Internal Medicine

Peripheral arterial occlusive disease (PAD)

definition

Peripheral arterial disease is a disease of the blood vessels. PAD leads to narrowing (Stenoses) or to close (occlusion) the main artery (aorta) or the arm and leg arteries, usually chronic. The arteries of the legs are most commonly affected (~ 90% of the cases).

Calcification of the arteries (arteriosclerosis) is responsible for this in over 95% of cases, and more rarely inflammation of the vessel walls (Vasculitis, e.g. M. Winiwarter-Buerger).
While initially no symptoms are noticeable, those affected notice pain when walking as well as pale and cold legs as they progress. This can increase to pain at rest or even tissue destruction (necrosis).

Read more on the topic: Atheromatosis

Synonyms in a broader sense

Arterial occlusive disease (AVK)
Intermittent claudication
Claudicatio intermittens
Smoker's leg
chronic arterial disease of the extremities

Special forms

Lériche syndrome (special form of PAD)
Winiwarter-Buerger's disease (rare cause of PAD, also: Buerger's syndrome, thrombangiitis obliterans (TAO)
English: Buerger’s disease
Takayasu syndrome (rare cause of PAD)

English: Peripheral Arterial Occlusive Disease (PAOD)

Stages of peripheral arterial disease

The stages of the peripheral arterial disease are according to the symptoms according to "Fontaine " assigned.

Stage I. is usually an incidental finding in the course of a medical examination, for example if the pulses in the extremities are difficult to feel. At this stage the bottlenecks are very small and do not cause any discomfort for the person concerned. Should Leg pain occur these must be taken seriously.
In stage II Peripheral arterial occlusive disease makes the patient a few complaints. The constrictions are so advanced that it comes to the picture that the peripheral arterial occlusive disease is nicknamed "Intermittent claudication"Has given: After a few meters it comes due to the undersupply of the muscles (Calves, thighs, buttocks) with oxygen from the blood to leg pain (Claudicatio intermittens).
These symptoms improve after a break.
Stage II is divided into Stage IIa where the symptom-free walking distance is greater than 200 meters.
in the Stage IIb the symptoms described occur already below 200 meters.
The suffering in Stage III is particularly great because the pain also occurs here at rest and is particularly pronounced when lying down. In the further course of the disease (Stage IV) the tissue is damaged by the severe circulatory disorder: Chronic wounds, dead tissue and ulcers can occur. An amputation cannot be ruled out here to prevent inflammation from spreading in the body from these points.

frequency

Approximately 3% of the population over 60 years of age suffer from one symptomatic peripheral arterial occlusive disease (PAD), i.e. they have symptoms. It occurs particularly frequently in smokers, as smoking is the most important risk factor.

With increasing age, the frequency of PAD also increases; it is found in over 5% of those over 70 years of age. Are there Men 4 times as often affected like women.

Around half of those affected suffer from narrowing of the femoral arteries, the pelvic arteries are affected in a third and only around 15% have the Lower leg- and Foot arteries.

complaints

Pain: peripheral arterial occlusive disease (PAD)

Since the constriction occurs in different places and can be of different severity, the symptoms also differ. What they have in common, however, is that the pulse (transmitted heartbeat) below (distal) the narrowing can no longer be felt until the narrowing is 90%.

Even at this stage, however, those affected can still be symptom-free. This depends on the bypass circuits (collaterals) and the general physical resilience (e.g. due to other diseases such as heart failure).

Often the first symptoms that those affected notice are pain when exercising, usually when walking (uphill), climbing stairs or doing sport. These occur beyond (distal) the bottleneck and are therefore dependent on the location of the change. They are usually expressed in a spasmodic, later stabbing, knocking feeling.

This pain forces those affected to stop repeatedly after walking a certain distance. The pain disappears after a while. The tissue has to do more work under stress and therefore uses more oxygen to generate energy. As soon as one comes to rest, this oxygen requirement decreases again and the pain disappears.

Many patients are therefore only able to walk short distances. In order not to attract attention, they always stop after a certain distance and look at the shop windows, as if they were window shopping. This has led to PAD also becoming known as “intermittent claudication” (intermittent claudication). Lower leg pain is very typical.

For more causes of lower leg pain, see: Pain in the lower leg

The pain is caused by a lack of oxygen in the tissue (ischemia) of the affected leg (arm). In addition, the affected extremity, especially the feet, often becomes pale and cool.

diagnosis

The doctor can suspect peripheral arterial occlusive disease while talking to the patient.
The physical examination may corroborate this suspicion. The physical exam is divided into looking at the skin (Skin color, wounds), pressing the pulse (Attenuated / no pulses in peripheral arterial disease) and checking the skin temperature and sensation in the leg.

Clinical function tests, such as trying to walk on the treadmill, can also be used to diagnose peripheral arterial disease. Diagnostic imaging is used to show the blood flow to the affected areas. Here will be Ultrasonic, CT (with and without contrast agent) or MRI used.
Some blood values are also diagnostic parameters for peripheral arterial occlusive disease.

Note: impaired wound healing

Even at this stage, wound healing in the affected area is disturbed (microangiopathy) and even small wounds only heal very slowly. A process that also occurs in diabetics. So-called coagulation factors, scavenger cells (macrophages) and growth factors are required for normal wound healing. These are transported with the blood, which is why wound healing is poorer in peripheral arterial occlusive disease. Oxygen is also required to supply the newly developing tissue.
For this reason, regular and good foot care and the care of even small injuries is very important! (see therapy).

