A standardized case‐report form was used to collect demographics, clinical data, and procedural characteristics. Stroke subtype was classified according to the criteria of the Trial of ORG 10172 in Acute Stroke Treatment.19 Symptomatic intracranial hemorrhage (sICH) was defined as that detected within 72 hours after EVT, according to the criteria of the Heidelberg Bleeding Classification.20 Collateral status was assessed based on digital subtracted angiography using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology grading system, with grade 0 to 1 representing poor collateral status and grade 2 to 4 representing moderate to excellent.21Follow‐up of modified Rankin Scale at 3 months was conducted at each center, either by telephone or outpatient visit. Mortality at 3 months was recorded.