Spinal metastases: perioperative and oncological outcomes after separation surgery versus expanded anterior column resection: a retrospective cohort study.

PURPOSE: To compare perioperative outcomes and assess associations of surgical approach with overall survival (OS) and composite local recurrence after separation surgery (SS) versus expanded anterior column resection (EACR) for spinal metastases. METHODS: This single-center retrospective cohort included 167 patients treated from August 2018 to August 2021 (SS, n = 50; EACR, n = 117). Follow-up ended at death, last contact, or December 31, 2024. OS was modeled using multivariable Cox regression and propensity-score overlap weighting. Composite local recurrence (radiographic regrowth or recurrent level-specific neurological symptoms) was modeled using Fine-Gray regression with death as a competing event. RESULTS: Compared with SS, EACR was associated with greater blood loss (1388.9 vs 1055.0 mL; P = 0.006), longer operative time (296.5 vs 255.3 min; P < 0.001), and greater 48-hour drainage (297.9 vs 228.0 mL; EACR, n = 116; P = 0.008). Median OS was 17 months after EACR and 13 months after SS (log-rank P = 0.326). For SS versus EACR, the adjusted mortality hazard ratio was 1.16 (95% confidence interval [CI] 0.76-1.76), and the overlap-weighted estimate was 1.12 (95% CI 0.55-2.26). The adjusted subdistribution hazard ratio for composite local recurrence was 0.74 (bootstrap 95% CI 0.33-1.51). CONCLUSIONS: SS was associated with a lower perioperative burden, with no significant differences in adjusted OS or composite local recurrence compared with EACR. More extensive tumor resection may not necessarily provide additional benefit and should be weighed against the increased surgical burden.