Neurological Complications of Preoperative Embolization of Spinal Metastasis: A Systemic Review of the Literature Identifying Distinct Mechanisms of Injury.

Abstract Background Preoperative embolization of spinal metastases may improve outcome of resection by reducing surgical blood loss and operative time. Neurological complications are rarely reported and the mechanisms leading to injury are poorly described. Methods We present two illustrative cases of embolization-related neurological injury from distinct mechanisms and the findings of a systemic literature review according to the Preferred Reporting Items for Systemic Reviews and Meta-Analysis of similar complications. Results A 77-year-old with a history of renal cell carcinoma (RCC) presented with gait dyscoordination and arm pain/weakness. MRI revealed a C7/T1 mass causing severe compression of the C7/T1 roots and spinal cord. Following embolization and tumor resection/fusion, lethargy prompted imaging showing multiple posterior circulation infarcts thought secondary to reflux of embolic particles. A 75-year-old male with RCC presented with L1 level metastasis causing conus compression and suffered paraplegia following superselective particle embolization presumed secondary to flow disruption of the artery of Adamkiewicz. Review Analysis of the literature yielded instances of cranial infarction/ischemia occurring in ten patients within six articles, spinal cord ischemia/infarction occurring in seventeen patients in twelve papers, and symptomatic post-embolization tumoral swelling in five patients within five papers. Conclusions Neurological injury is a risk of preoperative embolization of spinal metastasis from either compromise of spinal cord vascular supply or cranial stroke from reflux of embolic particles. Post-procedural tumor swelling rarely leads to clinical deficit. Awareness of these complications and the presumed mechanisms of injury may aid clinicians in implementing interventions and in counseling patients prior to treatment.