Preoperative hypoalbuminemia predicts early complications, mortality, and discharge disposition following surgical resection of spinal metastases: a nationwide study.

PURPOSE: Patients undergoing surgery for spinal metastases often have limited physiologic reserve. Although hypoalbuminemia is a recognized risk marker, its graded association with short-term postoperative outcomes and discharge disposition has not been well defined in large national cohorts. We evaluated the relationship between preoperative serum albumin and early postoperative outcomes following surgery for spinal metastases. METHODS: Adults undergoing surgery for metastatic extradural spinal tumors (laminectomy or tumor excision with or without fusion) were identified in ACS-NSQIP (2010-2022). Hypoalbuminemia was defined as albumin < 3.5 g/dL and stratified as mild (3.0-3.49), moderate (2.5-2.99), or severe (< 2.5). Primary outcomes were any 30-day complication, 30-day mortality, and non-home discharge. Multivariable logistic regression adjusted for demographic, clinical, and operative factors. Exploratory machine-learning models assessed discrimination and variable importance. RESULTS: Among 4,126 patients, 1,534 (37.2%) were hypoalbuminemic. Hypoalbuminemia was associated with higher rates of complications, mortality, non-home discharge, and longer hospitalization (all p < 0.001), with outcomes worsening stepwise across albumin strata. After adjustment, hypoalbuminemia independently predicted complications (OR 1.52), mortality (OR 2.73), and non-home discharge (OR 1.89) (all p < 0.001). Albumin ranked among the most influential predictors in machine-learning models. CONCLUSION: Preoperative hypoalbuminemia shows a dose-dependent, independent association with early morbidity, mortality, and post-acute care needs after surgery for spinal metastases, supporting its use in perioperative risk stratification and care planning.