To maintain patency of an upper extremity arteriovenous fistula (AVF), placement of a covered stent after percutaneous transluminal angioplasty is better than surgery alone, a new study finds.

The Arteriovenous Stent Graft in the Treatment of Venous Outflow Stenosis in AV Fistula Access Circuits (AVeNEW) study examined outcomes from 280 patients with AVF stenosis of 50% or more and circuit dysfunction. Investigators randomly assigned 142 patients to covered stent placement after surgery and 138 patients to percutaneous transluminal angioplasty alone.

Target lesion primary patency was maintained by a significantly higher proportion of the stent than no stent group at 6 months (78.7% vs 47.9%) and 12 months (55.8% vs 21.2%), Bart Dolmatch, MD, of Mountain View Interventional Radiology in California, and colleagues reported in Kidney International. At 24 months, the covered-stent group had a higher rate of target lesion primary patency (40.0% vs 11.6%), fewer target-lesion reinterventions (1.6 vs 2.8), and a longer mean interval between target-lesion reinterventions (380.4 vs 217.6 days).

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Access circuit primary patency was comparable between groups at 6 months. Within 2 years, 195 new lesions occurred in the covered-stent group, 146 new lesions occurred in the surgery-only group, and 16 new thromboses occurred in each group. A third of patients had a nontarget stenosis that required treatment at study enrollment.

The primary safety outcome was 30-day freedom from an adverse event involving the access circuit that required reintervention or surgery, led to hospitalization or longer length-of-stay, or resulted in death. The primary safety outcome occurred in 95.0% of the covered stent group and 96.4% of the surgery-only group, meeting the noninferiority criterion for safety.

Compression of the covered stent occurred in 2 cases and were treated with a repeat angioplasty. A total of 59 patients died prior to study completion.

“Given the high morbidity and mortality for patients with renal failure on hemodialysis (approximately 21% mortality during our 24-month study), if a covered stent can improve the care and lives of these patients by even a modest reduction in the number of interventions, their use seems to have little downside,” Dr Dolmatch’s team wrote. The investigators acknowledged that a future trial is needed to compare covered stents and drug-coated balloons for stenosis.

Disclosure: This research was supported by C. R. Bard/Becton, Dickinson and Company. Please see the original reference for a full list of disclosures.


Dolmatch B, Cabrera T, Pergola P, et al; AVeNEW Trial Investigators. 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 March 27, 2023. doi:10.1016/j.kint.2023.03.015