Constriction and occlusion of the leg artery | Leg artery

Constriction and occlusion of the leg artery

Constrictions or blockages in the area of the aorta can occur suddenly (acute) or over a longer period of time (chronic). Behind the popularly known “shop window disease” or “smoker’s leg” is a chronic narrowing or occlusion of the aorta. This vascular disease belongs to the complex of peripheral arterial occlusive diseases.

It is usually caused by a “vascular calcification” (arteriosclerosis), which can lead to a narrowing and eventually also to an occlusion of the leg artery. As a result, the vessels behind the constricted area are not supplied with blood well, the flow rate of the blood is reduced and the arterial blood pressure decreases. As a result, the tissue is less well supplied and discomfort such as pain, a feeling of cold, sensations of discomfort in the legs (paresthesia), changes in skin and nails and changes in the colour of the legs.

The body can make use of a number of compensatory mechanisms to compensate for the lack of supply. In addition to an improvement in the oxygen uptake and energy production of the less supplied leg section, in some cases bypass circuits, so-called collateral circuits, can also be formed. Consequently, the tissue can continue to be supplied with nutrients and oxygen.

These compensations lead to the fact that only when the occlusion is about 75%, significant complaints occur. In order to determine a chronic occlusive disease of the aorta, the patient’s medical history, including the risk factors for arteriosclerosis, is first recorded. Then the legs are examined closely.

This is followed by palpation of the pulses and listening to the aorta. The Ratschow position test is also performed, in which the patient lies on his back and rides a bicycle with his legs in the air for about 2 minutes. In addition, a measurement of the blood flow velocity (Doppler ultrasound examination) and an imaging of the vessels using a contrast medium (angiography) can provide information about the condition of the leg artery.

In the case of slight narrowing, walking training and a change in lifestyle are recommended to prevent further vascular diseases. If necessary, the therapy can be supplemented with additional medication. In the case of medium-strong constrictions, minimally invasive catheter-based interventions are often performed.

These include dilatation using a small balloon catheter or the removal of arteriosclerotic deposits using a catheter. In the case of more severe constrictions and occlusions, surgery of the leg artery is recommended. The acute occlusion of the leg artery must be distinguished from chronic vascular occlusion.

This emergency is caused by blood clots (embolus) that have been infiltrated into the artery and which obstruct the vessel. The origin of such an embolus can be the heart. Cardiac arrhythmia such as atrial fibrillation and diseases of the heart valves or valve replacements can be the cause of the formation of a blood clot (thrombus).

Furthermore, such thrombi can also develop in aneurysms and be washed away. Characteristic features of an acute occlusion of the aorta are pain, paleness of the leg, the absence of leg pulses below the occlusion, paralysis of the leg muscles, sensory disturbances of the leg and finally a state of shock. After the emergency doctor has determined the acute occlusion of the aorta, an attempt must be made to restore the blood supply to the leg as quickly as possible. To do this, a high dose of heparin, an anticoagulant, is administered and the blood flow is restored by means of a surgical procedure in which the clot is removed. Strong painkillers are also given.