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Arteriovenous fistula (AVF) complications are classified based on fistula outcomes. This review aims to update colour Doppler (CD) and pulse wave Doppler (PWD) roles in managing early and late complications of the native and prosthetic AVF. Vascular access (VA) failure occurs because inflow or outflow stenosis activates Wirchow’s triad inducing thrombosis. Therefore, the diagnosis of the tributary artery and outgoing vein stenosis will be the first topic considered. Post-implantation complications occur from the inability to achieve AVF maturation and dialysis suitability due to inflow/outflow stenosis. Late stenosis is usually a sequence of early defects repaired to maintain patency. Less frequently, in the mature AVF or graft, complications are acquired ‘de novo’. They derive either from incorrect management of vascular access (haematoma, pseudoaneurysm, prosthesis infection) or wall pathologies (aneurysm, myxoid valve degeneration, kinking, coiling, abnormal dilation from defects of elastic structures). High-resolution transducers (10–20 MHz) allow the characterization of the wall damage, haemodynamic dysfunctions, early and late complications even if phlebography remains the gold standard for the diagnosis for its sensitivity and specificity.

Central venous cannulation is a frequent need for urgent or scheduled hemodialysis. Many studies confirmed the pivotal role of ultrasound in this procedure. Vascular access guidelines strongly recommend ultrasound guidance. Its usefulness has been demonstrated not only in reducing complications of venipuncture but more recently for the evaluation of central venous catheter (CVC) placement and real-time check for possible complications. The use of ultrasound requires a precise technique for the correct handling of the probe and the needle movement. Different approaches as the out-of-plane, in-plane, and oblique methods are available, enabling the most appropriate for the individual case. Although the learning curve for CVC ultrasound placement is usually fast, formal training and certification for beginners are strongly recommended.