The Solaris DE Endoprosthesis for the Treatment of AV Access Stenosis or Occlusion

Inclusion Criteria: * The participant has a mature AV Fistula (AVF) or Graft (AVG) in the arm created ≥ 30 days before the initial procedure and is in use for dialysis therapy * The participant has clinical and/or hemodynamic evidence of a venous outflow obstruction or AV fistula or graft dysfunction. The stenotic lesion is ≥ 50%, with a maximum length of 8 cm and a distal reference vessel diameter from 4.0 mm to 9.0 mm * The participan provides written informed consent prior to any study-specific procedure * The participan is willing to undergo all follow-up evaluations according to the specified schedule over 24 months Angiographic Inclusion Criteria: * The target lesion originates ≥ 3 cm from the cannulation segment (needling zone) * The target lesion is located: 1. In one arm (including the cephalic arch) in a participant with AVF, and not in the cannulation segment, OR 2. In the anastomosis or juxta-anastomosis in a participant with AVF (a juxta-anastomosis is defined as a location where the stent crosses the venous anastomosis) * The target lesion includes a de novo stenotic lesion or restenosis * The target lesion is ≥ 5 cm from the arterial anastomosis * The target lesion has ≥ 50% stenosis according to the operator's visual judgment * The distal reference vessel diameter of the target lesion is between 4.0 mm and 9.0 mm by the operator's visual judgment * Single or multiple target lesions measuring ≤ 8 cm in total length by the operator's visual judgment * Single or multiple target lesions should be covered by a single stent or multiple overlapping stents, provided they are treated as a single lesion with a maximum length of 8 cm * Successful target lesion pre-dilatation is defined as crossover of the guidewir resulting in full expansion of the pre-dilatation balloon * The participant has up to 1 (one) non-target lesion in the access circuit requiring intervention in the initial procedure. The non-target lesion must be at least 10 cm away from the target lesion. The non-target lesion can only be treated with standard PTA alone * Does not have stent implanted or it has been in the access circuit for ≥ 30 days since placement and patent with ≤ 30% stenosis and located ≥ 5 cm from the target lesion * The non-target lesion must be successfully treated at the time of the initial procedure (success measured as ≤30% residual stenosis and no complications). Exclusion Criteria: * Pregnant, breastfeeding or with intention to become pregnant in the next year * The participant has any major endovascular or surgical procedure planned (including in the access circuit) within 30 days of the initial procedure * It was not possible to pre-dilate the lesion to be treated with Solaris DE * Planned surgical revision of the access site * Known or suspected infection of the hemodialysis access site, systemic infection and/or sepsis * Patients on immunosuppressive therapy * Known active coagulopathy or bleeding diathesis * Known hypersensitivity to nickel titanium alloy, contrast or sirolimus * Contraindication to antiplatelet, anticoagulant or thrombolytic therapies * Known allergy to contrast agents or medications administered to perform endovascular intervention that cannot be adequately premedicated * Life expectancy of less than 12 months * Has a stent or endoprosthesis located anywhere in the AV access circuit that is not patent (\> 30% stenosis) or implanted \< 30 days * The participant's hemodialysis access is expected to be abandoned within 6 months * The participantis is enrolled in another trial involving an investigational product (pharmaceutical, biological or medical device) * The patient has a permanent central venous catheter (CVC) for dialysis access, except when its use is temporary, as a bridge to treatment through the access circuit, with a plan for removal after a successful dialysis session after the initial procedure Angiographic Exclusion Criteria: * The target lesion is located inside an endoprosthesis * Target lesion treatment would involve the cannulation segment (needling zone) * The target lesion is \< 5 cm from the arterial anastomosis * There was a dissection or rupture of the treated vessel during the initial treatment that could not be controlled * Evidence of an aneurysm, pseudoaneurysm or acute thrombus (i.e. one that has been treated ≤ 15 days) within the target lesion * The target lesion is, and/or Solaris DE would be placed anywhere: 1. Through the elbow 2. In a region that causes bending of the endoprosthesis or bony protrusion over it 3. In the cannulation segment (needling zone) 4. Inside any part of a pre-existing stent or endoprosthesis (apart from an access arteriovenous graft) 5. Lower extremity 6. Non-synthetic graft 7. Central thoracic veins located proximal to the cephalic vein arch * The target lesion is located in such a way that the insertion of a stent would result in a "kink" area that requires a stent bridge between the Solaris DE and an existing stent or stent graft * The individual has more than 1 (one) non-target lesion (≥ 50% stenosis) that requires intervention in the initial procedure