Blocked carotid artery – What to do?

Introduction

A “blocked” carotid artery is a narrowing of the main cervical artery (Arteria Carotis) due to deposits on the vessel wall (Arteriosclerosis), so that the blood flow to the head/brain is difficult or reduced. This narrowing of one of the carotid arteries on the left or right side of the neck is also known in medicine as “carotid stenosis” (stenosis = narrowing). In this case, fats, blood clots, calcium and connective tissue are deposited in the innermost vascular wall layer, which means that the carotid artery is not only narrower, but also harder and less elastic.

The main trunk of the carotid artery (Arteria carotis communis) as well as its inner (Arteria carotis interna) or outer (Arteria carotis externa) exit vessel can be affected. Generally, more men than women are affected by a blockage or narrowing of the carotid arteries, and the risk of developing this condition increases with age and with certain secondary diseases such as diabetes mellitus (see Consequences of diabetes), overweight (see Consequences of overweight), high blood lipid levels (see Hyperlipidaemia), high blood pressure, etc. Statistics show that 0.2% of men under 50 years of age and 7.5% of men and 5% of women over 80 years of age are affected.

The causes

The most common cause of blocked or constricted carotid arteries is “vascular calcification” of the innermost layer of the vessel wall. To be more precise, it is not only pure vascular calcification – also known as arteriosclerosis – but also deposits of fats, blood clots and lime as well as an overgrowth of these deposits with connective tissue and vascular muscles, so that the blood vessel gradually narrows further due to plaque formation and the blood can no longer flow unhindered. Certain illnesses and stimulants are risk factors for such vascular calcification, including high blood pressure, diabetes mellitus, overweight, smoking and elevated blood lipid levels (these risk diseases can be summarized as metabolic syndrome).

The larger these deposits or plaques become in the vascular walls of the carotid artery, the more it becomes clogged and the less well the blood can flow towards the head and brain, so that in the case of severe constriction there may even be an undersupply of blood. The larger the plaque becomes, the greater the risk that it will become unstable, become detached and be washed away until it gets stuck in a smaller vessel in the brain and displaces it completely – a stroke may result. In order to diagnose a blocked carotid artery, in addition to a detailed anamnesis and the search for typical accompanying secondary diseases, a physical examination is also necessary, during which a weakened pulse rate in the affected carotid artery may be noticed.

In addition, a flow noise can be noticed when listening to the carotid artery with a stethoscope. On the basis blood value determinations can be searched for increased blood fat/cholesterol, blood sugar values and changed coagulation parameters. With the help of a special ultrasound examination, the so-called Doppler sonography, the extent of the constriction can then be visualized.

Even more precise vascular imaging can be achieved by means of computer tomography (CT angiography) or magnetic resonance imaging. The degree of narrowing of carotid arteries is determined by means of a specific ultrasound examination (duplex sonography), in which the peak velocity of the blood flow in the respective blood vessel and the quotient of the peak velocity in the internal carotid artery and the common carotid artery, as well as the extent of the narrowing caused by plaques, are measured. The higher the speed of the blood flow in a vessel, the higher the constriction and the more blocked the carotid artery is in this case. The constrictions are divided into different degrees, a so-called stenosis degree of <50%, 50-69%, 70-89% and >90%.