A non-bioabsorbable, implantable device intended to be used for the extraluminal (external) support of an arteriovenous fistula (AVF) to facilitate viable maturation and patency of the AVF for haemodialysis. It is a metal mesh structure intended to improve the characteristics of the AVF (e.g., luminal uniformity, flow capability, luminal strength/stability) to reduce the risk of failure from adverse events such as thrombosis, intimal hyperplasia, and stenosis.