['It was reported that pathogenesis of access failure of hemodialysis patients through progressive stenosis was followed by thrombosis. Nonionic contrast media increase platelet degranulation within an angioplasty-damaged vessel by releasing procoagulant molecules, which might contribute to acute thrombosis and restenosis. An adequate level of heparin provides satisfactory thrombin inhibition during routine angioplasty. This study was performed to evaluate the effect of immediate hemodialysis after percutaneous transvenous angioplasty (PTA) to remove nonionic contrast media or other factors while injecting heparin continuously.', 'From September 9, 1998 - May 15, 2002, successful PTAs were performed in 66 patients with arteriovenous fistula who were not given any inhibitors of platelet aggregation. Hemodialysis was performed in 31 cases immediately after PTA, and in the remainder, hemodialysis was performed the next day. Patients were randomized and fistula patency rates were compared in these 2 groups on March 20, 2004.', 'The patency rates after PTA in patients who were dialyzed immediately, were significantly higher than those who were dialyzed the next day (p = 0.0120).'] Does immediate hemodialysis after percutaneous transvenous angioplasty increase patency rates of arterio-venous fistula?