Background and purpose:
General anesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies. We examined the association between GA and thrombectomy outcomes in pooled data from five randomized trials.
Methods:
Patient-level data were pooled from trials comparing endovascular thrombectomy (predominantly using stent retrievers) with standard care in anterior circulation ischemic stroke patients (HERMES Collaboration): MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA. The primary outcome was ordinal analysis of modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modeling with a random effect for trial incorporated in all models.
Results:
Of 1287 patients, 634 were allocated to endovascular thrombectomy and general anesthesia was used in 153/609 (25%) of endovascular-treated patients with anesthesia information available. Although dysphasic patients are sometimes felt to be less co-operative and require GA, the rate of GA was 25% in both right and left hemisphere patients. At baseline, GA and non-GA patients had similar age, NIHSS and time to randomization. Endovascular thrombectomy was associated with increased odds of improved functional outcome at 3 months, regardless of whether GA (cOR 1.73 95%CI 1.10-2.72, p=0.02) or non-GA (cOR 2.61 95%CI 2.01-3.40, p<0.001) was used. The odds of improved outcome were, however, significantly greater for those treated under non-GA (OR 1.59 95%CI 1.12-2.26, p=0.01). Pneumonia was more common in the GA group (16% vs 9% p=0.03). Rates of vessel perforation were similar in GA (0.7%) vs non-GA patients (1.8%, p=0.52). Delay between randomization and reperfusion was greater in GA versus non-GA patients (median 98 vs 75 min, p<0.001).
Conclusions:
Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment is still worthwhile in those who require anesthesia for medical reasons.