Unusual clinical course after carotid artery stenting using a filter device: A case report

Carotid artery stenting (CAS) for severe internal carotid artery stenosis has recently been introduced as an alternative to carotid endarterectomy. Here, we present an unusual clinical course of a patient after CAS using the Angioguard filter device. Case : We present the case of a 75-year-old man who suffered from cerebral infarction in the left thalamus. Three-dimensional computed tomography confirmed asymptomatic stenosis (83%) in the left internal carotid artery. Carotid artery stenting (CAS) was performed using a distal protection filter device (Angioguard, Cordis, Miami Lakes, FL, USA). Following poststenting dilatation, the patient became drowsy and he developed left hemiplegia. Cerebral angiography showed no slowing or stopping of blood flow, and no delayed filling to the venous phase. Diffusion-weighted magnetic resonance imaging (DW-MRI) demonstrated multiple tiny cortical infarctions in the left frontal-parietal lobes ipsilateral to the operated side. The symptoms of the patient appeared more serious than the DW-MRI findings suggested. After CAS, the patient showed good recovery after receiving medical treatments for about 2 weeks. Conclusion : We suspected that liquified microplaques (<100 μm) passed through the pores of the filter device and embolized cerebral arterioles or capillaries, which might have caused the symptomatic cerebral infarction. Although most cerebral infarctions following CAS are asymptomatic, the filter device used here could not ensure complete absence of the development of symptomatic cerebral infarction. Therefore, farther improvement of the filter device is necessary in order to reduce the incidence of microembolisms causing symptomatic cerebral infarction. Moreover, the characteristics of carotid plaques and the hemodynamics of the carotid artery must be evaluated before performing CAS, and then the most appropriate treatment from the various therapeutic options should be selected.