Carotid stenting or carotid surgery in average surgical-risk patients: interpreting the conflicting clinical trial data.

There are generic as well as carotid-specific trial design considerations that have the potential to materially affect the outcomes and interpretation of comparative studies between carotid artery stenting and carotid endarterectomy. Recently, a series of trials in patients who are at average risk for carotid surgery have been reported. The European trials have all suffered from allowing an imbalance in operator experience between stenting and surgery and have consistently allowed stenting procedures without embolic protection. The combination of inexperienced operators and lack of embolic protection may be responsible for their negative stenting results. The Carotid Revascularization with Endarterectomy vs. Stenting Trial avoided both of these problems, having a threshold of experience for operators as well as mandating embolic protection be used. The Carotid Revascularization with Endarterectomy vs. Stenting Trial demonstrated noninferiority for stenting compared with surgery in average-risk symptomatic and asymptomatic patients, leading to Food and Drug Administration approval of a stent and protection for this indication. This has been recently followed by guidelines supporting the role of stenting compared with surgery from a broad range of professional societies.