What is subclavian steal syndrome?
Subclavian steal syndrome is a circulatory disorder of the brain. It occurs by a narrowing of an arm artery near the clavicle (arteria subclavia). Patients often experience dizziness or vision problems. The subclavian steal syndrome can be cured by invasive procedures. Here you can read everything about the subclavian steal syndrome.
Subclavian steal syndrome is a very rare circulatory disorder of the brain. It occurs when arteria subclavia is narrowed. This constriction is usually caused by a calcification of the vessels. In order to better understand the causes of a subclavian steal syndrome, a look at the anatomy is worthwhile:
The brain is supplied with blood by the right and left carotid arteries as well as by the right and left vertebral arteries. These arteries are connected to each other via intermediate blood vessels.
The left carotid artery arises from the main artery (aorta). On the left the left subclavian artery branches off. The right half of the body is supplied by the brachiocephalic trunk from the aorta. This is then divided into the right artery subclavian and the right carotid.
From the right and left subclavian arteries arise the respective vertebral arteries. It runs along the vertebral body in the direction of the skull and supplies parts of the brain there. The subclavian artery continues along the clavicle along the armpit and takes the blood supply to the arms.
Because of the course of the blood vessels, the carotid arteries, the vertebral arteries, and the subclavian artery are connected with each other.
Subclavian steal syndrome and subclavian steal phenomenon
Subclavian steal syndrome is referred to as such when there are different signs of disease occurring at the same time and in a context related to each other. One also speaks of a symptom complex. The subclavian-steal phenomenon is to be distinguished. Doctors use this term when the cause of a possible subclavian-steal syndrome is present, but the patient does not (yet) show symptoms that is asymptomatic.
Subclavian steal syndrome symptoms
The Subclavian-steal syndrome manifests itself through various symptoms of disease, which usually only affect one half of the body. Not all of the following symptoms are common: Some patients remain dyspnoeic (asymptomatic, subclavian-steal phenomenon) in constriction of the subclavian artery.
The following symptoms are typical in subclavian steal syndrome:
- Dizziness, disturbances of balance, earaches
- Visual disturbances, muscular paralysis
- Disturbances of consciousness
- Paralysis, sensory disturbances
- Speech, swallowing disorders
- Headache at the back of the head
In subclavian-steal syndrome, the symptoms are often increased as the patient moves the affected side’s arm.
Subclavian-steal syndrome causes and risk factors
Cause of subclavian steal syndrome is a strong constriction (stenosis) or a occlusion (occlusion) of the subclavian artery or brachiocephalic trunk.
Through the constriction, too little blood reaches the arm of the affected side. In order to ensure the blood supply to the arm, the subclavian artery tightens the vertebral artery, which normally accompanies the brain. The bloodstream of the vertebral artery is turned around and the blood flows from it into the subclavian artery and no longer into the brain.
Because of these compensatory or bypass mechanisms in subclavian steal syndrome, blood is absent in the brain. Especially if the affected arm has a higher blood requirement as with movement, the deficiency supply in the brain is strengthened. This results in particular on the affected side to failure symptoms such as dizziness or visual disturbances.
Risk factors for subclavian steal syndrome
Patients suffering from a subclavian-steal syndrome are particularly at risk of having a vascular disease. Above all calcifications (arteriosclerosis) cause the blood vessels to narrow. Risk factors for this are smoking, increased blood fat levels and lack of exercise. In addition, malformations of the vessels can also lead to a constriction.
Subclavian steal syndrome diagnosis
To diagnose a subclavian steal syndrome, your doctor may use different examination methods. First, he asks you about your medical history (anamnesis). He will ask you the following questions, among other things:
- Are you often dizzy?
- Does the dizziness intensify after a strain on the arms?
- Is the dizziness wavering, twisting or undirecting?
- Do you suffer from blood transfusion?
- Do you have problems with the heart or the vessels?
Your doctor will then examine you physically. Among other things, he senses the pulse and measures the blood pressure. If the pulse is weakened on one side and there is a blood pressure difference of more than 20 mmHg between the two arms, this indicates a possible constriction of the subclavian artery.
Your doctor also listens to your heart and surrounding blood vessels. In a constriction of the subclavian artery, he can hear a non-normal flow sound.
If you suspect a subclavian steal syndrome, your doctor may ask for further investigation. The first-choice method is Doppler or duplex sonography. This is an ultrasound examination, which both the vessels as well as the blood flow can be represented. Thus, a possible constriction of the subclavian artery and a reversal of the blood flow in the vertebral arteries can be presented.
Other imaging procedures can be used in addition to the diagnosis of subclavian steal syndrome. This includes an X-ray examination of the vessels using computer tomography or magnetic resonance tomography (CT or MRI angiography).
Subclavian steal syndrome must be distinguished from aortic arch syndrome, which may lead to similar symptoms.
What is the treatment for subclavian steal syndrome?
Treatment of subclavian steal syndrome occurs in several ways. If severe symptoms are present, the patient experiences a high pressure. If a severe narrowing or occlusion of the subclavian artery has been observed, an invasive therapy is performed. Invasive refers to an intervention in which the body is invaded (for example, during an operation). Common methods are percutaneous transluminal angioplasty (PTA) and the use of a bypass.
Transluminal angioplasty and bypass
In a transluminal angioplasty (PTA), a catheter is advanced over a blood vessel to the constriction. A balloon is placed there, which spreads the vessel.
In addition, subclavian steal syndrome can be treated as a preventive measure. An attempt is made to reduce the risk of a possible closure of the subclavian artery. Because such a narrowing of the vessels often arises in arteriosclerosis, it is necessary to treat them or to prevent them. Accordingly, you should not smoke, eat low-fat and balanced diet and exercise regularly.