Stroke from carotid endarterectomy: when and how to reduce perioperative stroke rate?

OBJECTIVES: To analyse four years of CEA with respect to the underlying mechanisms of perioperative stroke and the role of intraoperative monitoring in the prevention of stroke. PATIENTS AND METHODS: From January 1996 through December 1999, 599 CEAs were performed in 404 men and 195 women (mean age: 65 years, range: 39-88). All operations were performed under general anaesthesia using computerised electroencephalography (EEG) and transcranial Doppler (TCD). Any new or any extension of an existing focal cerebral deficit, as well as stroke-related death were registered. Perioperative strokes were classified by time of onset (intraoperative or postoperative), outcome (minor or major stroke), and side (ipsilateral or contralateral). Stroke aetiology was assessed intraoperatively by means of EEG, TCD, completion arteriography or immediate re-exploration, and postoperatively by duplex sonography, computerised tomography (CT) or magnetic resonance imaging (MRI) of the head.
RESULTS: Perioperative stroke or death occurred in 20 (3.3%) patients. In four operations stroke was apparent immediately after surgery. Mechanisms of these strokes were ipsilateral carotid artery occlusion (1) and embolisation (3). In 16 patients stroke developed after a symptom-free interval (2-72 h, mean 18 h) due to occlusion of the internal carotid artery on the side of surgery (9). Other mechanisms were: contralateral occlusion of the internal carotid artery (1), postoperative hyperperfusion syndrome (1), intracerebral haemorrhage (1), and contralateral ischaemia due to prolonged clamping (1). In three procedures the cause was unknown.
CONCLUSIONS: In our experience most strokes from CEA developed after a symptom-free interval and mainly due to thromboembolism of the operated artery. We suggest the introduction of additional TCD monitoring during the immediate postoperative phase. Copyright 2001 Harcourt Publishers Limited.