Long-term Results of Interwoven Nitinol Stents to Treat the Radiocephalic Anastomotic Arteriovenous Fistula Stenosis

Introduction: Juxta-anastomotic stenosis (JXAS) is a common problem afflicting the arteriovenous fistula (AVF). This study aimed to evaluate the safety and long-term efficacy of an interwoven nitinol stent (Supera, Abbott Vascular, Santa Clara, CA, USA) in the treatment of radiocephalic AVF JXAS. Methods: A single-center, retrospective, observational study was conducted of patients with failing AVF due to JXAS treated with an interwoven nitinol stent. End points included JXAS target lesion primary patency, access circuit primary patency, assisted access circuit primary patency, and endovascular intervention rate (EIR). Results: Sixty patients were treated with a Supera stent in the JXAS between February 2014 and March 2020. One patient was excluded (AVF used for illicit drug use), leaving 59 patients (67.8% male, mean age 66.9 +/- 11.4 years [range: 40-84]) with typical medical comorbidities. Overall, 45.8% of patients had previous AVF intervention. The stent was inserted with a 100% technical success rate with a mean follow-up of 729.6 +/- 456.0 days (range: 5-2182 days). Juxta-anastomotic stenosis target lesion primary patency was 68.2 +/- 6.6%, 53.3 +/- 7.5%, and 46.2 +/- 8.1% at 12, 24, and 36 months, respectively. The EIR was .64 (0-3.29) procedures/patient/year, after which the assisted access circuit primary patency rate was 94.3 +/- 3.2% at 12, 24, and 36 month time points. Three thrombosed circuits occurred which were all successfully salvaged with no difference in patency by indication for procedure and no AVFs lost/abandoned out to 3 years. Avoidance of stent post-dilatation and the presence of stent mal-apposition were associated with improved primary patency, and reduced EIR, which may suggest an importance in vessel preparation prior to stent implantation. Conclusion: Interwoven nitinol stent treatment of the failing AVF with JXAS results in promising 3 year JXAS patency, with a low rate of endovascular re-intervention for those circuits developing restenosis. All AVFs were maintained over 3 years, demonstrating this treatment allows for long-term radiocephalic AVF vascular access.