[Treatment of severe asymptomatic carotid stenosis]

Severe (reduction of vessel diameter by more than 70%) asymptomatic carotid artery stenosis is associated with a risk of cerebrovascular accident of 2-5% in the year following diagnosis. Results of large, prospective, randomized studies suggest that prophylactic carotid endarterectomy may be beneficial in this situation. However, the elements that must be taken into consideration before deciding to operate on an individual patient are extremely complex. Age and comorbidity (especially cardiovascular conditions) must be considered, as well as perioperative risk and expected medium- and long-term benefits, as compared with optimal conservative treatment. Decision analysis may be of considerable help in such a complex situation by considering objectively and explicitly all these epidemiologic and individual variables. Specifically, the technique makes it possible to simulate threshold probabilities of perioperative complications above which the risks of prophylactic endarterectomy outweigh its benefit, expressed as 5-year survival free of cerebrovascular event. These thresholds are 4%, 3% and 2% for a patient aged 65, 75 and 85 respectively. If 2-year event-free survival is considered, the surgical risk should not exceed 1.5% for a patient aged 65 years or 1% above that age. This type of analysis makes it possible to individualize the guidelines of international panels of experts, but ultimately the decision to operate or not must also consider the psychological profile of the patient and his attitude towards risk ("risk-seeking or risk-averse").