Peripheral arterial disease (PAD)
Your arteries carry blood rich in oxygen and nutrients from your heart to the rest of your body. When the arteries in your legs become blocked, your legs do not receive enough blood or oxygen, and you may have a condition called peripheral artery disease (PAD), sometimes called leg artery disease.
PAD can cause discomfort or pain when you walk. The pain can occur in your hips, buttocks, thighs, knees, shins, or the tops of feet. Arterial leg disease is considered a type of peripheral arterial disease because it affects the arteries, blood vessels that carry blood away from your heart to your limbs. You are more likely to develop PAD as you age. One in 3 people age 70 or older have PAD. Smoking or having diabetes increases your chances of developing the disease earlier.
The aorta is the largest artery in your body, and it carries blood pumped out of your heart to the rest of your body. Just beneath your belly button in your abdomen, the aorta splits into the two iliac arteries, which carry blood into each leg. When the iliac arteries reach your groin, they split again to become the femoral arteries. Many smaller arteries branch from your femoral arteries to take blood down to your toes.
Your arteries are normally smooth and unobstructed on the inside but, as you age, they can become blocked through a process called atherosclerosis, which means hardening of the arteries. As you age, a sticky substance called plaque can build up in the walls of your arteries. Plaque is made up of cholesterol, calcium, and fibrous tissue. As more plaque builds up, your arteries narrow and stiffen. Eventually, enough plaque builds up to reduce blood flow to your leg arteries. When this happens, your leg does not receive the oxygen it needs. Physicians call this leg artery disease. You may feel well and still have leg artery disease or sometimes similar blockages in other arteries, such as those leading to the heart or brain. It is important to treat this disease not only because it may place you at a greater risk for limb loss but also for having a heart attack or stroke.
What are the symptoms?
You may not feel any symptoms from peripheral artery disease at first. The most common early symptom is intermittent claudication (IC). IC is discomfort or pain in your legs that happens when you walk and goes away when you rest. You may not always feel pain; instead you may feel a tightness, heaviness, cramping, or weakness in your leg with activity. IC often occurs more quickly if you walk uphill or up a flight of stairs. Over time, you may begin to feel IC at shorter walking distances. Only about 50 percent of the people with leg artery disease have blockages severe enough to experience IC.
Critical limb ischemia is a symptom that you may experience if you have advanced peripheral artery disease. This occurs when your legs do not get enough oxygen even when you are resting. With critical limb ischemia, you may experience pain in your feet or in your toes even when you are not walking.
In severe peripheral arterial disease, you may develop painful sores on your toes or feet. If the circulation in your leg does not improve, these ulcers can start as dry, gray, or black sores, and eventually become dead tissue (called gangrene).
What causes peripheral artery disease (PAD)?
Atherosclerosis causes peripheral artery disease. As you get older, your risk of developing leg artery disease increases. People older than age 50 have an increased risk of developing the disease, and men have a greater risk than women.
Other factors that increase your chances of developing the disease include:
High blood pressure
High cholesterol or triglycerides
High levels of homocysteine, an amino acid in your blood
Weighing over 30 percent more than your ideal weight
What tests will I need?
First your physician asks you questions about your general health, medical history, and symptoms. In addition, your physician conducts a physical exam. Together these are known as a patient history and exam. As part of your history and exam, your physician will ask you if you smoke or have high blood pressure. Your physician will also want to know when your symptoms occur and how often. As part of the physical exam, your physician will conduct pulse tests, which measure the strength of your pulse in arteries behind your knees and feet.
After your exam, if your physician suspects peripheral artery disease, he or she may perform tests, such as:
Ankle-brachial index (ABI), which compares the blood pressure in your arms and legs
Blood tests for cholesterol or other markers for artery disease
To better understand the extent of your leg artery disease, your physician may also recommend duplex ultrasound, pulse volume recording, magnetic resonance angiography (MRA), or angiography.
