The updated and long awaited guidelines from the American Academy of Neurology are available on line in full text. Their previous guidelines were published in 1990.
Two large Class I studies provide good data for their recommendations regarding symptomatic carotid stenosis (CS), the NASCET trial and the ECST. Entry into the studies required a TIA or non-disabling stroke within the previous 6 months.
For symptomatic patients with stenosis greater than 70% ( but less than "near total" occlusion) carotid endarterectomy (CE) is recommended if the surgical stroke or death frequency is believed to be less than 6% and the patient has an expected survival of five years or more. The absolute risk reduction is 16% with a NNT of 6.3.
If the stenosis is less than 50%, surgery is not recommended and medical treatment is preferred.
In regard to asymptomatic patients CE should be considered if the stenosis is 60-99 % and the surgical stroke or death risk is less than 3% and the patient has an expected 5 year or greater survival.
Due to the slow accumulation of big time Class I studies we may have gone about as far as we are likely to go any time soon with learning about CE versus medical treatment, but what about carotid stents? The jury is just beginning to hear the evidence and there are advocates with convincing arguments on each side.
Coronary stents have certainly become worthy rivals of CABGs and catheter treatment of cerebral aneurysms -at least in some clinical situations-may be better than surgical clipping. I believe that increasingly we will see more and more endovascular catheters at work and less classical surgery. I wonder how long it will take for enough data with head to head ( or neck to neck) comparisons between CE and stenting to accumulate to determine the role of catheters versus surgery in this setting.