Peripheral Artery Disease
When leg arteries become narrowed or blocked by plaque it causes peripheral Arterial Disease (PAD), a condition that raises the risk of heart attack, stroke, leg amputation and death. As patients are unaware of this condition generally, PAD remains under-diagnosed and under-treated. In PAD, characteristically, there is a reduction in blood flow to the lower extremities due to plaque build-up in the leg arteries (also known as atherosclerosis). A combination of fats, cholesterol and other substances constitutes plaque. Size of plaque can grow to significantly reduce blood flow through an artery.
Blood flow to the legs and feet is reduced when leg arteries are hardened and clogged. Peripheral arteries remain blocked, completely or partially, and cause pain, changes in skin color and temperature, sores or ulcers and difficulty walking. PAD, if left untreated, can lead to Critical Limb Ischemia (CLI), a condition where not enough blood is being delivered to the leg to keep the tissue alive. Gangrene ensues due to total loss of circulation to the legs and feet leading to amputation. Hardened arteries, in addition, found in people with PAD are a sign that they are likely to have hardened and narrowed arteries to the heart and the brain. That is why people with PAD are at high risk for having a heart attack or a stroke. They may become disabled and not be able to go to work, with poor quality of life.
- Cigarette smoking
- Being overweight (a body mass index over 30)
- Raised blood pressure (140/90 millimeters of mercury or higher)
- High cholesterol (total blood cholesterol over 240 milligrams per deciliter)
- Advancing age, especially after reaching 50 years of age
- Positive family history of peripheral artery disease, heart disease or stroke
- Increased homocysteine, a protein component that helps build and maintain tissue
PAD is a chronic disease with risk factors that include:
Smokers or people with diabetes have the greatest risk of developing peripheral artery disease due to reduced blood flow.
Atherosclerosis is the main cause of peripheral artery disease. Fatty deposits (plaques) build up in your artery walls and reduce blood flow in atherosclerosis. This disease can and usually does affect arteries throughout your body although the heart is usually the focus of discussion of atherosclerosis. Atherosclerosis in the arteries supplying blood to your limbs causes peripheral artery disease. The cause of peripheral artery disease, less commonly, may be blood vessel inflammation, injury to your limbs, unusual anatomy of your ligaments or muscles, or radiation exposure.
Generally, most people with peripheral artery disease have mild or no symptoms. Some people have leg pain when walking (intermittent claudication). The symptoms of intermittent claudication include muscle pain or cramping in your legs or arms that's triggered by activity, such as walking, but disappears after a few minutes of rest. Pain is localised to the area supplied by the clogged or narrowed artery. Pain in the calf is the most common location.
There is a wide variation in the severity of intermittent claudication, ranging from mild discomfort to debilitating pain. Walk or doing other types of physical activity could be a hard task due to severe intermittent claudication.
Other symptoms of peripheral artery disease include:
- Cramps and pain in your hip, thigh or calf muscles after activity, such as walking or climbing stairs (intermittent claudication)
- Numbness or weakness in leg
- Feeling cold in your lower leg or foot, especially when compared with the other side
- Ulcers on your toes, feet or legs that won't heal
- Color change of your legs
- Loss of hair or slower hair growth on your feet and legs
- Decreased growth of your toenails
- Shiny skin on your legs
- Absent pulse or a weak pulse in your legs or feet
- Erectile dysfunction in men
Progression of peripheral artery disease can lead to pain that may even occur when you're at rest or when you're lying down (ischemic rest pain). Its intensity could be strong enough to disrupt sleep. Temporary relief could be obtained by hanging your legs over the edge of your bed or walking around your room.
To diagnose peripheral artery disease, your doctor may rely on the following tests:
- Physical exam. On physical examination, your doctor may find signs of PAD such as a weak or absent pulse below a narrowed area of your artery, whooshing sounds (bruits) over your arteries that can be heard with a stethoscope, evidence of poor wound healing in the area where your blood flow is restricted, and decreased blood pressure in your affected limb.
- Ankle-brachial index (ABI). One of the most common tests to diagnose PAD is ABI. The doctor will compare the blood pressure in your ankle with the blood pressure in your arm. Your doctor uses a regular blood pressure cuff to get a blood pressure reading and a special ultrasound device to evaluate blood pressure and flow. Doctor will ask you to walk on a treadmill and have readings taken before and immediately after exercising to capture the severity of the narrowed arteries during walking.
- Ultrasound. Doppler ultrasound is a special ultrasound imaging technique that can help your doctor evaluate blood flow through your blood vessels and identify blocked or narrowed arteries.
- Angiography. In this test a dye (contrast material) is injected into your blood vessels to view blood flow through your arteries as it happens. The flow of the contrast material is traced using imaging techniques, such as X-ray imaging or procedures called magnetic resonance angiography (MRA) or computerized tomography angiography (CTA). Another invasive procedure is catheter angiography. It involves guiding a catheter through an artery in your groin to the affected area and injecting the dye that way. This type of angiography, although invasive, allows for simultaneous diagnosis and treatment — finding the narrowed area of a blood vessel and then widening it with an angioplasty procedure or administering medication to improve blood flow.
- Blood tests. Blood tests need to be conducted to measure your cholesterol and triglycerides and to check for diabetes.
Plaque buildup in blood vessels leading to peripheral artery disease (atherosclerosis) leads to a risk of developing:
- Critical limb ischemia. Beginning of this condition is as open sores that don't heal, or an injury/ infection of your feet or legs. When such injuries or infections progress critical ischemia occurs and can cause tissue death (gangrene), sometimes requiring amputation of the affected limb.
