|Year : 2020 | Volume
| Issue : 4 | Page : 395-398
Outcomes from our model for a nurse-led vascular renal access surveillance clinic
Alison McGill, Nigel Pinto, Mandy Zweedyck, Jason Jenkins
Department of Vascular Surgery, Royal Brisbane and Women's Hospital, Herston, Australia
|Date of Submission||16-Feb-2020|
|Date of Decision||10-Mar-2020|
|Date of Acceptance||22-Mar-2020|
|Date of Web Publication||24-Dec-2020|
Department of Vascular Surgery, Royal Brisbane and Women's Hospital, Herston
Source of Support: None, Conflict of Interest: None
Background: A patent arteriovenous fistula (AVF) with adequate flow is essential for performing successful hemodialysis. However, the literature currently reports 1-year patency rates of 69%–74%. Surveillance of AVFs has been proposed to prevent failure of fistulas with the associated morbidity and mortality. We implemented a renal access surveillance clinic with the aims of detecting stenoses and arranging treatment to avoid underdialysis and thrombosis of AVFs. Methods: The nurse-led vascular renal access surveillance clinic (VRAC) of the Royal Brisbane and Women's Hospital was created in 2015. The surveillance program is run by a full-time vascular clinical nurse with experience in renal access. Over the 3-year period of 2015–2017, 1006 patients were in the surveillance program. We compared the rates of intervention on fistulas and the incidence of thrombosed fistula in the 5 years preceding the initiation of our VRAC surveillance program, with the 3 years after it was commenced. Results: Our results show that our rates of intervention on threatened fistulas have increased since the program was established, and that the percentage of thrombosed fistulas has remained stable. Allowing this early triage has expedited management and freed more outpatient clinic time. Conclusion: We have compared outcomes before and after implementation of a nurse-led dialysis access surveillance program and have found that the percentage of thrombosed fistulas has remained stable as the rates of intervention have increased for threatened fistulas.
Keywords: Chronic kidney disease, hemodialysis, nursing, vascular access
|How to cite this article:|
McGill A, Pinto N, Zweedyck M, Jenkins J. Outcomes from our model for a nurse-led vascular renal access surveillance clinic. Indian J Vasc Endovasc Surg 2020;7:395-8
|How to cite this URL:|
McGill A, Pinto N, Zweedyck M, Jenkins J. Outcomes from our model for a nurse-led vascular renal access surveillance clinic. Indian J Vasc Endovasc Surg [serial online] 2020 [cited 2022 Nov 26];7:395-8. Available from: https://www.indjvascsurg.org/text.asp?2020/7/4/395/304630
| Introduction|| |
Maintaining patency of arteriovenous fistulas (AVFs) for renal access is an important part of care for patients receiving dialysis, as access complications are one of the leading causes of morbidity and hospitalization in patients with renal failure. A systematic analysis published in 2017 found that AVFs for renal access have a 1-year patency rate of 64%–79%. As well as patency, adequate function of the fistula is required for successful hemodialysis. Surveillance of fistulas has been proposed as a method to detect fistulas at risk for failure, so that early treatment can be arranged to preserve renal access.[3-5] Treatment options include open and endovascular surgery to investigate and treat stenoses. These operations have inherent risks associated with treatment. Therefore, surveillance needs to strike a balance between preventing graft thrombosis and unnecessary interventions. There have been studies evaluating different methods of surveillance, with a lack of clarity for the best approach to monitoring and surveillance.,,
A systematic review published in the journal Medicine in 2018 reviewed 9 randomized control trials and found a significant reduction in fistula thrombosis with ultrasound surveillance. However, the same benefit was not found for arteriovenous grafts.
As one of the main reasons for hospitalization in renal failure patients, access complications contribute a significant part of the cost of health care in these patients and effects their quality of life. Studies investigating the health economics of fistula surveillance also showed that outpatient surveillance of fistulas led to decreased inpatient admissions, decreased length of hospital stay, decreased waiting time to surgery, and decreased cost of care. Therefore, establishing an effective surveillance program to identify fistulas at risk and prevent fistula thrombosis would lead to reduced hospitalizations and improve quality of life for patients on dialysis.
| Methods|| |
Ethics exemption was obtained for this project from the hospital's Human Research Ethics Committee. Our tertiary hospital services a catchment area of approximately one third of Queensland, which has a population of 4.7 million people. In 2017 in Queensland there were 2074 people having hemodialysis. Of these, 1707 were through an AVF or graft. There were 201 new AVFs or grafts created in our state in 2017. The Australia and New Zealand Dialysis and Transplant Registry shows that the prevalence of AVFs has increased by 19% since 2011, which is an average of 3% per year. The prevalence of hemodialysis has also been increasing by an average of 4% per year over the same time period. The growth in prevalence of hemodialysis makes the creation and maintenance of well-functioning AVFs an ongoing priority for vascular and renal units.
