Final Two-Year Results of the Prospective, Randomized AVeNEW Trial Comparing the Covera Covered Stent to Angioplasty for Treatment of Stenosis in Dysfunctional Hemodialysis Arteriovenous Fistula

Sunday, March 5, 2023

3:54 PM – 4:03 PM

Location: Phoenix Convention Center, 222AB

Presenting Author(s)

Bart L. Dolmatch, Attending

Attending
Palo ALto

Disclosure(s): Alio Medical, Inc.: Consultant (); Becton, Dickinson and Company: Consultant (); Medtronic Inc.: Consultant (); Merit Medical Systems, Inc.: Consultant (), Receipt of Royalties ()

Disclosure(s):

Bart L. Dolmatch, Attending: Alio Medical, Inc.: Consultant (); Becton, Dickinson and Company: Consultant (); Medtronic Inc.: Consultant (); Merit Medical Systems, Inc.: Consultant (), Receipt of Royalties ()

Purpose: To evaluate the hypothesis that use of a covered stent following percutaneous transluminal angioplasty (PTA) for treatment of upper extremity arteriovenous fistula (AVF) outflow stenosis provided better patency and clinical outcomes than PTA alone.

Materials and Methods:

Two hundred eighty (280) patients with stenotic lesions (≥ 50%) and clinical or hemodynamic evidence of AVF dysfunction were treated at 35 international centers. Patients were randomized (1:1) to PTA alone (n=138) or PTA plus covered-stent placement (n=142). Primary outcomes were 30-day safety, tested for non-inferiority between groups, and 6-month target lesion primary patency (TLPP), tested for superiority. Access circuit primary patency (ACPP) at 6 months and TLPP at 12 months were hypothesis-tested secondary outcomes while other clinical observations were recorded through two years.

Results:

30-day safety was non-inferior between groups (p = 0.002). TLPP was statistically superior for the covered-stent group at 180 days (78.7% vs. 47.9% PTA; p < 0.001) and 365 days (55.8% vs. 21.2% PTA; p< 0.001) while the observed difference was 28.4% at 2 years. ACPP was not statistically different between groups at 6 months (p=0.09) but numerically favored the covered stent group through 2 years (difference:10.3% at1 year; 4.1% at 2 years). The mean number of target-lesion reinterventions was less for the covered-stent group (1.6 + 1.6) compared to the PTA group (2.8 + 2.0) with a longer mean time between reinterventions (163 days longer) at 2 years. Cumulative circuit patency was maintained at a high level in both groups through 2 years (91.3% covered stent and 92.7% PTA).

Conclusion:

AVeNEW was the first prospective, multicenter, randomized study of a covered stent used to treat AVF stenoses. TLPP was statistically superior for the covered stent group at 6- and 12-months with observed benefit through two years. ACPP for both groups was poor suggesting that access circuit patency is not strictly related to target lesion patency. Use of the Covera covered stent provided a safe alternative to PTA with fewer interventions needed to maintain a two-year cumulative AVF patency of over 90%.