Importance: No definitive conclusion can be made on the best choice of anesthesia for people with acute posterior circulation stroke during endovascular treatment. Only a few observational studies have focused on this topic in recent years, and they have differing conclusions.
Objective: To examine whether conscious sedation (CS) is a feasible alternative to general anesthesia (GA) during endovascular treatment in patients with acute posterior circulation stroke.
Design, setting, and participants: A randomized parallel-group exploratory trial with blinded end point evaluation (Choice of Anesthesia for Endovascular Treatment of Acute Ischemic Stroke [CANVAS II]) enrolled adult patients from March 2018 to June 2021 at 2 comprehensive care hospitals in China. Patients with acute posterior circulation stroke were enrolled, randomized, and monitored for 3 months. Of 210 patients admitted with acute ischemic posterior circulation stroke, 93 were recruited and 87 were included in the intention-to-treat (ITT) analysis after exclusions, 43 were assigned to GA and 44 to CS. All analyses were unadjusted or adjusted with the ITT principle.
Interventions: Participants were randomly assigned to CS or GA in a 1:1 ratio.
Main outcomes and measures: The primary end point was functional independence at 90 days evaluated with the modified Rankin Scale (mRS).
Results: A total of 87 participants were included in the ITT study (mean [SD] age, 62 [12] years; 16 [18.4%] female and 71 [81.6%] male). Of these, 43 were in the GA group and 44 in the CS group. The overall baseline median (IQR) National Institute of Health Stroke Scale (NIHSS) score was 15 (12-17). In the CS group, 13 people (29.5%) were ultimately transferred to GA. The CS group had a higher incidence of functional independence; however, no significant difference was found between the 2 groups (48.8% vs 54.5%; risk ratio, 0.89; 95% CI, 0.58-1.38; adjusted odds ratio [OR], 0.91; 95% CI, 0.37-2.22). However, GA performed better in successful reperfusion (mTICI 2b-3) under ITT analysis (95.3% vs 77.3%; adjusted OR, 5.86; 95% CI, 1.16-29.53).
Conclusion and relevance: The findings in this study suggest that CS was not better than GA for the primary outcome of functional recovery and was perhaps worse for the secondary outcome of successful reperfusion.
Trial registration: ClinicalTrials.gov Identifier: NCT03317535.