The Efficacy and Complications of Preoperative Embolization of Metastatic Spinal Tumors: Risk of Paralysis after Embolization

INTRODUCTION: This study investigated the efficacy and complications of preoperative embolization for spinal metastatic tumors, focusing on the etiology of post-embolization paralysis. METHODS: We retrospectively reviewed the data of 44 consecutive patients with spinal metastases treated between September 2012 and December 2020. Intraoperative blood loss and postoperative transfusion requirement were compared between the embolization (+) and (−) groups. Complications associated with embolization were reviewed. RESULTS: Overall, 30 patients (68%) underwent preoperative embolization. All the patients in both groups underwent palliative posterior decompression and fusion. The mean intraoperative blood loss in the overall population was 359 ml (range, minimum-2190 ml) and was 401 ml and 267 ml in the embolization (+) and embolization (−) groups, respectively. Four patients (9%) (2 patients from each group) required blood transfusion. There were no significant between-group differences in blood loss and blood transfusion requirements. All 7 patients with hypervascular tumors were in the embolization (+) group. Two patients experienced muscle weakness in the lower extremities on days 1 and 3 after embolization. There were metastases in T5 and T1-2, and magnetic resonance imaging after embolization showed slight exacerbation of spinal cord compression. The patients showed partial recovery after surgery. CONCLUSIONS: With the predominance of hypervascular tumors in the embolization (+) group, preoperative embolization may positively affect intraoperative bleeding. Embolization of metastatic spinal tumors may pose a risk of paralysis. Although the cause of paralysis remains unclear, it might be due to the aggravation of spinal cord compression. Considering this risk of paralysis, we advocate performing surgery as soon as possible after embolization.