[Stenting for carotid artery stenosis]

Carotid endarterectomy (CEA) was the only surgical treatment available before carotid artery stenting (CAS) was approved under Japan's national health insurance in 2008. Although some guidelines state that CAS is indicated only for patients who would be at high risk after CEA, the number of patients undergoing CAS is now greater than that undergoing CEA. In CAS, the most important point is protection of distal emboli that can lead to cerebral ischemia. There are three methods of protection. Filter protection involves a simple procedure without temporary occlusion of the internal carotid artery (ICA), but some risk from distal emboli remains. Balloon protection has less risk from distal emboli than filter protection, but requires temporary occlusion of the ICA. Flow reversal protection has the lowest risk from the effects of distal emboli but the highest risk of cerebral ischemia. The appropriate method depends on the characteristics of plaque and collateral circulation in each patient. On the other hand, two types of stent are available, the "closed-cell" and "open-cell" types. For successful CAS, it is necessary to determine the appropriate protection method and stent type in preoperative examinations such as magnetic resonance imaging, ultrasound, and cerebral angiography.