Background: The impact of anesthesia technique on the outcomes of mechanical thrombectomy for acute ischemic stroke remains an issue of debate, and has not been studied in clinical trials. We investigated the association of general anesthesia with outcomes in patients undergoing mechanical thrombectomy for ischemic stroke.
Methods: We performed a cohort study involving patients undergoing mechanical thrombectomy for ischemic stroke from 2009-2013, who were registered in the New York Statewide Planning and Research Cooperative System (SPARCS) database. An instrumental variable (hospital rate of general anesthesia) analysis was used to simulate the effects of randomization and investigate the association of anesthesia technique with case-fatality and length of stay (LOS).
Results: Of the 1,308 patients undergoing mechanical thrombectomy for acute ischemic stroke, 492 (37.6%) underwent general anesthesia, and 816 (62.4%) underwent conscious sedation. Employing an instrumental variable analysis, we identified that general anesthesia was associated with a 6.4% increased case-fatality (95% CI, 1.9% to 11.0%), and 8.4 days longer LOS (95% CI, 2.9 to 14.0) in comparison to conscious sedation. This corresponded to 15 patients needing to be treated with conscious sedation to prevent one death. Our results were robust in a sensitivity analysis utilizing mixed effects regression, and propensity score adjusted regression models.
Conclusions: Using a comprehensive all-payer cohort of acute ischemic stroke patients undergoing mechanical thrombectomy in New York State, we identified an association of general anesthesia with increased case fatality and LOS. These considerations should be taken into account when standardizing acute stroke care.