Usefulness of intraoperative cortical blood flow measurement by heat clearance method for monitoring cerebral ischaemia during therapeutic carotid ligation.

Changes of regional cortical blood flow (rCBF) was monitored by the heat clearance method during the operation of cervical carotid ligation combined with superficial temporal artery and middle cerebral artery anastomosis for the treatment of inaccessible aneurysms of the internal carotid artery in eight patients. There were three types of rCBF responses upon closure of the internal carotid artery, with or without bypass blood flow. Based on the responses, the internal carotid artery was ligated abruptly or occluded gradually. The usefulness of the method for monitoring cerebral ischaemia for therapeutic carotid ligation is discussed.