The Carotid artery in the neck is a common site for atherosclerosis. Therre are 4 main arteries that supply blood to the brain, 2 on each side, carotid and vertebral. These are linked in the circulation which means that there is a lot of reserve to keep the circulation going to our most important organ. So a narrowing of a carotid artery will often cause no symptoms. The concern however is that the presence of a narrowed carotid artery raises the chances of a stroke occurring in the future.
If a scan discovers that there is a significant (more than 50-70%) of the artery but there are no symptoms then there is some debate about treatment currently. Most importantly in this situation is to attend to all the risk factors for vascular disease. Good blood pressure, no smoking, diabetic control, cholesterol lowering medication, blood thinners (aspirin, clopidogrel) healthy lifestyle all come into this.
Major trials are currently looking at the role of carotid stenting or surgery in addition to the above measures for carotid stenosis without symptoms. Currently these procedures are used to remove the stenosis, and there is some evidence that this can benefit some, but not all, patients reducing the risk of stroke to some degree. The information from the currrent trials will help us decide if we need to do more or less of these procedures in future, which patients benefit most, and which procedure works best.
In some patients the carotid stenosis is discovered when they present with a TIA / mini-stroke. This is an important warning sign that the narrowed artery is causing small clots to develop and pass to the brain or eye. After these symptoms the risk of stroke is higher. Currently this is treated urgently to remove the stenosis with either an operation, carotid endarterectomy, or a stent. Again there is some overlap between the use of these procedures with evidence supporting the use of one or the other in different patients. The aim is to treat the carotid stenosis as safely as possible. Endarterectomy is still the first choice procedure when the patient is fit enough to undergo the procedure. In some patients with problems making surgery riskier (heart condition, previous neck surgery etc..) a stent may be a better option.