CLAUDICATION OVERVIEW Claudication, also known as peripheral arterial disease, is defined as a pain or discomfort in a group of muscles, usually in the legs, hips, or buttocks. It is worsened by exercise and relieved with rest.
Although many underlying medical problems can cause claudication, the most common cause is peripheral arterial disease. Peripheral artery disease causes deposits of fatty plaques on the vessel walls, narrowing the arteries in the legs (show figure 1). The terms peripheral artery disease and claudication can be used interchangeably.

CLAUDICATION RISK FACTORS The risk factors for developing claudication include: Cigarette smoking, Diabetes. Hyperlipidemia (elevated blood levels of lipids, including cholesterol and triglycerides). Hypertension (high blood pressure).
One study found that these risk factors cause claudication in 69 percent of patients; cigarette smoking was the most important factor [1] . In contrast, moderate alcohol consumption reduces the risk of peripheral arterial disease and claudication.

CLAUDICATION SYMPTOMS The pain and discomfort associated with claudication varies from person to person. Some people have severe, debilitating discomfort while others have no symptoms. In its severe form, the decrease in blood flow can lead to pain that occurs even at rest. Gangrene (a severe infection), limb amputation, and even death can occur in the most serious cases.
The severity of your symptoms will depend upon how narrowed your arteries are, the number of "alternate" secondary vessels that can provide blood when the damaged vessels cannot (called collateral circulation), and how hard you exercise.
The location of your pain depends upon the location of the arterial disease. A person may have buttock, thigh, calf, or foot pain, either alone or in combination.
Calf pain Calf pain is the most common complaint. It is usually described as a cramping pain that always occurs with exercise and is relieved with rest. Cramping in the upper two-thirds of the calf is usually due to the narrowing of an artery in the thigh (the superficial femoral artery), whereas cramping in the lower third of the calf is due to disease in the artery behind the knee (the popliteal artery).
Thigh pain ? Thigh claudication often results from the narrowing of an artery in the thigh (the common femoral artery), while foot claudication often occurs from narrowing of an artery in the lower part of the leg (the tibial or peroneal artery).
Pain at night Ischemia occurs when the oxygen supply to an area of tissue is reduced or cut off. A progressive decrease in blood flow in a limb can cause ischemic pain at rest. This discomfort typically occurs at night and involves the toes and ends of the foot. The area of pain may be small in people who develop an ischemic ulcer or gangrenous toe. The pain is frequently relieved by hanging the feet over the edge of the bed or by walking around. Chronic tissue ischemia may cause pain, frequently described as throbbing or burning with a severe shooting pain up the foot or leg.
Other symptoms People with claudication may notice that wounds heal slowly over the area of decreased blood flow. Some people have a cool foot or leg, shiny skin, hair loss, or nail changes.

CLAUDICATION DIAGNOSIS The diagnosis of claudication is based upon the signs and symptoms described above. Noninvasive tests can be performed to confirm the diagnosis and assess the severity of the disease.
Ankle-arm index The ankle-arm index (AAI), also called the ankle-brachial index, is often used to confirm the diagnosis of claudication. The AAI measures the resting and post-exercise blood pressures in the ankle and arm.
Other tests Blood pressure can be measured at various points in the legs to determine the level and extent of peripheral arterial disease. These are called segmental limb pressures.
Ultrasonography may also be used to see the severity and location of the narrowed vessels. Magnetic resonance angiography (MRA) is another noninvasive way of seeing the blood vessels, and is frequently required for those who are contemplating surgical treatment.

