Butylphthalide for Brain Edema After Endovascular Treatment

Inclusion criteria

• Age ≥18 years.
• Time from onset to randomization within 24 hours.
• Confirmed occlusion of the internal carotid artery or the M1 segment of the middle cerebral artery by digital subtraction angiography (DSA).
• NIHSS score ≥10 at onset, or NIHSS score >8 at 1 hour post-procedure (for those able to cooperate with NIHSS assessment), or CT-ASPECTS score 3-7 immediately post-procedure.
• Received endovascular treatment with successful reperfusion (mTICI ≥2b).
• Signed informed consent form by the subject or their legally authorized representative.

Exclusion criteria

• Pre-stroke modified Rankin Scale (mRS) score ≥2.
• Immediate post-procedure CT indicating PH2 hemorrhagic transformation or subarachnoid hemorrhage.
• Immediate post-procedure CT indicating cerebral herniation or planned decompressive craniectomy.
• History or evidence of intracerebral hemorrhage, subarachnoid hemorrhage, arteriovenous malformation, cerebral aneurysm, or brain tumor.
• Evidence (clinical or radiological) of concurrent infarction in the contralateral cerebral hemisphere that, in the investigator's judgment, may affect functional prognosis.
• Clinical or radiological evidence of vertebral or basilar artery occlusion.
• History of severe renal impairment (e.g., on dialysis) or estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m²; severe hepatic disease or alanine aminotransferase (ALT) >3× the upper limit of normal, or total bilirubin >2× the upper limit of normal.
• Use of butylphthalide within 7 days prior to enrollment.
• Known allergy to butylphthalide.
• Pregnancy.
• Breastfeeding women who do not agree (or whose legally authorized representative does not allow) to discontinue breastfeeding during the study drug administration period and for 7 days thereafter.
• Participation in other purely observational stroke studies, or expected survival <6 months unrelated to the current stroke, or unlikely to comply with follow-up requirements.
• Currently receiving another investigational drug with the same or similar mechanism of action as the study drug.
• Any condition that, in the investigator's opinion, makes the subject unsuitable for participation in the study.