Peripheral Artery Diseases is one of the occlusive atherosclerotic lesions. This condition causes blockage or narrowing of the blood vessels which carry blood from the heart to the lungs. It mainly affects the lower extremities of the body but can affect the upper extremities as well.
In 2019, the global market for peripheral artery disease reached nearly $ 4.5 million. By 2030, that number is expected to rise to nearly $ 9 million, according to market research company NMSC. This figure reflects the global market size of PAD in 2019 and 2030.
Risk Factors of Peripheral Artery Diseases:
Factors that can increase the risk of developing the peripheral arterial disease are as follow:
1. Age
2. Smoking (strong association with peripheral artery disease)
3. Hypertension
4. High levels of cholesterol
5. Obesity (BMI > 30)
6. Family history of peripheral artery disease, cardiac disease, or stroke
The prevalence of peripheral artery disease is 30% in patients, who are 70 years old without other risk factors, or 50 years old with risk factors such as diabetes and tobacco use. Reference: CMDT [ 2021] Pg 485
Pathophysiology of Peripheral Artery Diseases:
Atherosclerotic plaques are the most common cause of peripheral arterial disease. Other factors include inflammation of blood vessels, injury or radiation exposure. Atherosclerosis is the process of building up fat cells, cholesterol, and other substances in artery walls.
This build-up is known as plaque. This plaque builds up on the interior surface of the artery and hardens. The lumen of the affected artery becomes narrow, which leads to reduced blood flow to the extremities and internal organs.
Reduced blood flow causes a decreased amount of oxygen that reaches the muscle, resulting in muscle pain. Reduced blood flow to the extremities may result in ischemia.
Different levels of ischemia:
There are different levels of ischemia in peripheral artery disease which are as follow:
1. Aorto-illiac artery occlusion:
Pain in buttocks, thighs, +/- erectile dysfunction (Leriche syndrome)
2. Common iliac artery occlusion:
The Pain extends to just above the inguinal ligament.
3. Femoral artery occlusion:
Pain in the leg (below the inguinal ligament). Femoral pulse is felt but pulses below it cannot be felt.
4. Femoro-popliteal occlusion:
Pain is below the knee.
Signs and Symptoms of Peripheral artery diseases:
The most common presenting features of peripheral artery disease are:
1. Intermittent Claudication (cramping pain or tiredness induced by walking and relieved by rest)
2. Critical limb ischemia (includes 6P’s that are pallor, pain, paresthesia, paralysis, pulselessness, and poikilothermia)
3. Non-healing ulcers
4. Gangrene
5. Acute limb-threatening ischemia
6. Weak or absent pulses
7. Skin and hair changes
Investigations to diagnose peripheral artery diseases:
To establish a definitive diagnosis of peripheral artery disease, certain investigations are performed which includes:
1. Physical Examination:
Physical examination is very important to reach a definitive diagnosis. While performing a physical examination, you must look for the femoral pulse and distal pulses. In peripheral artery disease, femoral pulse and distal pulses are absent or very weak. Bruits may also hear over the aorta, iliac and femoral artery. Reference: CMDT [2021] Pg 485
2. Doppler and vascular findings:
The ratio of systolic blood pressure detected by Doppler examination at the ankle compared with the brachial artery (referred to as ankle-brachial index or ABI ). This difference is exaggerated by exercise. Reference: CMDT [2021] Pg 485
Interpretation of Ankle-Brachial index ABI:
| Result | Usual normal correlation |
| 1 | Normal |
| 0.6 – 0.9 | Claudication |
| 0.3 – 0.6 | Pain even on rest |
| < 0.3 | Impending |
3. Imaging:
Duplex ultrasound, CT angiography CTA and magnetic resonance angiogram MRA can find the anatomic position of the peripheral artery disease. Imaging is required only when symptoms necessitate intervention. Reference: CMDT [2021] Pg 485
4. Blood tests
Samples of blood can be sent to look for cholesterol levels and diabetes mellitus.
Treatment of Peripheral Arterial Diseases:
A. Medical and Exercise Therapy:
The cornerstone of peripheral artery disease treatment is to reduce cardiovascular risk factors and to supervise a structured exercise program. Essential elements include smoking cessation, lipid and blood pressure management, weight loss, and anti-platelet therapy. Reference: CMDT [2021] Pg 485
B. Endovascular Therapy:
When atherosclerotic lesions are focal, they can be effectively treated with angioplasty and stenting. Reference: CMDT [2021] Pg 486
C. Surgical Intervention:
A prosthetic bypass graft that bypassed the diseased artery segment is a highly effective and durable in treatment of peripheral artery disease. Reference: CMDT [2021] Pg 486
A figure represents the number of people being treated for peripheral artery disease (PAD) in France by 2018, according to the age group. That year, more than 264,000 people aged 75 and over were treated for PAD.
Complications of Peripheral Artery Diseases:
Peripheral artery disease if left untreated can lead to
1) Stroke
2) Heart attack
3) Critical limb ischemia
4) Gangrene (can lead to amputation)
Prevention of Peripheral Artery Diseases:
The best ways to prevent peripheral artery disease are as follow:
1. Smoking Cessation
2. Maintain a healthy weight
3. Exercise regularly
4. Good glycemic control (in case of diabetes)
5. Cholesterol and blood pressure control
6. Diet modification
Prognosis of Peripheral Artery Diseases:
Patients with isolated aorto-illiac disease may have a further reduction in walking distance without intervention, but symptoms rarely progress to rest pain or threatened limb ischemia. Reference: CMDT [2021] Pg 486
When to see a Doctor:
Patients with a progressive reduction in the walking distance despite of risk factor modification and supervised exercise program and those with limitations that interfere with their activities of daily living should be referred for consultation with a vascular surgeon. Reference: CMDT [2021] Pg 486
