Normal arteries are smooth and unobstructed on the inside. As years go by, their inside lining becomes thick and narrow because atheromatous plaques build up in their wall. The plaques are made of cholesterol, calcium, destructed cells and fibrous tissue. This process is called atherosclerosis or hardening of the arteries, and is similar to furring in the water pipes.
A plaque may be complicated by bleeding in it, cracking of its surface and blood clotting. Complicated atherosclerosis may cause narrowing (stenosis) or complete blockage (occlusion) of an artery, and usually occurs close to the areas where arteries divide into branches.
Arteries carry blood rich in nutrients and oxygen from the heart to the rest of the body. When the arteries in the legs get enough plaque so that blood flow in them is reduced, because of stenosis or occlusion, the condition is called peripheral occlusive arterial disease (POAD). The arteries which may be affected by POAD are the abdominal aorta, the iliac, the femoral, the popliteal and the tibial arteries.
POAD may not cause any symptoms in the early stages. Much less than 50% of people with POAD have blockages in their arteries severe enough to experience symptoms. If blood flow to the feet is significantly reduced, intermittent claudication or (in more serious cases) critical limb ischaemia may occur.
The most common symptom is intermittent claudication. This is an ache or cramp in the leg muscles (calves, thighs, buttocks, feet) when you walk and goes away when you rest. You may not feel pain but heaviness, weakness or numbness in the leg with activity. It often occurs more quickly if you walk faster or uphill, when the requirements of the muscles in blood and oxygen increase. Over time, you may begin to have intermittent claudication in shorter distances.
The situation of advanced POAD is called critical limb ischaemia, i.e. when blood flow to a leg is so much reduced that the tissues of the foot do not get enough oxygen when you are resting. You will get pain in the foot or toes even when you are not moving, worse at night when the legs are raised. Things will get more serious if the skin of the calf, foot or toe breaks down into a painful sore which won’t heal (nonhealing leg ulcer). Critical ischaemia threatens the viability of the leg. If the circulation is not improved, the sores may progress into dead tissue, called gangrene.
You may have no symptoms and still have atherosclerosis causing occlusive disease in your leg arteries or in the arteries supplying vital organs, like the heart or the brain.
It is important to treat this disease in the early stages, because it may increase the risk of losing a leg, but also of suffering a heart attack or a stroke. You run the same risk of these events as does an individual having already suffered a heart attack.
It is caused by atherosclerosis of the peripheral arteries (aorta and leg arteries).
It affects individuals of advanced age (usually over 60 years). One in three people over 70 years have POAD. Men have a greater risk than women.
It is much more common in smokers, diabetics, people with high cholesterol, people with high blood pressure and people with obesity. The conditions predisposing to atherosclerosis are called (atherosclerotic) risk factors. Coincidence of two or more risk factors increases the risk of POAD significantly.
TInitially, your physician will ask about your general health state, your symptoms and your medical history (other medical conditions and risk factors you may have). Then, he/she will examine you, especially in the abdomen and the legs (groins, behind the knees, feet) to assess the strength of your pulses in your arteries.
If your physician suspects POAD, it is possible to proceed to simple tests such as:
For more precise assessment of the extent of the disease and the severity of the blockages in your arteries – particularly if operative management is planned – the physician may organise:
Unfortunately, this is extremely unlikely. However, the situation may improve, because:
If your symptoms are mild, you do not need an operation. However, because arterial disease is a warning sign for a heart attack or a stroke, you must control any risk factors like smoking, diabetes, high blood pressure, high cholesterol etc
In many patients, intermittent claudication remains stable for long periods of time or improves. If, however, it restricts your walking and this affects your lifestyle, your vascular surgeon will discuss the treatment options with you.
In cases of critical limb ischaemia, an operation is usually required to improve the circulation to the leg, otherwise small superficial sores may develop into gangrene and the limb may be lost.
There are three lines of treatment: conservative management, open operation and endovascular procedure (balloon angioplasty and/or stenting).
Conservative management – This includes:
(i) Changes of lifestyle (See below What can I do to help myself?)
(ii) Medications. All patients need to take an antiplatelet drug (Aspirin or similar) and lipid-lowering drugs (statins, fibrates)
(iii) Walking exercise. Regular walking, for example at least 30 minutes 3-5 times a week, may help improve your symptoms within a few months
Arterial bypass operation with a graft – With this operation a new artery for blood flow to your leg is created bypassing the blockage of your artery. As bypass graft, the vascular surgeon uses a vein from your leg or a plastic tube, and connects it above and below the blockage. This procedure may be performed under general or spinal anaesthesia
Balloon angiopasty and/or stent placement – In certain cases like short blockages in large arteries, your vascular surgeon will select this procedure to increase the blood flow to your leg. This is commonly performed under local anaesthesia. The blockage is opened with a balloon under x-ray guidance. Occasionally, a metal stent is inserted to fit the dilated artery and hold it open. The value of this procedure is controversial in cases of intermittent claudication. The decision about the type of management depends upon the morphology and the extent of blockages as well as the general state of your health.
In certain cases, especially if there is gangrene, the vascular surgeon may recommend amputation surgery. This will happen if the circulation to the leg is very much reduced and cannot be improved.
Your vascular surgeon is the only physician qualified to offer all types of treatment for POAD and, therefore, able to recommend the option which is best for you.
Conservative management with a programme of walking is very helpful and safe. Because the surgical and endovascular procedures aren’t always successful, they are justified only in cases of very limiting intermittent claudication and critical ischaemia.
Very few people with intermittent claudication will ever be at risk of losing a leg through gangrene, particularly if they look after themselves appropriately. The simple instructions below are very effective.
On the contrary, critical ischaemia is a threat to the viability of the limb and it is the vascular surgeon’s job to prevent this outcome at all costs.
You should seriously consider changes that will help avert the chances to further damage your arteries. If you don’t, you are at increased risk for a heart attack, a stroke or further problems with the circulation to your feet.
These changes include: