Peripheral arterial disease (PAD) is caused by atherosclerosis that affects the extremities, more frequently the legs. Commonly known as hardening of the arteries, atherosclerosis is a build-up of cholesterol and calcium deposits on the inside walls of the arteries. These deposits are called plaques. The plaques build up and cause narrowing of the arteries that supply blood to the arms and legs. Eventually they can become so thick that they completely block the flow of blood through the arteries. Problems result when blood flow to the extremities is severely reduced.
What is Peripheral Arterial Disease?
Risk Factors and Prevention
Many of the risk factors for PAD are modifiable. This means they can be treated or controlled to prevent disease symptoms from progressing. A family history of PAD is a genetic risk factor that can’t be changed, but there are lifestyle changes that can be made to keep your circulation healthy and decrease your risk of developing the disease.
- Stop Smoking
- Control Diabetes
- Control High Cholesterol or Triglycerides
- Treat High Blood Pressure
- Maintain a Healthy Weight: BMI < 30
Success in treatment of PAD is often measured by how far you can walk without pain. Regular exercise improves your circulation the helps condition your muscles to use oxygen more efficiently.
What are the Symptoms of PAD?
PAD often does not have any symptoms in early disease. Symptoms begin to occur once the affected arteries have become significantly narrowed and the blood flow to the tissues they supply is affected. The first symptom is usually pain in the legs when walking or exercising that goes away with a short period of rest. This is called intermittent claudication (IC). One or both legs may be affected. As the disease worsens, pain occurs with shorter walking distances. Additional peripheral artery disease symptoms may include:
- Leg numbness or weakness
- Coldness in lower legs or feet
- Sores on feet or legs that won't heal
- A change in the color of lower legs or feet
- Hair loss or slower hair growth on feet and legs
- No pulse or a weak pulse in legs or feet
- Erectile dysfunction in men
Ischemic Rest Pain occurs when PAD progresses and pain occurs when you're at rest. It may occur at night and disturb sleep. Hanging your legs over the edge of the bed, or walking around the room may temporarily relieve the pain.
Critical Limb Ischemia occurs when PAD is severe. Painful ulcers develop on your toes. These are signs of poor oxygen supply to the tissues. If the blood supply does not improve, these ulcers can turn into gray or black sores called gangrene and the tissue dies. Prompt evaluation by a vascular specialist is warranted to determine what can be done to address this problem.
Stroke and Heart Attack. Atherosclerosis causes PAD. It also causes the same artery narrowing process in the arteries of the heart and the arteries that supply the brain. If you have PAD, you are at risk for stroke and heart attack as well.
How is PAD diagnosed?
A vascular specialist will review your medical history and ask for details about your symptoms and risk factors. After an examination of your vascular system, if the physician suspects peripheral arterial disease, he or she may order diagnostic tests to help determine the severity of your disease.
Ankle-Brachial Index (ABI) and Pulse Volume Recording (PVR) are common tests using a blood pressure cuff to compare the blood pressure in your arms to your legs and uses a Doppler probe to create a tracing of your pulse.
Arterial Duplex Ultrasound: is frequently used to evaluate the blood flow in arteries for any blockages.
Additional tests may be ordered to evaluate more serious disease:
- Magnetic Resonance Angiography (MRA)
- Computed Tomographic Angiography (CTA)
How is PAD Treated?
Early PAD can be treated with lifestyle modifications, control of risk factors. Statins are medications prescribed to lower cholesterol levels as well as decrease the inflammation in arteries that causes increased plaque development. Aspirin or another medication to keep blood platelets from sticking to plaque and causing blockages is commonly recommended as well. A regular walking program to improve circulation is essential. Careful foot care is important, with routine observation for any injuries or poorly healing wounds that may require immediate medical attention. Advanced disease may require surgical interventions.
Angiography is the best way to see if there are blockages in the arteries. Through an artery in the groin the vascular specialist is able to use a thin tube, called a catheter to take x-ray images of the anatomy. This can help identify what options are available to treat the blockages. This may be combined with a treatment at that same time, if it is felt to be appropriate.
Angioplasty and Stenting is a minimally invasive procedure used to treat localized blockages in larger arteries. After the angiography confirms that an endovascular (less invasive) approach is possible, the surgeon guides a wire through the arteries, on through the blocked area. Once at the site of the blockage, a special balloon, which is attached to the end of the catheter, is inflated. The balloon pushes the plaque in the artery against the artery walls, widening the opening for better blood flow. When stenting is necessary to keep a narrowed area open, the vascular surgeon may place a tiny mesh-metal tube in the artery. The stent remains permanently in your artery. After this procedure, blood flows more freely through your artery.
Bypass Surgery is used when a less invasive approach is not available. It creates a detour around a narrowed, or blocked, section of the artery. To create this bypass, a vascular surgeon prefers to use one of your own veins as the graft, but if you don’t have a healthy useable vein a synthetic graft can be used. Your vascular surgeon attaches the bypass graft above and below the area that is blocked. The blood flow is rerouted in the new path to supply tissues previously injured by insufficient blood supply.