[Case of internal carotid artery stenosis complicated with shower embolism during filter-protected carotid artery stenting].

Recently, carotid artery stenting (CAS) has gained a lot of interest as a potentially valuable minimally invasive alternative to carotid endarterectomy. Since the occurrence of distal embolization as a result of CAS is still a major concern, an embolus protection device is usually employed during the procedure. Here, we report a case of internal carotid artery (ICA) stenosis complicated with shower embolism during CAS with an embolus protection filter. A 77-year-old man who had a history of coronary bypass surgery was referred to our department for the treatment of carotid artery stenosis. Angiography showed high-grade stenosis at the origin of the right ICA. Plaque magnetic resonance imaging (MRI) showed a hyperintense lesion at the right ICA stenosis, indicating the presence of a lipid-rich plaque. Since cerebral circulation was impaired significantly in the right cerebral hemisphere, CAS was performed for the right ICA stenosis, with an embolus protection filter. A self-expandable stent was placed in the right ICA following predilation. During stenting, plaque protrusion was identified and treated with balloon angioplasty. The patient developed right hemiparesis postoperatively. MRI showed multiple infarction in the right cerebral hemisphere. The symptom resoeved 7 days later. A potential disadvantage of the filter device is incomplete protection from emboli or failure to protect against soluble mediators. An embolus protection filter is not suitable for capturing the debris from lipid-rich plaques.