Renal Artery Stenosis

Renal artery stenosis, also called renal artery disease, is narrowing of the arteries that send blood to your kidneys. One or both of these arteries can grow too narrow, typically due to plaque buildup along the artery walls. As the artery narrows, there’s less room for blood to flow through and reach your kidneys.

At first, your kidneys can adapt. But the narrowing may get worse over time and greatly reduce blood flow to your kidneys. This can lead to a range of issues, like high blood pressure and kidneys that are less able to filter waste out of your blood. Medications and changes to your daily habits are mainstays of treatment. Some people need a procedure to improve blood flow to their kidneys.

About 7 in 100 people over age 65 have renal artery stenosis. It’s more common among those who have peripheral artery disease (PAD) or congestive heart failure.

Symptoms of renal artery stenosis

Most people don’t have symptoms of narrow kidney arteries. Rather, healthcare providers notice signs during physical exams and tests. The two main signs of renal artery stenosis are:

• High blood pressure: When your kidneys can’t receive enough blood, they activate hormones that raise blood pressure throughout your body.
• Declining kidney function: Without enough blood flow, your kidneys may not work as well as they should. This usually happens later as renal artery stenosis gets worse.

Symptoms you may develop from very high blood pressure or poor kidney function include:

• Confusion
• Blurry vision
• Bubbly or foamy pee
• Itchy skin
• Loss of appetite
• Severe headaches
• Swelling
• Trouble sleeping
• Weakness or feeling very tired

Renal artery stenosis causes

The most common cause of renal artery stenosis is plaque buildup in your arteries (atherosclerosis), but some people develop it for other reasons. Here’s a breakdown:

• Atherosclerosis: Causes about 9 in 10 cases, mostly among adults over age 65
• Fibromuscular dysplasia: Causes about 1 in 10 cases, mostly among younger adults
• Vasculitis: Rare but possible cause, accounting for fewer than 1% of all cases

Risk factors

Renal artery stenosis has the same risk factors as plaque buildup in arteries throughout your body. These include:

• Diabetes
• High blood pressure
• High cholesterol
• Smoking or tobacco use

Many people who have renal artery disease also have plaque buildup in their heart arteries (coronary artery disease) and/or leg arteries (PAD).

Complications of this condition

Renal artery stenosis can lead to serious problems like:

• High blood pressure throughout your body that results from lack of blood flow to your kidneys (renovascular hypertension)
• Fluid buildup in your lungs that happens suddenly and keeps coming back (flash pulmonary edema)
• Damage to your kidneys that keeps them from working as they should (chronic kidney disease)
• Sudden drop in blood flow to your heart (acute coronary syndrome)
• Sudden decline in heart function (acute heart failure)

You might hear your healthcare provider use the term “Pickering syndrome.” This refers to flash pulmonary edema and reduced kidney function that occur together as complications of renal artery stenosis.

How doctors diagnose this condition

Healthcare providers commonly diagnose renal artery stenosis when running tests for other reasons. For example, an imaging test of other blood vessels in your belly and upper legs may show narrowing of your kidney arteries.

Sometimes, providers notice clues that make them suspect renal artery stenosis. For example, a physical exam and review of your medical history may show:

• Your blood pressure suddenly goes up after being well-managed for years.
• You have high blood pressure that won’t go down even though you’re taking multiple medicines.
• Your kidney function suddenly worsens without a clear cause.
• There’s a “whooshing” sound (bruit) when your provider listens to arteries in your belly with a stethoscope.

These findings might mean that your renal arteries are narrowed and reducing blood flow to your kidneys. To learn more, your provider may run one or more tests, including:

• Kidney function tests
• Ultrasound
• CT angiogram
• Magnetic resonance angiogram (MRA)
• Catheter angiogram

These can show if your renal arteries are narrowed and, if so, how narrow they’ve become. They also help your provider learn how well your kidneys are working. The results guide treatment.

How is renal artery stenosis treated?

The most common treatments for renal artery stenosis are medications and changes to your daily habits. Some people need a minimally invasive procedure to widen their renal arteries and help blood reach their kidneys. Nowadays, open surgery is the least common treatment for this condition.

Medications

There’s no single medicine for renal artery stenosis. But healthcare providers commonly prescribe several different medicines that improve blood flow in all your arteries and lower your risk of complications. These include:

• Blood pressure medicines to lower your blood pressure to a safer level
• Statins to lower your LDL cholesterol and limit plaque buildup in your arteries
• Aspirin to “thin” your blood and reduce your risk of a heart attack or stroke
• Oral diabetes medications to lower your blood sugar levels and manage diabetes

Changes to your habits

Your healthcare provider will likely recommend a variety of changes to lower your blood pressure and help your heart and blood vessels work at their best. They may advise you to:

• Quit smoking
• Reduce salt in the foods you eat
• Build up to at least 150 minutes of aerobic exercise per week (like walking or swimming)
• Maintain a weight that’s healthy for you

Procedures and surgeries

You may need a procedure if your blood pressure is still too high despite taking medicines or if you develop other complications. Options include:

• Renal artery stenting: This is a minimally invasive procedure, meaning it uses small cuts rather than a large incision. Your provider inserts a metal mesh tube into your renal artery. This props it open to let blood flow through more easily.
• Renal artery angioplasty: Your provider inflates a tiny balloon in your renal artery to widen it. Usually, providers put in a stent, as well. But if you have fibromuscular dysplasia, you may have only an angioplasty, without stenting.
• Renal artery bypass surgery: Your provider makes a new path for blood to flow around the narrowed artery. This is rare today thanks to angioplasty and stenting. Providers usually only do this surgery when procedures don’t help, or you need surgery on nearby vessels. 

When should I see my healthcare provider?

Your provider will tell you how often to come in for follow-up visits if you have renal artery stenosis. These are very important. Your provider will keep a close eye on your condition and look for signs of complications — like problems with your heart or kidney function.

Contact your provider if you have:

• Higher blood pressure readings than usual when you check at home
• Tiredness or weakness without a clear reason
• Loss of appetite
• The need to pee more often than usual
• Trouble sleeping
• Swollen hands, feet or ankles

Call 911 or your local emergency services number if you have:

• Chest pain or discomfort
• Cough that produces blood or frothy mucus
• Trouble breathing — which may feel like you’re gasping for air or suffocating
• Wheezing

What can I expect if I have this condition?

Renal artery stenosis is a condition that gets worse over time. Your healthcare provider will keep a close eye on how you’re feeling and run routine tests. Treatment can help slow the progression and lower your risk of complications.