The Department of Vascular Surgery at the Royal Brisbane and Women's Hospital created a nurse-led vascular renal access surveillance clinic (VRAC) in 2015. Prior to 2015 all referrals and reviews were conducted in the surgical outpatient setting. After an initial review in the outpatient clinic, follow-up reviews were organized to preform surveillance of the fistula. A renal access nurse was employed in the unit to coordinate referrals and surgery but did not review surveillance imaging or patients. From 2015, this role was expanded, and a full time vascular clinical nurse with experience in renal access began to run the surveillance program. The nurse-led surveillance program coordinates the care of patients with renal access from their initial referral, through reviews and surgery, to surveillance or discharge. All referrals from dialysis units and renal physicians are triaged by the nurse. Dialysis units are encouraged to refer early with problems based on clinical and functional parameters to identify threatened fistulas: abnormal clinical examinations, access flows <500 ml/min, a >25% reduction in volume flow on transonic, or problems on dialysis which include change in access flow rate, poor clearance, bleeding, cannulation problems, and clots when cannulating. Our clinical nurse coordinates the referral process, imaging, patient appointments, discussion with the relevant surgeon, and then communicates results, plans and follow-up to the patient and dialysis units. The renal access nurse also assesses patients and their surveillance imaging to identify patients with threatened fistulas. Our surveillance program includes patients who are predialysis, as well as those undergoing home and hospital-based dialysis. The protocol for surveillance is modeled on the department's protocol for surveillance of other grafts, including prosthetic and vein grafts and stents.
The surveillance regime follows a protocol based on intervention, clinical assessment, successful dialysis and follow-up imaging:
- Following an intervention, an ultrasound of the fistula is performed 4 weeks later, and the patient is clinically assessed, or the dialysis unit is contacted for clinical progress. Depending on these results, the patient either continues surveillance or is discharged from the surveillance program
- All newly created fistulas in predialysis patients are kept on surveillance with ultrasounds every four to 6 months until successfully commenced on dialysis
- All fistulas that are prosthetic grafts or have stents are also kept on surveillance with ultrasounds every four to 6 months.
Our clinical nurse has ongoing discussions with the treating vascular surgeon throughout surveillance.
Once discharged to the care of their dialysis unit and renal physician, they are re-referred through the original pathway for any new problems.
Over the 3-year period of 2015–2017, 1006 patients were in the surveillance program. We compared the rates of intervention on fistulas and the incidence of thrombosis fistula in the 5 years preceding the initiation of our VRAC surveillance program, with the 3 years after it was commenced.
| Results|| |
We evaluated the data on fistula interventions and thrombosis from 2010 to 2017. The VRAC surveillance was implemented in 2015. Unfortunately, prior to 2015 the only accessible reliable data was from the operating theatre systems and so only thrombosed fistulas that had surgical intervention were quantifiable. From 2015 with the surveillance program, data on fistula thromboses was recorded, including ones that underwent surgical intervention and ones that were abandoned.
Our department reviewed 237 patients with fistulas in 2015, including new referrals and reviews of fistulas already under surveillance. This number of patients with fistulas under review has increased each year to 338 in 2016, and 431 in 2017.
In Queensland in 2017, there were 1707 patients with AVFs. In our catchment, there were 637 patients with fistulas. This suggests that in 2017, approximately 68% of patients with fistulas in our catchment were under surveillance.
The primary outcome assessed was the incidence and overall percentage of thrombosed fistulas. [Graph 1] shows the incidence of thrombosed fistulas each year from 2010 onwards. The values for “thrombosed fistulas” refers to those that underwent operative intervention. The values from 2015 onwards denoted “total thrombosed fistulas” also includes thrombosed fistulas which were abandoned and has been included to show the discrepancy in data and that the rate of thrombosed fistulas remains relatively stable after 2015. This also demonstrates that from 2015, between 3 and 6 thrombosed fistulas per year did not undergo operative intervention and were abandoned. This shows that approximately 26% of thrombosed fistulas were abandoned in our cohort in the surveillance program.
Our average rate of thrombosed fistulas is approximately 12 per year. In 2017, this was a rate of 2.7% in our catchment population. The current data set does not show a significant difference between the rate of thrombosed fistula prior to 2015 and that after 2015 (P = 0.38). However, the incidence of thrombosed fistulas prior to 2015 is likely underestimated given the lack of data on abandoned fistulas. Also, given that the prevalence of dialysis dependence has been increasing in our region at a rate of 3% per year over this timeframe, this in fact may represent a reduction in thrombosed fistulas as a proportion of the total number of fistulas.
The secondary outcome of fistula interventions was evaluated, with the postulation that surveillance will detect more stenoses and so the rate of intervention will also increase. [Graph 2] shows the rates of intervention and fistula creation from 2010 onwards. The rates of interventions significantly increased in the 3 years after 2015 compared to the 5 years prior to 2015 (P = 0.003). Interestingly, the rate of fistula creations significantly decreased (P = 0.001), which may also reflect a reduction in fistula creation for thrombosed fistulas, as this number should also gradually increase over time with population growth and increase in prevalence of dialysis. Overall the total number of fistula operations did show a statistically significant increase after 2015 (P = 0.01).
| Discussion|| |
Overall the results show that the use of a surveillance program to detect threatened fistulas has successfully identified fistulas at risk of thrombosis and has likely led to a reduction in thrombosed fistulas.
