Peripheral Ischaemia

Peripheral ischaemia, commonly known as peripheral artery disease (PAD), is a condition where narrowed arteries reduce blood flow to the limbs—usually the legs—causing pain during activity and other serious complications.

Table of contents

• What is peripheral ischaemia?
• Symptoms and warning signs
• Causes and risk factors
• How it is diagnosed
• Treatment options
• Serious complications
• Living with peripheral ischaemia

What is peripheral ischaemia?

Peripheral ischaemia, also called peripheral artery disease (PAD) or peripheral vascular disease (PVD), is a condition in which narrowed arteries reduce blood flow to the arms or legs—usually the legs^[1]. When arteries become narrowed, the limbs don’t receive enough blood flow to keep up with demand, particularly during physical activity^[1].

peripheral artery disease, peripheral arterial disease, peripheral vascular disease

The condition affects more than 200 million people worldwide and around 12 million adults age 40 or older in the United States^[2]. The prevalence increases dramatically with age, affecting 12% to 20% of Americans 60 years and older, and increasing to nearly 50% in those 85 years and older^[9]. Anyone can develop peripheral ischaemia, but the risk goes up with age^[2].

Peripheral ischaemia is usually caused by atherosclerosis, which is the hardening and narrowing of the arteries over time due to the buildup of fatty deposits called plaque^[4]. The arteries have a smooth lining that prevents blood from clotting and promotes steady blood flow. When plaque builds up inside the artery walls, it narrows the space where blood can flow^[2].

• Lower limb arteries (legs and feet)
• Iliac arteries
• Femoral arteries
• Popliteal arteries
• Upper limb arteries (less common)

Symptoms and warning signs

Many people with peripheral ischaemia have no symptoms, or symptoms may be mild. In fact, more than 20% of patients with peripheral artery disease have no symptoms at all, and nearly the same percentage have atypical symptoms^[6]. Only about 10% of patients with PAD experience the classic symptom of intermittent claudication, which means “to limp”^[9].

When symptoms do occur, the most common is leg pain when walking. This discomfort is called intermittent claudication, and it happens when the arteries can’t keep up with the muscles’ increased demand for blood during activity^[2]. You might feel pain, cramping, numbness or fatigue in your calves, thighs or buttocks. The pain typically starts during physical activity like walking or climbing stairs, and it stops when you stop moving—usually within 10 minutes^[2].

The location where you feel discomfort depends on which artery is narrowed. Symptoms occur below the affected artery: discomfort in your buttocks, hip or thigh indicates narrowing of your lower aorta or iliac arteries, while discomfort in your calf indicates narrowing of your femoral or popliteal arteries^[2].

Other symptoms of peripheral ischaemia can include^[1][4]:

• Hair loss on your legs and feet
• Numbness or weakness in the legs
• Brittle, slow-growing toenails
• Ulcers (open sores) on your feet and legs that do not heal
• Changing skin colour on your legs, such as turning paler than usual or blue
• Shiny skin
• Coldness in the lower leg or foot
• Absent or diminished pulse in the legs or feet
• The muscles in your legs shrinking (wasting)

In males, erectile dysfunction may also occur when there is narrowing of the lower aorta or iliac arteries^[2].

As peripheral ischaemia progresses, you may experience leg or foot pain even when you’re resting. This often happens when you’re lying flat, and dangling your leg or feet over the edge of your bed may relieve the pain^[2].

If your symptoms develop quickly or get suddenly worse, it could be a sign of a serious problem requiring immediate treatment^[4]. Changes in skin colour or temperature are particularly concerning. A sudden blockage in your artery can make your skin turn purple, green, black or very pale. Your skin may also feel cool to the touch or like “pins and needles.” These are signs of severe peripheral ischaemia that require immediate medical attention^[2].

Causes and risk factors

The gradual buildup of plaque in the arteries, known as atherosclerosis, is the most common cause of peripheral ischaemia^[2]. Many plaque deposits are hard on the outside and soft on the inside. The hard surface can crack or tear, allowing blood clots to form around the plaque, making the artery even narrower^[2].

The most significant risk factors for peripheral ischaemia are^[9]:

• High cholesterol (hyperlipidemia)
• High blood pressure (hypertension)
• Diabetes mellitus
• Chronic kidney disease
• Smoking

The odds of having peripheral ischaemia increase with each additional risk factor. Having one risk factor increases risk by 1.5 times, while having three or more risk factors confers a 10-fold increase in risk^[9].

Smoking is particularly dangerous. It is the most significant risk factor for PAD, and in one large study, more than 80% of patients with PAD were current or former smokers^[9]. Smoking increases the risk of developing PAD fourfold^[3].

