A Cochrane review included 14 studies with a total of 4 596 operations, of which 3 526 were from the single largest trial (GALA). The studies compared local anaesthesia (cervical block in 13 studies and epidural block in 1 study) with general anaesthesia for carotid endarterectomy. There was no difference in the risk of stroke or death within 30 days of operation between the groups. There was a trend towards lower mortality within 30 days of operation with local anaesthetic, but neither the GALA trial nor the pooled analysis were powered to detect an effect on mortality reliably. There was no significant difference in myocardial infarction within 30 days of operation between the groups (table ).
| Outcome | Peto OR (95% CI) | Control (general anaesthesia) * | Intervention (local anaesthesia) * | Participants (studies) |
|---|---|---|---|---|
| *crude prevalences | ||||
| Any stroke within 30 days of operation | 0.92 (0.67 to 1.28) | 3.5% | 3.2% | 4 453 (12 studies) |
| Death within 30 days of operation | 0.61 (0.35 to 1.06) | 1.5% | 0.9% | 4 181 (10 studies) |
| Stroke or death within 30 days of operation | 0.85 (0.62 to 1.16) | 4.2% | 3.6% | 4 181 (10 studies) |
| Myocardial infarction within 30 days of operation | 1.53 (0.67 to 3.47) | 0.4% | 0.6% | 4 357 (11 studies) |
Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment and unclear blinding) and by imprecise results (wide confidence intervals).