All about peripheral vascular disease

What is peripheral vascular disease?

Peripheral vascular disease is the narrowing of one or more arteries (blood vessels) and it mainly affects arteries which take blood to the legs. This condition is also commonly referred to as ‘hardening of the arteries’.

The narrowing of the arteries is caused by the development of ‘fatty patches’ within the inside lining of arteries. The medical term for this is atheroma. The fatty patches can start off quite small and cause no problems at first, but over time they can increase in size and make the affected artery narrower. This reduces the blood flow through the affected section of artery, resulting in tissues having a reduced blood flow, leading to symptoms developing.

Risk factors and symptoms

Lifestyle risk factors which increase the likelihood of a person developing PVD include smoking, obesity, lack of exercise, an unhealthy diet, or excess alcohol. Other factors that increase the risk of developing PVD include high blood pressure, high cholesterol and diabetes. Advancing age and family history are often additional risk factors.

The typical symptom is pain in the calf, thigh, or buttock muscles when walking. This represents the earliest stage of peripheral vascular disease and is called ‘intermittent claudication’. When a person is walking, the muscles need extra blood to provide more oxygen to the muscles and remove toxins. If the artery is narrowed, the extra blood cannot be delivered to the muscles.

This results in the muscles being starved of oxygen and toxins building up, causing the muscles to ache and become weak. In the early stages of PVD, this can occur after walking quite a long distance (for example, half a mile).

However, if the narrowing of the arteries becomes worse, pain can be felt after just a 100-yard walk. Eventually a person may only be able to walk a few yards before experiencing pain. Resting usually relieves the pain within two or three minutes and then it is sometimes possible to walk further.

When the arteries are severely narrowed or blocked, the arteries cannot supply enough blood to the legs and a person develops what is known as ‘rest pain’. Typically, rest pain develops in the toes and feet and particularly at night when the legs are raised in bed, losing the help of gravity to supply blood to the feet. Eventually, the feet are painful all through the day and sleeping is very difficult due to the pain.

Ulceration and gangrene can occur in the most extreme cases. Any wound requires more blood than normal in order to heal. If that extra blood is not available, the wound never heals and in fact dies back, resulting in ulceration and dry-black gangrene. Urgent medical attention is required here.

Treatment

In the earliest stages of the disease, when a person is experiencing pain on walking, the correct treatment at this time can prevent progression of symptoms. The following measures are very important in the management of PVD:

• Stopping smoking - This is the single, most effective treatment and stopping is essential to improve walking distance and prevent progression of the disease.
• Walking - This has been shown to be the best form of exercise to improve the symptoms of PVD and should be undertaken daily. Regular exercise stimulates small arteries in the legs to enlarge and bypass the narrowed arteries, thereby improving the blood supply.
• Lose weight - Excess weight means that your muscles have to work harder in order to walk. Losing weight reduces the demand on the muscles and can cure symptoms of PVD alone.
• Aspirin - Taking an Aspirin is usually advised at a dose of 75-150mg a day to thin the blood. Alternatives are available for people who cannot take Aspirin.
• Cholesterol - Cholesterol-lowering medication is usually advised to help prevent the build-up of atheroma.
• Other medical conditions such as high blood pressure and diabetes should be kept well under control to prevent progression of PVD.

If symptoms do not improve with exercise and conservative management, a special X-ray called an angiogram would be needed. Under local anaesthetic, a needle is inserted into an artery - usually in the groin - and dye is injected. X-rays are taken as the dye is carried in the blood down the leg arteries.

This shows where the arteries are narrowed or blocked. An angioplasty involves a tiny balloon being inserted into the artery and inflating it where it is narrowed. Stretching the narrowed artery can improve the blood supply to the leg and therefore improve the symptoms.

Arterial bypass surgery can be performed when angioplasty has failed or is not possible. The operation is performed to bypass blocked arteries and improve the blood supply to a limb.