Arteriovenous grafts are used as the vascular access in 40-50% of hemodialysis patients. Grafts are prone to recurrent stenosis (narrowing) and thrombosis (clotting). Graft clotting is usually due to a narrowing at the site where the graft joins the vein. The standard treatment is to remove the clot and angioplasty the narrowed area. The long-term outcome is not good, lasting only about 1 month. Placing a stent (a small metallic, PTFE covered, spring) at the narrowed site may keep the graft open longer. Principal investigator's preliminary research data suggest that placing a stent at the stenotic site prolongs graft patency following thrombectomy, as compared to conventional angioplasty.