Jugular venous neurone‐specific enolase and s‐100 levels after carotid endarterectomy under local or general anaesthesia

Background: Previous studies using near infrared spectroscopy have indicated that carotid endarterectomy (CEA) performed under local anaesthesia (LA) preserves cerebral cytochrome oxidase and autoregulation compared with surgery under general anaesthesia (GA). The hypothesis that LA offers a degree of protection against ischaemic cerebral injury has thus been investigated by measuring ipsilateral jugular venous neurone-specific enolase (NSE; a glycolytic enzyme released from injured neurones) and s-100 (a protein released from glial cells) during and after CEA. Methods: Sixteen patients with symptomatic 70–99 per cent carotid stenosis were randomized (with ethics committee approval) to CEA with either LA (n = 7; mean stump pressure 48·5 (range 37–80) mmHg; none of seven shunted) or GA (n = 9; mean stump pressure 49·1 mmHg; five of nine shunted). Jugular venous samples were assayed for NSE and s-100 concentration (immunoluminometric assay) before carotid clamping, 5 min before and 5 min, 2, 4, 6, 8, 12 and 24 h after clamp release. Results: There were no neurological complications. Median (range) levels of s-100 were low and did not increase from baseline levels (GA 0·10 (0·08–0·11) μg l−1, LA 0·13 (0·12–0·17) μg l−1) in either group. Preclamp NSE levels were similar in both groups (LA 17·6 (15·2–20·7) μg l−1versus GA 21·5 (11·3–26·2) μg l−1; P = 0·37). Peak levels occurred at 2 h and were significantly higher in patients having GA (48·2 (31·4–61·3) versus 25·5 (16·6–27·8) μg l−1; P = 0·05, Mann–Whitney U test). Furthermore, the increase from baseline in patients having GA was also significant (P = 0·04) and NSE levels were higher at all time points up to 12 h, returning to baseline at 24 h. Conclusion: These results suggest that CEA performed under LA is associated with reduced cerebral ischaemic injury compared with GA, and are consistent with niroscopic data indicating improved cerebral oxygenation in these patients. Furthermore, NSE would seem to be a more sensitive marker of cerebral injury than s-100. © 2001 British Journal of Surgery Society Ltd