Dexmedetomidine can attenuate the activity of the sympathetic nervous system under stress response and improve ischemia-reperfusion injury. The investigators hypothesized that the prolonged sedation of dexmedetomidine after successful reperfusion of endovascular thrombectomy may improve the clinical outcome of acute ischemic stroke patients.

Endovascular treatment with mechanical thrombectomy is the standard treatment for acute large vessel occlusion.

Dexmedetomidine is a commonly used sedative in endovascular thrombectomy of acute ischemic stroke.

Dexmedetomidine can attenuate the activity of the sympathetic nervous system under stress response and improve ischemia-reperfusion injury.

The investigators hypothesized that the prolonged sedation of dexmedetomidine after successful reperfusion of endovascular thrombectomy may improve the clinical outcome of acute ischemic stroke patients.

Inclusion Criteria:

• 2≤NIHSS≤25
• mRS score before stroke was less than 3
• Acute ischemic stroke (including anterior circulation)
• mTICI rate 2b or 3
• According to the 2018 AHA/ASA guidelines for the management of acute ischemic stroke, patients who plan to receive mechanical thrombectomy under local anesthesia and sedation
• Informed consent was signed by patient or legal representative

Exclusion Criteria:

• Intracerebral hemorrhage occurred in the responsible vessel area in the past 6 weeks
• Patients who had received stent treatment at the responsible vessel in the past
• Neurological function was restored at or before angiography
• Patients who are allergic to heparin, aspirin, clopidogrel, rapamycin, lactic acid polymer, poly (n-butyl methacrylate), stainless steel, anesthetics and contrast agents or have contraindications
• Hemoglobin was less than 70g/L, platelet count was less than 50×109/L, international normalized ratio (INR) greater than 1.5 (irreversible), there are uncorrectable bleeding factors
• Blood glucose < 2.7 mmol/L or > 22.2 mmol/L
• Severe liver or kidney disfunction, ALT>3 times the upper limit of normal value or AST>3 times the upper limit of normal value, creatinine>1.5 times the upper limit of normal value
• Pregnant or lactating women
• Previous history of mental illness
• Stroke with other acute diseases or postoperative stroke of other operation
• Heart rate less than 50bpm, second or third degree of atrioventricular block (except for pacemaker implantation), systolic blood pressure less than 90mmHg (two vasoactive drugs were already infused continuously )

The study protocol and Informed Consent Form will be shared with other researchers.

The information will become available after the publishing of this study and will be available for 1-year after publishing.

Please contact by E-mail at thoth_safin@sina.com