Renal Artery Stenosis

What is renal artery stenosis?

The renal arteries are the two arteries that provide blood flow to the kidneys. Renal artery stenosis is when these arteries become abnormally narrow and starve the kidney of blood. Most commonly, this happens from the buildup of plaque within the artery, a condition known as atherosclerosis.

In extreme cases, renal artery stenosis can lead to kidney failure. The kidneys clean your blood and remove toxins and waste from the body. If the kidneys fail, prompt treatment is required.

Even before renal artery stenosis causes your kidneys to fail, kidney function can be impaired by the narrowing of the arterial passages. As renal artery function decreases, so do the kidneys.

What are renal artery stenosis symptoms?

Symptoms of renal artery stenosis are often subtle or absent early in the development of this condition. As the renal arteries continue to narrow, symptoms can appear and quickly worsen.

An early sign of renal artery stenosis is the sudden development of high blood pressure, also called renal hypertension. The kidneys normally provide the body with a hormone called renin that helps regulate blood pressure. When the kidney is impaired, your body can have trouble controlling blood pressure.

Other renal artery stenosis symptoms can include the following:

• Fluid retention and swelling in the body
• Heart failure
• Heightened fatigue
• Shortness of breath
• Weakness

Request an appointment with the Mass General Brigham heart specialist team to learn more about renal artery stenosis diagnosis and treatment.

What causes renal artery stenosis?

Atherosclerosis is the most common of renal artery stenosis causes. Atherosclerosis is the buildup of fatty plaque deposits within one or more arteries. These deposits attach to the sides of arteries, where they harden and create blockages in the blood vessel. Common risk factors for atherosclerosis include high cholesterol, nicotine consumption, smoking, diabetes, unhealthy body weight, high blood pressure, and unhealthy diet.

In some rarer cases, renal artery stenosis is caused by fibromuscular dysplasia. This congenital disorder causes an abnormal thickening of the tissue that forms the arterial walls. The arteries may not have significant plaque buildup when renal artery stenosis is caused by fibromuscular dysplasia. Instead, the abnormal thickening of the arterial walls caused by this disorder is enough to dangerously restrict the renal arteries.

How is renal artery stenosis diagnosed?

Symptoms often aren't noticed until this disease has become advanced. Still, a physical exam is often the first step in a renal artery stenosis diagnosis.

When the renal arteries are narrowed enough, they sometimes make a whooshing sound, called a renal bruit, that can be detected with a stethoscope. If your physician sees or hears signs of renal artery stenosis, they may order tests to confirm the diagnosis.

Diagnostic tests that can help identify this disease include the following:

• Abdominal duplex ultrasound
• Blood and urine analysis
• Computed tomography (CT)
• Doppler ultrasound
• Magnetic resonance angiography (MRA)
• Nuclear medicine testing
• Physical exam
• Renal angiogram

How is renal artery stenosis treated?

Treatment plans for renal artery stenosis involve lifestyle changes to reduce risk factors, medications to manage symptoms, and surgery to restore proper blood flow to the kidneys.

Non-surgical renal artery stenosis treatments

Depending on your case, your treatment plan may call for lifestyle changes that include focusing on a heart-healthy diet and getting healthy levels of physical activity. This is commonly done to help manage blood pressure and cholesterol.

Blood pressure medications to help reduce and regulate high blood pressure are commonly used to help treat renal artery stenosis symptoms. A wide variety of potential medications serve this function, and your doctor will work with you to find the best one for your case.

Renal angioplasty is a nonsurgical procedure that involves sliding a catheter up the vascular system until it reaches the blocked portion of the renal arteries. At that point, a balloon is inflated in the blocked portion, forcing it to expand. If needed, the surgeon may insert stents into the arterial wall to keep it from narrowing again.

Surgical renal artery stenosis treatments

More severe cases of renal artery stenosis may require surgery. Renal artery bypass surgery involves grafting a portion of healthy artery onto the renal arteries. This grafted portion circumnavigates the blocked area of the renal artery, creating an alternative route (or bypass) for the blood to take. Many people recover enough within a week to return to work.

An endarterectomy removes the afflicted portion of the renal arteries and the plaque buildup within that section. After the damaged piece of artery is removed, the healthy segments are reattached. Recovery from this procedure can take up to a month.

How to prevent renal artery stenosis

Because the most common cause of this disease is atherosclerosis, reducing your risk of developing atherosclerosis can also reduce your risk of developing renal artery stenosis. That means controlling high blood pressure and high cholesterol, increasing physical activity, losing weight, and quitting smoking.

How to live with renal artery stenosis

Many people with renal artery stenosis can return to their everyday lives with treatment. The prognosis can be more complicated in cases where the cause of renal artery stenosis is fibromuscular dysplasia. Treatments are not always as successful when the condition is caused by tissue thickening instead of plaque buildup.

If you’ve been diagnosed with or treated for renal artery stenosis, your physician may recommend continued lifestyle changes and medications after the primary treatment has concluded. This ongoing management can help prevent the recurrence of renal artery stenosis and can mitigate lingering symptoms.

Renal artery stenosis FAQs