[Endovascular treatment for carotid artery stenosis]

Carotid artery stenting (CAS) is an endovascular treatment for carotid artery stenosis, and is a less invasive method than carotid endarterectomy (CEA). Reimbursement of CAS with self-expanding stents and filter protection devices had started since 2008 in Japan for the patients with symptomatic stenosis (≥ 50%) and asymptomatic stenosis (≥ 80%) with CEA high risk due to systemic diseases, advanced age, high position, restenosis after CEA, and stenosis caused by radiation. The standard methods for filter-protected CAS is pre-dilatation with a small balloon to allow stent placement and post-dilatation with a balloon of a size smaller than the diameter of the normal internal carotid artery under 2 anti-platelets drugs and full heparinization. Distal embolism is the most important complication for the patients with vulnerable plaque, which is detected by ultrasound sonography or MRI. Bradycardia and hypotension may occur during and after CAS. Hyperperfusion may also occur in patients with impairment of the cerebrovascular reactivity, which is detected by single photon emission computed tomography (SPECT) with acetazolamide challenge. We should identify patients with high risk for CAS due to anatomy or vulnerability of the plaque to avoid periprocedural complication.