Renal artery angioplasty and stenting is a minimally invasive medical procedure used to treat renal artery stenosis, a narrowing of the renal arteries that supply blood to the kidneys. This procedure involves the insertion of a catheter with a small balloon into the affected artery, which is then inflated to widen the narrowed area. A stent, a small mesh tube, is often placed in the artery to help keep it open and maintain blood flow.