An Angioplasty procedure is preformed when there is a blockage shown in the fistulogram. This involves the insertion of a special tube, which has a tiny deflated balloon. The balloon is positioned at the site of the blockage and is then inflated. Following an angioplasty, if there still is not enough blood flow through the area of blockage, a metal mesh tube (stent) may be placed at the site. The stent will widen the vessel and improve the blood flow.