Other risk factors include^[3]:

• Increasing age, especially after reaching 50 years of age
• A family history of peripheral artery disease, heart disease or stroke
• High levels of homocysteine, a protein component that helps build and maintain tissue
• Obesity (a body mass index over 30)
• Male sex

Peripheral ischaemia is a systemic disorder, meaning atherosclerosis affects arteries throughout the body. The majority of patients with PAD also have clinically significant coronary artery disease (affecting the heart) or cerebrovascular disease (affecting the brain)^[6].

How it is diagnosed

If you experience recurring leg pain when exercising, you should see a doctor. Many people mistakenly think this is just part of growing older, but there’s no reason why an otherwise healthy person should experience leg pain^[4].

Peripheral ischaemia is usually diagnosed through a physical examination and by comparing the blood pressure in your arm and your ankle^[4]. This comparison is called the ankle-brachial index (ABI) or ankle brachial pressure index (ABPI). A difference between the two measurements may indicate PAD^[4].

Current guidelines recommend resting ankle-brachial index testing for patients with history or examination findings suggesting PAD^[9]. The vascular examination should include palpation of lower extremity pulses and listening for a “whooshing” sound (called a bruit) in the arteries of the legs using a stethoscope^[9].

Patients with symptoms of PAD but a normal resting ABI can be further evaluated with exercise ABI testing^[9]. However, routine ABI screening for those not at increased risk of PAD is not recommended^[9].

Your doctor may use additional tests to identify and locate blockages, including^[5]:

• Doppler Ultrasound: This form of ultrasound can measure the direction and speed of blood flow through the vessels
• CT angiography: An advanced X-ray procedure that uses a computer to generate three-dimensional images
• Magnetic resonance angiography (MR angiography): Uses radiofrequency waves in a strong magnetic field to construct two- and three-dimensional images of the blood vessels
• Angiogram: An X-ray study of the blood vessels taken using contrast dyes

Treatment options

Although there is no cure for peripheral ischaemia, lifestyle changes and medicine can help reduce the symptoms and prevent the condition from getting worse^[4]. Treatment is very important because having PAD is a sign that your blood vessels are unhealthy throughout your body^[4].

Lifestyle changes

The two most important lifestyle changes you can make are exercising more regularly and stopping smoking if you smoke^[4].

Regular exercise helps to reduce the severity and frequency of PAD symptoms while also reducing the risk of developing other cardiovascular diseases^[14]. Walking is one of the best exercises you can do. It’s normally recommended that you walk as far and as long as you can before the symptoms of pain become intolerable, then rest until the pain goes. Begin walking again until the pain returns. Keep using this “stop-start” method until you’ve spent at least 30 minutes walking in total. Do this several times a week^[14].

Supervised exercise therapy, which may involve group exercise sessions with other people with cardiovascular disease led by a trainer, is often recommended. The exercise programme usually involves 2 hours of supervised exercise a week for 3 months^[14].

Stopping smoking will reduce your risk of PAD getting worse and of developing other serious cardiovascular diseases. Research has found that people who smoke after receiving their diagnosis are much more likely to have a heart attack and die from a complication of heart disease than people who quit after their diagnosis^[14].

Other important lifestyle changes include^[14]:

• Eating a balanced diet
• Managing your weight
• Cutting down on alcohol
• Controlling diabetes properly if you have it

Medications

Different medicines can be used to treat the underlying causes of peripheral ischaemia while also reducing your risk of developing other cardiovascular diseases^[14].

Statins are prescribed if blood tests show that your levels of LDL cholesterol (“bad cholesterol”) are high. Statins work by helping to reduce the production of LDL cholesterol by your liver^[14].

Antihypertensives are medications used to treat high blood pressure. A common type is an angiotensin-converting enzyme (ACE) inhibitor, which blocks the actions of hormones that help regulate blood pressure, thereby decreasing blood pressure^[14].

Antiplatelet therapy, which includes medicines to prevent blood clots, is recommended for patients with symptomatic peripheral ischaemia. One of the biggest potential dangers if you have atherosclerosis is that a piece of fatty deposit (plaque) could break off and form a blood clot that blocks an artery^[14].

For patients with claudication, treatment with cilostazol may be recommended. This medicine helps get more blood to the legs and lowers pain, which might make exercise easier^[1].

Procedures and surgery

Surgical revascularization should be considered for patients with lifestyle-limiting claudication who have an inadequate response to lifestyle changes and medications^[9]. Surgery may also be used in severe cases^[4].

Minimally invasive endovascular treatments are often used. These procedures include^[5]:

• Angioplasty: A tiny balloon is inserted through a puncture in the groin. The balloon is inflated one or more times to open the artery
• Stents: Metal mesh tubes that provide scaffolding are left in place after an artery has been opened using a balloon angioplasty
• Atherectomy: A procedure to remove plaque buildup from the artery

For more severe cases, open surgical procedures such as bypass grafting may be necessary. Lower extremity bypass grafting uses a vein (your own or a synthetic replacement) to create a new path around a blocked artery^[10].

