This is a prospective, randomized, open label, blinded-end point, single-center study, aiming to investigate the effect of head down position in anterior circulation large vessel occlusion patients with successful recanalization after endovascular treatment.

Inclusion Criteria:

• Age ≥ 18
• Anterior circulation large vessel occlusion who received endovascular treatment within 24 hours of stroke onset;
• National Institute of Health Stroke Scale (NIHSS) ≥ 6 before endovascular treatment;
• Successful recanalization (mTICI 2b-3) after endovascular treatment;
• Cerebral circulation time based on DSA of the stroke side was slower than that of the healthy side after successful recanalization;
• ASPECTS ≥ 6 on CT or DWI;
• Absence of parenchymal hematoma on CT images done in the angio suite immediately after the procedure;
• Modified Rankin Scale score before stroke onset ≤ 1;
• Signed informed consent by patient or their legally authorized representative.

Exclusion Criteria:

• Hemorrhagic stroke: cerebral hemorrhage, subarachnoid hemorrhage;
• Severe hepatic or renal dysfunction, increase in ALT or AST (more than 2 times of upper limit of normal value), increase in serum creatinine (more than 1.5 times of upper limit of normal value) or requiring dialysis;
• After recanalization, severe and sustained (i.e., > 5 minutes) uncontrolled hypertension (systolic blood pressure over 180mmHg or diastolic blood pressure over 105 mmHg) refractory to antihypertensive medication;
• More than four retrieval attempts in the same vessel;
• Cardiac insufficiency (NYHA Class ≥II);
• Pregnancy, plan to get pregnant or during lactation;
• The estimated life expectancy is less than 6 months due to other serious diseases;
• Other conditions unsuitable for this clinical study assessed by researcher.