Peripheral arterial disease (PAD), also referred to as peripheral vascular disease (PVD), is a condition which causes arteries to narrow and block and most commonly affects the blood supply to the legs.
A history of smoking, high blood pressure, raised cholesterol, coronary heart disease and diabetes are all risk factors for developing PAD. Age is also a factor, and around one in five people in the UK who are over 60 are believed to have some form of it, although many of these will be asymptomatic. Having a family history of PAD also increases your risk of developing it.
PAD is particularly troublesome in the arteries supplying the legs. When we walk, the blood supply to our muscles is increased because they need more oxygen. If there is narrowing of the artery supplying the leg, it can't keep up with demand and the leg starts to ache and seize up until we feel the need to stop and rest.
When we stop, the problem soon resolves itself.
The amount of oxygen the muscles need to receive from the blood diminishes and in a moment or two the impaired arteries have been able to supply the temporary deficit. This condition is known as intermittent claudication.
Often both legs are affected, although one may be more symptomatic. When our arteries are narrowed, how far we can walk before we encounter this symptom will depend on how badly they are affected and how fast we walk.
Intermittent claudication can progress to a situation where, even at rest, there is pain in the legs. This may affect your sleep and be detrimental to your quality of life.
There is also the danger of further progression to ulcer formation or gangrene. It should be emphasised that this is a rare development and that usually intermittent claudication does not progress beyond the level described above.
There are other disorders that cause pain in the legs and so a GP needs to rule these out before diagnosing PAD and formulating a treatment plan or referring a patient to hospital.
Diagnosis is made by examination of the pulses and by comparing blood pressure in a patient's arm and ankle (a test called the ankle-brachial pressure index). If blood pressure is lower in the leg than the arm, this indicates the likelihood of a diagnosis of PAD. Once PAD has been diagnosed, it is important to treat the causes of the problem to stop it deteriorating and possibly spreading and causing blockages in arteries other than those already affected.
In determining the best treatment for patients with intermittent claudication, doctors will assess the general medical condition and needs of the patient. PAD tends to affect older people, some with co-morbidities, such as chronic obstructive pulmonary disease (COPD), who will be less able to lead active lifestyles.
The aim for patients within this group will be to enable them to be as comfortably mobile as possible and a treatment plan will be agreed between the doctor and patient with this in mind.
In other cases, where the demands of a job or other aspects of a patient's lifestyle require a much greater degree of mobility, more invasive treatment options may need to be considered and these will be outlined later.
Even following referral to hospital, in some cases it may be considered advisable to ask patients to wait a little prior to undergoing treatment, to see if their mobility improves over time. A consultant will weigh up the risks and benefits of intervention versus conservative, non-surgical treatment, and in many cases will advise the latter.
If you are diagnosed with PAD, there are measures you can take to minimise the risk of deterioration and to improve your overall health. A diagnosis of PAD means that there are blocked areas within your arteries and this can put you at greater risk of a heart attack or stroke.
Embarking on a combination of lifestyle changes and taking your prescribed medication regularly will help to considerably minimise this risk.
Clearly if you are a smoker, it is important that you stop. Dietary changes to help lower the bad cholesterol (LDL) in the blood will be of benefit, as well as taking prescribed medication to treat raised cholesterol levels and high blood pressure. Another drug which is recommended by the National Institute for Health and Care Excellence (NICE) to help with claudication is naftidrofuryl oxalate (Praxilene).
Exercise - especially walking - is beneficial to improve arterial health, strengthen leg muscles and improve walking distance. It is recommended that these periods of exercise last at least 20 minutes and are undertaken three or more times a week. It is worth bearing in mind that anything you can do to help the arteries in your legs will also help all the other arteries in your body.
Treatment options vary, according to your symptoms and general condition. Most patients will not be treated surgically but will be advised on what has caused their symptoms and what they can do to avoid further deterioration and to improve their quality of life.
The surgical option is available if conservative measures, such as the lifestyle changes mentioned above and medication for conditions which are in themselves risk factors in the presence of PAD, are failing to provide adequate control and symptom relief.
Before deciding to perform surgery, your consultant will scan your arteries to see where and how long the blockages are and to consider the pros and cons of operating on them. The consultant will take into account your age and mobility level and needs when selecting the best intervention to offer you.
Angioplasty can be performed as a day case or may require an overnight stay in hospital. It is a form of keyhole surgery, in which, under local anaesthesia, a balloon is passed into a narrowed artery. It is then inflated, so that a channel can be opened, enabling blood to flow through it.
This procedure may be the treatment of choice where the blockages are not long or complicated and it has a high initial success rate. However, it is a first line treatment and may well need to be repeated if the arteries block off again.
A surgical bypass involves attaching a tube (either an artificial artery or a surface vein taken from your leg) above and below the blockage in your artery. This allows blood to flow from the undamaged portion of the artery through the bypass and back into the artery below the blockage.
This is a considerably bigger operation than an angioplasty and you would need to stay in hospital for a week or so and to be out of action for some six weeks.
Bypass grafts are reserved either for patients who have had repeat angioplasties which have ultimately become blocked again, requiring further intervention, or for patients with long and complicated blockages whose cases are complex.
Because of this, there is a higher risk attached to them but they can often treat blockages that could not be adequately addressed by an angioplasty alone and they have a better long-term success rate.
Surgeons may choose to combine an angioplasty with a surgical bypass, as the techniques are not mutually exclusive and can deliver good results when used together.
While surgery for severe cases of PAD has an impressively high success rate, it is fair to say that often simple compliance with advice, exercise and prescribed medication render surgery unnecessary. When intermittent claudication is mild, it is best treated with non-surgical measures and may even resolve with these.