Emergency Conversion to General Anesthesia During Endovascular Therapy and Stroke Outcomes: A Retrospective Matched Study

Background: In endovascular treatment (EVT) for ischemic stroke, conversion from non-general anesthesia (non-GA) to general anesthesia (GA) may be necessary. This study aims to evaluate the effects of intra-EVT emergency GA conversion on patient outcomes and to identify potential risk factors for such conversions. Methods: A retrospective cohort study was conducted on ischemic stroke patients who underwent EVT without GA at a tertiary hospital in China. The primary outcome was the modified Rankin scale (mRS) score at 90 days. Secondary outcomes included procedural duration, rates of successful reperfusion, discharge status, and mRS scores at 1 and 3 months. Multivariable logistic regression, propensity score matching (PSM), and coarsened exact matching (CEM) were utilized to control for confounding factors. Results: Among 418 screened patients, 215 met eligibility criteria (non-GA=172, GA conversion=43). The 3-month mRS scores were similar between GA and non-GA groups across all analyses. However, GA conversion significantly reduced the likelihood of achieving mRS scores of 0 to 3 at discharge (unmatched: OR=0.37; PSM: OR=0.29; CEM: OR=0.33) and at 90 days (unmatched: OR=0.41; PSM: OR=0.38; CEM: OR=0.36). CEM analysis indicated that GA conversion significantly increased the 1-month mortality (OR=2.76). High National Institutes of Health Stroke Scale (NIHSS) scores and the absence of atrial fibrillation emerged as independent predictors of GA conversion. Conclusions: During EVT, the conversion from non-GA to GA is associated with significant hemodynamic fluctuations and may adversely affect both short-term and long-term neurological outcomes. The likelihood of GA conversion increases with higher NIHSS scores or in the absence of atrial fibrillation.