Intervention for asymptomatic carotid stenosis

When asymptomatic carotid stenosis is discovered, four questions arise. 

The answers to these questions are different for asymptomatic carotid stenosis than for symptomatic stenosis, because the risk of stroke on medical treatment alone is lower distal to an asymptomatic stenosis (Fig. 28.1). 

The more pragmatic Medical Research Council Asymptomatic Carotid Surgery Trial (ACST) has probably produced more widely generalizable results (Halliday et al. 2004). Between 1993 and 2003, ACST randomized 3120 patients with 60% mainly asymptomatic carotid stenosis (12% had symptoms at least six months previously) to immediate endarterectomy plus medical treatment versus medical treatment alone or until the operation became necessary. Surgeons were required to provide evidence of an operative risk of 6% 

Risk of carotid endarterectomy for asymptomatic carotid stenosis 

There are a large number of case series with very different reported surgical stroke risks, for the same reasons as in symptomatic carotid stenosis (Ch. 27). Overall, the risk is about 

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Due to the very low event rates in patients with asymptomatic lesions of moderate severity (<60% diameter stenosis), it is unknown whether currently available interventional techniques can improve long-term outcomes over those achievable with optimal medical management. Also unresolved are the indications for carotid stenting in asymptomatic individuals with contralateral carotid occlusion (53) and those undergoing major cardiac or vascular surgery (54). 

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