This observational study aims to investigate the real-world effectiveness and safety of different treatment strategies for acute ischemic stroke (AIS) in Chinese children under 18 years of age.

Its primary research question is: In real-world clinical practice, does endovascular therapy (e.g., stent retriever thrombectomy, aspiration thrombectomy) improve 90-day functional outcomes in pediatric AIS patients with acute anterior or posterior circulation large vessel occlusion? Children under 18 years of age receiving routine AIS diagnosis and treatment at approximately 25-35 study centers across China will undergo neurological function assessments, imaging examinations, and evaluations of growth, development, and psychosocial status at baseline, 24 hours post-procedure, 7 days post-procedure or at hospital discharge, and at 90 days and 6 months post-onset. Adverse events will also be documented.

Inclusion Criteria:

• Age >28 days and <18 years;
• Presence of stroke-related symptoms (hemiparesis, facial palsy, aphasia, altered level of consciousness, seizure, headache) or atypical symptoms (sudden lethargy or irritability, crying, feeding difficulties, incontinence, sensory loss, ataxia, vertigo, nausea and/or vomiting, neck pain, fever);
• First-ever stroke and onset within ≤7 days prior to admission;
• Acute ischemic stroke confirmed by computed tomography (CT) or magnetic resonance imaging (MRI);
• Legal guardian provides signed informed consent;
• For children aged ≥8 years to <18 years who are conscious and without comprehension impairment, assent obtained from the child;

Exclusion Criteria:

• Lack of imaging examination or stroke diagnosed without imaging
• History of hypoxic-ischemic encephalopathy
• Ischemic stroke caused by cerebral venous system
• Concurrent presence of indistinguishable ischemic and hemorrhagic stroke

This study will prospectively enroll consecutive patients aged 28 days to <18 years with acute ischemic stroke (AIS) from approximately 25-35 participating centers across China. Eligible patients must have first-ever stroke with onset ≤7 days prior to admission, confirmed by computed tomography (CT) or magnetic resonance imaging (MRI). Both patients receiving standard medical therapy alone and those receiving endovascular treatment (including stent retrieval, aspiration thrombectomy, balloon angioplasty, stenting, or intra-arterial thrombolysis) will be included. Patients with lack of imaging confirmation, history of hypoxic-ischemic encephalopathy, ischemic stroke caused by cerebral venous system, or concurrent indistinguishable ischemic and hemorrhagic stroke will be excluded. The study aims to enroll a target sample size of >1000 patients.

Due to ethical and regulatory restrictions: enrollment of pediatric participants (age <18 years), collection of sensitive clinical, imaging, and biospecimen data (blood and thrombus samples), and compliance with Chinese human genetic resources management regulations. Informed consent obtained does not include provisions for public sharing of individual participant data.