Comparison between Surgical and Endovascular Hemodialysis Arteriovenous Fistula Interventions and Associated Costs
The data for the surgical cohort (SAVF) was obtained from the United States Renal Data System standard analytical files(USRDS). The data for the endovascular cohort (EAVF) was obtained from the NEAT study. Medicare payment rates for any intervention performed after creation of the fistula was used as a proxy for cost comparison (both technical and professional). Two groups of patients in each cohort were described. Incident patients are not yet on dialysis but have a fistula created in anticipation where as prevalent patients are on dialysis. The two cohorts were matched 1:1 using a propensity matching system. In the incident group, 27 and in the prevalent group 33 patients from each cohort (SAVF vs EAVF) were compared.
In the incident group the event rates were 0.74/Patient Year(PY) for the EAVF cohort whereas it was 7.22/PY for the SAVF cohort(P<0.0001) resulting in a cost difference of $16,494/patient. In the prevalent group the event rates were 0.46/PY and 4.1/PY respectively for the EAVF and the SAVF cohorts (P<0.0001) resulting in a cost difference of $13,389/patient. Additional sensitivity analysis removing central venous catheter related events for the incident group brought the event rates lower for both cohorts at 0.62/PY(EAVF) and 3.84/PY(SAVF) with a cost difference of $11,290/patient. A time to event analysis at 1 year showed 70% of the incident group who underwent endovascular fistula creation were free from intervention compared to 18% in the surgical cohort. These numbers for the prevalent group were 62% and 18%. All these values were significant at P<0.05.
Health care costs curtailment without compromising quality of care is the mantra of the future. Value of a procedure is determined by the simple formula of outcome/cost. This paper compared propensity matched patients who underwent endovascular versus surgical fistula creation for outcomes and costs. The findings favor endovascular fistula creation to be more valuable than surgical creation. This is applicable in both patient population ie those who are not on dialysis (incident group) and those who are on dialysis (prevalent group). The intervention rates and costs are much lower for the EAVF cohort irrespective of whether they are or are not on dialysis.
The authors appropriately address the limitations of this study. The NEAT study (EAVF cohort) were patients from Canada, Australia and New Zealand whereas the USRDS (SAVF cohort) are from the US. A propensity match may not capture differences in processes of care such as multidisciplinary care. The NEAT study had a large number of incident patients (almost 50%) which may skew the data in favor of EAVF as these patients are not on dialysis. The study is retrospective and the cost are not the real numbers but Medicare rates. Notwithstanding these deficiencies, the study is a powerful indicator that endovascular creation of AV fistulas is a valuable tool. Further randomized studies addressing the outcomes will be needed to bring this new tool to be the procedure of choice for creation of vascular access.
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Arnold RJG, Han Y, Balakrishnan R, et al. Comparison between Surgical and Endovascular Hemodialysis Arteriovenous Fistula Interventions and Associated Costs. J Vasc Interv Radiol 2018; 29:1558-66 e2.
Anil K Pillai, MD
Associate Professor and Section Chief,
University of Texas Health Science Center