フィルターディバイスを用いたCAS後に特異な経過をたどった1症例  [in Japanese] Unusual Clinical Course after Carotid Artery Stenting using a Filter Device: A Case Report  [in Japanese]

CAS(carotid artery stenting)は,内頚動脈高度狭窄症に対する治療として,さらに増加すると思われる.今回,われわれは,フィルターディバイスを用いたCAS後に特異な経過をたどった症例について報告する.75歳男性,無症候性左内頚動脈狭窄症(約83%)に対し,後拡張直後に傾眠,右完全麻痺となった.アンギオ上,異常所見なし.術後MRI上の脳塞栓に比し,症状はきわめて悪かったが,術後2週間でほぼ完全に回復した.CAS後の脳梗塞はほとんどが無症性であり,症候性脳梗塞との関連性はないとされるが,完全に症候性脳梗塞を防ぐことはできず,今回のようにプラークによる脳塞栓を起こす可能性があるため,microembolismをさらに減らす必要性があると思われる.

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 (<100μm) 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, further 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.