Angina of the leg
Intermittent claudication (from the Latin claudicare, to limp), is one of the first symptoms of arteriosclerosis obliterans, which is a narrowing of the arteries in the legs. This results in a deficient blood supply in ‘exercising muscle’.
Pain, usually in the calves, is felt after walking a short distance. The distress is described as pain, ache, cramp or a tired feeling. It is felt most commonly in the calf but also the feet, thigh, hip, or buttocks.
It is relieved quickly by rest (usually in 1 – 5 min), and the patient can walk as far again before the pain recurs. By definition claudication never occurs at rest. The progression of the disease is indicated when the distance the patient can walk diminishes.
Similar symptoms related to exertion can occur with involvement of the arms.
The disease may progress so that ischaemic pain occurs at rest, often at night and in the feet. This pain is relieved by hanging the feet over the side of the bed and moving around.
The predisposing life style which may lead to the disease includes smoking unhealthy eating habits, obesity, and lack of exercise. Hypertension, diabetes and high cholesterol levels are other predisposing factors.
Patients with claudication have widespread disease of all arteries. They invariably have disease in the vessels in the heart.
Who gets it and who is at risk?
Smokers are the people most at risk, because nicotine has a constricting effect on the arteries and predisposes to atherosclerosis.
A history of pain on walking and a clinical examination form the basis of diagnosis. If intermittent claudication is the only symptom, the leg may appear normal, but the pulses are reduced or absent.
The level at which the artery is blocked, and the location of intermittent claudication are closely related.
Disease of the aorta – the large artery which supplies the whole body - frequently causes claudication in the buttocks or hips and may cause impotence in addition to pain in the calves.
If the arteries are blocked, the feet become pale after one to two minutes if they are elevated, and red once they are placed down again. The redness should return within 15 seconds in a normal person. This is delayed in someone with blocked arteries.
A foot lacking in oxygen due to blocked arteries (ischaemic) is painful, cold and often numb. The skin may be dry and scaly with poor nail and hair growth. As ischaemia worsens the skin may ulcerate, especially after any trauma to the area. Ulceration is characteristically on the toes or heel or occasionally on the leg. There is usually no swelling but a severely ischaemic leg may be shrunken and wasted.
More extensive obliterative disease may compromise the viability of tissues and frequently leads to necrosis (tissue death) or gangrene.
To confirm the clinical findings, the most widely used method is a doppler ultrasound or duplex doppler study. This evaluates the degree and location of arterial insufficiency. It is a simple, non-invasive procedure which uses the fact that the frequency of ultrasound waves changes when they are reflected from a moving surface, in this case, blood within the arteries.
If surgery is being contemplated then an arteriogram may be necessary. This is a procedure where contrast is injected into a major vessel and an X-ray is taken. This provides a ‘road map’ of the arteries so that surgery may be planned.
The doctor can then decide on the most suitable treatment.
When considering whether the symptoms of claudication should be treated, the doctor will decide if the pain is severe enough to stop the patient doing their normal activities. That means that a person who has to walk a long distance for their job is more likely to be operated on than a person who only needs to walk around the house.
Claudication is reversible but will naturally progress to irreversible damage to the leg unless something is done. An ulcer may form on the leg or gangrene may develop. The first indication that this may happen is that the pain may become constant. Once this occurs, some form of surgical procedure must be performed to save the limb.
Patients with intermittent claudication should walk for 60 minutes daily, if possible. When discomfort occurs, they should stop, allow the pain to subside, and then walk again. This is known as walking through claudication and will, over time, significantly improve the distance a patient can walk without discomfort. This occurs because the exercise stimulates the formation of new small arteries in the muscles which then take the place of the blocked arteries.
Patients should stop smoking immediately – continuing to smoke will prevent any relief of the claudication and will hasten the progression to complications such as gangrene. This is particularly true in diabetics who develop small vessel disease as a result of their illness anyway, which is further exacerbated by smoking.
When a patient is sleeping, blocks should be used to elevate the head of the bed 10-15cm.
Prophylactic foot care is especially important. Shoes should be well fitting and well ventilated. The toenails should be kept short and evenly cut. Patients should try to avoid trauma to the foot because of the possibility of ulcers forming. Regular visits to a podiatrist are recommended.
Exercise and giving up smoking are the mainstay of treatment in patients with claudication only. However, claudication is usually a sign of more widespread vascular disease, so this should also be investigated.
In severe cases, surgery is used to clear or bypass blocked vessels. In some cases the diseased portion of the artery may be replaced or bypassed by venous or artificial graft to allow free flow of blood. If the patient does not stop smoking, all these types of surgery are eventually unsuccessful and the artery will block again.
If treated early the prognosis is very good. Otherwise the disease may progress to slow, insidious development of tissue ischaemia, and amputation of the foot or even the whole leg, may eventually be necessary.
The best way to prevent progression is to stop smoking.
When to see your doctor
If you experience cramping pains in your calves, thighs or buttocks when walking or doing other forms of exercise, then you should see your doctor as soon as possible.
Reviewed by Dr K. Michalowski