Peripheral arterial occlusive disease (PAD)

Overview: What is peripheral arterial disease?

Peripheral arterial disease is a circulatory disorder, mostly in the legs and much less frequently in the arms. In the vast majority of cases, the cause is vascular calcification, arteriosclerosis. The vessels become increasingly constricted due to deposits of calcium, fat and proteins; they harden and lose their elasticity. Blood flow in the vessel in which the bottleneck is located is reduced or stops completely if the vessel closes completely. Then the muscles of the legs (and sometimes the arms) receive less blood – and thus lack oxygen and nutrients. The muscles of the limbs are less and less efficient.

Peripheral arterial occlusive disease is also abbreviated to PAD. Colloquially, lay people also call it smoker’s leg. The name “smoker’s leg” comes from the fact that smokers are particularly likely to develop PAD – smoking is in fact the most important risk factor. Due to the disturbed blood circulation in the legs, the affected persons feel pain in the muscles after a certain walking distance and have to stop.

Initially, PAD causes no symptoms and affected individuals experience few limitations in their daily lives. However, advanced PAD is very painful, initially when walking, and later at rest. In the final stage, those affected are then threatened with infection and even blood poisoning and the death of parts of their limbs if they do not receive treatment. We need to treat the blocked vessels so that affected individuals become more mobile again, their quality of life returns and amputation is prevented.

PAD – age and incidence

PAD is a common condition that occurs more often with age. In Switzerland, about one in five people over the age of 65 is affected. Mostly, they are men of older age.

Atherosclerosis is generally more common as the years of life progress. It is part of a natural aging process. Not only the organs and tissues age, but also the vessels. However, some risk factors favor vascular calcification, for example smoking, lack of exercise or diseases such as high blood pressure, elevated blood lipids and diabetes mellitus (diabetes).

Peripheral arterial disease: causes and risk factors

People with PAD suffer from circulatory problems in the extremities. The legs are most frequently affected, the arms much less frequently. The cause of peripheral arterial disease is usually arteriosclerosis. In vascular calcification, deposits (plaques) form in the arteries (vessels that carry oxygen-rich blood from the heart to the extremities) and increasingly narrow them. Furthermore, they harden and are less elastic. Because blood flow is reduced in the narrowed vessels, the muscles and nerves in the legs or arms receive too little blood, oxygen and nutrients. The limbs and muscles are increasingly less efficient in PAD, which is particularly noticeable when running and walking.

Arteriosclerosis often manifests itself not only in the arteries of the limbs, but also in other organs, for example the heart, brain or kidneys. Then there is a risk of heart attack, stroke and kidney disease.

We know some risk factors that promote calcification and vascular stiffening. The most important are:

• Age – you have no influence on this
• Genes – you also have no influence on this
• Smoking -is considered a major risk factor for vascular calcification
• Diabetes mellitus – a long-term elevated blood sugar level attacks the arteries, they “sugar up” – you can positively influence the blood sugar level
• High blood pressure (hypertension) – the vessels (especially arteries) suffer when they have to withstand permanently high pressure
• Elevated blood fats, for example cholesterol – are deposited on the artery walls
• Lack of exercise – accelerates the aging process
• Unhealthy diet (fast food) – also accumulates on the walls of blood vessels
• Stress – accelerates the aging process

Other causes of PAD – beyond arteriosclerosis – are very rare. Possible causes are vascular wall inflammations, for example thrombangiitis obliterans.

Symptoms: Peripheral arterial occlusive disease causes pain

PAVK usually develops insidiously. Initially, most do not experience any symptoms. However, the arteries in the legs become increasingly constricted. Larger bottlenecks eventually cause discomfort in the legs (rarely arms). The following symptoms are indicative of PAD:

• Pain in the calf, foot, thigh, or buttocks; at first, the pain is apparent only with physical exertion, such as walking. The pain occurs as soon as the muscles receive too little oxygen/nutrients during physical exertion. This is the reason why the discomfort occurs only after a certain walking distance (about 200 meters).

Symptoms in the late stage

• Pain in the feet/arms at rest (in bed and when the limb is elevated)
• Cool, pale skin
• Dry skin on the legs and feet
• Restricted mobility of toes/fingers, numbness of toes/fingers
• Heavily horny soles of the feet
• Very slow growing toenails
• Poorly healing wounds
• If no oxygen/nutrients reach the tissue at all, the tissue dies (necrosis). Often the heel and toes are affected. Medical professionals refer to this as a “leg infarction.”

We divide PAD into four stages – depending on the symptoms and severity of the disease:

• Stage I: Calcifications are present in the arteries, but do not yet cause any symptoms.
• Stage II: Pain occurs when the muscles are loaded and exercised, for example when walking; it intensifies with higher loads, such as when running uphill. If the pain-free walking distance is more than 200 meters, stage II is present; if it is less than 200 meters, affected persons have reached stage III.
• Stage III: Now the pain occurs not only during movement, but also at rest when the muscles are not working, especially when lying down.
• Stage IV: Poorly perfused tissue dies, wounds also heal worse, the feet are pale and cold.

