The primary objective is to investigate whether treatment with Adacolumn can ameliorate the progression of cerebral edema within 72 hours in patients with anterior circulation ischemic stroke. The secondary objective is to explore if Adacolumn could improve acute neurologic status, functional outcomes, treatment requirements and safety in patients with anterior circulation ischemic stroke.

This is a prospective, randomized, controlled trial evaluating Adacolumn therapy in patients with acute ischemic stroke due to anterior circulation large-artery occlusion presenting within 10 hours of stroke onset. Eligible patients who meet all inclusion and no exclusion criteria will be randomized in a 1:1 ratio to the Adacolumn group or the control group, with 5 patients enrolled in each arm (total n=10).

All participants will have undergone guideline-based endovascular thrombectomy for acute ischemic stroke, together with standard medical management. In the Adacolumn group, each patient will undergo four scheduled Adacolumn treatment sessions in addition to endovascular thrombectomy and standard medical therapy. Patients in the control group will receive endovascular thrombectomy and standard medical treatment alone. Each participant will be followed for 90 days after enrollment.

The objective of the trial is to evaluate the effect of Adacolumn therapy on cerebral edema in patients with anterior circulation large-artery occlusion stroke. The primary endpoint is the change in net water uptake (NWU) measured on CT at 72-78 hours post reperfusion, compared to the immediate post-reperfusion CT.

Inclusion Criteria:

1. Age 18-80 years, regardless of gender;
2. A clinical diagnosis of acute ischemic stroke;
3. Proven large vessel occlusion in ICA or MCA-M1 occlusion (carotid occlusions can be cervical or intracranial, with or without tandem MCA lesions) determined by MRA or CTA or DSA;
4. NIHSS score ≥10 at screening;
5. Pre-stroke mRS score <2 (independent in all activities of daily living);
6. Time from stroke onset to initiation of the first Adacolumn treatment is ≤24 hours, stroke onset is defined as the last time the patient was known to be at their neurological baseline (wake-up strokes qualify if within this time window);
7. All endovascular thrombectomy procedures must strictly adhere to the "2024 Chinese Stroke Association Guidelines for Reperfusion Therapy in Acute Ischemic Stroke" and the latest prescribing information/instructions for use regarding indications, contraindications, and procedural standards;
8. Written informed consent obtained from the patient or legally authorized representative.

Exclusion Criteria:

1. Decompressive craniectomy performed before enrollment or between enrollment and initiation of study treatment;
2. Patients who receive intravenous thrombolysis (including bridging therapy) for the index ischemic stroke episode before or during endovascular thrombectomy; or undergo permanent intracranial or extracranial stent implantation (including intracranial stent-assisted thrombectomy or carotid stenting) during the index endovascular procedure;
3. After endovascular thrombectomy: extensive contrast extravasation (diffuse subarachnoid high density or parenchymal high density not consistent with hematoma), new subarachnoid hemorrhage（SAH）, or symptomatic intracranial hemorrhage (sICH);
4. Large-vessel occlusion is attributed to other determined etiologies per TOAST classification, such as tumor-related, dissection-related, or other clearly identifiable non-LAA/non-CE causes.
5. Clinical signs of brain herniation, such as unilateral or bilateral fixed dilated pupils and/or other loss of brainstem reflexes attributable to cerebral edema or herniation in the investigator's opinion;
6. Intracranial lesions conferring markedly increased bleeding risk (known brain tumor, arteriovenous malformation, aneurysm);
7. Inability to undergo MRI;
8. Absolute neutrophil count <1.5×10⁹/L or >15×10⁹/L
9. Absolute monocyte count > 1.0 ×10⁹/L;
10. Red blood cells <3.0×10¹²/L ;
11. Active internal bleeding or bleeding tendency (such as platelet count <100×10⁹/L, INR >1.7, PT >15 seconds);
12. Marked hypercoagulability (fibrinogen >700 mg/dL);
13. Intracranial or spinal surgery or severe head trauma within the past 3 months;
14. Refractory hypertension (persistent systolic blood pressure >185 mmHg or diastolic >110 mmHg);
15. Known allergy to components of the blood purification system (including adsorption membrane, anticoagulants);
16. Acute ST-segment elevation myocardial infarction and/or acute decompensated heart failure and/or corrected QT interval >520 ms and/or history of cardiac arrest within the past 6 months(pulseless electrical activity, ventricular tachycardia, ventricular fibrillation, or asystole);
17. Body temperature >38°C or active infection;
18. Active autoimmune disease or immunodeficiency;
19. Participation in another interventional clinical trial within the past 30 days;
20. Any other condition deemed unsuitable for participation by the investigator.