Our results have shown that our surveillance program is effective in detecting significant fistula stenoses as shown by the significantly increased rate of interventions since 2015. Our data shows a stable absolute rate of thrombosed fistulas before and after implementation of the surveillance program. However, this likely represents a reduction in thrombosed fistulas over the 8-year period. The prevalence of dialysis increased by 4% each year, and the prevalence of AVFs increased by 3% each year. Therefore, the incidence of thrombosed fistulas should have also increased at a rate of 3% each year to remain stable and proportionate to the overall number of fistulas. Given our rate remained stable, we can deduce that this represents a reduction in thrombosed fistulas of approximately 3% per year.
In addition, the rate of fistula creations significantly decreased. We would also have expected this rate to have increased by 3% each year, in keeping with the state-wide data on AVF prevalence. This may also be account for by a reduction in thrombosed fistulas as fewer new fistulas would have been created after a loss of a fistula due to thrombosis and suggests that the increased rates of intervention are being successful in maintaining functioning fistulas.
The additional benefits of the surveillance program identified during the study are a more efficient referral pathway for vascular access; the ability to assess patients with fistulas in regional locations without the need for outpatient clinic appointments; improved communication with dialysis units; and improved data collection on intervention rates and outcomes. The surveillance program allows assessment and planning intervention without clinical review in the outpatient setting. If clinical review by the surgeon is needed, the patient can be reviewed in the consultant outpatient clinic, but often this is unnecessary due to the clinical information from the dialysis unit and the ultrasound report. The patient is usually planned for an intervention and clinically assessed on the day of their procedure by the operating surgeon. This reduces time in hospital, time travelling, time off work and the costs associated with these for patients. It also conserves outpatient clinic resources.
We have also had positive feedback from the renal access coordinators at the dialysis units regarding the nurse surveillance program. The dialysis units feel that the benefits of the program are a streamlined referral process, an accessible coordinator for our institution, and anecdotally have reported a decrease in the number of thrombosed fistulas since 2015.
The main limitation of this study is the incompleteness of data collection prior to 2015. Having access to only operative interventions means the incidence of fistula thrombosis before 2015 is likely underestimated. Without complete data is it less clear if the nurse surveillance clinic has been successful in reducing the rates of thrombosed fistulas.
Fortunately, with the commencement of the nurse surveillance program, the clinical nurse also keeps updated data records for a number of areas in renal access, including thrombosed fistulas. This will allow future analysis and hopefully will show a trend to reduced thrombosed fistulas.
| Conclusion|| |
This study shows that a nurse-led renal access surveillance program is effective at detecting fistulas at risk of thrombosis. This has resulted in a stable rate of thrombosed fistulas, which is important in our region where dialysis rates and prevalence of fistulas are increasing. Our surveillance program provides a streamlined referral process for timely evaluation and intervention in renal access to prevent morbidity and hospitalization and reduce the cost of healthcare in patients with renal access.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Krivitski N. Why vascular access trials on flow surveillance failed. J Vasc Access 2014;15 (Suppl 7):S15-9.
Bylsma LC, Gage SM, Reichert H, Dahl SL, Lawson JH. Arteriovenous fistulae for haemodialysis: A systematic review and meta-analysis of efficacy and safety outcomes. Eur J Vasc Endovasc Surg. 2017;54:513-22.
Kidney Dialysis Outcomes Quality Initiative, National Kidney Foundation. II. Clinical practice guidelines and clinical practice recommendations for anemia in chronic kidney disease in adults. Am J Kidney Dis 2006;47:S16-85.
Polkinghorne K. Vascular access surveillance, the CARI guidelines. Nephrology 2008;13 (Suppl 2):s1-11.
Schmidli J, et al
. Editor's choice – Vascular Access: 2018 clinical practice guidelines of the European society of vascular surgery. Eur J Vasc Endovasc Surg 2018;55:757-818.
Jiang S, Stewart G, Barnes E, Jardine M, Razavian M, Gallagher M. Effect of a vascular access surveillance program on service provision and access thrombosis. Semin Dial 2013;26:361-5.
Valliant A, McComb K. Vascular access monitoring and surveillance: An update. Adv Chronic Kidney Dis 2015;22:446-52.
Hwang SD, Lee JH, Lee SW, Kim JK, Kim MJ, Song JH. Comparison of ultrasound scan blood flow measurement versus other forms of surveillance in the thrombosis rate of hemodialysis access: A systemic review and meta-analysis. Medicine (Baltimore) 2018;97:e11194.
Thomas SD, Ip EC, Katib N, Pugh D, Lennox A, Endre Z, et al
. A comprehensive renal vascular access clinic results in improved patient outcomes and reduced costs. ANZ J Surg 2018;18:185-90.