Renal stenting is a catheter based procedure. The catheter acts as a guide to place the stent in the renal artery to open a narrowing or blockage. Stents come in a variety of strengths, sizes, and other properties. Stent selection for each procedure depends upon many factors, including the size of the artery, the location of the plaque build-up or blockage and the severity of arterial narrowing.
Renal artery disease is a condition caused by the narrowing of the arteries leading to one or both kidneys. This narrowing, or stenosis, is usually caused by a build-up of fatty and/or calcium deposits called plaque on the inside of the arteries. Over time, this plaque build up, also called atherosclerosis or hardening of the arteries, can progress to a total blockage of the artery.
The diagnosis of renal artery stenosis is growing more common, in part because of the widespread use of diagnostic tools such as captopril scintigraphy, duplex scanning, magnetic resonance angiography, and the use of aortic injection during arteriography for other indications. The increased frequency of diagnosis coupled with the current popularity and technical feasibility of renal artery angioplasty and endovascular stent placement is changing the approach to renal artery disease.
Prior to the the renal artery stenting procedure, the surgeon may choose to perform a balloon angioplasty. The physician will insert a catheter into the femoral artery and guide it through the blood vessel to the renal artery. This catheter has a small balloon on the end that the doctor can inflate when it reaches the area of the renal artery that is blocked by plaque. This flattens the plaque against the wall of the artery. To keep the plaque from closing the artery again, a stent is put in place which is basically a small metal tubular structure that supplies essential blood flow to the kidneys. The stent acts as scaffolding, keeping the artery stretched open and maintaining adequate blood flow through the vessel after it is opened with a balloon.
Renal artery stents are exposed to blood flow and may cause clots to form until they become covered with tissue by the body. Medications are taken during this time, and possibly longer, to prevent formation of blood clots. Sometimes new blockages develop in the renal arteries months or years later at a different site in a renal vessel. Occasionally, renal stents re-narrow. Because of the possibility of re-stenosis and / or new blockages, the cardiologist wants you to follow-up with a diagnostic testing schedule. You must adhere to your testing and follow-up schedules below and call your cardiologist’s office to schedule any tests that are not pre-scheduled. You will be asked to drink lots of fluids to flush the contrast dye out of your system. You will have to stay in bed for several hours, keeping your leg straight so the entry site in your groin can heal well. You may need to stay in the hospital for one or two days.