General Anesthesia Versus Conscious Sedation for Mechanical Thrombectomy in Acute Anterior Circulation Ischemic Stroke

BACKGROUND: Retrospective studies suggested that general anesthesia (GA) for mechanical thrombectomy has worse outcomes compared with conscious sedation (CS). However, randomized single-center trials suggested noninferiority of GA to CS. We investigated the impact of anesthesia techniques on thrombectomy, and hypothesized that the routine use of GA with a defined protocol would not adversely affect thrombectomy delivery or outcomes. METHODS: A total of 451 consecutive patients receiving mechanical thrombectomy for anterior circulation ischemic stroke from 2016 to 2019 were identified from the local registry. Patients were divided into cohort A when both GA and CS were used, and cohort B (from October 2017) when GA became the default method. Favorable functional outcome was defined as modified Rankin scale of 0 to 2 at 3 months. Intraprocedural blood pressures were audited annually. RESULTS: In cohort A, compared with patients receiving CS, patients with GA had prolonged median arrival to arterial puncture time (26 versus 18 minutes; P<0.001) and comparable favorable functional outcome at 3 months (37.7% versus 45.1%; P=0.355). In cohort B, the median arrival to arterial puncture was reduced to 10 minutes, with comparable favorable functional outcome of 46.7%, and reduced mortality compared with cohort A (14.2% versus 22.7%; P=0.024). Yearly audits demonstrated good adherence to the protocol. Binary logistic regression analysis showed only old age (odds ratio [OR], 1.04; 95% CI, 1.02-1.07 [P=0.003]), high National Institute of Health Stroke Scale at presentation (OR, 1.17; 95% CI, 1.08-1.26 [P<0.001]), and poor collateral status (OR, 0.29; 95% CI, 0.12-0.72 [P=0.008]) were independent factors predicting for poor prognosis, not GA (OR, 0.71; 95% CI, 0.32-1.60 [P=0.408]). CONCLUSIONS: Patients treated under GA for mechanical thrombectomy achieved comparable functional outcome at 3 months compared with those under CS. Through practice and a defined protocol, GA for mechanical thrombectomy can achieve sustainable good functional outcomes. Large clinical trials are needed to confirm these findings.