Aortic stent. Angiogram of a section through a patient's abdomen and left kidney, showing a stent (mesh, lower left) implanted in the infrarenal aorta for the treatment of aortic stenosis caused by atheromatous plaques. Also seen are dilated pyelo-calicean pelvis and cavities suggesting a left renal blockage, probably caused by a ureteral kidney stone (calculus). Stents are mesh tubes used to widen and reinforce blocked and/or weakened passages in the body. Here, the aorta has become narrowed (stenosed) due to the build-up of atheromatous plaques. The stent is being used to widen the aorta and restore proper blood flow.