Thrombectomy Outcomes With General vs Nongeneral Anesthesia

Background and ObjectivesThe effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Collateral status on perfusion imaging may help identify the optimal anesthesia choice.MethodsIn a pooled patient-level analysis of EXTEND-IA, EXTEND-IA TNK, EXTEND-IA TNK part II, and SELECT, EVT functional outcomes (modified Rankin Scale score distribution) were compared between general anesthesia (GA) vs non-GA in a propensity-matched sample. Furthermore, we evaluated the association of collateral flow on perfusion imaging, assessed by hypoperfusion intensity ratio (HIR) – Tmax > 10 seconds/Tmax > 6 seconds (good collaterals – HIR < 0.4, poor collaterals – HIR ≥ 0.4) on the association between anesthesia type and EVT outcomes.ResultsOf 725 treated with EVT, 299 (41%) received GA and 426 (59%) non-GA. The baseline characteristics differed in presentation National Institutes of Health Stroke Scale score (median [interquartile range] GA: 18 [13–22], non-GA: 16 [11–20],p< 0.001) and ischemic core volume (GA: 15.0 mL [3.2–38.0] vs non-GA: 9.0 mL [0.0–31.0],p< 0.001). In addition, GA was associated with longer last known well to arterial access (203 minutes [157–267] vs 186 minutes [138–252],p= 0.002), but similar procedural time (35.5 minutes [23–59] vs 34 minutes [22–54],p= 0.51). Of 182 matched pairs using propensity scores, baseline characteristics were similar. In the propensity score–matched pairs, GA was independently associated with worse functional outcomes (adjusted common odds ratio [adj. cOR]: 0.64, 95% CI: 0.44–0.93,p= 0.021) and higher neurologic worsening (GA: 14.9% vs non-GA: 8.9%, aOR: 2.10, 95% CI: 1.02–4.33,p= 0.045). Patients with poor collaterals had worse functional outcomes with GA (adj. cOR: 0.47, 95% CI: 0.29–0.76,p= 0.002), whereas no difference was observed in those with good collaterals (adj. cOR: 0.93, 95% CI: 0.50–1.74,p= 0.82),pinteraction: 0.07. No difference was observed in infarct growth overall and in patients with good collaterals, whereas patients with poor collaterals demonstrated larger infarct growth with GA with a significant interaction between collaterals and anesthesia type on infarct growth rate (pinteraction: 0.020).DiscussionGA was associated with worse functional outcomes after EVT, particularly in patients with poor collaterals in a propensity score–matched analysis from a pooled patient-level cohort from 3 randomized trials and 1 prospective cohort study. The confounding by indication may persist despite the doubly robust nature of the analysis. These findings have implications for randomized trials of GA vs non-GA and may be of utility for clinicians when making anesthesia type choice.Classification of EvidenceThis study provides Class III evidence that use of GA is associated with worse functional outcome in patients undergoing EVT.Trial Registration InformationEXTEND-IA: ClinicalTrials.gov (NCT01492725); EXTEND-IA TNK: ClinicalTrials.gov (NCT02388061); EXTEND-IA TNK part II: ClinicalTrials.gov (NCT03340493); and SELECT: ClinicalTrials.gov (NCT02446587).