Description

Renal artery stenosis is the narrowing of one or more arteries that carry blood to your kidneys (renal arteries).

The narrowing of the arteries prevents enough oxygen-rich blood reaches the kidneys. Your kidneys need adequate blood flow to help filter waste products and remove excess fluids. The reduction in blood flow to the kidneys can cause damage to the renal tissue and increased blood pressure across your body.

Symptoms

Renal artery stenosis often do not cause any signs or symptoms until it is advanced. The condition may be discovered by chance during the tests to something more. Your health care provider also may suspect a problem if you have:

  • The high blood pressure that begins suddenly or gets worse, without explanation
  • The high blood pressure that begins before age 30 or after age 50 years old

As renal artery stenosis progresses, other signs and symptoms may include:

  • The high blood pressure that is difficult to control
  • A whooshing sound as the blood flows through a narrowing of the vessels (blow), which your doctor listening through a stethoscope placed over your kidneys
  • Elevated levels of protein in the urine, or other symptoms of a problem with kidney function
  • The worsening of renal function during treatment for high blood pressure
  • Fluid overload and swelling in the tissues of your body
  • Resistant to the treatment of heart failure

When to seek medical advice

Make an appointment with your doctor if you have any persistent signs or symptoms that worry you.

Causes

The two main causes of renal artery stenosis include:

  • The accumulation of kidney (renal) arteries. Fats, cholesterol and other substances (plaque) can build on and in the kidney the walls of the arteries (atherosclerosis). As these deposits grow larger, it can harden and reduce the blood flow, cause renal scarring and, finally, close the artery. Atherosclerosis occurs in many areas of the body and is the most common cause of renal artery stenosis.
  • Fibromuscular dysplasia.In fibromuscular dysplasia, the muscle in the wall of the artery does not grow as it should. This often starts in childhood. The renal artery may have narrow sections alternating with wider sections, giving a lace-look at the images of the artery. The renal artery can reduce both the kidney does not get enough blood. This can lead to high blood pressure at an early age. This can occur in one or both kidneys. Experts do not know what causes fibro-muscular dysplasia, but the condition is more common in women and it can be something that is present at birth (congenital).

Fibromuscular dysplasia. In fibromuscular dysplasia, the muscle in the wall of the artery does not grow as it should. This often starts in childhood. The renal artery may have narrow sections alternating with wider sections, giving a lace-look at the images of the artery.

The renal artery can reduce both the kidney does not get enough blood. This can lead to high blood pressure at an early age. This can occur in one or both kidneys. Experts do not know what causes fibro-muscular dysplasia, but the condition is more common in women and it can be something that is present at birth (congenital).

Narrowing of the renal arteries and fibromuscular dysplasia can affect other arteries in your body, as well as its renal arteries, and cause complications.

Rarely, renal artery stenosis results of other conditions, such as inflammation of the blood vessels or of a growth that develops in the abdomen and causes pressure on the kidneys and arteries.

Risk factors

Most cases of renal artery stenosis result from narrowing of kidney arteries. The risk factors that cause the narrowing of the arteries most likely in the kidneys and other parts of your body include:

  • Aging
  • High blood pressure
  • High cholesterol
  • Diabetes
  • Obesity
  • Smoking and other tobacco use
  • A family history of early heart disease
  • Lack of exercise

Complications

Possible complications of renal artery stenosis include:

  • High blood pressure
  • The kidney failure, which requires dialysis or a kidney transplant
  • The retention of fluids in the legs, causing swelling of the ankles or feet
  • Shortness of breath due to a sudden buildup of fluid in the lungs

Diagnosis

For the diagnosis of renal artery stenosis, your doctor may start with:

  • A physical exam that includes your provider of listening through a stethoscope over the kidney areas for sounds that may mean the artery to the kidney is reduced
  • A review of your medical history
  • Blood and urine tests to check your kidney function
  • Blood and urine tests to measure levels of hormones that regulate blood pressure

Imaging tests commonly done to diagnose renal artery stenosis include:

  • The Doppler ultrasound. High-frequency sound waves to help your doctor see the arteries and the kidneys and the verification of their function. This procedure also helps your doctor find blockages in the blood vessels and measure its severity.
  • CTscan. During a ct scan, an X-ray machine linked to a computer and creates a detailed picture that shows cross-sectional images of the renal arteries. You may receive an injection of dye to show the flow of blood.
  • The magnetic resonance angiography (MRA). MRA uses radio waves and magnetic fields to produce detailed 3D images of the renal arteries and kidneys. An injection of dye into the arteries contours of the blood vessels during imaging.
  • Renal arteriography. This special type of X-ray examination will help your doctor find blockages in the arteries of the kidney and, at times, open the narrow part with a balloon or stent. Before an x-ray, the doctor will inject a contrast medium in the renal arteries through a long, thin tube (catheter) to visualize the arteries and display the blood flow more clearly. This test is done, especially if it is also likely that you will need a small tube (stent) is placed in the blood vessel to expand.

Treatment

The treatment for renal artery stenosis may involve lifestyle changes, medication, and a procedure to restore blood flow to the kidneys. Sometimes a combination of treatments is the best approach. Depending on your general health status and symptoms, you may not need any specific treatment.

