ARTEMIS: Umbilical Cord-Derived Mesenchymal Stromal Cells (UC-MSCs) After Mechanical Thrombectomy for Acute Ischemic Stroke

This study will evaluate the safety and feasibility of administering umbilical cord-derived mesenchymal stromal cells (UC-MSCs) following mechanical thrombectomy in adults with acute ischemic stroke. Acute ischemic stroke occurs when a blood clot blocks blood flow to part of the brain, potentially causing brain tissue damage and neurological impairment. The study will include 10 adults aged 18 to 70 years. All participants will receive standard stroke care, including mechanical thrombectomy to remove the blood clot. Participants will be randomly assigned to one of two groups. One group will receive standard care plus a single dose of 20 million MSCs derived from allogeneic donated umbilical cord tissue. The cells will be delivered through a microcatheter into the artery supplying the affected part of the brain. The other group will receive standard care without the cell treatment. Both groups will receive physical rehabilitation. Researchers will follow participants for six months. They will monitor health problems and assess recovery, disability, blood markers, and brain scans. The main goal is to determine whether this treatment can be administered safely and feasibly. It is not yet known whether the treatment will improve recovery after stroke.

Inclusion Criteria: 1. Age 18 to 70 years; 2. Acute ischemic stroke diagnosed clinically; 3. Acute ischemic stroke confirmed by CT or MRI; 4. Eligible for mechanical thrombectomy that can be performed within six hours of symptom onset; 5. National Institutes of Health Stroke Scale (NIHSS) score from 6 to 20; 6. Pre-stroke modified Rankin Scale (mRS) score less than 2; 7. Successful reperfusion (mTICI 2b or 3) on angiography after thrombectomy; 8. Written informed consent from the patient or a legally authorized representative. Exclusion Criteria: 1. Previous stroke; 2. Infarct in the cerebellum or brainstem; 3. Small lacunar infarct (lesion smaller than 15-20 mm); 4. Subarachnoid, intraventricular, or intracerebral hemorrhage, or a structural brain lesion such as a tumor, on CT or MRI; 5. Midline shift, cerebral edema, or an infarct in an inaccessible location on CT or MRI; 6. Candidate for decompressive craniectomy; 7. Known coagulation or hematologic disorder (e.g., aplastic anemia) or current anticoagulant use (e.g., warfarin); 8. Uncontrolled blood glucose; 9. Known hepatic, renal, or heart failure; 10. Myocardial infarction within the past 6 months; 11. History of seizures within the past 6 months; 12. History of cancer; 13. Known intellectual, cognitive (e.g., dementia) or psychiatric disorder that would impair understanding of, or adherence to, study procedures and follow-up; 14. Pregnancy or breastfeeding; 15. Allergy to contrast media.