Peripheral arterial occlusive disease diagnosis

The diagnosis of PAD always begins with a discussion of your medical history (anamnesis). We ask you some questions that already provide the first suspicious facts. Some examples:

• What complaints do you suffer from, since when and how intense are they?
• Do you smoke? If yes: Since when and how much do you smoke?
• What kind of food do you eat?
• What about exercise and sports in your everyday life?
• Do you have any known diseases, for example high blood pressure, diabetes mellitus or elevated blood lipids?

Then a physical examination is performed. We look for pulses, palpate the affected extremity, and examine it for changes. In addition, we check the skin. For example, the temperature of the extremities, any wounds present, and the color of the skin are important.

A pressure measurement on the legs, feet or arm shows whether vessels are constricted – in addition, no pulse can be felt at the affected site. Listening with a stethoscope also provides evidence of vasoconstriction. The flow noises are an indication of this.

Further examinations for the diagnosis of PAD

• Treadmill walking test: we determine the walking distance you can cover on a treadmill without pain. This provides clues to the stage of PAD.
• Doppler test: a special ultrasound examination in which we place an ultrasound probe on the arteries of the ankles. This allows blood pressure to be measured in the peripheral vessels. Then we compare these values with the blood pressure on the arms. This ankle-brachial index (ABI) provides evidence of vasoconstriction or occlusion. Diabetics may also have a comparable toe-arm measurement.
• Color-coded duplex ultrasonography: An ultrasound examination that can be used to visualize the arteries and possible narrowings, as well as the flow velocity of the blood and the direction of blood flow.
• Angiography: an X-ray examination using contrast medium to visualize the arteries
• Computed tomography (CT): An X-ray examination that images the body “in slices” and produces high-resolution, three-dimensional cross-sectional images. Vascular calcifications are clearly visible.
• Magnetic resonance imaging (MRI = magnetic resonance imaging): Radiology uses strong magnetic fields to produce detailed cross-sectional images of the inside of the body.

In many cases, not only are the vessels in the legs narrowed, but atherosclerosis can also affect the coronary arteries (coronary artery disease) or brain arteries. Then there is an increased risk of a heart attack or stroke. We therefore often perform further examinations to check the condition of the organs.

PAD: prevention, early detection, prognosis

By far the most important cause of PAD is arterial calcification (arteriosclerosis). Certain risk factors favor vascular calcification, and you can influence some of them yourself. In fact, they depend on your lifestyle. Some tips on how you can prevent PAD:

• Refrain from smoking. If you already smoke, try to quit smoking. Seek professional help(smoking cessation advice) if you can’t do it on your own. Also talk to your health care provider, who can help you with withdrawal medications. And don’t give up if you relapse. Most smokers need several attempts to get away from their vice permanently.
• Eat a healthy diet: fruits, vegetables, whole grains, legumes, fish, healthy unsaturated fats from plant sources and little meat. Also, drink enough, between 1.5 and two liters per day.
• Make sure you maintain a healthy body weight. Try to reduce any excess weight and lose a few kilos. Nutritional counseling can also be helpful.
• Move as much as possible in your daily life (goal 10,000 steps/day): Climb stairs instead of taking the elevator. Ride your bike to work instead of getting in your car. Buy a pedometer or use mobile apps.
• Exercise. Endurance sports such as swimming, cycling, Nordic walking or hiking are recommended.

Certain conditions such as high blood pressure, diabetes, and elevated blood lipids increase the risk of peripheral arterial disease. Get adequate treatment for such conditions.

Course and prognosis in PAD.

You can partially influence the course and prognosis of PAD yourself. You can slow down the disease if you pay attention to a healthy lifestyle: don’t smoke, eat healthily, and get plenty of exercise. You can’t cure atherosclerosis itself, but you can slow its progression. Well-controlled blood pressure, blood lipid and blood sugar levels can also halt the progression of PAD. It is also important that they seek medical advice at an early stage in order to recognize the disease and, above all, to be able to minimize the risk factors. Then the prognosis is more favorable.

Without treatment, however, the disease continues to develop and can lead to a wide variety of consequences:

• Acute complete vascular occlusion (atherothrombosis): This is an emergency that we must treat immediately.
• There is a risk that tissue will die and we will have to amputate limbs or parts of them.
• In addition, people with PAVK have an increased risk of heart attack and stroke. This is because it is usually not only the arteries in the legs that are affected, but also those in the heart and brain.

Medical experts have calculated that PAD can shorten life expectancy by about ten years. Mortality among affected individuals is twice that of the general population.

Peripheral arterial disease: treatment with different strategies

You can actively participate in the treatment of PAD yourself when it comes to healthy lifestyle. The key measures are:

• Stop smoking.
• Eat healthy.
• Exercise regularly: Minimum 30 minutes daily on all days of the week.