SS13 - Improved AV Fistula Usability with Fewer Interventions Leads to Reduced Annualized Cost of AV Fistula Patients: A Propensity-Score Matched Comparative Prospective Study

Objectives: A vascular external support for arteriovenous fistula (AVF) creation (VasQ, Laminate Medical, Tel Aviv) has improved functional success in multiple European studies. Herein is the first complete report of the U.S. Pivotal Comparative Study results with cost-analysis is presented for VasQ over a 24-month period.

Methods: The U.S. Pivotal study prospectively enrolled 144 patients (90% brachiocephalic and 10% radiocephalic) at 15 sites. A group of 782 patients treated by the same surgeons from the study immediately prior to the VasQ trial enrollment period was developed from the Medicare claims database as a comparative group. Demographic, procedural and post-procedural data was collected for up to 24 months post-surgery. To emulate randomized studies, a propensity score weighting method (inverse probability treatment weighting using average treatment effect) was applied to the claims data. Statistical comparisons of primary patency (freedom-from-intervention), functional success (continuous use for dialysis over a minimum of 30 days), and post-creation intervention rates were made against the matched comparator group as well as calculating payer cost. Descriptive comparisons were made for primary failure rate (abandonment before first use by 6-month follow-up) and 24-month cumulative patency (freedom from abandonment) rates against published meta-analyses.

Results: The median diameter of vessels at the VasQ AVF creation site was 4.25 mm (2.0 - 6.6 mm) arterial and 3.95 mm (2.3 - 7.8 mm) venous. Incidence of steal (4.2%), infection (0.7%), and (pseudo)aneurysm (0.7%) at 24 months compared favorably with standard AVF creations. Demographic data for VasQ and Medicare control groups before and after weighting were typical of a U.S. population (Table I). VasQ AVFs demonstrated superior primary patency, functional success and intervention rates compared against the matched cohort (Table II). Primary failure of 7.9% for VasQ AVF patients compared favorably to the 22.0% to 32.2% reported in contemporary U.S. meta-analyses. Cumulative patency of 76.7% [95%-CI: 67.7%-83.4%] at 24-months for VasQ was superior to contemporary meta-analyses reporting 53.7% to 63.0% for standard AVFs. No difference in cumulative patency was observed between patients requiring interventions and those that did not, demonstrating VasQ did not inhibit the ability of physicians to maintain patency. The nearly 50% reduction in access interventions with VasQ at 6 months resulted in an annualized cost-reduction of $7,764.19 per pt-yr.

Conclusions: The VasQ vascular external support device delivered more functional fistula success, with earlier usability and fewer interventions, reducing overall costs of fistula creation.