Survival of patients undergoing surgery for metastatic spinal tumours and the impact of surgical site 2 infection

Summary
Background
Patients with metastatic spinal tumours have a limited prognosis. Surgical complications that may result in prolonged hospitalization or readmission are highly undesirable. Surgical site infection (SSI) is one such complication, which can, in extreme cases, lead to death.

Aim
To assess the impact of SSI on patient survival after surgery for spinal metastases.

Methods
Demographic, operative, and survival data were collected on 152 patients undergoing surgery for spinal metastasis at a large UK tertiary referral centre. American Society of Anesthesiologists (ASA) grade and the Revised Tokuhashi Score (RTS) were determined as measures of health status and prognosis, respectively, at baseline. A semi-parametric Cox proportional hazards survival analysis was used to assess the relationships between covariates and survival.

Findings
Seventeen patients (11.2%) experienced SSI. Overall, median survival time from operation was 262 days (95% confidence interval: 190–334 days) and 12-month survival was 42.1%. RTS (hazard ratio: 0.82; 95% confidence interval: 0.76–0.89; P < 0.001) and ASA grade (1.37; 1.03–1.82; P = 0.028) were significantly associated with survival, with better survival found in patients with higher RTS and lower ASA scores. Infection status was of substantive importance, with better survival in those without SSI (P = 0.075).

Conclusion
Twelve-month survival in patients undergoing surgery for spinal metastasis is ∼42%. RTS and ASA scores may be used as indicators of patient survival either in combination or individually. Whereas SSI has some negative impact on survival, a larger study sample would be needed to confirm whether this is statistically significant