Middle Meningeal Artery Embolization (MMAE) Versus Surgical Evacuation for Recurrent and Refractory Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis

Background: Recurrent and refractory chronic subdural hematoma (cSDH) remains a significant neurosurgical challenge due to high recurrence rates and morbidity associated with repeated surgical interventions. Middle meningeal artery embolization (MMAE) has recently emerged as a minimally invasive alternative, but its efficacy compared to surgical evacuation in this specific subgroup has not been systematically evaluated. Methodology: A systematic search of Pubmed was conducted to identify studies reporting outcomes of MMAE and surgical evacuation in recurrent or refractory cSDH cases. Pooled efficacy rates and complication rates were extracted and analyzed using fixed-effects meta-analysis. Statistical significance was assessed with a p-value threshold of 0.05. Results: Sixteen studies were included in the meta-analysis. 181 patients underwent surgical evacuation while 97 patients underwent MMAE for recurrent and refractory cSDH. MMAE demonstrated significantly higher efficacy with a pooled success rate of 95% versus 84% for surgery (p=0.002, I2=0). Complication rates were lower in the MMAE group (6%) versus the surgical group (10%), though the difference was not statistically significant (p=0.06, I2=0). Conclusions: MMAE shows promise as a highly effective and safe treatment modality for recurrent and refractory cSDH, potentially surpassing surgical evacuation in both efficacy and safety. Given these findings, MMAE should be strongly considered not only as a salvage therapy but also as a frontline treatment option in this challenging patient population. Further high-quality randomized controlled trials are warranted to confirm these results and refine patient selection criteria.