Arteriovenous fistula (AVF) is the preferred access type, offering longer access survival, lower risk of mortality, and reductions in rate of infection. AVF also requires fewer interventions following successful maturation and use.
Recent studies have suggested that maturation and maintenance of function may require two or more additional procedures following the initial AVF creation. Additional procedures notwithstanding, a proportion of AVFs do not become usable for hemodialysis, requiring patients to rely on temporary central venous catheters prior to creation of a functional AVF.
An alternative to the traditional open surgical approach for AVF creation, a new endovascular catheter-based system (the everlinQ endoAVF System) has been developed that uses a minimally invasive method to create an endoAVF. The system creates a side-to-side anastomosis without open surgery or dissection of vessel. The NEAT (Novel Endovascular Access Trial) was conducted to assess the efficacy and safety of endoAVF creation in patients with stage 4 chronic kidney disease (CKD) requiring vascular access for hemodialysis.
Marc Glickman, MD, and colleagues conducted a retrospective observational study designed to provide insight into the potential economic impact of endoAVF creation. The researchers compared the rates and associated costs of procedures performed following the initial AVF creation to facilitate or maintain AVF usability between patients with the endoAVF system (endoAVF cohort) and a propensity score-matched cohort of Medicare beneficiaries with a traditional surgical AVF (SAVF cohort). Results were reported in the Journal of Vascular Access [doi:10.5301/jva.5000723].
The study utilized data from the Centers for Medicare & Medicaid Services 5% Medicare Standard Analytical Files from 2010 to 2014 as well as clinical data from NEAT. NEAT, a single-arm, prospective, multicenter study, included 60 evaluable patients who had an endoAVF created and were followed for one year.
The 60 patients in NEAT comprised the endoAVF cohort in the current study. They were matched in a 1:1 ratio to patients in the SAVF cohort. Comparisons of the two cohorts were made of event rates of procedures required post-creation to facilitate and maintain the AVFs, along with the associated costs.
Using 1:1 propensity score matching of baseline demographic and clinical characteristics, of 3764 adult Medicare SAVF patients, 60 were successfully matched to the 60 patients in the endoAVF cohort. Following matching, baseline demographic and clinical characteristics were balanced between the two cohorts. Mean age was 61.1 years in the SAVF patients and 60.0 in the endoAVF patients; 37% of SAVF patients and 39% of endoAVF patients were male; and 36% of each cohort were white.
The total procedure rate for the matched SAVF cohort was 3.43 per patient-year, compared with 0.59 per patient-year for the endoAVF cohort (P<.05). Compared with SAVF, event rates per patient year for endoAVF were lower for angioplasty (0.93 vs 0.04), thrombectomy (0.20 vs 0.04), catheter placement (0.43 vs 0.11), arteriovenous graft creation (0.07 vs 0.02), new surgical creation of AVF (0.30 vs 0.11), and vascular access-related infections (1.23 vs 0.02), all P<.05.
Average cost for post-creation procedures were US $13,033 for the SAVF cohort and US $1794 for the endoAVF cohort; costs for the endoAVF cohort were US $11,240 lower in the endoAVF cohort than in the SAVF cohort. In a secondary analysis using only Medicare patients whose index date event was direct arteriovenous anastomosis versus the endoAVF cohort, there were no statistically significant differences in results of the cost comparisons.
Because the mean follow-up time in the endoAVF cohort was longer than in the SAVF cohort (10.9 months vs 6 months), the researchers conducted a sensitivity analysis with data on endoAVF patients censored at 6 months. The sensitivity analysis demonstrated a total event rate of 3.43 per patient-year for the SAVF cohort compared with 0.78 per patient-year for the endoAVF cohort (P<.05). The cost comparison revealed a savings in average procedure-related costs for the endoAVF cohort of US $10,533 per patient-year compared with the SAVF cohort.
The researchers cited some limitations to the study, including the use of Medicare data for the SAVF cohort patients; the presence of a procedure or diagnostic code on a medical claim does not guarantee the presence of the procedure or of the diagnosis unless they are validated against medical charts. Further, Medicare inpatient, outpatient, and Part B claims were used to estimate post-creation procedure-related costs, without inclusion of any pharmacy costs or costs related to diagnostic procedures. Finally, in the SAVF cohort, pre-dialysis status could not be determined; approximately half of the patients in the NEAT cohort were pre-dialysis and thus may have required fewer post-creation AVF procedures.
In conclusion, the researchers said, “The rates of post-creation procedures were found to be significantly lower in patients who had AVF created by an endovascular approach (endoAVF) compared with the traditional surgical approach. The associated average cost of procedures to attain and maintain the AVF in the first year following AVF creation was lower in the endoAVF cohort compared with the SAVF cohort. Longer follow-up of endoAVF clinical outcomes and their economic impact will be insightful and important for its wider adoption.”
- Researchers conducted a retrospective observational study to compare the rates and associated costs of procedures performed following creation of an arteriovenous fistula (AVF) with those following creation of an endovascular AVF (endoAVF).
- The post-procedure event rate for patients in the surgical AVF (SAVF) cohort was 3.43 per patient-year, versus 0.59 per patient-year in the endoAVF cohort.
- The average cost of post-creation procedures was US $13,033 for the SAVF cohort versus US $1794 for the endoAVF cohort.