Postoperative pulmonary complications after surgery for spinal metastases from lung cancer: a six-center risk...

Early identification of postoperative pulmonary complications (PPC) is crucial in patients undergoing surgery for spinal metastases. Patients with lung cancer-derived spinal metastases (LC-SM) appear to be particularly vulnerable to PPC. However, the incidence, risk factors, and prognostic significance of PPC in this population remain poorly defined, and commonly used PPC risk scores have not been adequately validated in this setting.

This study aimed to: (1) characterize the incidence of PPC in patients with LC-SM after surgery and determine its association with early postoperative mortality; (2) identify risk factors for PPC in this population, explore the value of a series of inflammatory and nutritional indices, and develop a multivariable model; and (3) externally validate three established PPC risk scores (the ARISCAT score, the Arozullah Postoperative Pneumonia Risk Index, and the Arozullah Respiratory Failure Risk Index) and assess their clinical utility.

Retrospective multicenter cohort study.

A total of 419 patients with spinal metastases from lung cancer who underwent open spinal surgery at six tertiary centers between January 2018 and March 2025 were included.

Outcome measures included the occurrence of PPC within 14 days after surgery and postoperative survival time.

The association between PPC and early postoperative mortality was assessed, and overall survival was analyzed using Kaplan-Meier methods. Multivariable logistic regression with minimum Akaike information criterion was performed to identify perioperative factors associated with PPC. Discrimination (receiver operating curve), calibration (calibration plot, intercept, and slope), the overall performance (Brier score), and decision curve analysis were used to assess the overall performance of the final multivariable model and three conventional PPC risk scores.

PPC occurred in 50 of 419 patients (11.9%) and was associated with worse survival (median overall survival, 4.43 vs. 14.39 months, p<.01), as well as higher 30-day (26.0% vs. 2.4%) and 90-day (42.0% vs. 11.1%) mortality. Independent risk factors for PPC were longer ventilation time (OR 1.16, 95% CI 1.09-1.24), blood transfusion (OR 1.12, 95% CI 1.02-1.23), liver metastasis (OR 2.64, 95% CI 1.26-5.54), prior systemic chemotherapy and/or thoracic radiotherapy (OR 2.52, 95% CI 1.26-5.05), pre-existing pulmonary abnormalities (OR 2.07, 95% CI 1.01-4.24), and male sex (OR 2.26, 95% CI 1.03-4.93). The final model showed good discrimination and precision-recall performance (area under the curve [AUC] 0.825; 5-fold cross-validated AUC 0.803; bootstrap-corrected AUC 0.781; area under the precision-recall curve [PR-AUC] 0.533), with good calibration and clinical net benefit. Conventional PPC risk scores showed limited predictive value (ARISCAT: AUC 0.659, PR-AUC 0.234; Arozullah pneumonia: AUC 0.541, PR-AUC 0.140; Arozullah respiratory failure: AUC 0.643, PR-AUC 0.063).

Patients with LC-SM represent a distinct high-risk population for PPC after spinal surgery, which is associated with early postoperative mortality. Conventional PPC risk scores and inflammation and nutrition indices showed limited applicability in this setting. Longer ventilation time, blood transfusion, liver metastasis, prior systemic chemotherapy and/or thoracic radiotherapy, pre-existing pulmonary abnormalities, and male sex were identified as independent risk factors for PPC. These findings suggest that spine surgeons should pay attention to perioperative pulmonary vulnerability in this population, especially when evaluating surgical indications, interpreting preoperative chest CT findings, and planning perioperative respiratory management.