Added Value of Adjunctive Middle Meningeal Embolization to Surgical Evacuation for Chronic Subdural Hematoma: Comprehensive Meta-Analysis Based on Controlling Confounders.

BACKGROUND AND OBJECTIVES

Chronic subdural hematoma (CSDH) often recurs after surgical evacuation, with rates ranging from 2% to 37%. Middle meningeal artery embolization (MMAE) has emerged as a potential adjunct to surgery to reduce recurrence. The aim of this study was to systematically review the added value of adjunctive MMAE to surgical treatment (MMAE+S) compared with surgical treatment alone (S) in managing CSDH with consideration to matching and randomization status of the 2 groups.

METHODS

A systematic search identified 16 studies encompassing 1814 patients (939 MMAE+S, 1440 S). Five studies were randomized trials, 3 studies were matched studies, and the remaining were unmatched cohorts. Data on recurrence, radiological and functional outcomes, complications, and hospital stay were analyzed using a random-effects meta-analysis. The risk of bias was evaluated using Risk of Bias in Nonrandomized Studies of Interventions and Risk of Bias in Randomized Trials tools.

RESULTS

The 2 treatment groups were comparable regarding all preoperative characteristics except for antithrombotic use which was higher in the MMAE+S group (P = .03). Compared with surgery alone, the MMAE+S group had significantly lower recurrence rates (4.7% vs 17.7%, relative risk [RR] 0.31, P < .01) and reduced postoperative hematoma thickness (standardized mean difference [SMD] -0.17, P = .04), volume (SMD -0.25, P = .01), and midline shift (SMD -0.24, P = .01). Reduced recurrence was also observed in the subgroup of matched/randomized studies (RR 0.28, P < .01) and only randomized studies (RR 0.28, P < .01). Complication rates were comparable between the 2 groups when analyzing all (RR 0.90, P = .46), matched/randomized (RR 1.05, P = .62), and only randomized studies (RR 1.05, P = .63). The outcomes were influenced by the choice of embolic agent and timing of embolization, with liquid agents, and postoperative embolization showing slightly better outcomes compared with other embolization approaches. Functional outcomes, complications, mortality, and length of hospital stay were comparable between groups.

CONCLUSION

MMAE combined with surgery effectively reduces CSDH recurrence and improves radiological outcomes without increasing complications. These findings support MMAE as a valuable adjunct to surgical treatment, warranting further research to optimize its clinical application.