Serious complications

Peripheral ischaemia can lead to serious complications, particularly if left untreated. The condition acts as a marker for systemic atherosclerosis, meaning patients with PAD have an equivalent cardiovascular risk to patients with previous heart attack and require aggressive risk factor modification to improve their long-term survival^[3].

Critical limb ischaemia

Critical limb ischaemia (CLI), also called chronic limb-threatening ischaemia, is a severe blockage in the arteries of the lower limbs which markedly reduces blood flow^[5]. It is the most severe form of peripheral artery disease^[10].

Critical limb ischaemia is a chronic condition that results in severe pain in the feet or toes, even while resting. The most prominent features are intense foot or leg pain that often wakes you up at night, and non-healing sores on the feet or legs^[5].

Other symptoms of critical limb ischaemia include^[5][10]:

• Pain or numbness in the feet
• Shiny, smooth, dry skin of the legs or feet
• Thickening of the toenails
• Absent or diminished pulse in the legs or feet
• Open sores, skin infections or ulcers that will not heal
• Dry gangrene (dry, black skin) of the legs or feet
• Cold hands, feet or legs
• Skin discoloration or discharge from gangrene

Critical limb ischaemia is life-threatening. It significantly increases the risk of major medical complications, including death. Within one year of developing critical limb ischaemia, almost 1 in 3 people have an amputation, and about 1 in 4 people die, most commonly from heart disease or stroke^[10]. The mortality rate following diagnosis can exceed 50 percent, which is higher than many cardiovascular diseases^[11].

Critical limb ischaemia requires prompt treatment. Restoring proper blood flow to the hands and feet can help reduce the chances that you’ll need an amputation^[10]. If none of the treatments adequately restore blood flow, amputation may be necessary^[10].

Other cardiovascular complications

The blockages in the arteries in the legs can also affect other areas of your body, such as the arteries supplying the heart and brain. This means that having PAD makes you more likely to develop other forms of cardiovascular disease, such as^[4]:

• Coronary heart disease
• Stroke
• Heart attack
• Angina

Acute limb ischaemia

Acute limb ischaemia is a sudden loss of limb perfusion (defined as within 14 days) typically due to an embolus or blood clot forming in the artery^[11]. If you suddenly lose feeling in your foot and cannot move it, and if it is blue or paler and colder than the other foot, seek medical care immediately—call emergency services right away^[5]. Patients with acute or limb-threatening limb ischaemia should be referred immediately to a vascular surgeon^[9].

Living with peripheral ischaemia

Peripheral ischaemia is a lifelong medical condition. Once you have been diagnosed with PAD, you will see a healthcare provider regularly who specializes in vascular (blood vessel) diseases. You will need to take steps to prevent complications^[17].

Foot and leg care

People feel PAD most often in their legs, especially the calves or thighs. Taking care of your feet and legs is particularly important^[18].

Check your feet and toes every day for sores, cracks, or anything that doesn’t look right. Sores may not heal well. Look for even minor problems such as scratches, blisters, and small cuts^[18]. Wear shoes that fit you well. You want to be as comfortable as possible when you walk^[18].

It’s best to skip compression socks. They don’t help with PAD and can actually cause more harm. If you wear them to prevent swelling or blood clots, check with your doctor to see whether they’re still a good idea^[18].

Staying active

Because of your pain, you may be cutting back on activity. But you need to exercise when you have PAD. It is good for just about everyone who has this condition^[18]. Listen to your body and learn when to pause. If your legs bother you on a stroll, take a break. Wait for the pain to fade and begin again^[18].

You may have to start slowly, but the more you walk, the farther you will be able to go. And the more you move, the better it is for you^[18]. Working out does more than reduce your PAD symptoms—it also helps to lower your blood pressure and “bad” cholesterol levels^[18].

Managing other health conditions

If you have diabetes, it’s important to manage it properly. Having poorly controlled diabetes can make your PAD symptoms worse and raise your chances of developing other forms of cardiovascular disease^[14]. People with diabetes are four times more likely to develop critical limb ischaemia than those who are diabetes-free^[20].

PAD can cause severe pain and disrupt your life. If you’re dealing with depression or anxiety, it’s important to access support to look after your mental wellbeing^[14].

Taking your medications

Take prescribed medications regularly and keep up with your appointments. Once you’re diagnosed, continuing with your treatment plan is essential for preventing complications^[18].

Warning signs to watch for

PAD can lead to complications such as trouble managing daily activities without help because of reduced mobility, chronic poor blood flow in your leg, serious infections that develop from foot sores, and a sudden drop in blood flow to your leg^[17].

Call emergency services or seek medical help right away if you suddenly lose feeling in your foot and cannot move it and if it is blue or paler and colder than the other foot. Quick treatment is essential^[5][17].