Carotid artery stenting trials: conduct, results, critique, and current recommendations

The carotid stenting trialists have demonstrated persistence and determination in comparing an evolving technique, carotid artery stenting (CAS), against a mature and exacting standard for carotid revascularisation, carotid endarterectomy (CEA). This review focuses on their endeavours. A total of 12 1-on-1 randomised trials comparing CAS and CEA have been reported; 6 of these can be considered major, and 5 of these reflect (in part) current CAS standards of practice and form the basis of this review. At least 18 meta-analyses seeking to compare CAS and CEA exist. These are limited by the quality and heterogeneity of the data informing them (e.g., five trials were stopped prematurely such that they collectively failed to reach recruitment target by >4000 patients). The Carotid Stenting Trialists' Collaboration Publication represents a prespecified meta-analysis of European trials that were sufficiently similar to allow valid conclusions to be drawn; these trials and conclusions will be explored. When the rate of myocardial infarction (MI) is rigorously assessed, CAS and CEA are equivalent for the composite end point of stroke/death and MI, with more minor strokes for CAS and more MIs for CEA. These outcomes have a discrepant impact on quality of life and subsequent mortality. The all-stroke death outcomes for patients <70 years old are equivalent, with more minor strokes occurring in the elderly during CAS than CEA. There are significantly more severe haematomas and cranial nerve injuries after CEA. The influence of experience on outcome cannot be underestimated.