Abstract： Objective:To investigate the efficacy, safety and surgical experience of middle meningeal artery embolization using polyvinyl alcohol particle in treating chronic subdural hematoma (CSDH).Methods:A total of 51 CSDH patients (25 accepted first treatment, 19 had invalid atorvastatin treatment, and 7 recurred after burr hole drainage) admitted to Department of Neurosurgery, First Affiliated Hospital of Army Medical University from May 2021 to August 2022 were enrolled. The characteristics of middle meningeal artery were evaluated by three-dimensional time-of-flight (3D TOF) MRA before embolization. With confirmation of no surgical contraindications, unilateral or bilateral embolization of the middle meningeal artery with polyvinyl alcohol particle was performed under local anesthesia. The hematoma recurrence rate and proportion of patients with reduction of maximum hematoma thickness>50% at 2 months after embolization were used as primary outcomes to evaluate the efficacy. Complications and embolization-related adverse events were recorded, and the experiences were retrospectively summarized.Results:For all 51 patients, the characteristics of the middle meningeal artery shown in the preoperative 3D TOF MRA were consistent with those in the intraoperative angiography; 16 patients with unilateral hematoma showed thickened bilateral middle meningeal arteries in preoperative 3D TOF MRA, bilateral blood supply was confirmed by intraoperative angiography and bilateral middle meningeal artery embolization was performed. Interventional embolization was successful in all 51 patients, including unilateral embolization in 19 and bilateral embolization in 32, with a total of 83 sides of embolizations. After embolization, hematoma was absorbed and symptoms improved in 48 patients, and hematoma recurrence was observed in 3 patients (5.9%), with an overall success rate of 94.1%. Excluding the 3 patients with hematoma recurrence, 39 patients completed the 2-month follow-up, and these patients had the maximum hematoma thickness reduction>50%. No mortality, complications or surgery-related adverse events were observed in them.Conclusion:Middle meningeal artery embolization with polyvinyl alcohol particle is safe and effective in treating CSDH; once bilateral middle meningeal artery blood supply is indicated by preoperative MRA in patients with unilateral hematoma, bilateral angiography and embolization should be considered during interventional treatment.