One-and-done middle meningeal artery embolization with next-generation optiblock coils: streamlining workflow for chronic subdural hematoma

PURPOSE: Middle meningeal artery (MMA) embolization is an adjunct or alternative to surgery for chronic subdural hematoma (cSDH), but data on coil-forward strategies remain limited. The purpose of this study is to evaluate safety and outcomes after MMA embolization using Optiblock coils engineered for efficient mechanical vessel occlusion. METHODS: Clinical data was extracted for a retrospective cohort of adults treated from February 2023 to December 2024 with ≥ 1 Optiblock coil; adjunctive embolic agent allowed. Symptoms, modified Rankin Scale (mRS), maximal SDH thickness, and midline shift were assessed at serial timepoints. McNemar's test and the Friedman test were used for longitudinal comparisons, with α = 0.05. RESULTS: Thirty-one patients underwent embolization (mean age 74.0; 84% male). Procedures used a mean of 1.28 coils with an average total coil length of 27.2 cm. The most common Optiblock coil used was 3.5 mm x 20 cm. Embospheres (MERIT medical) were used as an adjunct in 87% of cases. Mean SDH thickness decreased from 14.8 mm pre-operatively to 8.9, 4.4, and 2.1 mm at ~ 1, 3, and 6 months post-operation (p < 0.05), corresponding to 40%, 71%, and 86% reductions; midline shift decreased concordantly (p < 0.05). mRS improved from 2.2 at baseline to 0.6 and 0.1 at first and last follow-up, respectively (p < 0.001). No periprocedural complications were noted. Interval surgical drainage was performed in 2 patients (6.5%) after initial isolated MMA embolization. Two delayed deaths occurred, both from known cardiovascular conditions unrelated to embolization. CONCLUSION: Optiblock-based MMA embolization was associated with low complication and reintervention rates and substantial clinical, functional, and radiographic improvement. These coils offer an efficient alternative and/or adjunct to liquid/particle embolization, particularly in cases where particle or liquid embolization is contraindicated or technically unfeasible.