A First-In-Man Study to Assess Safety and Efficacy of Ultra High Pressure PTA Balloon ULTRAVIOLET in Treating A-V Fistula Stenosis

Inclusion Criteria: * Patients able to understand the purpose of the study, voluntarily agree to participate and signed Informed Consent form * Patients with impaired haemodialysis access due to narrowed lesions, as indicated by contrast or ultrasound or clinical diagnosis. * Indications for percutaneous endovascular therapy with diameter stenosis \>50% and fistula's hemodynamic showing abnormalities (thrombosis in the AVF, high venous pressure, re-circulation, abnormal physical examination, decrease in dialysis efficiency, decrease in blood flow through the vascular access) * Target lesion is a resistant de novo or restenotic lesion * The target lesion is located in the reflux vein from the anastomotic site of arteriovenous fistula (AVF) to the distal end of the subclavian vein (excluding the anastomotic site of AVF); if there are no target lesions, they should be treated with standard angioplasty balloon before treating the target lesion. Exclusion Criteria: * Female of childbearing potential, unless a recent pregnancy test is negative, who possibly plan to become pregnant any time after enrolment into this study; * Patients who are actively participating in another drug or device investigational study, who have not completed the primary endpoint follow-up period; * Patients who have undergone major surgical procedures (such as open chest surgery, head surgery) within 30 days before being enrolled in the study; * Patients who plan to undergo major surgical procedures (such as open chest surgery, head surgery) within 30 days after being enrolled in the study; * Immature AVF (not used for dialysis; due to insufficient inner diameter, inability to ensure successful puncture, and inadequate blood flow, this access has not been used for successful dialysis); * AVF has been implanted with a stent.