Stenosis should be treated if the diameter is reduced by >50% and is accompanied with a reduction in access flow or in measured dialysis doses. Other indications for stenosis treatment are dificulties in cannulations, painful arm oedema, prolonged bleeding time after cannulation or after removal of the canullae (due to high venous pressure) and hand ischemia due to arterial inflow or distal stenosis. A stenotic lesion, due to intimal hyperplasia, is the most cause for low access flow. In radial-cephalic arteriovenous fistula, 55-75% of these stenosis are located close to the areteriovenous anastomosis and 25% in venous outflow tract. In bracial-cephalic and/or basilic arteriovenous fistula, the typical location (55%) is at the junction of the cephalic with the subclavian vein and the basilic with the axillary vein, respectively. An arterial inflow stenosis >2cm from the anastomosis is uncommon, but may endanger the flow in the arteriovenous fistula.