[What are high-risk atherosclerotic carotid stenoses?]

Atherosclerotic carotid stenosis carry a double risk: local, of ipsilateral stroke, and general, of myocardial infarction and vascular death. The local risk is mainly correlated with the presence of relevant symptoms and with the degree of stenosis. It is virtually absent in stenosis < or = 30% but reaches 17% per year in symptomatic stenosis > or = 90%. The other factors which increase the local risk are: the progression of stenosis, the presence of ulceration, the extent of atherosclerosis (contralateral carotid occlusion, ischemic heart disease), the number and severity of vascular risk factors. The general risk is mainly cardiac and is related more to the extent and severity of the underlying atherosclerotic disease than to the morphology of stenosis or the presence of symptoms. This also holds true for the surgical risk, which is, in addition, heavily related to the technical conditions of the operation. The treatment of a patient with carotid stenosis should be discussed on a case by case basis. Medical treatment applies to all stenoses whereas surgery applies only to stenoses which carry a high local risk and a low general and surgical risk. The efficacy of surgery is thus maximal in the group of high symptomatic stenosis.