Predictive factors of the 30-day mortality after surgery for spinal metastasis: Analysis of a nationwide database.

Background: Surgical procedure for symptomatic spinal metastasis is expected to improve the quality of life. Factors related to short-term perioperative mortality after surgery for spinal metastasis may be different from those related to long-term mortality, which have classically been used to determine the indication for surgery. The purposes of this study were to evaluate factors related to the 30-day mortality after surgery for spinal metastasis and create an integer risk scoring system.

Methods: Using the Diagnosis Procedure Combination database from 2010 to 2016, we extracted data of patients who underwent surgical procedure for spinal metastasis. Multivariable logistic regression analysis was performed to clarify the association between patient backgrounds and the 30-day postoperative mortality. We created a risk scoring system using regression coefficients to estimate the 30-day mortality for each patient.

Results: Among 3524 patients, the 30-day mortality was 2.6%. Factors associated with a higher 30-day mortality were male sex (odds ratio, 2.50 [95% confidence interval, 1.45-4.31]), emergency admission (1.80 [1.11-2.92]), rapid growth tumors (3.83 [2.49-5.90]), and non-skeletal metastasis (2.27 [1.42-3.64]). In patients with the maximum risk score of five, the 30-day mortality was 16.2%.

Conclusions: Factors related to the 30-day mortality were male sex, emergency admission, rapid growth tumors, and non-skeletal metastasis. These findings provide spine surgeons and patients knowledge of the potential risk of short-term perioperative mortality and allow them to consider the risk of surgery.