Does Carotid Endarterectomy (CEA) change the natural history?
A non-randomised study by Moneta et al.6 suggested that in patients with high grade ACS, those treated medically were more likely to experience neurological symptoms and carotid occlusion (45%) than the surgically treated group (9%).A number of trials have looked at this question. The Casanova Trial (1991) from Germany and the Veterans Administration Trial (1991) suggested that CEA does offer an advantage over medical treatment in high grade ACS, but felt that large studies were necessary to evaluate this. The largest randomised study to date is the Asymptomatic Carotid Artery Study (ACAS) in the USA which recruited 1662 patients who had 60-99% internal carotid artery stenosis and were randomised to receive medical therapy or surgery. The results of this trial have been interpreted by different groups to back up their own viewpoints. The trial showed that the estimated 5-year risk of ipsilateral stroke or any perioperative stroke or death was 11% for the medical group and 5.1% for the
