simulation models and other techniques for improving cannulation success, reducing complications and improving patient satisfaction

Define expert cannulator and determine how such expert cannulators can maintain their expertise and be best used to improve overall cannulation success within a unit and for individual patients

Identify obstacles to achieving complication-free cannulation and strategies to mitigate such obstacles

RCTs to assess standard needles versus plastic cannulas in preserving AV access patency and reducing complications

RCTs to assess impact of needle size and pump speed on long-term AV access patency

Identify best practices for mechanics of cannulation, including needle type and size, angle of insertion, and graduated flow rates

Evaluate outcomes associated with alternative cannulation devices

Evaluate the safety, efficacy, and patient satisfaction with using plastic cannulas

Disease Outcomes Quality Initiative (KDOQI) VA Guideline Work Groups, and sadly so many of the questions they raised remain unanswered. Real future improvements in cannulation-related outcomes will require the 2019 KDOQI VA Guideline’s recommended research areas to be properly addressed. I remain optimistic that the kidney community is willing and able to keep improving cannulation with more progress in the next 5–10 years than I have witnessed in my 40 years of nephrology nursing.

References:

Liu Z, Zhang Z, Kunkel D, et al. Is experience in haemodialysis cannulation related to expertise? A metrics-based Investigation for skills assessment. Ann Biomed Eng. 2021 Jul;49(7):1688-1700. doi: 10.1007/s10439-020-02708-5. Epub 2021 Jan 8. PMID: 33417054; PMCID: PMC8263797.

Liu Z, Bible J, Petersen L, et al. Measuring cannulation skills for haemodialysis: Objective vs. subjective assessment. Front Med (Lausanne). 2021 Nov 30;8:777186. doi: 10.3389/fmed.2021.777186. PMID: 34917637; PMCID: PMC8669158.

Singapogu R, Chowdhury A, Roy-Chaudhury P, et al Simulator-based haemodialysis cannulation skills training: a new horizon? Clin Kidney J. 2020 Dec 6;14(2):465-470. doi: 10.1093/ckj/sfaa206. PMID: 33623670; PMCID: PMC7886575.

Zhang Z, Liu Z, Singapogu R. Extracting subtask-specific metrics toward objective assessment of needle insertion skill for haemodialysis cannulation. J Med Robot Res. 2019 Sep-Dec;4(3-4):1942006. doi: 10.1142/s2424905x19420066. Epub 2020 Apr 14. PMID: 33681506; PMCID: PMC7932179.

Niyyar VD. Ultrasound-based simulation for cannulation in outpatient haemodialysis units: An educational protocol. J Vasc Access. 2021 Jul;22(4):585-589. doi: 10.1177/1129729819891530. Epub 2019 Nov 29. PMID: 31782682.

Schoch M, Bennett PN, Currey J, et al. Point-of-care ultrasound use for vascular access assessment and cannulation in haemodialysis: A scoping review. Semin Dial. 2020 Sep;33(5):355-368. doi: 10.1111/ sdi.12909. Epub 2020 Aug 3. PMID: 32744355; PMCID: PMC7496621.

Smith V, Schoch M, Andie Xu Q, et al. The use of haemodialysis plastic cannula in prevalent patients with kidney failure: A feasibility crossover randomised trial study. J Ren Care . 2022 Dec;48(4):253-261. doi: 10.1111/jorc.12411. Epub 2022 Feb 4. PMID: 35119213.

Marticorena RM, Dacouris N, Donnelly SM. Randomised pilot study to compare metal needles versus plastic cannulae in the development of complications in haemodialysis access. J Vasc Access. 2018 May;19(3):272-282. doi: 10.1177/1129729817747535. Epub 2018 Feb 28. PMID: 29772982; PMCID: PMC6161775.

Nalesso F, Garzotto F, Muraro E, et al. Fistula cannulation with a novel fistula cannula: A review of cannulation devices and procedures. Blood Purif 2018;45(1-3):278-283. doi: 10.1159/000485594. Epub 2018 Jan 26. PMID: 29478068.

Smith V, Schoch M. Plastic cannula use in haemodialysis access. J Vasc Access. 2016 Sep 21;17(5):40510. doi: 10.5301/jva.5000521. Epub 2016 Mar 10. PMID: 26980628.

Vasc-Alert, a pioneer in vascular access surveillance, has announced the publication of a study in the Journal of Vascular Access (JVA) validating its Vasc-Alert surveillance technology for dialysis patients.

THE STUDY SHOWS THAT THE technology reliably predicts which patients may suffer from stenosis, or blockage, in their access—and may even be better than clinical monitoring alone. “We knew the Vasc-Alert technology was effective, but these results showed that it performs even better than we anticipated,” said study co-author Robert Provenzano (Ascension St John Hospital, Detroit, USA).

The study, at Henry Ford Hospital in Detroit, examined 38 patients who were receiving dialysis through an arteriovenous (AV) access. Researchers performed a physical and ultrasound exam on all these patients, comparing the results to the access risk score produced by Vasc-Alert’s proprietary algorithm that predicts how likely the patients were to suffer from access complications.

The technology works by using data that is already collected by the dialysis machines, such as arterial and venous pressures, to derive the pressures in the vascular access. This means that it requires no additional staff effort or time to test the access, reducing the burden on overworked dialysis personnel, Vasc-Alert argue. These results are then reduced to a simple one to 10 access risk score. The higher the score, the more likely it is that patients will experience stenosis and require an intervention to prevent complications.

In the study, half of the patients had scores of one, two, or three (meaning low risk) and half had scores of eight, nine, or 10 (high risk). The researchers evaluated both groups of patients for access stenosis by both physical and ultrasound examinations, or what is called clinical monitoring. Patients identified with high risk scores were seven times more likely to experience stenosis than patients with low risk scores.

Lalathaksha Kumbar (Henry Ford Hospital, Detroit, USA), lead author of the study, estimates that the technology can decrease the incidence of thrombosis by “at least 30–40%”.