Treatment Durability After Subdural Evacuating Port System, Middle Meningeal Artery Embolization, and Combined Therapy for Chronic Subdural Hematoma

BACKGROUND AND OBJECTIVES: Chronic subdural hematoma care is evolving beyond burr holes and craniotomy to minimally invasive options such as subdural evacuating port system (SEPS) and middle meningeal artery (MMA) embolization. The optimal initial strategy and role of combined SEPS and MMA remains uncertain. The aims of this study were to compare outcomes after SEPS alone, MMA embolization alone, and combined SEPS and MMA and to assess the effect of hematoma size and antithrombotic therapy on treatment durability. METHODS: We conducted a retrospective cohort study of patients with chronic subdural hematoma treated at a single level 1 trauma center between January 2021 and March 2024. Patients were categorized by initial intervention (SEPS, MMA, or combined SEPS and MMA). Outcomes included treatment failure, radiographic worsening ≤6 months, clinical improvement, length of stay, and discharge disposition. Subgroup analyses were stratified by hematoma thickness (<20 vs ≥ 20 mm) and by anticoagulant (AC)/antiplatelet (AP) use, including timing of resumption. RESULTS: Among 220 patients (SEPS 149, MMA 31, combined 40), the median hematoma size was 20 mm and differed by treatment (SEPS 21 mm, MMA 16 mm, combined 17.5 mm; P < .001). Treatment failure occurred in 23.6% overall (SEPS 26.8%, MMA 16.1%, combined 17.5%; P = .09). The Kaplan-Meier test suggested greater durability for MMA and combined therapy (log-rank P = .088). Among smaller hematomas (<20 mm), MMA had the lowest observed failure rates, while outcomes converged for larger hematomas (≥20 mm). In the AC/AP subgroup (N = 104), MMA-based strategies trended toward lower failure rates and were associated with earlier and more frequent AC/AP resumption compared with SEPS. CONCLUSION: MMA embolization, whether performed alone or with SEPS, was associated with favorable durability and facilitated earlier AC/AP resumption. MMA alone trended toward lower failure rates in smaller collections, while combining SEPS with MMA achieved comparably durable outcomes in larger or more complex cases. Prospective, size-stratified trials are warranted to validate these findings.