What is intermittent claudication?
Intermittent claudication is the tight cramp like pain felt typically in the calf muscle on walking when the blood supply to the lower limb is limited. The word is derived from the Latin verb, claudere, to limp. The severity of the claudication is defined by the distance walked before onset of the pain. On resting or slowing down, the pain passes off within a few minutes. Walking up hill, carrying a heavy bag or rushing all shorten the claudication distance.
Although unpleasant, intermittent claudication is a relatively benign condition as far as the leg is concerned. Most patients either stay the same or improve and only a small minority (5%)
progress to critical limb ischaemia. Diabetics and patients who continue to smoke have a worse prognosis.
Are there other conditions that resemble intermittent claudication?
Other conditions may mimic intermittent claudication. The main culprit is spinal claudication due to congestion of the spinal canal. This is usually a result of wear and tear of the lumbar spine. The pain of spinal claudication resembles intermittent claudication but the onset is variable; patients have good days and bad days. This is never so with vascular claudication which is very consistent. The pain of spinal claudication extends beyond the calf muscle up the back of the thigh and round on to the shin. There is often a history of back problems and straight leg raising may be limited.
How is intermittent claudication treated?
The priority with intermittent claudication is to recognise it as a warning sign of potential hardening of the arteries elsewhere in the body, and address this before intervening with the legs.
Risk factor modification
In many respects the true significance of intermittent claudication is not the symptom but the risk of death from other aspects of vascular disease. Claudicants have a mortality around three times that of age-matched controls, mainly due to coronary heart disease strokes and aneurysms. Attention to vascular risk factors including smoking, hypertension, antiplatelet and statin therapy is therefore of paramount importance. Modification of vascular risk factors is explained in more detail in the section of the website devoted to atherosclerosis (please see Conditions Treated, Prevented and Cured)
Many patients can cure their intermittent claudication by walking as much as possible. "Walking through the pain"
, i.e. continuing to walk as long as possible after the pain starts encourages collateral blood vessels to open up. Patients effectively do their own bypass. Simply advising patients to walk achieves limited benefit but supervised exercised programs are highly effective.
Pletal (generic name cilostazol)
is a very interesting drug which is very helpful for some patients who have intermittent claudication. Walking distance can be improved significantly. Cilostazol also seems to benefit some patients with more severely impaired limb circulation, and may have beneficial effects after angioplasty, though it was not designed primarily for this purpose. It is likely that this drug will be used more widely in the future. Not everyone can take cilostazol since it is contraindicated in some cardiac disorders.
Angioplasty and stenting
Angioplasty is most effective for stenoses or short blockages high up in the legs. Blockages lower down can also be treated, but the risks are somewhat higher and the benefits less certain.
Angioplasty and stenting are described in the Techniques and Services section of the website.
The value of exercise therapy and the effectiveness of angioplasty have greatly reduced the number of patients who end up requiring operations for intermittent claudication. In selected patients however, surgery is highly effective and durable. This is particularly so for blockages and narrownings of the common femoral artery in the groin which is easily accessible surgically and not readily treated with angioplasty. Here a localised endarterectomy to remove the block may be the best treatment. Other surgical techniques are effective to remove or bypass blockages or the iliac and femoral arteries. Bypasses extending below the knee are rarely used to treat claudication, but are used frequently to treat more severe forms of leg ischaemia.