Duplex ultrasound uses high-frequency sound waves to measure real-time blood flow and detect blockages or other abnormalities in the structure of your blood vessels
Pulse volume recording measures the volume of blood at various points in the legs using an arm blood pressure cuff and a Doppler probe
Magnetic resonance angiography (MRA) uses magnetic fields and radio waves to show blockages inside your arteries
Computed tomographic angiography (CTA) uses specialized CT scans and contrast dye to show blockages inside your arteries
Angiography, which produces x-ray pictures of the blood vessels in your legs using a contrast dye to highlight your arteries
Physicians usually reserve angiography for people with more severe forms of leg artery disease.
How is leg artery disease treated?
If your peripheral artery disease is detected early, you can make lifestyle changes to help you manage your disease. See the section entitled “What Can I Do to Stay Healthy?”
Your physician may also recommend medication to treat conditions that worsen or complicate leg artery disease. These medications may include cholesterol-lowering drugs (statins) or blood pressure-lowering medications. You may also need to take medications that reduce blood clotting to minimize the chances of clots blocking your narrowed arteries.
If you do not have a disqualifying medical condition, such as heart failure, your physician may also prescribe cilostazol (Pletal), which can improve the distance you are able to walk without discomfort or pain. Other drugs your physician may prescribe include aspirin and clopidogrel (Plavix), either of which can decrease your chances of developing blood clots.
Exercising and walking regularly, for instance walking at least 30 minutes 3 times each week, may help improve your symptoms.
In more severe cases of leg peripheral disease, lifestyle changes and medication may not be enough to improve your symptoms. Also, if your disease has advanced, your physician may recommend surgical or minimally invasive treatments. The choice of the treatment depends upon the pattern and extent of the blockages as well as other factors, such as your general health and the presence of other medical conditions. Your vascular surgeon will help you determine which is the best option for your particular situation. Sometimes a combination of the various tools available may be required for the most favorable results.
Angioplasty and stenting
In some cases of peripheral artery disease, your physician may recommend angioplasty and stenting. This procedure is considered to be minimally invasive in comparison to open surgery. It is most effective for more localized blockages in the larger arteries. In an angioplasty, your physician inserts a long, thin, flexible tube called a catheter into a small puncture over an artery in your arm or groin. The catheter is guided through your arteries to the blocked area. Once in place, a special balloon, which is attached to the catheter, is inflated and deflated several times. The balloon pushes the plaque in your artery against your artery walls, widening the vessel. In some circumstances, your vascular surgeon may then place a tiny mesh-metal tube, called a stent, into the narrowed area of your artery to keep it open. The stent remains permanently in your artery. After this procedure, blood flows more freely through your artery. Other devices, such as atherectomy catheters, are currently being developed and are under evaluation to determine their effectiveness.
Bypass surgery creates a detour around a narrowed, or blocked, section of a leg artery. To create this bypass, your vascular surgeon uses one of your veins or a tube made from man-made materials. Your vascular surgeon attaches the bypass above and below the area that is blocked. This creates a new path for your blood to flow to your leg tissues and is particularly effective for extensive artery blockages.
An endarterectomy is a way for your surgeon to remove the plaque from your artery. To perform an endarterectomy, your vascular surgeon makes an incision in your leg and removes the plaque contained in the inner lining of the diseased artery. This leaves a wide-open artery and restores blood flow through your leg artery. The effectiveness of this method depends upon the particular location and extent of the arterial blockage.
In extreme cases, especially if your leg has gangrene and is not salvageable, your surgeon may recommend amputating your lower leg or foot. Amputation is a treatment of last resort. Vascular surgeons usually only perform it when the circulation in your leg is severely reduced and cannot be improved by the methods discussed already. More than 90 percent of patients with gangrene who are seen by vascular specialists can avoid amputation or have it limited to a small portion of the foot or toes.
What can I do to stay healthy?
Lifestyle changes that help you manage your leg artery disease include:
Managing diabetes by maintaining healthy blood sugar levels
Lowering high cholesterol
Lowering high blood pressure
Eating foods low in saturated fats and calories
Maintaining your ideal body weight
Exercising and walking regularly, for instance walking at least 30 minutes 3 times each week