Peripheral Arterial Disease (PAD)

What is PAD?

Normally the arteries carry blood away from the heart and deliver it to the body including the legs. This allows the leg muscles to exercise and work normally.

PAD is a blockage in the circulation to the legs (poor circulation). This results in poor blood supply to the legs and feet which can result in leg pain or fatigue. In severe cases it can result in gangrene and amputation.

PAD is a common cause of disability and is one of the more frequent manifestations of atherosclerosis or generalized vascular disease.

What causes PAD?

PAD is caused by blockage in the arteries supplying blood to the legs. The cause of the blockage is atherosclerosis or "hardening" of the arteries. This is the same disease that can cause heart attacks and strokes but in this case it is affecting the arteries of the legs.

Atherosclerosis occurs in the legs related to: smoking, diabetes, high blood pressure, elevated cholesterol, aging and heredity. Some of these factors can be controlled or treated, some can't.

What are the symptoms of PAD?

In it's mildest form PAD is silent, causes no symptoms and can only be detected with diagnostic testing.
As PAD progresses patients develop pain or fatigue in the legs with excercise. This affects the major muscles of the calf, thigh or buttock. The discomfort usually occurs at the same distance of walking every time (consistent) and resolves within a few minutes of resting (relief). This is called claudication.

When PAD is more severe there is pain even at rest and at night (usually in the foot). Skin breakdown (ulcer) or dead tissues (gangrene) can occur at this point. This is called critical limb ischemia. If this occurs there is a risk of amputation.

Diagnosis and tests for PAD

Usually a physical exam of the pulses of the leg and a simple Doppler ultrasound of the leg arteries will diagnose the presence and severity of PAD.

Further testing with CT scan (a non invasive XRay), MR scan (a non invasive magnetic scan) or an angiogram (an invasive XRay) may be needed to plan the best treatment of PAD.

Lifestyle modification for PAD

The most important thing for patients with PAD to do is to continue to exercise as much as they are able. Walking to the point of discomfort trains the leg muscles to work better and promotes improved circulation.

It is also important to:
- immediately stop smoking
- loose weight if overweight
- diet to decrease cholesterol
- limit salt intake to decrease high blood pressure

Non-surgical and medical management for PAD

All patients with atherosclerosis should be taking a number of medications to prevent progression of their disease and this includes patients with PAD. These also minimize the chance of other vascular complications such as stroke and heart attack.

Medications:
1. Aspirin or other antiplatelet agent
2. One of the "statin" drugs to lower cholesterol
Check with your doctor. Sometimes other medications are indicated as well.

Guidelines for Intervention for PAD

All patients with critical limb ischemia should have an intervention to prevent gangrene and risk of amputation. This applies to patients with leg or foot pain at rest when the cause is PAD. This also applies to patients with ulcers or gangrene when the cause is PAD.

Patients with claudication (leg pain with exercise only) are not at risk of amputation and intervention should be done only if the symptoms are disabling (preventing normal activity). Mild claudication symptoms do not need intervention.

Surgical treatment for PAD

Surgery can provide durable treatment for PAD, relieve symptoms and prevent amputation. Surgery involves removal of the blockages in the artery or in some cases bypass around the blockage.

Surgery for PAD is usually a major operation and should be done only when the walking disability is severe or when there is critiical limb ischemia and risk of amputation.

Endovascular Treatment for PAD

Endovascular treatment of PAD offers a less invasive intervention than surgery to improve blocked arteries from PAD. It involves dilation of narrow or blocked arteries (balloon angioplasty) or dilation and stenting. The stent is a metal latice that holds the artery open.

Endovascular treatment is less invasive than surgery with faster recovery but still has some risks. It should only be done (like surgery) for disability or critical limb ischemia.
Endovascular treatment is not always possible or the best treatment for PAD.

When should I see my doctor?

You should see your doctor if you think you have PAD to discuss whether further investigation or treatment is needed.

Things that suggest you may have PAD are:
- cramping of the leg muscles with walking short distances that is relieved when you rest
- pain in the lower leg or foot all the time especially at night
- skin breakdown with ulcers on the foot
- black areas on the foot or toes that may be gangrene

Also all diabetics should be assessed for PAD if they are having any foot care done.

References and Resources

• Mayo Clinic website
• Vascular Web