A clinical trial to assess if drug-coated balloons are an effective treatment for arteriovenous fistulas in patients on haemodialysis

INTERVENTION: DESIGN AND METHODOLOGY Patients who agree to take part will be allocated by chance into one of the three groups. Fistulas will be treated with (1) paclitaxel‐coated balloons (2) sirolimus‐coated balloons or (3) uncoated balloons. The researchers will compare the outcomes for each of the two groups treated with paclitaxel or sirolimus‐coated balloons with the control group who were treated with uncoated balloons. They will follow up for 1 year and see how long it takes for the fistula to block or for the patient to need another balloon treatment. SUMMARY OF WHAT WILL HAPPEN TO PARTICIPANTS 1. After potential participants have read the information sheet, had the opportunity to ask questions, and given written consent we will check that they fit the criteria to take part in the study. 2. They will then have a balloon treatment to their fistula which is needed for medical reasons, whether they are taking part in this study or not. 3. Following the clinically‐indicated balloon treatment, inclusion and exclusion criteria will be checked again, including a residual stenosis of less than 30% (indicating a successful procedure). If the participant remains eligible they will be randomised to one of three groups. 4. Participants will receive a second treatment (under X‐ray guidance) with either a paclitaxel‐coated balloon, sirolimus‐coated balloon, or a similar uncoated balloon straight away. 5. In some hospitals, patients will also be invited to have an ultrasound scan of their fistula before, immediately after, and three months after the balloon treatment. If someone does not wish to have the ultrasound scans they can still take part in the rest of the research study. 6. Following the second balloon treatment, study visits will occur every 3 months for 1 year. No additional vis CONDITION: Arteriovenous fistulas for haemodialysis ; Urological and Genital Diseases PRIMARY OUTCOME: Time to end of treatment segment primary patency (TSPP). TSPP ends when any of the following occurs: (a) clinically driven re‐intervention to the treatment segment; (b) thrombotic occlusion considered to be due to restenosis at the treatment segment; (c) surgical intervention that excludes the treatment segment from the access circuit; (d) abandonment of the AVF due to an inability to retreat the treatment segment. SECONDARY OUTCOME: 1. Time to loss of primary patency at any treatment segment; 2. Time to end of access circuit primary patency. Access circuit primary patency ends when any of the following occurs: (a) access circuit thrombosis, (b) an intervention (either radiological or surgical) anywhere in the access circuit, or (c) the AVF is abandoned due to an inability to treat any lesion.; 3. Time to AVF abandonment. AVF abandonment occurs when the AVF is abandoned, regardless of radiological or surgical intervention, with or without a thrombosis event. Multiple/repetitive treatments for stenoses that restore patency are compatible with cumulative patency. ; 4. Number of radiological or surgical interventions; 5. Adverse events (e.g. thrombosis, infection localised to AVF, rupture of AVF); 6. Intima‐media thickness and degree of stenosis measured using ultrasound at 3 months; 7. Patient quality of life assessed by EQ‐5D‐5L and VASQoL at 6 and 12 months INCLUSION CRITERIA: 1. Patients (18 years or over) who have an AVF in the arm which has been used for at least 8 dialysis sessions in the preceding 4 weeks 2. An indication for a fistuloplasty as determined by the local clinical team 3. The access circuit is free of synthetic graft material or stents 4. Patient able to give informed consent 5. Patient willing and able to comply with all study‐related procedures 6. People who are not breastfeeding, not pregnant, not intending to become pregnant or not intending to father children, within two years of study treatment 7. No evidence of active systemic or local (to the fistula) infection 8. No known hypersensitivity or contraindication to contrast medium which cannot be adequately premedicated 9. No known hypersensitivity or contraindication to paclitaxel or sirolimus 10. One or two treatment segments. Each treatment segment will contain one or more stenoses of at least 50% 11. Each treatment segment will be a