Peripheral Arterial Disease

Peripheral arterial disease (PAD) is a common circulatory problem caused by narrowed arteries. It is commonly known as peripheral vascular disease, hardening of the arteries, or atherosclerosis. Arteries are functionally known to carry oxygen and nutrient-rich blood from the heart to all body areas. PAD occurs in the arteries that carry oxygen-rich blood to the limbs (arms and legs). People who develop peripheral arterial disease do not receive enough blood supply, usually to their legs. This causes symptoms, most notably, leg pain, especially while walking. This is termed as claudication.

 

Healthy arteries consist of the smooth lining that prevents blood clotting and promotes uniform blood flow throughout the body. In peripheral arterial disease, the arteries slowly become narrowed or blocked due to plaque formation. Plaque comprises excessive fat, cholesterol, and other substances floating through the bloodstream. If the arteries become narrowed or blocked, they won't be able to deliver adequate blood and nutrients to nourish organs and other tissues, causing damage to the tissues and eventually leads to tissue death. The rate at which PAD progresses varies with each person and depends on many factors, such as which part of the body the plaque has formed, the size of the plaque, and the person's overall health.

 

Signs and symptoms associated with PAD

 

Many people with peripheral artery disease experience no or mild symptoms. Some people have claudication (pain in leg when walking). Symptoms of claudication involve muscle pain or cramping in the legs or arms that are triggered by activity like walking, jogging, or other physical activity. But the pain disappears after a few minutes of rest. The site of the pain depends on the location of the clogged or narrowed artery. However, calf pain is the most common location.

 

Peripheral artery disease signs and symptoms include:

• Painful cramping in one or both of the hips, thighs, or calf muscles after certain activities
• Leg numbness or weakness
• Coldness or calmness in the lower leg or foot, especially when it is compared with the other side
• Sores or wound on the toes, feet, or legs that won't heal easily
• Change in the color of the limbs
• Slower growth of hair or hair loss on legs and feet
• Slower growth of the toenails
• Shiny skin on the legs
• No or a weak pulse in the legs or feet
• Erectile dysfunction in men

 

What causes PAD?

 

The most significant cause of peripheral artery disease is atherosclerosis. In atherosclerosis, fatty deposits or plaques build up in arterial wall’s inner lining and reduce blood flow.  Plaque is made up of cholesterol, fat, fibrous tissue, proteins, and calcium. Although atherosclerosis usually focuses on the heart, the disease can generally affect arteries throughout the body. When it takes place in the arteries supplying blood to the limbs, it causes peripheral artery disease. A less common cause of peripheral artery disease can be inflammation in the blood vessel, injury to the limbs, unusual anatomy of the ligaments or muscles, or any kind of radiation exposure.

 

Risk factors

 

Factors that may raise the risk of developing peripheral artery disease include:

 

• Smoking
• Diabetes
• Being obese
• High blood pressure
• High cholesterol
• Growing old
• Not getting enough physical activity
• Unhealthy eating patterns
• Any previous history or family history of peripheral artery disease, stroke, or heart attack
• Higher homocysteine levels (a protein component that helps build and maintain tissue)

 

People who smoke or have diabetes possess a greater risk of developing peripheral artery disease due to reduced blood flow.

 

Complications

The peripheral arterial disease can lead to a few complications, including:

 

1. Chronic (long-term) poor blood flow in the leg (critical limb ischemia): The condition occurs when an injury or infection progresses and leads to tissue death or gangrene. Gangrene is a serious complication that may require amputation. 

 

2. Serious infections: If an individual develops sores on the feet, the sores can get infected. The infection can then spread to the tissues and muscles, the bone, or the bloodstream. The risk of such complications is greater for individuals who have comorbidities like diabetes.

 

3. Stroke and heart attack: Atherosclerosis causing peripheral artery diseases aren't limited to the legs only. Fatty deposits also build up in arteries supplying blood to the heart and brain.

 

Prevention

 

The best way to prevent claudication is by maintaining a healthy lifestyle. Few preventive measures as given below:

 

• Quit smoking
• If diabetic, keep the blood sugar in good control
• Exercise regularly
• Manage cholesterol and blood pressure levels
• Eat low saturated fat foods
• Maintain a healthy weight

 

Diagnosis

A doctor may diagnose PAD based on medical history, physical examination, and few investigations:

 

1. Physical examination - The doctor may find signs of PAD during a physical examination, such as a weak or absent pulse below or nearby a narrowed area of the artery, whooshing sounds over the arteries that can be audible with a stethoscope and decreased blood pressure in the affected limb.

 

2. Ankle-brachial index (ABI) - This is the most common test help to diagnose peripheral arterial disease. It is the measurement of the blood pressure in the lower legs compared to the arm's blood pressure. The ABI screening helps evaluate the amount of blood flow to the legs and feet, which is generally low in a person with PAD.

 

3. Ultrasound - Special ultrasound screening techniques, such as Doppler ultrasound, can help analyze the blood flow through the blood vessels and recognize narrowed or blocked arteries.

 

4. Angiography - An imaging technique uses a contrast material, injected into the blood vessels, and allows the healthcare provider to view blood flow through the arteries. The doctor can trace the flow of the contrast material using imaging techniques:

 

    a) X-ray imaging
    b) Magnetic resonance angiography (MRA)
    c) Computerized tomography angiography (CTA)

 

5. Blood tests - A sample of the blood can measure cholesterol and triglycerides levels and check for blood sugar level.

 

Sources:
https://www.nhlbi.nih.gov/health-topics/peripheral-artery-disease
https://www.mayoclinic.org/diseases-conditions/peripheral-artery-disease/symptoms-causes/syc-20350557#:~:text=Peripheral%20artery%20disease%20(also%20called,to%20keep%20up%20with%20demand.