Trials of carotid endarterectomy
The number of carotid endarterectomies performed per year in the USA rose from 15,000 in 1971 to 107,000 in 1985.
Stroke may be caused by a number of underlying problems - carotid disease is only one of them. In the late 1980s, therefore, there was uncertainty about the usefulness of carotid endarterectomy.
2 major trials were set-up. One in North America and one in Europe. They were both published in 1991, the European Carotid Surgery Trial (ECST) in the Lancet and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) in the New England Journal of Medicine.
These trials both showed that surgery was beneficial only in those patients with a severe narrowing of the carotid artery (70 - 99% stenosis) with appropriate symptoms.
There is less evidence to support surgery in patients with severe narrowing of the carotid arteries but without symptoms.