は じ め に 対側頚動脈閉塞を伴った頚部内頚動脈狭窄症例では,両 側の脳循環代謝障害を伴っていることが多くその予後はよ くない.無症候でも内科的治療だけでは 6 年間で 38% の stroke 発症率であったとの報告 1) や症候性では 2 年間に 69% の stroke 発症率であったという報告もある 2) .このよ うな症例に一側の血行再建術を行った場合,術後両側で脳 循環代謝の改善が得られればその後の stroke 予防効果も 大きいと思われる. これまでにわれわれは PET を用いて,慢性期脳虚血症 例の misery perfusion の有無を検出し手術適応を検討し てきた 7) .また,術前後で脳循環代謝を評価することは手 Summary: We analyzed changes in cerebral hemodynamics due to reconstructive vascular surgery using positron emission tomography (PET) in 4 patients with severe internal

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... id artery (ICA) stenosis and contralateral ICA occlusion. Three patients had carotid artery stenting (CAS), while the remaining had superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery. Preoperative cerebral blood flow (CBF) studies of all patients demonstrated various decreases in CBF in a resting state and cerebral vascular reactivity (CVR) to acetazolamide (ACZ) and an increase in the oxygen extraction fraction (OEF) on both sides. These parameters improved on both sides after CAS was performed. Our results indicate that CAS performed on a stenosis contralateral to the site of occlusion will improve cerebral hemodynamics bilaterally and indirectly, patient prognosis. But further clinical trials are required to determine whether CAS significantly reduces in stroke above the occlusion.