Adjunct Middle Meningeal Artery Embolization Versus Surgery for Chronic Subdural Hematoma: A Systematic Review and Meta-Analysis.

Background: The procedure of middle meningeal artery embolization (MMAE) has emerged as a minimally invasive therapy for chronic subdural hematoma (CSDH). Previous studies comparing MMAE with conventional treatment for CSDH did not differentiate primary/upfront, adjunct, or rescue MMAE, and included both conservative and surgical treatment in the comparison group. We conducted a systematic review and meta-analysis to compare outcomes after adjunct MMAE (MMAE combined with surgical evacuation) versus surgery alone for CSDH.

Methods: PubMed, Embase, Cochrane, Web of Science, and Scopus databases were searched to August 2023. Primary outcomes were treatment failure and reoperation. Secondary outcomes were complications, mortality, length of hospital stay, 30-day readmission, and follow-up modified Rankin Scale (mRS) > 2. Additional data from our institution was included.

Results: 12 published studies and our data yielded 57,165 patients, of whom 1,065 (1.9%) received adjunct MMAE and 56,100 (98.1%) surgery alone. Compared to surgery alone, adjunct MMAE was associated with lower rates of treatment failure (OR = 0.43 [0.23-0.83], p = 0.01), reoperation (OR = 0.45 [0.22-0.90], p = 0.02), and 30-day readmission (OR = 0.50 [0.34-0.73], p < 0.001). Length of hospital stay (MD = 2.49 [-0.51, 5.49], p = 0.10) was non-significantly longer in the adjunct MMAE group. Both groups had comparable rates of treatment-related complications (OR = 0.89 [0.52-1.53], p = 0.67), mortality (OR = 1.05 [0.75-1.46], p = 0.78), and follow-up mRS > 2 (OR = 0.91 [0.39-2.12], p = 0.83).

Conclusions: Adjunct MMAE reduces treatment failure, reoperation, and readmission rates without increasing morbidity and mortality. MMAE may be considered as an adjunct to surgical evacuation to reduce CSDH recurrence. Randomized trials will further establish the evidence for adjunct MMAE and its role in the management of CSDH.