Management of Chronic Subdural Hematoma in Thrombocytopenia: Middle Meningeal Artery Embolization - Based Strategies Versus Medical Management or Surgery Alone

BACKGROUND: Thrombocytopenia complicates management of chronic subdural hematoma (cSDH), but no study has compared middle meningeal artery embolization (MMAE) with surgery or medical management in this population. We evaluated MMAE-containing strategies versus medical management or surgery alone in cSDH with platelets below 100×103/µL. METHODS: Using the TriNetX Research Network, we identified adults with cSDH and platelets below 100×103/µL (or below 50×103/µL for the severe-thrombocytopenia analysis). We performed three propensity-score-matched comparisons: standalone MMAE versus medical management and surgery plus MMAE versus surgery alone at platelets <100×103/µL; and standalone MMAE versus medical management at platelets <50×103/µL. The primary outcome was 90-day all-cause mortality; the secondary outcome was surgical evacuation (a composite of surgical evacuation or mortality at platelets <50×103/µL). RESULTS: After matching, cohorts ranged from 147 to 373 patients per group (standardized mean differences below 0.10 for nearly all covariates). At platelets <100×103/µL, standalone MMAE was associated with lower mortality than medical management (26.9% vs 37.3% hazard ratio 0.65 [95% CI 0.50-0.85]), and surgery plus MMAE was associated with lower mortality than surgery alone (20.5% vs 30.7%; hazard ratio 0.61 [95% CI 0.38-0.97]). At platelets <50×103/µL, the mortality comparison between standalone MMAE and medical management did not reach significance (34.2% vs 44.0%; hazard ratio 0.72 [95% CI 0.49-1.05]). Subsequent surgical evacuation did not differ significantly in any comparison. CONCLUSIONS: For patients with cSDH and thrombocytopenia, management strategies incorporating MMAE were associated with lower 90-day mortality than medical management or surgery alone. Prospective confirmation is needed, including in severe thrombocytopenia, where the mortality comparison did not reach significance.