Covered Stent Improves PTA Outcomes in Upper Extremity Fistulae

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Placement of a covered stent provides better outcomes than percutaneous transluminal angioplasty (PTA) alone in hemodialysis patients with stenosis of upper extremity fistulae, concludes a randomized trial in Kidney International.

The multicenter Arteriovenous [AV] Stent Graft in the Treatment of Venous Outflow Stenosis in AV Fistula Access Circuits (AVeNEW) study enrolled 280 patients with stenosis of 50% or greater in an upper extremity AV fistula (AVF). Patients were randomly assigned to PTA alone or PTA followed by placement of the Covera self-expanding covered stent. A 6-month target lesion primary patency (TLPP) rate was compared between groups.

Thirty-day safety outcomes were “significantly non-inferior” between the two procedures. Patients receiving the covered stent had superior patency compared with PTA alone: 78.7% versus 55.8% at 6 months and 47.9% versus 21.2% at 12 months, respectively. Six-month access circuit primary patency was similar between groups.

On secondary outcome analysis at 2 years, TLPP was 40.0% in the covered-stent group versus 11.6% with PTA. Stent placement was associated with fewer target-lesion revascularizations (1.6 versus 2.8) and a longer interval between reinterventions (249.5 versus 217.6 days).

Stenoses of hemodialysis AVFs are commonly treated with PTA, but the restenosis rate is high. The AVeNEW study is the first large, randomized trial, to date, to compare the benefits of covered-stent placement with PTA alone.

The results show improvement in TLPP in the covered stent group at 6 and 12 months, with observational evidence of a continued patency advantage at 24 months. Safety outcomes are similar between groups. The researchers conclude, “Overall, the use of the Covera covered stent…provided a safe alternative to angioplasty with statistically superior TLPP results and modest clinical benefit for patients” [Dolmatch B, et al. Prospective, randomized, multicenter, clinical study comparing a self-expanding covered stent to percutaneous transluminal angioplasty for treatment of upper extremity hemodialysis arteriovenous fistula stenosis. Kidney Int, published online ahead of print March 27, 2023. doi: 10.1016/j.kint.2023.03.015;].