Renal artery stenosis occurs when an artery in the kidney narrows. This causes a decrease in blood flow to that kidney. The kidneys are a pair of bean-shaped organs. They filter and remove waste from the blood. Stenosis is narrowing that restricts an opening.
Each kidney regulates the body’s blood pressure to make sure that each organ has enough oxygenated blood. This happens by activating the renin-angiotensin hormone system.
Renal artery stenosis triggers the release of these hormones. This release causes hypertension, which is also known as high blood pressure.
There are several diseases of arteries that can cause them to become narrowed, including:
- Atherosclerosis—the most common
- Fibromuscular dysplasia
Factors that increase your risk of developing renal artery stenosis include:
Most patients with renal artery stenosis have no symptoms. However, it may also cause:
- Fluid retention
- Shortness of breath
- Ankle swelling
If both renal arteries are blocked, kidney failure occurs.
Your doctor will ask about your symptoms and medical history. A physical exam will be done. If you have elevated blood pressure, a search for its cause can involve many different tests. Unless there is a specific reason to suspect renal artery stenosis, it may not be considered at first.
Your bodily fluids may be tested. This can be done with:
- Repeat blood pressure measurements
- Blood tests
- Urine tests
Images may be taken of your kidneys. This can be done with:
- X-rays with contrasting dye
- X-rays with contrast injected directly into the renal arteries
- Radioisotope imaging
- CT or MRI scans with or without injected contrast agents
Your heart's activity may be measured. This can be done with an electrocardiogram.
Talk with your doctor about the best treatment plan for you. If there is significant stenosis and you are healthy, repairing the renal artery may be considered before medical treatment. Treatment options include:
Standard treatment for hypertension may be enough if blood pressure can be controlled and the kidneys are functioning well enough. There are many medications that lower blood pressure. You may need several to achieve adequate control. These medications are effective in people who have one blocked renal artery. ACE inhibitors should not be used if hypertension is caused by renal artery stenosis of both kidneys.
A thin tube is threaded into the renal artery from a puncture in your groin. The tube includes a balloon, laser, or other device that will open the narrowed artery.
If angioplasty cannot be done on the artery, a surgeon may decide to repair the condition through an incision in your abdomen.
Nephrectomy is an option if the affected kidney has been so damaged that it no longer works, but still causes high blood pressure.
Renal artery stenosis is an unusual cause of hypertension, but an important one because it is curable. The best way to detect hypertension is to have routine blood pressure measurements.
You can also prevent atherosclerosis by exercising regularly, eating a heart healthy diet, quitting smoking, and drinking less alcohol.
- Reviewer: Adrienne Carmack, MD
- Review Date: 05/2014 -
- Update Date: 05/28/2014 -