Survival after surgery for spinal metastatic disease: a nationwide multiregistry cohort study

OBJECTIVES: To evaluate survival after surgery and indications for surgery due to spinal metastatic disease. DESIGN: A retrospective longitudinal multiregistry nationwide cohort study. SETTING: 19 public hospitals in Sweden with spine surgery service, where 6 university hospitals account for over 90% of the cases. PARTICIPANTS: 1820 patients 18 years or older undergoing surgery due to spinal metastatic disease 2006–2018 and registered in Swespine, the Swedish national spine surgery registry. INTERVENTIONS: Decompressive and/or stabilising spine surgery due to spinal metastatic disease. PRIMARY OUTCOME: Survival (median and mean) after surgery. SECONDARY OUTCOMES: Indications for surgery, types of surgery and causes of death. RESULTS: The median estimated survival after surgery was 6.2 months (95% CI: 5.6 to 6.8) and the mean estimated survival time was 12.2 months (95% CI: 11.4 to 13.1). Neurologic deficit was the most common indication for surgery and posterior stabilisation was performed in 70.5% of the cases. A neoplasm was stated as the main cause of death for 97% of the patients. CONCLUSION: Both median and mean survival times were well above the generally accepted thresholds for surgical treatment for spinal metastases, suggesting that patient selection for surgical treatment on a national level is adequate. Further research on quality of life after surgery and prognostication is needed.