CLAUDICATION TREATMENT The treatment of claudication may involve medical and/or surgical therapies. There are also a number of percutaneous interventional (balloon) procedures that may be beneficial.
Most people with claudication are treated initially with medical therapy [2] . This includes risk factor modification, antiplatelet drugs (drugs that reduce blood clotting in an artery, a vein or the heart), and exercise training or rehabilitation. Other drugs may also be helpful in some patients. Less commonly, surgery or another invasive procedure is necessary.
Reduce risk factors As mentioned above, the main risk factors for claudication are cigarette smoking, diabetes mellitus, high blood pressure, and high cholesterol or lipids. All people with claudication should work to control these risk factors. Lowering cholesterol can prevent worsening of peripheral arterial disease and reduce the symptoms of claudication. A blood LDL-cholesterol l evel below 100 mg/dL (2.6 mmol/L) is recommended.
Treatment may include lifestyle changes (diet and exercise) and/or lipid-lowering medications.. Quitting smoking and improving control of diabetes and high blood pressure will not improve claudication symptoms (ie, pain), but can help to reduce the risk of coronary artery disease.
Exercise Exercise rehabilitation programs can help reduce the symptoms of claudication, including increasing the distance and time that one can walk before developing symptoms [3].
Exercise rehabilitation includes walking on a treadmill or a track for 45 to 60 minutes at least three times per week. This program should continue for at least three months. Each session is supervised on a one-to-one basis by an exercise physiologist, physical therapist, or nurse. The intensity of exercise can be adjusted based upon symptoms or other cardiovascular problems (such as an abnormal heart rhythm or chest pain) that develop during exercise.
Most patients who respond to an exercise program can expect improvement within two months. Patients who are motivated achieve the best results. The benefits of exercise diminish when exercise training stops.
Antiplatelet medications Antiplatelet agents (medications that reduce blood clotting in an artery, vein, or the heart) are recommended for all patients with claudication. While these medication may only modestly improve symptoms, treatment reduces the need for vascular surgery and a decreases the risk of myocardial infarction (heart attack), stroke, or death from vascular disease.
Aspirin (81 to 100 mg/day) is an accepted antiplatelet medication for people with peripheral arterial disease. Treatment with another antiplatelet agent, clopidogrel (Plavix), has modest advantages compared with aspirin alone in preventing stroke, myocardial infarction, and peripheral arterial disease [4]. However, it is significantly more expensive than aspirin.
Other medical therapies A number of other medical therapies may be helpful in people with claudication that does not respond to the above measures. Cilostazol ? Cilostazol (Pletal) is the most effective medication for treatment of claudication symptoms, particularly when combined with exercise. A clinician may recommend cilostazol in people who have a limited ability to walk due to claudication. This is especially true for people who do not respond adequately to other measures and those who do not want or who are not healthy enough for surgery.
Cilostazol should be taken one-half hour before or two hours after eating because high fat meals increase the amount of drug absorbed by the body. Diltiazem, omeprazole, and grapefruit juice should not be taken at the same time as cilostazol. Cilostazol may be taken safely with aspirin and/or clopidogrel.
Potential side effects of cilostazol include headache, loose or soft stools, diarrhea, dizziness, and palpitations. Cilostazol is not used in patients with heart failure. Pentoxifylline ? Pentoxifylline (Trental) has been available for many years for treatment of claudication, although studies of its effectiveness have shown mixed results. It is less effective than cilostazol, but may be used if cilostazol fails to reduce symptoms. Potential side effects include upset stomach, nausea, and vomiting. Ginkgo biloba ? A number of studies have suggested that ginkgo biloba may improve symptoms of claudication. However, most studies had a flawed design, making it difficult to conclude that ginkgo is safe and effective. In addition, herbal products are not monitored or regulated in the United States, raising concerns about purity and consistency of doses in some formulations. Ineffective treatments ? Chelation therapy (the repeated intravenous infusion of EDTA) and vitamin E supplementation have been investigated as treatments for claudication. However, studies have shown no benefit and these treatments are not recommended.


Surgery and percutaneous interventions In most people, claudication can be managed by reducing risk factors, exercise, and medications. People who have incapacitating claudication that prevents them from working or carrying out other important tasks, and those who experience pain at rest may be candidates for a surgery that opens or bypasses the blockage (a revascularization procedure).
Percutaneous intervention ? A percutaneous (through the skin) intervention is generally recommended before surgery since it is less invasive and has fewer risks. Percutaneous procedures are performed through a small incision in the skin. Balloon angioplasty involves threading a guidewire with a deflated balloon into a narrowed or blocked vessel. The balloon is then inflated and subsequently deflated, which allows blood to flow more freely through the vessel.
In some cases, a stent is used to hold the vessel open after angioplasty. A stent is an expandable tube often made of mesh wire. The goal of a stent is to prevent restenosis, when the vessel becomes narrowed again. Stents work better in some vessels than in others.
Previously, angioplasty was reserved for the treatment of single, short segment narrowings or blockages. With advancements in technology, angioplasty is now routinely used in more extensively diseased arteries before a surgical bypass. Angioplasty can also be used in people who are not healthy enough for surgery. (See "Percutaneous interventional procedures in the patient with claudication").
Surgery Revascularization surgery involves using a graft (a vein or artery taken from elsewhere in the body) to bypass the narrowed or blocked area of the blood vessel, thereby restoring blood flow. The best candidates for surgery are those who are otherwise healthy, under the age of 70 years, nondiabetic, and have little disease beyond the main area of blockage. Many people with diabetes and those over age 70 years are able to have successful surgery, but it is important for these patients to understand the surgical risks.
People who are under 40 years old may not be good candidates for surgery because they tend to have an aggressive form of atherosclerosis that frequently recurs after surgery.
After surgery, a medication (eg, aspirin) is often used to prevent the graft from becoming blocked by a blood clot.

WHERE TO GET MORE INFORMATION Your healthcare provider is the best s ource of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.


REFERENCES

1. Meijer, WT, Grobbee, DE, Hunink, MG, et al. Determinants of peripheral arterial disease in the elderly: the Rotterdam study. Arch Intern Med 2000; 160:2934.
2. Hiatt, WR. Medical treatment of peripheral arterial disease and claudication. N Engl J Med 2001; 344:1608.
3. Leng, GC, Fowler, B, Ernst, E. Exercise for intermittent claudication. Cochrane Database Syst Rev 2000; :CD000990.
4. A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). CAPRIE Steering Committee. Lancet 1996; 348:1329.
5. Mohler ER, 3rd. Peripheral arterial disease: identification and implications. Arch Intern Med 2003; 163:2306.

From © 2009 UpToDate, 10-10-2009