Lifestyle changes

If your blood pressure is severe or moderately elevated, a healthy lifestyle — the limitation of salt, eating healthy foods and getting regular physical activity can help control your blood pressure.

Medicine

High blood pressure — even when mainly related to renal artery stenosis — can often be successfully treated with medication. To find the medication or combination of medications may require time and patience.

Some of the medications commonly used to treat high blood pressure associated with stenosis of the renal artery include:

  • Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (arbs), which helps relax the blood vessels and block the formation or the effects of a natural chemical in the body called angiotensin II, which constricts the blood vessels
  • Diuretics, also known as water pills, which help your body to remove excess sodium and water
  • Beta-blockers and alpha-blockers and beta, which may have the effect of making the heart beat slowly and with less force or widening (dilating) your blood vessels, depending on the medication that you use
  • Calcium channel blockers, which help to relax the blood vessels

If atherosclerosis is the underlying cause of the renal artery stenosis, your doctor may also recommend that aspirin and cholesterol-lowering drugs. What medications are best for you depends on your individual situation.

Procedures

For some people, a procedure may be recommended to restore the flow of blood through the renal artery to improve blood flow to the kidneys.

The results of the comparative clinical trials of drugs with renal failure, angioplasty and stent placement did not show a difference between the two treatment approaches in reducing the high blood pressure and improve kidney function for people with moderate stenosis of the renal artery. Procedures for opening the container should be considered for people who don't do well in medicine, who can't tolerate the drugs, which are often retain liquids and have treatment-resistant heart failure.

Procedures for the treatment of renal artery stenosis may include:

  • Renal angioplasty and stent placement. In this procedure, doctors extend the narrowing of the renal artery and the location of a device (stent) inside your blood vessel that holds the walls of the blood vessel open and allows a better flow of blood.
  • Bypass surgery of the Renal artery. During a bypass procedure, the doctors of the graft in a substitute for the blood vessels of the renal artery to make a new route for blood to reach the kidneys. Sometimes this means that the connection of the renal artery of a vessel of some other place, such as the liver or the spleen. These operations are performed more frequently if the angioplasty is not correct, or when there is a need for additional surgical procedures.

Lifestyle and home remedies

As part of his plan of treatment for renal artery stenosis, your doctor may recommend making certain lifestyle changes:

  • Maintain a healthy weight. When the weight increases, so does blood pressure. If you are overweight, losing weight may help to lower your blood pressure.
  • Restrict salt in your diet. Salt and salty foods cause your body to retain fluid. This can increase the volume of your blood and, in turn, increase your blood pressure.
  • Be physically active. Be physically active on a regular basis can help you lose weight, lower your risk of heart disease, reduce cholesterol and lower blood pressure. Check with your doctor before you begin an exercise program, especially if you have high blood pressure, and has not been active in the past.
  • Reduce stress. The reduction of stress levels can lower your blood pressure.
  • Drink alcohol only in moderation, if at all. Too much alcohol can increase your blood pressure.
  • Do not smoke. Tobacco injures blood vessel walls and speeds up the process of hardening of the arteries. If you smoke, talk with your doctor to help you quit smoking.

Preparing for your appointment

For the stenosis of the renal artery, which you can start by seeing your family doctor or a general practitioner. However, you may be referred to a physician that specializes in diseases that affect the kidneys (nephrologist) or a heart and the blood vessels specialist (cardiologist), especially if the blood pressure is difficult to control or renal function worsens.

Here's some information to help you prepare for your appointment, as well as what to expect from your doctor.

What you can do

To prepare for your appointment:

  • Write down the symptoms you are experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
  • Make a list of all the medicines, vitamins, and supplements you are taking, including the dosage.
  • Share your key medical information with your doctor, including past or current smoking or use of other tobacco products.
  • Ask a family member or friend to accompany you. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Write questions to ask their doctor.

For the stenosis of the renal artery, some basic questions to ask your doctor include:

  • What is the most likely cause of my symptoms?
  • What kinds of tests do I need? Do these tests require any special preparation?
  • Is this condition temporary or long-term?
  • What will happen with my kidney?
  • What treatments are available, and which do you recommend?
  • What side effects can I expect from treatment?
  • I have other health conditions. How can I best manage these conditions?
  • You should follow the dietary restrictions? What about the restrictions of the activity?
  • Is there a generic alternative to the medicine you're prescribing for me?
  • What is the appropriate level for blood pressure? Is there anything I can do to help lower?
  • Do you have any printed material that I can take with me? What sites do you recommend?

In addition to the questions you have prepared, do not hesitate to ask other questions as they occur during your appointment.

What to expect from your doctor

Your doctor may ask you a series of questions, such as:

  • When did you first begin experiencing symptoms?
  • Are a current or past smoker, or use any other tobacco products?
  • Nothing seems to improve or worsen your symptoms?
  • Do you know what your average blood pressure values?
  • Have you had your kidney function measured?
  • Does someone in your family has a history of high blood pressure or kidney disease?
Symptoms and treatment of Renal artery stenosis