| What is intermittent
claudication?
Claudication comes from the Latin word claudicatio
meaning "limping" and the term intermittent claudication therefore means
that the sufferer intermittently limps. What tends to happen is a sensation
of tightening in the back of the calf muscle, in one or sometimes both legs,
although sometimes it also occurs in the thigh muscles or buttocks. The pain
is due to the muscles having insufficient blood to supply their oxygen needs
during exercise, a condition called ischaemia . This occurs after a variable
distance of walking, in some patients after just a few steps and in others
after a mile or more. At the shorter distances the pain is usually too severe
to allow continued walking but in milder forms it is uncomfortable and a
nuisance, making the individual slow down rather than stop. Sometimes the
leg also feels "dead" and sometimes the foot feels numb. All these symptoms
almost always improve or disappear within ten minutes of stopping walking.
The affected person often finds that their quality of life is impaired because
of difficulty in getting regular walking exercise, taking a long time, with
many stops, in getting to the shops, or carrying out activities which involve
using the legs such as golf, bowls and dancing.
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Why does it happen?
The main cause is a narrowing in one of the main arteries,
most commonly the femoral artery in the thigh, or sometimes the iliac artery
in the lower abdomen. There are several medical causes for the narrowing
but by far the most common is a condition called atherosclerosis. This means
a thickening of the lining of the artery with a disease process which eventually
narrows the artery more and more until in some cases it blocks completely.
Atherosclerosis happens for a number of reasons some of which are smoking,
genetic, and diet related. This is the same condition that also occurs elsewhere
in the body, in other arteries such as the coronary arteries in the heart.
There is therefore a similarity between claudication and angina pains in
the chest caused by narrowing of the coronary arteries. Indeed, many patients
with one condition also suffer the other.
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Why is claudication important?
First, it is not uncommon. Although it can occur in
any age group it is more common in the middle aged and elderly. It is estimated
that around five per cent of people aged over 65 suffer the symptoms and,
although it is not exclusive to men, it is certainly more common. Second,
as indicated above, the symptoms in the leg may be an early warning that
there is disease elsewhere and may alert the individual (or more likely his
or her doctor) to this fact who can then take further steps to help with,
for example, coronary artery disease. Third, a very small proportion of people
with claudication get worse and need surgical treatment to help. This will
usually only be necessary if the circulation deteriorates to the point of
suffering pain at rest in the feet and particularly at night. It is important
to realise that only one or two per cent of people per year with this condition
ever deteriorate to this point and need surgery. Whilst it is true to say
that there is a chance of losing a leg as a result of the condition, this
is extremely unlikely. In fact, the vast majority of people with this condition
improve significantly if they follow the advice of their GP or specialist.
It is interesting to note that the narrowing in the artery referred to above
very rarely goes away. There do appear, however, to be many mechanisms which
allow the symptoms to improve despite the continued presence of the narrowing
or blockage.
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What can I do about the condition if I have
it?
First, do not be afraid of walking. Many patients fear
going out because they think that harm will come to them. There is no evidence
that this is the case and, indeed, a programme of walking exercise is definitely
beneficial in terms of being able to improve the walking distance. There
are many ways in which exercise can be carried out but few hospitals currently
provide exercise classes specifically for this condition. In general it is
left up to the patient to work out a programme over several months of trying
to steadily increase the number of walks per day and the length of each walk.
Second, it is essential to stop smoking. Not only is it possible that the
disease process will be slowed or halted by doing this but also, if any treatment
is later required, then the chances of the treatment working are greater
if cigarettes have been completely abolished. Even one cigarette can have
significant effects on the circulation. Furthermore it is probably even more
important to stop smoking to protect the coronary arteries from further
deterioration.
Your GP or specialist will often check your blood
cholesterol and advise whether you should alter your diet to reduce the fat
content or in some case advise on the need to take medication to lower the
blood cholesterol.
Many patients are prescribed low dose Aspirin. This
is not to try to stop the pain but it is thought that a single tablet each
day (the dose ranges from 75 to 300mgs) might reduce the rate of deterioration
of the condition, and again might even protect the coronary arteries.
Alcohol consumption probably does not significantly
affect the disease although there is a suggestion, as in heart disease, that
when taken in moderation (one to two units per day) there might be marginal
effects. However it is probably not worth starting alcohol if you do not
drink at present.
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What investigations will I need?
It is quite possible that none at all will be necessary.
Sometimes it is perfectly possible for your doctor to make the diagnosis
based on your history and a simple bedside examination, feeling your pulses
in the legs and feet. Sometimes it is useful to listen to the blood flowing
in the foot arteries using a hand held Doppler machine which can also be
used to measure the blood pressure in these arteries. This is a simple harmless
and painless bedside procedure. Occasionally a specialist will recommend
you have a Duplex Ultrasound scan. This is completely harmless and painless
and gives an indication of the site of disease in an artery and its severity.
The test is sometimes used to try to predict whether further treatments such
as angioplasty (see below) are possible. Rarely, and usually for those patients
who are suffering very badly, the specialist might request a test called
an angiogram or arteriogram. This requires a short stay in hospital, sometimes
overnight, and involves the x-ray specialist (radiologist) taking a series
of x-rays of the artery. A local anaesthetic is used before passing a small
needle into the artery in the groin or sometimes the elbow. A dye is injected
and when this passes down the arteries it can be seen very clearly on an
x-ray. This is often essential information before your specialist can decide
if an angioplasty or even surgery is possible.
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What is an angioplasty?
This is a technique, rather like angiography, where
a fine tube or catheter with a balloon on the end can be put inside the artery.
When the balloon is inserted within the narrowed area and then inflated it
will stretch up this area. This restores the artery blood flow, and improves
the circulation and symptoms. However neat and simple this might seem in
theory, there is very little evidence from clinical studies to show that
angioplasty provides long term benefit for patients with mild and moderate
severity claudication. There does appear to be a short effect in improving
the walking distance of patients for about six or twelve months. However,
one always has to bear in mind that the vast majority of patients who have
no treatment such as this will improve greatly anyway. Therefore a very careful
consideration of the risks and benefits of this procedure is undertaken in
every individual case and what is suitable for one is not necessarily suitable
for another person. By and large, angioplasty is a relatively safe procedure
when carried out in the legs. However, like all "invasive" procedures there
are some risks and these include bleeding and bruising, allergies to the
dye given, and damage to the artery from the catheters put in. The success
of the procedure in stretching up the artery again depends on the location
and severity of disease. As a general rule, however, the success tends to
be somewhat better in the iliac than the femoral arteries and for a narrowed
area rather than a complete blockage.
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Bypass surgery
As mentioned above this is rarely necessary. There
are a number of different types of procedure which the vascular surgeon might
employ to create a diversion of blood around a blocked artery. Most commonly
this involves using one of the patient's own veins or sometimes a synthetic
tube which is implanted in the leg. The operation is usually carried out
under a general anaesthetic, although sometimes a spinal anaesthetic is used.
The hospital stay is in the order of seven to fourteen days and, although
there is quite a lot of pain immediately after the operation, the results
are often very good in terms of improving walking distance. Having said this,
the overall risk to the patient from a procedure such as a leg bypass is
substantially greater than from angioplasty and this explains why so few
patients undergo the procedure for claudication alone.
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this page was compiled by
Mark Whyman MS FRCS
on behalf of the Gloucestershire Vascular Group
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