When arteries and veins are connected for hemodialysis, the veins will sometimes become narrowed due to the increased pressure of the arterial blood entering the fistula or graft.
When this happens, an interventional radiologist or surgeon may perform a procedure called angioplasty, in which a temporary balloon is inflated in the fistula or graft or in the outflow veins to re-expand the walls. Occasionally an internal stent may also be needed to keep the vein open. These are procedures that can be done in the clinic during the fistulagram.