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24-Month Results from the Prospective, Multi-Center AVeVA Study

Presented During:

Sat, 6/13/2020: 12:23 PM  - 1:32 PM 
Webinar  
Room: Webinar  

Final ID:

13 

Authors:

B Dolmatch1, B Dolmatch1

Institutions:

1N/A, Mountain View, CA

First Author:

Bart L. Dolmatch, MD, FSIR  
N/A
Mountain View, CA

Co-Author:

Bart L. Dolmatch, MD, FSIR  
N/A
Mountain View, CA

Presenting Author:

Bart L. Dolmatch, MD, FSIR  
N/A
Mountain View, CA

Purpose:

To assess the use of the self-expanding COVERA™ Vascular Covered Stent to treat stenotic lesions at the venous anastomosis of upper extremity hemodialysis arteriovenous (AV) grafts.

Materials:

Fourteen study centers in the U.S. treated 110 patients with venous anastomotic stenosis ≥ 50% and clinical dysfunction in their AV grafts. Patients received PTA followed by COVERA™ Vascular Covered Stent placement. Primary endpoints were 30-day safety and 6-month target lesion primary patency (TLPP), both compared to performance goals (PG) derived from previous pivotal studies and the literature. Secondary measures included TLPP, access circuit primary patency (ACPP), secondary circuit patency, index of patency function (IPF), and the number of reinterventions needed to maintain patency through 24 months.

Results:

Freedom from primary safety events at 30 days was 96.4% while TLPP at 6 months was 70.3% [90% CI 61.9%, 77.7%], both superior to PGs of 88% (p=0.002) and 40% (p=0.0001), respectively. Seventy-five patients completed 24-month follow up (68.2%); 27 patients died before completion of the study while 8 patients were lost to follow up, withdrew, or were withdrawn by the investigator. TLPP (Kaplan-Meier survival estimate) was 54.2% [95% CI 43.7%, 63.6%] at 365 days and 36.9% [26.6%, 47.1%] at two years (730 days). ACPP (K-M analysis) was 16.7% at 365 days and 7.8% at 730 days. Secondary patency, maintenance of the access circuit until abandonment, was 85.4% at 12 months and 73.6% at 24 months. The number of reinterventions to maintain patency of the access circuit was 3.6 ± 3.1 at 24 months (1.6 ± 1.9 at the target lesion) while the IPF was 177.9 ± 153.2 days (380.3 ± 270.7 days at the target lesion).

Conclusions:

Placement of a covered stent for arteriovenous anastomotic graft stenosis in hemodialysis patients afforded significantly better TLPP and freedom from safety events compared to pre-specified performance goals at six months. At 24 months, the TLPP rate was 37%. With ongoing intervention, nearly 74% of the AV grafts remained patent at two years.

Abstract Categories:

Dialysis Interventions

Keywords:

Arteriovenous graft (AVG)
Covered self expanding stents
Hemodialysis graft