As the disease progresses, the symptoms can worsen and pain can occur even at rest. This usually happens at night or after the leg has been lifted, as the blood pressure drops at night and it is difficult for the blood to pass through the constriction.

In the final stage of PAD, tissue loss (necrosis), black discoloration (gangrene) of the legs and ulcers (ulcers) can occur. In extreme cases, this can go so far that an amputation is necessary.

Also read our article Toe amputation.

The nerves can also be damaged by an insufficient supply of blood (and thus oxygen) (ischemic neuropathy). This leads to false perceptions (paresthesia), which can express themselves in different ways. Numbness (hypoesthesia), but also painful and burning processes (causalgia), which usually begin in the feet, are possible.

Read more on the topic: Gangrene

therapy

The therapy of peripheral arterial disease depends on the stages of the disease.
In the early stages of the disease, it helps to change lifestyle and thus reduce cardiovascular risk factors.
This includes, for example:

a healthy eating
Move and the
Quitting smoking

The blood lipid levels and an existing one high blood pressure should be reduced in order to protect the vessels. Furthermore has lots of movement a good side effect - the more you move, the higher the oxygen demand of the muscles. So if you move a lot every day, the body forms new blood vessels, so-called collaterals, in order to be able to supply the muscles with sufficient oxygen. These collaterals limit the extent of the peripheral arterial occlusive disease because the surrounding muscles get more oxygen again.

In general, the legs should be stored low so that enough blood can get into the legs and injuries should be avoided, as wound healing is more difficult. In the low stages of peripheral arterial disease, drug therapy is also helpful.
To become one blood-thinning drugs, such as ASS or Clopidogrel are used to prevent a clot from forming in the narrowed vessels (thrombus) forms.
If this is already the case, so-called thrombolytics are also used, which can dissolve the clot again. If the peripheral arterial occlusive disease is at a more advanced stage, surgical therapy can also be considered in addition to conservative therapy.

In the field of operative therapy there are different options. One possibility is that Angioplasty, in which the narrowed blood vessel is expanded again by a catheter inserted through the vascular system. This procedure is minimally invasive, which means that only one blood vessel has to be punctured to insert the catheter. In addition, a thrombendartereectomy can be performed surgically, in which the blood vessels are surgically exposed and reopened. Alternatively, you can block the nerves (Sympathectomy), which are responsible for narrowing the vessels in the affected area. Another possibility is that Bypass surgery.
During this operation, a vessel made of either the body's own or foreign material is inserted, which bypasses the constriction and still provides enough blood to the following tissue.

maintenance

If there is peripheral arterial disease, patients must be particularly careful with their legs and feet because of those associated with the disease Circulatory disorders make wound healing more difficult and chronic large wounds can develop from even the smallest wounds.
It is therefore advisable to inspect the feet and legs daily for pressure points or wounds and to use a mirror for the areas that are difficult to see.

A medical one Foot care helps to keep the feet in good condition and professionally removes cracked calluses. Furthermore, one should avoid injuries to the feet and, if they occur, consult a doctor in good time, who can control the healing process. In addition, the skin should be regularly applied, preferably before going to bed or after showering.
Urea-containing cream is recommended as this active ingredient is particularly effective against dry skin.

localization

A subdivision is made according to the location of the vasoconstriction and divided into three types:

Type Frequency Location Pain Missing pulses
Aortic iliac type 35% main artery (aorta), Iliac or pelvic artery (Iliac artery) Buttocks, thighs from the groin
Femoral type 50% femoral artery (A. femoralis), Knee artery (A. poplitea) Calf from the back of the knee (A. poplitea)
Peripheral type 15% lower leg and foot arteries Sole of the foot Foot pulses (A. dorsalis pedis) (A. tibialis posterior)

Staging (according to Fontaine-Ratschow)

Stage I: No complaints (detectable changes)
Stage II: stress pain (Claudicatio intermittens)
Stage IIa: pain-free walking distance> 200m
Stage IIb: pain-free walking distance <200m
Stage III: pain at rest (critical undersupply)
Stage IV: pain at rest, additional tissue loss (necrosis), blackening (gangrene), ulcers (critical undersupply)

Other illnesses with similar symptoms (differential diagnosis)

However, the symptoms of this disease are by no means completely unique, so there are a number of other diseases that need to be considered.
Orthopedic diseases of the feet, knees or pelvis can lead to pain when walking and exerting themselves. This includes e.g. Hip osteoarthritis, knee osteoarthritis, Leg shortening or Pelvic inclination.

Various nerve diseases or damage can also cause pain or feelings of numbness and cold. This is possible if the (peripheral) nerves are damaged or if the spinal cord is constricted / trapped, e.g .:

Spinal stenosis of the lumbar spine
Root irritation syndromes of the lumbar spine
Herniated disc of the lumbar spine

It is also possible that instead of the blood flow (through the arteries), the blood flow (through the veins) is obstructed. This can be done as part of a CVI (chronic venous insufficiency). This can even lead to ulcers.

These can also go through Injuries (Trauma), so that a PAD does not automatically have to be present.

Long-term consequences of diabetes mellitus can lead to nerve damage and even cause pain at rest (diabetic polyneuropathy).

Finally, there are connective tissue diseases and systemic diseases (affect the whole body). This group is very diverse and also includes very rare diseases. (Lupus erythematosus, scleroderma, amyloidosis, cryoglobulinemia and many more).