Mapping the evidence on endovascular management of chronic subdural hematomas: A scoping review

Objective: To systematically map the currently available evidence from clinical trials on middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH) and propose potential management pathways for patient selection. This is critical given that cSDH represents a growing neurosurgical challenge, and surgical drainage (burr-hole craniostomy or craniotomy) remains the current gold standard treatment. Methods: A scoping review was conducted following the PRISMA-ScR protocol to map emerging trials and systematically identify critical knowledge gaps. The search covered international public clinical trial registries using specific terms like "chronic," "subdural hematoma," and "embolization." A rigorous selection process was used for active clinical trials comparing the minimally invasive MMAE option with the conventional surgical approach. Results: The initial search yielded 27 active clinical trials. Only 4 (14.8%) are currently completed, with 13 (48.1%) in the recruitment phase. The remaining 37% are classified as active, withdrawn, or of unknown status. Only three active studies (EMBOLISE, MAGIC-MT, and STEM) have published relevant partial results. To date, no high-level evidence has demonstrated that MMAE is superior to conventional surgery. Conclusions: Based on the synthesis of available trial data, a potential management algorithm is proposed for the endovascular treatment of cSDH. MMAE has emerged as a promising option for reducing recurrence, but it has not yet supplanted surgery as the standard of care. Knowledge gaps persist regarding optimal timing, the utility of adjunct therapies, and long-term outcomes, but this algorithm establishes a foundation for future high-quality studies.