Outcomes of emergency conversion to general anesthesia during thrombectomy for anterior circulation stroke

The optimal anesthetic strategy during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) remains debated. While general anesthesia (GA) and non-GA approaches are widely used, the impact of emergency conversion (EC) from non-GA to GA is unclear. We evaluated outcomes of patients undergoing EC compared with those managed with primary GA or non-GA. We conducted a multicenter observational study of consecutive anterior circulation large vessel occlusion patients with pre-stroke modified Rankin Scale (mRS) <= 2 treated with MT between January 2022 and December 2023 across three centers. Patients were categorized as GA, non-GA, or EC. Inverse probability weighting (IPW) with multivariable adjustment was applied. The primary outcome was 90-day mRS shift; secondary outcomes included pneumonia and 3-month mortality. Among 669 patients, 399 (59.6%) underwent GA, 188 (28.1%) non-GA, and 82 (12.3%) EC. No significant differences were observed in 90-day functional outcomes for EC versus GA (adjusted common OR [acOR] 0.74; 95% CI, 0.48-1.14; p = 0.170) or EC versus non-GA (acOR 0.70; 95% CI, 0.40-1.20; p = 0.193). Compared with EC, non-GA patients had lower pneumonia risk (acOR 0.17; 95% CI, 0.07-0.45; p = 0.001), while GA was associated with reduced 3-month mortality (acOR 0.48; 95% CI, 0.28-0.85; p = 0.011). Emergency conversion was not linked to worse functional outcomes compared with GA or non-GA. However, EC was associated with higher pneumonia risk relative to non-GA and increased mortality compared with GA. Larger prospective studies are warranted to clarify the impact of EC during MT.