A medical device includes an elongate body having a distal and proximal end, a pair of anchors at the distal end and spacers extending along its length. The body is delivered to an AV fistula using a catheter connected to the proximal end by a tether. The body when deployed at the fistula is suspended within the flow stream and spaced from walls of a blood vessel. The body deflects blood flow to cause an increase in vascular wall shear stress, which has been found to induce a positive vascular remodeling.