RecruitingDiagnostic testBlood Flow Conditions and Sounds in AVFsThis is a prospective non-pharmacological interventional study aimed at investigating the relationship between the blood flow condition and the arteriovenous fistula (AVF) sound, with the ultimate aim of predicting the AVF clinical, in patients with end-stage renal disease (ESRD) who require the creation of a vascular access for extracorporeal circulation.