Inclusion Criteria:  Patient age ≥18 years The clinical diagnosis was acute ischemic stroke Large vascular lesions were detected by head CT, CTA, MRI, MRA or DSA Preoperative baseline NIHSS score > 4 MRS 0-1 before this stroke Mechanical thrombectomy was performed Use Reco thrombectomy bracket  Exclusion Criteria:  epileptic seizure Sudden coma Neurological loss symptoms quickly improved Imaging was negative, but clinical symptoms did not rule out subarachnoid hemorrhage Previous intracranial hemorrhage, subarachnoid hemorrhage, and brain tumor (with mass effect) History of head trauma within 3 months prior to surgery History of arterial puncture with difficulty in compression and hemostasis within one week prior to surgery Physical examination revealed evidence of active bleeding or trauma (e.g. fracture) Women are known to be pregnant or breastfeeding Severe allergies to contrast agents are known