Are neurologic events occurring during carotid artery surgery predictive of postoperative neurologic complications?

Per- and postoperative neurologic complications occurring during carotid artery surgery may be related to different mechanisms. Nevertheless, recent studies suggest that they are related and that patients who develop reversible neurologic events peroperatively are at risk of postoperative neurologic complications. We, therefore, studied 265 patients operated under regional anaesthesia to assess the incidence and the pathogenesis of per- and postoperative neurologic disorders and their relationship.

Neurologic function was adequately assessed in 261 patients during surgery. The operation was uneventful in 234 patients, while 27 suffered from transient ischaemic neurologic deficit occurring mainly during carotid artery clamping.

Postoperative neurologic complications occurred in 6 (2.5%) of the patients who were symptom-free during surgery and in 1 (3.7%) of the patients who experienced neurologic deficit during surgery (NS). In this group, two additional patients had peroperative neurologic deficit which lasted a few hours postoperatively so that the total incidence of postoperative neurologic deficit (11.1%) was significantly higher than in the other group (P < 0.05). Emboli (N = 3) and carotid artery thrombosis (N = 3) were the main causes of postoperative neurologic deficit.

We conclude that patients who have suffered from a peroperative neurologic complication were more frequently in an unstable neurologic condition postoperatively. However, the incidence of "new" neurologic deficit, separated by a free interval from the one occurring peroperatively, was not significantly different in this group.