Dialysis vascular accesses called arteriovenous fistulas ( AVF) are essential to ensure extra-renal purification by hemodialysis for patients with chronic end-stage renal disease. Complications of dialysis AVF cause significant morbidity and hospitalization. Dialysis AVF angioplasties are frequently used to treat stenosis, the 1st complication concerning them and which announces the complete thrombosis which may be the definitive loss of the AVF. Historically performed under X-ray, the progression in the quality of ultrasound scanners allows today to perform this procedure under echo-Doppler guidance and thus to avoid both radiation and the injection of iodinated contrast products and their complications. It is thus possible to preserve residual renal function, a situation with a better prognosis, or to help the maturation of the AVF without precipitating the patient towards dialysis. The procedure can then be less costly, requiring a much lighter infrastructure.

The complication rates of ultrasound angioplasty remain poorly known because only a few series have been published. In addition, the evolution of the echo-Doppler parameters of the AVF is unknown during angioplasty and it is difficult to know which are the most reliable to distinguish during the procedure a "good angioplasty gesture" from an incomplete angioplasty to be continued. The proposed study would provide initial insight into the question posed.

This is an observational, retrospective study on data from routine care. All angioplasties concerning major patients, meeting the inclusion criteria and performed during the inclusion period will be taken into account. (For this purpose, a list of procedures performed at the Vichy Hospital will be established via the angioplasty procedure reports.

In order to establish the evolution of the echographic parameters over time, the echographic data will also be collected from each follow-up report corresponding to each procedure until the end of the follow-up. These reports correspond to the normal post-intervention control ultrasounds at 1 month, 3 months and the annual visits. If intermediate ultrasounds are available, their reports will also be used.

In the case of a patient having an emergency angioplasty, the data of the control ultrasound triggering the intervention will be used as pre-intervention data.

Inclusion Criteria:

• Patients over 18 years old
• Patient undergoing whose fistula is treated by angioplasty under echo-doplerat the Vichy Hospital Center between 01/01/2015 and 31/12/2019

Exclusion Criteria:

• Patients who are minors,
• Patients with an AVF with a flow rate < 100 mL/min.
• Patients with acute or chronic, segmental or total occlusion of an AVF segment
• Patients with acute or chronic, segmental or total thrombosis of an AVF segment
• Patients whose main obstacle is located on the arterial side.
• Intervention that required the use of X-rays.

Patients with end-stage renal disease treated by dialysis whose AVF angioplasties is performed under echo-doppler at the Vcihy Hospital Center

All of the individual participant data collected during the trial, after deidentification.

Immediately following publication ending 5 years following arti

Researchers who provide a methodologically sound proposal. Proposals should be directed to Fabrice.Abbadie@ch-vichy.fr