The Impact of Preoperative Embolization on the Outcomes of Surgical Resection of Spinal Metastatic Tumors: A Systematic Review and Meta-analysis

Introduction: The vertebral column is the most common site of bony metastasis. When indicated, surgical resection of hypervascular metastatic lesions may be complicated by significant blood loss, the need for blood transfusion, and incomplete tumor resection due to poor visualization and premature abortion of the operation. In select cases, preoperative arterial embolization of hypervascular metastatic tumors may help minimize intraoperative bleeding and reduce operative times.  This systematic review and meta-analysis aims to evaluate the effectiveness of preoperative arterial embolization of metastatic tumors to the spine.

Methods: PubMed was searched from January 1, 1966, and May 22, 2023. The articles addressing preoperative embolization of metastatic spinal tumors were retained for full-text review.

Results: Of the 1,674 articles generated by the search, 69 were selected for full-text review. Following a full-text review, 29 articles met inclusion criteria, including one randomized controlled trial and 28 retrospective studies. Our review demonstrated Level III evidence that preoperative selective arterial embolization may help reduce operative blood loss by a mean of -284.37 mL (95% CI 462.43−276. 21, p=0.002) and improve survival by 1.20 months (95% CI 1.14−1.26, p< 0.001) in patients with spinal metastatic tumors. However, the trend toward lower estimated blood loss in the embolized group is mainly driven by studies conducted before 2012. The pooled analysis shows that preoperative embolization did not impact operative time and the need for transfusion.

Conclusion : Preoperative arterial embolization of metastatic tumors to the spine is relatively effective in reducing blood loss and improving patient survival. No effect was observed for preoperative embolization on operative time or the need for transfusion.