Preoperative middle meningeal artery embolization is associated with reduced reoperation rates in chronic subdural hematoma

Background: Middle meningeal artery embolization (MMAE) has recently emerged as a promising adjunctive therapy to surgical evacuation for patients with chronic subdural hematoma (cSDH). However, the optimal timing of MMAE relative to surgery remains poorly defined. Therefore, this large retrospective cohort study aimed to assess the impact of MMAE timing (preoperative vs. postoperative) on 6-month outcomes in patients with cSDH, focusing on rates of repeat surgery and mortality. We hypothesized that preoperative MMAE would be associated with lower rates of reoperation compared to postoperative MMAE. Methods: Adult patients with nontraumatic cSDH who underwent surgery with adjunctive MMAE were identified using ICD-10 codes from the TriNetX database. A 1:1 propensity score matching approach was used to balance baseline characteristics between groups. The primary outcomes were repeat surgery and all-cause mortality within 6 months. Results: A total of 338 matched patients (n = 338; 169 in each group) were included in the final analysis. Preoperative MMAE was associated with significantly lower odds of repeat surgery compared to postoperative MMAE (7.1% vs. 17.8%; OR 0.35, p = 0.003). No significant difference was observed in 6-month all-cause mortality between the groups. Conclusion: Preoperative MMAE is associated with reduced odds of repeat surgery compared to postoperative MMAE at 6 months. These findings support consideration of MMAE timing in surgical planning. Further prospective studies are warranted to validate these results.