Volumetric resolution of chronic subdural hematomas treated with surgical evacuation versus middle meningeal artery embolization during immediate, early, and late follow up: propensity-score matched cohorts.

Background: Literature on volumetric resolution and recurrence over time between surgical evacuation alone (SEA) and standalone middle meningeal artery embolization (MMAE) in comparable chronic subdural hematoma (cSDH) patients is limited.

Methods: A retrospective database analysis of cSDH patients managed with either SEA or MMAE was conducted. Propensity-score matching was performed for axial and coronal lengths, maximum diameter, and midline shift. Volumetric measurements at multiple time intervals and recurrence were compared between the groups.

Results: 48 matched hematoma pairs in patients with similar demographics, comorbidities, medications, and symptoms were obtained. Median volume was significantly lower at 24 hours in the SEA group (12.6 mL vs 52.7 mL, p<0.001) but not at remaining intervals. Median volume reduction was significantly greater in the SEA group at 24 hours (39.1 mL vs 8.8 mL in the MMAE group, p<0.001) and at 3-12 weeks (50.8 mL vs 23.7 mL, p<0.001), but not at remaining intervals. The SEA group had a significantly greater median hematoma resolution rate at 24 hours (39.1 mL/day vs 8.8 mL/day, p<0.001) and 3-12 weeks (1 mL/day vs 0.4 mL/day, p<0.001), but not at remaining intervals. Near-complete resolution at 3-12 weeks and 12-60 weeks was not significantly different between groups. Overall, the recurrence rate was significantly higher in the SEA group (22.9% vs 4.2%, p=0.01).

Conclusions: In comparable cSDH patients, SEA resulted in better volumetric outcomes in immediate postoperative and early follow-up periods, as expected. However, this difference was not significant at more distant follow-up intervals. Furthermore, surgical patients experienced a significantly higher rate of recurrence.