Treatment
The natural history of intermittent claudication can be considered in 2 parts: that of the leg and that of the patient as a whole.
The leg usually does well in that most remain stable or improve. Some will deteriorate and the overall risk of a major amputation is only 1% - 3.3% at 5 years. The patients, however, are at higher risk of heart attack and stroke because arterial disease is generalised and overall about 30% will die within 5 years from these problems.
This has to be taken into account together with quality of life issues when considering the best treatment for a patient with intermittent claudication.
MEDICAL AND EXERCISE MANAGEMENT
The aim of medical management is to increase the survival of a patient with intermittent claudication. The general advice was to 'stop smoking and keep walking'. Nowadays, in addition to this and lifestyle measures to tackle atherosclerosis , certain drugs have been shown to be of benefit in prolonging survival in patients with arterial disease:
 | antiplatelet drugs - act on certain cells in the blood to make them less sticky. Aspirin and clopidogrel are the most commonly used. Aspirin is cheaper but has higher risk of causing bleeding from the stomach. Clopidogrel is slightly more effective and causes less bleeding but is more expensive. Overall these drugs reduce the risk of a cardiovascular event (heart attack or stroke) from 6% per year to 4.5% per year. Furthermore, they reduce the risk of requiring an operation by 85%. |
| anticholesterol drugs - the statins (pravastatin or simvastatin). These reduce the risk even further from 4.5% per year to 3% per year. |
| cilostazol (pletal) - this is a new drug licensed for use in intermittent claudication. It works in many different ways. It has to be taken to 12 weeks to assess whether it will help or not. I f it does not work by then, it can be stopped. |
Exercise has been shown to improve walking distance and to reduce cardiovascular events. Exercise does not have to be vigorous - merely walking for 30 minutes in divided periods each day is sufficient. Exercise is good for the leg and for the general health of the patient. The leg muscles adapt to having less blood and exercise encourages the formation of 'collateral' vessels - these are small vessels that bypass the blockage in the main artery.
It is recommended that these measures be tried for about a year before assessing the outcome and need for further intervention.
ANGIOPLASTY
See the section on angiogram and angioplasty for more information. The aim is stretch open a segment of narrowed or blocked artery using a balloon in the x-ray department. The blockage should not be too long and suitable patients are usually selected form a duplex scan. There are risks involved with angioplasty with a risk of amputation (0.2%) and death (0.1%).
The success rate depends on the artery and the degree of disease. Some 90% of iliac angioplasties are still open at 5 years for a narrowing. For a short narrowed segment of superficial artery, at 5 years 70% may still be open whereas only 50% will still be open if originally treated for a blocked segment.
I will only put a patient forward for angioplasty if they are not coping with their symptoms and have already tried medical and exercise management. The patient has to understand that there are risks - all be it small.
SURGICAL BYPASS
If the symptoms are severe and the patient is not suitable for angioplasty I will consider an operation to bypass the blockage. An angiogram is usually used to decide on the exact operation needed. The bypass material will be usually the patients own leg vein (the long saphenous vein is used) or a synthetic graft (dacron or PTFE). For a patient with intermittent claudication the iliac artery or the superficial femoral artery will need to be bypassed. The following show how this can be done.
To bypass a blocked iliac artery, an ilio-femoral bypass may be used. This is usually a synthetic graft. If the iliac system on the other side is normal, a femoral-femoral cross-over graft may be used. Again this is usually a synthetic graft. If both iliac systems are diseased, the aorta is used to provide the inflow artery and an aorto-bifemoral graft is constructed using synthetic material (dacron).
To bypass a blocked superficial femoral artery, a femoro-popliteal bypass is needed. This may be the patients own vein or a synthetic graft (if the bypass is to the above-knee part of the popliteal artery).
The risks of surgery involve a 2% death rate and 18% rate of complications - these are usually heart, chest and wound related. Infection of the synthetic graft may occur in 1-3% of cases. This can pose a significant risk of limb loss if it occurs. These grafts do not last forever, about 70% of vein grafts will be working at 5 years and about 50% of synthetic grafts.
The decision to operate is therefore not taken lightly and the patients have to understand that there are significant risks involved.