Peripheral Arterial Disease (PAD)
Peripheral arterial disease (PAD), also known as peripheral vascular disease (PVD), is a very common condition affecting 10 million Americans and 12 to 20 percent of Americans age 65 and older each year. PAD develops most commonly as a result of atherosclerosis (hardening of the arteries), which occurs when cholesterol and scar tissue build up, forming a substance called plaque inside the arteries that narrows and clogs arteries. This is a very serious condition. The clogged arteries cause decreased blood flow to the legs, which can result in pain when walking, and eventually gangrene and amputation. People with PAD are at increased risk for heart disease, aortic aneurysm and stroke. PAD is also a marker for diabetes, hypertension, and other conditions.
- Age (higher occurrence in patients over 50 years old)
- Family history of vascular disease, such as PAD, aneurysm, heart attack or stroke
- High cholesterol and/or high lipid blood test
- Inactive lifestyle
- Personal history of high blood pressure, heart disease, or other vascular disease
- Trouble walking that involves cramping or tiredness in the muscle with walking or exercising, which is relieved by resting
- Pain in the legs or feet that awakens you at night
Those who suffer from PAD may experience a combination of the following symptoms:
- Claudication (leg pain that occurs when walking/exercising and disappears when the person stops the activity)
- Numbness and tingling in the lower legs and feet
- Coldness in the lower legs and feet
- Ulcers or sores on the legs and/or feet that do not heal
- Change in the color of the legs
- Hair loss on feet and legs
- Changes in nails
- Ischemic rest pain (where pain occurs whether at rest or lying down)
Arteries are blood vessels that carry oxygen and nutrients from your heart to the rest of your body. Healthy arteries are flexible, strong and elastic. Over time, however, too much pressure in your arteries can make the walls thick and stiff, thus sometimes restricting blood flow to your organs and tissues. This process is called arteriosclerosis, or hardening of the arteries. Atherosclerosis is a specific type of arteriosclerosis, but the terms are often used interchangeably. Although atherosclerosis is often considered a heart problem, it can affect arteries anywhere in your body. For example:
- When arteries leading to your limbs are affected, you may develop circulation problems in your arms and legs called peripheral arterial disease.
- When arteries to your heart are affected, you may have coronary artery disease, chest pain (angina) or a heart attack.
- When arteries supplying blood to your brain are affected, you could have a transient ischemic attack (TIA) or stroke.
- Atherosclerosis can also lead to a bulge in the wall of your artery (aneurysm).
Detection and Diagnosis
The physician may find signs of narrowed, enlarged or hardened arteries during a physical exam. These include:
- A weak or absent pulse below the narrowed area of the artery
- Decreased blood pressure in an affected limb
- Whooshing sounds (bruits) over the arteries, heard with a stethoscope
- Signs of a pulsating bulge (aneurysm) in the abdomen or behind the knee
- Evidence of poor wound healing in the area where blood flow is restricted
Depending on the results of the physical exam, your doctor may suggest one or more diagnostic tests, including:
Doppler Ultrasound. This test involves the use of a special ultrasound device (Doppler ultrasound) to measure blood pressure at various points along the arm or leg. These measurements can help the physician gauge the degree of any blockages, as well as the speed of blood flow in your arteries.
Ankle-Brachial Index. Comparing the blood pressure in the ankle with the blood pressure in the arm is known as the ankle-brachial index. An abnormal difference may indicate peripheral vascular disease, which is usually caused by atherosclerosis.
Electrocardiogram (ECG). An electrocardiogram records electrical signals as they travel through your heart. An ECG can often reveal evidence of a previous heart attack or one that’s in progress. If signs and symptoms occur most often during exercise, the physician may ask you to walk on a treadmill or ride a stationary bike during an ECG.
Arteriogram. To better view blood flow through the heart, the patient’s artery is injected with a special dye under x-ray. This is known as an arteriogram. The images outline narrow spots and blockages, which can also be repaired or treated during the same procedure (see angioplasty or stent placement below).
Other Imaging Tests. The use of other imaging techniques such as a CT scan and MRI to evaluate the arteries is becoming much more common. They are less invasive than the conventional arteriogram because there is no need for arterial puncture or sedation. The studies are called CTA (CT Arteriogram) or MRA (MR Arteriogram), and images can be provided in 3D reconstruction for evaluation of hardening and narrowing of large arteries, as well as aneurysms and calcium deposits in the artery walls.
Once PAD has been diagnosed, several treatment options are available:
Medication. Various drugs can slow, or sometimes even reverse, the effects of atherosclerosis. Common choices include:
- Cholesterol medications
- Anti-platelet medications (aspirin)
- Anticoagulants (heparin or Coumadin®)
- Blood pressure medications (beta blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers)
Surgery. If a patient has severe symptoms, a blockage that threatens muscle or skin tissue survival, surgery is another alternative. Surgery can include:
- Endarterectomy. In some cases, fatty deposits must be surgically removed from the walls of the narrowed artery. When the procedure is done on the arteries in the neck, it is known as a carotid endarterectomy.
- Bypass surgery. In this situation, a graft bypass may be created using a vessel from another part of the body of a tube made of synthetic fabric. This allows blood to flow around the blocked or narrowed artery.
Interventional radiology. Most endovascular techniques these days are performed by interventional radiology, and include:
- Thrombolytic therapy. In less common circumstances, if an artery is blocked by a blood clot, the physician may insert a clot-dissolving drug into the artery at the point of the clot to break it up.
- Angioplasty and stenting. In this procedure, a flexible wire is inserted across the blocked or narrowed part of the artery. A deflated balloon mounted on a catheter (long thin tube) is then passed over the wire into the narrowed area. The balloon is then inflated, compressing the deposits against the artery walls.
Lifestyle changes can help prevent or slow the progression of atherosclerosis, including:
- Stop smoking. Smoking damages the arteries. Quitting is the best way to halt the progression of atherosclerosis and reduce the risk of complications.
- Exercise. Regular exercise conditions the muscles to use oxygen more efficiently. Physical activity can also improve circulation and promote the development of new blood vessels that form a natural bypass around obstructions (collateral vessels).
- Eat well. A healthy diet based on fruits, vegetables, and whole grains — and low in saturated fat, cholesterol and sodium — can help control weight, blood pressure and cholesterol.
- Manage stress. It is important to reduce stress as much as possible. Practicing healthy techniques such as muscle relaxation and deep breathing will help achieve that goal.
It is important to emphasize that above all the other issues, smoking and diabetes are the greatest risk factors for PAD, possibly leading to critical limb ischemia (poor blood flow) and subsequent amputation. Stopping smoking and controlling diabetes with diet and medications will greatly reduce the likelihood of PAD.