Optimizing Surgical Strategies: A Systematic Review of the Effectiveness of Preoperative Arterial Embolization for Hypervascular Metastatic Spinal Tumors.

Background: 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.

Objective: Our aim was to evaluate the effectiveness of preoperative arterial embolization of metastatic tumors to the spine.

Study Design: A systematic review of the literature with a subsequent metaanalysis of the collected data was conducted to achieve this aim.

Methods: PubMed and MEDLINE were searched since inception until May 22, 2023. The primary outcome of this study was Estimated Blood Loss (EBL), while secondary outcomes included number of patients requiring blood transfusions, duration of operation, and survival.

Results: Twenty-nine studies were included, yielding 14,199 patients, from which 1,134 underwent surgery with adjunctive embolization. Our review demonstrated that preoperative arterial embolization in patients with spinal metastatic tumors can help reduce EBL 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) compared to those without embolization. Upon running subgroup analyses, the reduction in EBL appeared to be mainly driven by the embolization of hypervascular tumors, while that of non-hypervascular ones appeared to have no significant impact. The pooled analysis shows that preoperative embolization did not impact operative time and the need for transfusion.

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