Patient Information - Intermittent Claudication

'The information contained in this patient information sheet is not a substitute for medical advice or
treatment, and the Society recommends consultation with your doctor or health care professional'

1. What is Intermittent Claudication?

• The pain you feel in your legs is called intermittent claudication. It is caused by narrowing or blockage in the main artery taking blood to your leg. This is due to hardening of the arteries (atherosclerosis). Over the years cholesterol and calcium build up inside the arteries.
• This occurs much earlier in people who smoke and those who have diabetes, high blood pressure or high levels of cholesterol in the blood.
• The blockage means that blood flow in the leg is reduced. The circulation is sufficient when you are resting, but when you start walking the calf muscles cannot obtain enough blood. This causes cramp and pain which gets better after resting for a few minutes. If greater demands are made on the muscles, such as walking uphill, the pain comes on more quickly.

2. Does the blockage ever clear itself?

• Unfortunately not, but the situation can improve because smaller arteries (the collateral circulation) may enlarge to carry blood around the block in the main artery. Your muscles also adapt to their new restricted blood supply.
• Many people notice some improvement in their pain as the collateral circulation develops. This normally happens within six to eight weeks of the start of the claudication symptoms.

3. How is Claudication detected?

• A blockage in the circulation can be detected by examining for the pulses in the legs. A blockage will lead to loss of one or more pulses in the leg.
• Using an ultrasound device (handheld continuous wave doppler) the blood pressure in the foot can be measured and compared with arm blood pressure. This measure is called the ABPI (ankle brachial pressure index) and is expressed as a ratio. The ABPI provides an objective measure of the lower limb circulation.
• A duplex (ultrasound) study may be performed. This allows the size of the vessels to be determined. It can help to select patients who would then be able to proceed directly with balloon angioplasty or stenting (see other advice sheets).
• Sometimes an arteriogram may be performed. An arteriogram is an X-ray of the arteries performed by injecting contrast (dye) into the artery at groin level. The contrast outlines the flow of blood in the arteries as well as any narrowings or blockages.
• Some centres will use magnetic resonance angiography to help examine the arterial supply (blood supply) to your legs or arms.

4. Do I need treatment?

• Claudication is neither limb nor life threatening. It is not necessary to treat it if the symptoms are mild.
• Claudication is a warning signal to control risk factors for heart attack, angina and stroke. Your blood pressure, cholesterol, weight, smoking history and diabetic control all need good control.
• Claudication often remains stable with no deterioration in walking distance over long periods. Less than one in ten patients will notice any reduction in walking distance during their lifetime.
• If symptoms worsen, treatment is available, and your Vascular Surgeon will discuss the options with you.

5. What treatments are available?

• General measures to improve walking distance include stopping smoking, taking more exercise and making sure you are not overweight.
• Blood tests to rule out other causes of atheroma are often done. These will include a blood sugar test to exclude diabetes, thyroid and kidney function tests and a cholesterol test.
• There are a number of drugs on the market said to improve walking distance. Generally these are not used by Vascular Surgeons because the evidence for their usefulness is very limited.
• There is evidence that taking Aspirin 75mg daily or Clopidogrel 75mg daily is generally good for people with circulation disorders (heart, brain and legs).
• The Heart Protection Study has also shown that even patients with normal cholesterol benefit from taking a statin agent. It is likely therefore that the surgeon will recommend starting statin therapy even if your cholesterol level is normal.
• There are three approaches to treating the claudication itself:

-     Exercise has been shown to more than double walking distance. Some hospitals can offer an exercise programme with structured exercises. Where this is not available, a brisk (the best you can do) walk three times a week lasting 30 minutes will normally noticeably improve walking distance over 3-6 months.
-     Angioplasty (stretching the artery where it is narrowed with a balloon) may help to improve walking distance for some people. Overall it is less effective in the longer term than simple exercise. Angioplasty is usually limited to narrowings or short complete blockages (usually less than 10cm) in the artery.
-     Bypass surgery is usually reserved for longer blockages of the artery, when the symptoms are significantly worse. There may be very short distance claudication, pain at rest, ulceration of the skin in the foot, or even gangrene in the foot or toes.

6. Is Treatment Successful?

• The simple exercise programme is very successful at increasing the walking distance. It provides a long term solution for the majority of people, and most importantly it is safe.
• Because surgery (and to a lesser extent angioplasty) is not always successful, it can normally only be justified when the claudication is truly disabling or the viability of the limb is perceived to be threatened (usually there will be pain keeping you awake at night, or ulceration or gangrene of the foot or toes).
• Half of the bypasses performed will need some “maintenance” procedure to keep them going. This may be an X-ray procedure or might involve further surgery.

7. How can I help myself?

• There are several things you can do which may help. The most important is to stop smoking, take regular exercise and lose weight.
• If you are a smoker you should make a determined effort to give up completely. Tobacco is harmful for two reasons. Firstly, it speeds up the hardening of the arteries, which is the cause of the trouble and secondly, cigarette smoke prevents development of the collateral vessels which get blood past the blockage.
• The best way to give up is to choose a day when you are going to stop completely rather than trying to cut down gradually. If you do have trouble giving up please ask your doctor who can give you advice on additional help, or put you in touch with a support group.
• It is important not to be overweight. This is because the more weight the legs have to carry around the more blood they will need. If necessary your doctor or dietician will give you advice about a weight reducing diet.

8. What is the risk of losing my leg?

• Very few patients with intermittent claudication will ever be at risk of losing a leg through gangrene. It is the job of your doctors and indeed yourself to prevent this outcome at all costs.
• If there is thought to be any risk to the limb a Vascular Surgeon will always act to save the leg if at all possible.
• You can minimise the risk of progression of your symptoms by following the advice in this Information Leaflet.
• It is the simple measures which are the most effective. The vast majority of patients do not need X-ray or surgical procedures to treat their symptoms.

The Vascular Society is grateful to Mr Simon Parvin and members of the Audit and Research Committee for writing this information leaflet.

March 2006