Causative & risk factors
PAD is caused by atherosclerosis. Atherosclerosis is characterized by deposition of streaks of fat in the inner walls of the blood vessels. Apart from the fatty deposits, inflammatory cells, proteins and calcium contribute to the deposition. These deposits along with fat are termed as plaques. These plaques cause blockage or narrowing of the arteries. As a result the blood supply to the end organs is hampered, leading to development of ischemia.
Sometimes, peripheral artery disease can occur as a result of vasculitis, injury or exposure to radiation.
As age advances (>50 years) the risk of developing peripheral artery disease increases. Smokers are more prone to develop PAD. Having underlying conditions such as diabetes, hypertension, obesity or high cholesterol levels are associated with a higher risk of developing peripheral artery disease. Those with a family history of heart disease or stroke are more prone for developing PAD.
Clinical presentation
Many patients with peripheral artery disease may remain asymptomatic or develop only mild symptoms. The symptoms of peripheral artery disease will depend upon which body part is involved. Legs are the most commonly affected site.
The patient develops intermittent claudication, which causes mild discomfort or even severe pain in the legs. There may be numbness, weakness, coldness or discoloration of the legs. The skin overlying the legs becomes shiny. The hair and nail growth in the affected areas may be stunted. Open ulcers may be present on the legs. The pulse in the legs may be weak or absent.
Patients with PAD have a higher risk of developing complications such as a heart attack or stroke.
Investigations
Diagnosing peripheral artery disease is challenging because the symptoms it produces can easily be misdiagnosed, both by the patient and the doctor.
A common test used to diagnose PAD is the Ankle-Brachial Index. In this the difference between the blood pressures of the arm and the ankle is assessed. The blood pressure in the ankle is found to be lower than that in the arm. Special tests such as a Doppler ultrasound, CT angiography or MR angiography may be performed.
Treatment
The aim of treatment in peripheral artery disease is to manage the symptoms and prevent complications. Lifestyle changes form an important part of treatment. These include losing excessive weight, eating a low-fat diet, exercising regularly and avoidance of smoking.
Medications are prescribed to treat any underlying medical conditions such as diabetes, hypertension etc. Aspirin or other anticoagulants are prescribed to prevent blood clotting.
When a blood clot has already been formed in a specific artery, thrombolytic therapy i.e. injection of a thrombolytic drug can be done at the site of the clot.
Surgical intervention may be necessary in some cases. Commonly performed surgical procedures include angioplasty or bypass.
