The Effect Of Anesthesia On Thrombectomy Outcomes Is Modified By Collateral Flow: Pooled Patient Level Analysis From EXTEND-IA, EXTEND-IA TNK Part I And II, And SELECT

Background: The effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Collateral status on perfusion imaging may help identify the optimal anesthesia choice. Methods: In a pooled patient level analysis of EXTEND-IA, EXTEND-IA TNK, EXTEND-IA TNK part II and SELECT, EVT Functional outcomes (mRS distribution) were compared between general anesthesia (GA) vs non-general anesthesia (non-GA). Further, we assessed the impact of collateral flow on perfusion imaging evaluated by hypoperfusion intensity ratio (HIR) - Tmax10 sec/Tmax6 sec) on the association between anesthesia type and EVT outcomes. Results: Of 731 treated with EVT, 305 (42%) received GA and 426 (58%) non-GA. The baseline characteristics were similar, except for presentation NIHSS (median [IQR] GA 18 [13-22], non-GA 16[11-20], p<0.001) and ischemic core volume (GA 14.1mL [3-37] vs non-GA 9mL [0-31], p=0.002). GA was associated with longer LKW to arterial access (203min [158-267] vs 186min [138-252], p=0.002), but similar procedural time (36min [23-59] vs 34min [22-54], p=0.36). Non-GA was independently associated with improved functional outcomes (adj cOR 1.42, 95%CI 1.05-1.93, p=0.024) and lower mortality (17% vs 11.3%, p=0.025). Patients with poor collaterals (HIR≥0.4) had improved functional outcomes with non-GA (adj cOR 1.53, 95%CI 1.02-2.29, p=0.038), while no difference was observed in those with good collaterals-HIR<0.4 (adj cOR 1.38, 95% CI 0.84-2.27, p=0.21). Conclusion: GA was associated with worse functional outcomes after EVT, particularly in patients with poor collaterals. These findings have implications for randomized trials of GA vs non-GA.