Renal artery stenosis is the narrowing of one or more arteries that carry blood to
your kidneys (renal arteries).
Narrowing of the arteries prevents normal amounts of oxygen-rich blood from reaching your kidneys. Your kidneys need adequate blood flow to help filter waste products and remove excess fluids. Reduced blood flow may increase blood pressure in your whole body (systemic blood pressure or hypertension) and injure kidney tissue.
Renal artery stenting is a procedure to open the renal arteries -- the large blood vessels that carry blood to the kidneys -- when they have become blocked due to renal artery stenosis (narrowing of the renal artery). Stenting opens the blockage and restores normal blood flow.
The kidneys help to control the amount of salt and fluid in the body by filtering blood and making urine. When the blood cannot get to the kidneys to remove salt and water, fluid builds up in the body. In addition, the kidney releases a hormone called renin that promotes the retention of salt and water and also causes the blood vessels in the body to become more rigid. Together, this results in a type of high blood pressure called renovascular hypertension. High blood pressure puts extra strain on the heart and other organs. Renovascular hypertension can also cause kidney failure, which can lead to dialysis or a kidney transplant.
Renal artery stenosis may cause no signs or symptoms until the condition reaches an
advanced state. Most people with renal artery stenosis have no signs and symptoms.
The condition is sometimes discovered incidentally during testing for some other reason. Your doctor may also suspect a problem if you have:
As renal artery stenosis progresses, other signs and symptoms may include:
The two main causes of renal artery stenosis include:
Rarely, renal artery stenosis results from other conditions such as inflammation of the blood vessels (vasculitis); a nervous system disorder that causes tumors to develop on nerve tissue (neurofibromatosis); or a growth that develops in your abdomen and presses on your kidneys' arteries (extrinsic compression).
Most cases of renal artery stenosis result from atherosclerosis. Risk factors for atherosclerosis of the renal arteries are the same as for atherosclerosis anywhere else in your body and include:
Imaging tests commonly done to diagnose renal artery stenosis include:
How is renal artery stenting done?
Renal artery stenting is done during a procedure called angioplasty, which involves
inserting a small catheter in the diseased renal artery. An angioplasty catheter has
a balloon on its end in order to inflate or dilate the narrowed area. Angioplasty is
a minimally invasive procedure, which means that it is performed through small
incisions rather than by cutting the body open.
Angioplasty takes place in a cath lab , a room equipped with special X-ray and imaging machines. You are also given a contrast dye that makes your arteries easier to see on the imaging equipment. You may feel some discomfort during the procedure, but it is generally not painful.
During the angioplasty:
What are the risks of renal artery stenting?