Preoperative Embolization of Spine Tumors: Are We Actually Improving Survival?

Introduction: While preoperative spine tumor embolization helps to decrease blood loss, less is known regarding how embolization influences recurrence and survival. In patients undergoing metastatic spine surgery, we sought to determine whether preoperative embolization impacted: 1) local recurrence and 2) overall survival.

Methods: A retrospective, cohort study was undertaken of patients undergoing metastatic spine surgery for extradural disease between 2010-21. Inclusion criteria were: intermediate/radioresistant tumors with spinal cord compression undergoing surgery. The primary exposure variable was preoperative embolization. The primary outcome variables were local recurrence, time to local recurrence, and overall survival. Multivariable Cox regression, controlling for age, total decompressed levels, other organ metastasis, and postoperative radiotherapy/chemotherapy was performed.

Results: Of 349 patients undergoing spine surgery for metastatic disease, 32 (9.2%) underwent preoperative embolization. With a median follow-up of 303 (IQR:109.5-694.5) days after surgery, 42 (12.0%) patients experienced LR and 231 (68.5%) died. Median time to local recurrence and death was 106 (IQR=39-232.5) and 170 (IQR=67-517) days, respectively. Most patients who underwent tumor embolization had renal cell cancer (71.9% vs. 7.9%, p< 0.001) and a lower KPS (70.3 vs 65, p=0.045) preoperatively. Postoperatively, those undergoing preoperative embolization were more likely to require ICU care (75% vs 43.5%, p< 0.001) and receive chemotherapy (56.3% vs.37.5%, p=0.039). No difference was seen in local recurrence between the two groups (15.6% vs 11.7% p=0.566); however, preoperative embolization significantly increased the median time to local recurrence (309 vs. 97.5 days, p=0.005). Patients with tumor embolization had improved 1-year survival (78.1% vs 54.6%,p=0.010) and a longer time to death (784.8 vs 419.2 days p=0.008). Multivariable Cox regression showed that preoperative embolization had decreased risk of death at 1-year (HR=0.30, 95%CI=0.14-0.64, p=0.002) but no significant association with overall survival (HR=0.66, 95%CI=0.43-1.01, p=0.053). Among renal cell cancer patients, preoperative embolization did not influence recurrence or survival (p>0.05).

Conclusion : In patients undergoing surgery for metastatic spinal disease, spine tumor embolization may potentially improve time to local recurrence and 1-year survival. More research is needed to elucidate the mechanism behind these associations.