Intermittent Claudication is caused by narrowing or blockage in the main artery taking blood to your leg (femoral artery). This is due to hardening of the arteries (atherosclerosis). The blockage means that blood flow in the leg is reduced. Blood circulation is usually sufficient when 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.
Claudication usually occurs in people over fifty; However, it can appear much earlier in people who smoke and have diabetes, high blood pressure, or high cholesterol.
Unfortunately, the blockage causing the claudication won’t clear itself, but the situation may improve. Smaller arteries in the leg can enlarge to carry blood around the block in the main artery. This is known as collateral circulation. Many people notice some improvement in their pain as collateral circulation develops. This usually happens within six to eight weeks of the onset of symptoms of claudication.
How is claudication recognized?
A blockage in the circulation can be identified by examining the impulses and blood pressure in the legs. A blockage leads to the loss of one or more impulses in the leg. The blood pressure in your feet is measured with a portable ultrasound device called a continuous wave doppler.
Blood pressure in the foot can be measured and compared to arm blood pressure (which is usually normal). This measurement is known as the ABPI (Knuckle Brachial Pressure Index) and is expressed as a ratio. The ABPI provides an objective measure of blood flow to the lower extremities.
Sometimes an arteriogram can be done. An arteriogram is an X-ray of the arteries that involves injecting contrast material (dye) into the artery at the level of the groin. The contrast describes the blood flow in the arteries and any narrowing or blockages.
Claudication is usually not a threat to the limbs and does not need treatment for mild symptoms. The claudication often remains stable without the walking distance deteriorating over long periods of time. Fewer than one in ten people will walk less in their lifetime. However, if your symptoms worsen, treatments are available that you can discuss with your vascular surgeon.
General measures to improve walking distance include quitting smoking, getting more exercise, and making sure you are not overweight. Blood tests are often done to rule out other causes of atherosclerosis. These include a blood sugar test to rule out diabetes, thyroid, and kidney function tests, as well as a cholesterol test.
There are a number of drugs on the market that claim to improve walking distance. These are not used by vascular surgeons as evidence of their effectiveness is very limited. There is some evidence that aspirin or clopidogrel is generally good for people with poor circulation (heart, brain, and legs). Please contact your family doctor or vascular surgeon for more information.
There are three approaches to treating claudication itself:
The exercise has been shown to be within walking distance more than twice. Some hospitals may offer a structured exercise program. If this is not available, walking distance will usually improve noticeably over three to six months if you do brisk 30 minutes three times a week (the best you can do).
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.
Is the treatment successful?
The simple exercise program is very effective in increasing the walking distance. It offers a long term solution for the majority of people and, most importantly, is safe.
Since surgery (and to a lesser extent angioplasty) is not always successful, it can usually only be justified when a limb is at risk. There will usually be pain keeping you up at night, or ulcers or gangrene of the foot or toes. Half of the bypasses performed must be serviced in order for them to continue. This could be an x-ray or some other type of surgery.
What is the risk of losing my leg?
Very few patients with intermittent claudication are ever at risk of losing a leg to burn wounds. It is the vascular surgeon’s job to prevent this result at all costs. If the limb is believed to be at risk, a vascular surgeon will always act to save the leg, if at all possible. You can minimize the risk of your symptoms getting worse by following the guidelines below. It is the simple measures that are most effective. The vast majority of patients don’t need x-rays or surgery to relieve their symptoms.
How can I help myself?
There are several things you can do that can help. Most importantly, you stop smoking and exercise regularly. If you are a smoker, make a determined effort to give up completely. Tobacco is particularly harmful to claudicants for two reasons:
Smoking accelerates the hardening of the arteries, which is the cause of the problems
Cigarette smoke prevents the development of the collateral vessels that carry blood past the blockage.
The best way to give up is to choose a day when you want to quit altogether rather than trying to cut down gradually. If you have trouble giving up, please ask your doctor who can give you advice on additional help or contact a support group.
It’s also important not to be overweight. The more weight the legs have to carry, the more blood the muscles need. If necessary, your doctor or dietitian will advise you on a weight loss diet.