Preoperative prediction of cerebral ischaemia due to carotid occlusion

Abstract

The vast majori ty of patients tolerate clamping of the carotid artery, wi thout signs of cerebral ischaemia. There is no doubt , however , that a subgroup of pat ients exists wi th insufficient collateral circulation w h o will develop ischaemia wi thout protect ive measures , and this is seen most clearly in those patients w h o undergo carotid endar te rec tomy u n d e r local anaesthesia, 10-15% of w h o m have clinical signs of ischaemia when the carotid ar tery is c lamped (Table 1). Similar figures are seen wi th electroencephalogram (EEG) recording w h e n the operat ion is pe r fo rmed u n d e r general anaesthesia, and in cases wi th contralateral occlusion, some 20-25% will have signs of hypoper fus ion dur ing clamping. Even though few of these patients will develop a stroke w h e n the operat ion is per formed wi thout a shunt ,