Safety and Efficacy of Onyx Embolization in Spinal Tumor Procedures: A Systematic Review and Meta-Analysis

Introduction: Onyx embolization has emerged as a promising technique for spinal tumor embolization due to its high devascularization rate and low incidence of complications. Nevertheless, there is currently a lack of comprehensive, well-established evidence to systematically evaluate its outcomes. Our objective is evaluate the safety and efficacy of Onyx embolization in spinal tumor procedures.

Methods: Following the PRISMA guidelines, we conducted a systematic review and meta-analysis. To be included, the articles had to report specific outcomes of Onyx embolization for spinal tumors (complications, mortality, blood loss, tumor devascularization, or reduction in tumor blush).

Results: We selected 11 out of 2941 articles, encompassing 127 patients. Among them, no major complications or persistent neurological deficits were reported, and no deaths occurred as a result of the embolization procedure. Of the 63 patients with available data, two complications were observed: one infarct leading to transient neurologic deficit and one clinically silent vessel perforation related to the microcatheter. Thus, the complication rate was 1% (95% CI: 0% - 6%). Blood loss during surgery ranged from 100-1500 mL (4 studies). Complete tumor blush reduction was achieved in 52% of the cases (95% CI: 16% - 88%) across 32 patients. Three studies reported a median percentage of tumor devascularization of 91% (86.1%-97.5%).

Conclusion : Onyx embolization for spinal tumor procedures appears to be a safe technique, as evidenced by the absence of major complications or deaths. However, the determination of its efficacy remains challenging due to limited data availability and substantial heterogeneity across studies. These findings highlight the need for future research to address this knowledge gap and further validate our results.