Safety and efficacy of a new covered stent in hemodialysis vascular access outflow stenosis: A Brazilian multicenter retrospective study

Abstract

Background: Vascular stenosis commonly leads to dysfunction in hemodialysis vascular access. Although percutaneous transluminal angioplasty is an established treatment, stent utilization has increased in the last decade as an alternative solution to extend the access function. This study evaluated the safety and initial results of a new impermeable covered stent for treating vascular access outflow stenosis.

Methods: Investigators retrospectively analyzed 114 hemodialysis patients treated with polytetrafluorethylene-covered stents from September 2018 to September 2022 across four centers. Lesions treated were de novo or restenotic and located in the venous graft anastomosis, outflow segment, cephalic arch, and basilic swing point. Patients were followed by in-person physical examination at 1, 3, and 6 months, and Duplex ultrasound was performed to evaluate the vascular access circuit and in-stent restenosis. The primary efficacy endpoint was target lesion primary patency at 1, 3, and 6 months. Secondary endpoints included access circuit primary patency and secondary patency at 1, 3, and 6 months. The primary safety endpoint was freedom from local or systemic serious adverse events through 30 days post-procedure.

Results: Forty-four patients had thrombosed access at the initial presentation, and 41 patients presented with recurrent stenosis. The target lesion primary patency rates at 1, 3, and 6 months were 100%, 89.4%, and 74%, respectively. The access circuit primary patency rates were 100% at 1 month, 85% at 3 months, and 62.7% at 6 months. The secondary patency rates at 1, 3, and 6 months were 100%, 96.4%, and 94.6%, respectively. In the adjusted multivariate Cox regression analysis, only recurrent lesions and female gender were associated with reduced primary patency rates. No serious adverse event was observed through the first 30 days post-procedure.

Conclusion: In this retrospective analysis, a new covered stent was shown to be safe and effective for treating peripheral outflow stenosis in vascular access.

Keywords: Hemodialysis; covered stent; stenosis; stent graft; vascular access.

Figure 1.

Study device: (a) SOLARIS multidirectional, impermeable electrospinning PTFE membrane and (b) three tantalum marker bands (distal/proximal).

Figure 2.

Example of procedural outcomes in a patient with brachiobasilic AVF with stenosis at the swing point: (a) angiography of a basilic vein transposition with severe stenosis at the swing point identified during a thrombectomy procedure, (b) final angiography after implantation of the Solaris 9 × 60 mm coated stent (stent graft), and (c) control angiography 7 months after the initial procedure without evidence of restenosis.

Figure 3.

(a) The target lesion primary patency rates were 100% at 1 month, 89.4% at 3 months, and 74% at 6 months, (b) the access circuit primary patency rates were 100% at 1 month, 85% at 3 months, and 62.7% at 6 months, (c) the target lesion secondary patency rates at 1, 3, and 6 months were 100%, 96.4%, and 94.6%, respectively, and (d) target lesion patency by segments 6 months after stent implantation.