Discussion

Introduction: Materials for embolization have also evolved over time, and now generally consist of solid (particles/coils) or liquid agents. Nevertheless, the comparative effectiveness of solid versus liquid embolic agents in MMA embolization for CSDH is poorly reported.

Data analysis was performed using MedCalc®. Depending on the type of outcome measure, the effect size was estimated using both odds ratio and continuous meta-analysis. Both random and fixed effect models were assessed. The significance was set at a P-value < 0.05.

Methods: This is a PRISMA-compliant study. Variable combinations of keywords and MESH terms were used to query PubMed, MEDLINE Plus, COCHRANE, EMBASE, and CINAHL databases for human studies published through June 2023.
Article screening was performed using COVIDENCE software. Studies were included if they reported a head-to-head comparison between the particles (and or coils) versus liquid embolic materials for MMA embolization for CSDH. Technical, radiological, and/or clinical outcomes were accepted as study end-points.

Results: The combined database search yielded 32 articles, of which 14 qualified for full-text review, and three were included in the final analysis. 220 procedures were performed with particles/coils and 102 with liquid embolic agents. Solid particles were associated with a decreased risk of recurrence (OR 0.074; 95% confidence interval (CI): 0.00921 to 0.586; P = 0 014). Particles were also associated with significantly higher size reduction standardized mean difference (SMD) 0.399; SE 0.176; 95% CI 0.0517 to 0.747; P = 0.025. Study heterogeneity Egger’s test and publication bias (I2) were insignificant.
Conclusion

Conclusion : This study illustrates the paucity and inconsistency of the literature on the effects of materials used in MMA embolization for CSDHs. Solid materials appear to have a significant positive effect on outcomes, but the magnitude of this effect has not yet been confirmed.