Inclusion Criteria:  Diagnosis of acute ischemic stroke; Imaging confirmed intracranial large vessel occlusion: intracranial internal carotid artery (ICA), middle cerebral artery (MCA M1/M2), anterior cerebral artery (ACA A1/A2), basilar artery (BA), vertebral artery (VA V4), and posterior cerebral artery (PCA P1); Initiation of any type of endovascular treatment, including intra-arterial thrombolysis, mechanical thrombectomy, aspiration, angioplasty, and stenting; Verbal and written informed consent was provided at the time of admission by patients or their legal authorized representatives.  Exclusion Criteria:  No evidence of large vessel occlusion on digital subtraction angiography.