Sarcopenia as a Prognostic Factor for 90-Day and Overall Mortality in Patients Undergoing Spine Surgery for Metastatic Tumors: A Multicenter Retrospective Cohort Study.

BACKGROUND: Novel methods in predicting survival in patients with spinal metastases may help guide clinical decision-making and stratify treatments regarding surgery vs palliative care. OBJECTIVE: To evaluate whether the frailty/sarcopenia paradigm is predictive of survival and morbidity in patients undergoing surgery for spinal metastasis. METHODS: A total of 271 patients from 4 tertiary care centers who had undergone surgery for spinal metastasis were identified. Frailty/sarcopenia was defined by psoas muscle size. Survival hazard ratios were calculated using multivariate analysis, with variables from demographic, functional, oncological, and surgical factors. Secondary outcomes included improvement of neurological function and postoperative morbidity. RESULTS: Patients in the smallest psoas tertile had shorter overall survival compared to the middle and largest tertile. Psoas size (PS) predicted overall mortality more strongly than Tokuhashi score, Tomita score, and Karnofsky Performance Status (KPS). PS predicted 90-d mortality more strongly than Tokuhashi score, Tomita score, and KPS. Patients with a larger PS were more likely to have an improvement in deficit compared to the middle tertile. PS was not predictive of 30-d morbidity. CONCLUSION: In patients undergoing surgery for spine metastases, PS as a surrogate for frailty/sarcopenia predicts 90-d and overall mortality, independent of demographic, functional, oncological, and surgical characteristics. The frailty/sarcopenia paradigm is a stronger predictor of survival at these time points than other standards. PS can be used in clinical decision-making to select which patients with metastatic spine tumors are appropriate surgical candidates.

Analysis of Outcomes Between Traditional Open versus Mini-Open Approach in Surgical Treatment of Spinal Metastasis.

OBJECTIVE: The treatment of spinal metastasis carries significant surgical morbidity, and decompression and stabilization are often necessary. Less invasive techniques may reduce risks and postoperative pain. This study describes the differences between a mini-open (MO) procedure and a traditional open surgery (OS) for symptomatic spinal metastasis, and reports differences in outcome for similar patients undergoing each procedure. METHODS: We describe a MO technique and retrospective analysis of 20 OS patients who were matched to 20 MO patients by histology, spinal region, and levels instrumented. MO surgery combined a traditional midline exposure for tumor resection with transfascial pedicle screw fixation. Outcome measures included estimated blood loss (EBL), operative time (OT), length of stay (LOS), transfusion rate, complication rate, ASIA Impairment Scale motor score (AMS), and pain scores. Statistical analysis used unpaired t tests and Fisher exact test. RESULTS: Average age of the patients was 58.3 years. Forty-eight percent of patients were women. Average number of levels treated was 5.9. Both groups had similar LOS (P = 0.98), OT (P = 0.30), perioperative complication rates (P = 0.51), transfusion rates (P = 0.33), and AMS (P = 0.17). EBL was found to be significantly lower in the MO group than the open group (805 ± 138 mL vs. 1732 ± 359 mL, respectively; P = 0.019). The MO group had a significant reduction in postoperative pain (-1.71 ± 0.5 vs. 0.33 ± 0.7, P = 0.018). CONCLUSIONS: Although further studies are needed, the MO approach appears to result in decreased blood loss and postoperative pain, without compromising neural element decompression or spinal stability. These findings are consistent with the use of muscle sparing, minimally invasive pedicle screw fixation.