High-risk症例に対する頸動脈内膜剥離術(CEA)の要点(<特集>頸部頸動脈病変の治療)  [in Japanese] Frequency and Management of High-risk Patients for Carotid Endarterectomy(<Topic>Management of Carotid Stenosis)  [in Japanese]

Carotid endarterectomy (CEA) is becoming a standard treatment of the internal carotid artery (ICA) stenosis in Japan. But frequency of high-risk patients for CEA and management of high-risk patients to reduce operative complications have not been well established. The purpose of this study is to determine frequency of high-risk patients for CEA and to discuss management of high-risk patients. Between 1984 and 2002, 230 CEAs under general anesthesia were performed in our institute. High-risk patients for CEA were defined according to the following criteria: (1) patients older than 71 years, (2) patients with stenosis positioned higher than the second cervical vertebra, (3) patients vul-nerable to ischemia during cross-clamping of the ICA, (4) patients at risk of hyperperfusion, and (5) patients with ischemic heart disease. Fifty-one high-aged patients (22%) were operated without any complications due to high age. Twentyone patients (14%) had high-positioned stenosis. There were no complications due to high position. Cerebral ischemia after cross-clamping of the ICA occurred in 24% of the patients according to the intraoperative monitorings of ICA stump pressure, somatosensory evoked potential, and oxygenation of the cerebral cortex. Hyperperfusion, diagnosed by the ICA flow, velocity of the middle cerebral artery by TCD, and postoperative measurement of cerebral blood flow, occurred in about 5% of the patients. To avoid ischemic complications, we have routinely used a T-shaped internal shunt and maintained the systemic blood pressure during CEA. Management of hyperperfusion comprised strict control of the systemic blood pressure and barbiturate therapy. Ischemic heart disease was associated in 24% of the patients. Coronary artery revascularization such as coronary artery bypass grafting (CABG), coronary angioplasty, or stenting were performed in 4 patients before CEA. We have not done combined CABG and CEA. There was no nyocardiac infarction in the perioperative time. In this series, perioperative mortality and morbidity were 0% and 1.7% respectively. Although there were fewer perioperative complications, proper monagement for high-risk patiensts is essential.