En Bloc Spondylectomy versus Separation Surgery for Spinal Metastases: A Systematic Review and Meta-analysis

Introduction: Spinal metastases are commonly treated surgically using either en bloc spondylectomy or separation surgery with adjuvant radiotherapy. However, the comparative effectiveness of these approaches remains unclear.

Methods: A systematic review and meta-analysis were conducted, searching PubMed, Embase, Scopus, and Web of Science from inception through January 2024. Studies comparing en bloc spondylectomy to separation surgery for metastatic spinal tumors were included. Primary outcomes were overall survival (OS), progression-free survival (PFS), operative blood loss, and post-operative infection rates.

Results: Thirty-nine studies (2,967 patients) met inclusion criteria. En bloc spondylectomy (n=642) was associated with significantly higher intraoperative blood loss compared to separation surgery (n=2,325) (1595.5 ± 574.8 ml vs 754.5 ± 228.5 ml, p < 0.001). No significant differences were observed in OS (35.7 ± 21.5 vs 26.5 ± 22.2 months, p=0.307), PFS (22.8 ± 20.2 vs 25.2 ± 28.1 months, p=0.870), or post-operative infection rates (1.05% vs 1.67%, p=0.255) between en bloc and separation surgery, respectively. Good clinical outcomes (Frankel grade D or E) were achieved in 93.2% of en bloc cases and 69.8% of separation surgery cases (p=0.443). Subgroup analyses revealed that kidney metastases had improved PFS with separation surgery (p=0.012), while thyroid and colorectal metastases had higher recurrence risk with en bloc spondylectomy (p=0.039 and p=0.025, respectively). Lumbar spine metastases showed higher recurrence risk with separation surgery (p=0.038).

Conclusion : While en bloc spondylectomy was associated with greater intraoperative blood loss, both techniques demonstrated comparable oncologic and functional outcomes. The choice between these approaches should be individualized based on patient factors, tumor characteristics, and surgical expertise. Further prospective studies are needed to refine patient selection criteria for these procedures in the management of spinal metastases.