Renal Artery Stenosis
Renal artery stenosis is a narrowing of the arteries that carry blood to one or both of the kidneys.
Usually seen in older people with hardening of the arteries (atherosclerosis), renal artery stenosis can worsen over time.
The condition can cause high blood pressure and kidney damage; as the body senses less blood is reaching the kidneys, it misinterprets the cause as low blood pressure. This signals the release of hormones from the kidney that cause an increase in blood pressure. Over time, renal artery stenosis can lead to kidney failure.
In more than 90% of patients, renal artery stenosis is caused by atherosclerosis, commonly known as hardening of the arteries, as plaque builds up in the walls of the blood vessels leading to the kidneys.
Renal artery stenosis usually does not cause any specific symptoms.
Other contributing factors include older age, high blood pressure, an abnormal cholesterol level, chronic kidney disease or other vascular diseases, and diabetes.
On rare occasions, renal artery stenosis can be caused by fibromuscular dysplasia, a condition in which the cells in the walls of the arteries undergo abnormal growth. More commonly seen in women and younger people, fibromuscular dysplasia is potentially curable.
Sometimes, the first sign of renal artery stenosis is high blood pressure that is extremely difficult to control, along with worsening of previously well-controlled high blood pressure, or elevated blood pressure that affects other organs in the body.
Renal artery stenosis is often discovered in patients who are undergoing tests for another reason.
If your doctor suspects that you have renal artery stenosis, tests may be ordered to confirm a diagnosis. These include:
- Blood tests and urine tests to evaluate kidney function
- Kidney ultrasound to show the size and structure of the organ
- Doppler ultrasound to measure blood flow to the arteries and kidney
- Viewing a 3D image of the kidneys and their blood vessels can be helpful, your vascular surgeon may also order a magnetic resonance arteriogram and computed tomographic angiography.
The first line of treatment for renal artery stenosis is usually medication to control high blood pressure.
Patients may also be asked to take other medications such as cholesterol-lowering drugs and aspirin.
In some cases, an angioplasty may be recommended. This procedure involves inserting a catheter into the body through a blood vessel, where it is guided to the damaged renal artery. A balloon on the catheter is then inflated to open up the inside of the artery, and a stent can be placed to keep the area open.
For some patients, surgery to bypass the narrowed or blocked portion of the artery or to remove a non-functioning kidney may be required.