- Stroke and heart attack. Process of plaque formation and atherosclerosis that causes the signs and symptoms of peripheral artery disease isn't limited to your legs. Fat deposits also build up in arteries supplying your heart and brain.
There are two major goals of treatment for peripheral artery disease. Managing symptoms, such as leg pain, so that you can resume physical activities is the primary goal. To stop the progression of atherosclerosis throughout your body to reduce your risk of heart attack and stroke is the secondary goal.
These goals can be accomplished with lifestyle changes. Quitting the smoking habit is the single most important thing you can do to reduce your risk of complications. You need additional medical treatment if lifestyle changes are not enough. Your doctor may prescribe medicine to prevent blood clots, lower blood pressure and cholesterol, and control pain and other symptoms.
- Cholesterol-lowering medications. The doctor may prescribe you a cholesterol-lowering drug called a statin to reduce your risk factor of heart attack and stroke. The goal for people who have peripheral artery disease is to reduce low-density lipoprotein (LDL) cholesterol, the "bad" cholesterol, to less than 100 milligrams per deciliter (mg/dL), or 2.6 millimoles per liter (mmol/L). This goal is reduced further if you have additional major risk factors for heart attack and stroke, especially diabetes or continued smoking.
- High blood pressure medications. If your blood pressure is high, your doctor may prescribe medications to lower it. This therapy aims to reduce your systolic blood pressure (the top number of the two numbers) to 140 millimeters of mercury (mm Hg) or lower and your diastolic blood pressure (the bottom number) to 90 mm Hg or lower. Your blood pressure target is under 130/80 mm Hg if you have diabetes.
- Medication to control blood sugar. It becomes even more important to control your blood sugar (glucose) levels if you also have diabetes. Discuss what your blood sugar goals are with your doctor and find out what steps you need to take to achieve these goals.
- Medications to prevent blood clots. It's important to reduce your risk of blood clots as peripheral artery disease is related to reduced blood flow to your limbs. Complete blockage can occur due to a blood clot in an already narrowed blood vessel and cause tissue death. Daily aspirin may be prescribed by your doctor to help prevent blood clots.
- Symptom-relief medications. Many medications like cilostazol are available these days that increase blood flow to the limbs, both by preventing blood clots and by widening the blood vessels. This drug is indicated to treat symptoms of claudication, such as leg pain, for people who have peripheral artery disease.
Angioplasty and surgery
In extreme cases, angioplasty or surgery may be necessary to treat peripheral artery disease that's causing intermittent claudication:
- Angioplasty. A small hollow tube (catheter) is threaded through a blood vessel to the affected artery in this procedure. A small balloon on the tip of the catheter is inflated at that point to reopen the artery and flatten the blockage into the artery wall, while at the same time stretching the artery open to increase blood flow. It may be required to insert a mesh framework called a stent in the artery to help keep it open. This is the same procedure doctors use to open heart arteries.
- Bypass surgery. In this procedure your doctor may create a graft bypass using a vessel from another part of your body or a blood vessel made of synthetic fabric. This technique allows blood to flow around — or bypass — the blocked or narrowed artery.
- Thrombolytic therapy. Your doctor may inject a clot-dissolving drug into your artery, if you have a blood clot blocking an artery, at the point of the clot to break it up.
Supervised exercise program
Your doctor may prescribe a supervised exercise training program, in addition to medications or surgery, to increase the distance you can walk pain-free. Regular exercise improves symptoms of PAD by a number of methods, including helping your body use oxygen more efficiently.
The symptoms of peripheral artery disease can be managed effectively with lifestyle measures and the progression of the disease can be slowed, especially by quitting smoking. To stabilize or improve PAD:
- Stop smoking. Constriction and damage of your arteries is contributed by smoking and is a significant risk factor for the development and worsening of PAD. Quitting is the most important thing you can do to reduce your risk of complications. Ask your doctor about smoking cessation options if you're having trouble quitting on your own. There are medications available to help you quit.
- Exercise. It is important to exercise regularly to ensure success in treatment of PAD. Success is often measured by how far you can walk without pain. Proper exercise helps condition your muscles to use oxygen more efficiently. With the help of your doctor, you can develop an appropriate exercise plan. He or she may refer you to a claudication exercise rehabilitation program.
- Eat a healthy diet. A diet low in saturated fat can help control your blood pressure and cholesterol levels, which contribute to atherosclerosis.
- Avoid certain cold medications. Remedies for cough and cold that are available over-the-counter contain pseudoephedrine that can constrict your blood vessels and may increase your PAD symptoms.
Careful foot care
Care of the feet is very important in addition to the above suggestions. Follow this advice to care for your feet:
- Daily washing of feet is important. After washing dry them thoroughly and moisturize often to prevent cracks that can lead to infection. Don't moisturize between the toes, however, as this can encourage fungal growth.
- Your shoes should be well-fitting.
- Treat aggressively any fungal infections of the feet, such as athlete's foot.
- Take care when trimming your nails.
- Don't walk barefoot.
- Treat bunions, corns or calluses.
- Consult a doctor at the first sign of a sore or injury to your skin.
Maintain a healthy lifestyle to prevent claudication. That means:
- Quit smoking.
- Keep your blood sugar in good control if you have diabetes.
- Regular exercise is a must. Aim for 30 minutes at least three times a week after you've gotten your doctor's OK.
- Reduce your cholesterol and blood pressure levels, if applicable.
- Eat foods that are low in saturated fat.
- Be in your healthy weight range.