Introduction: The goal of this study is to evaluate thirty-day outcomes after craniotomy for metastatic tumor, and to build a predictive scale that may be an adjunct when risk-stratifying patients preoperatively.
Methods: Patients who underwent craniotomy for an intracranial metastasis were extracted from the prospective National Surgical Quality Improvement Program registry (NSQIP, 2011-2013). Multivariable logistic regression evaluated predictors of developing an adverse event (death, a major neurologic or medical complication, reoperation, or nonroutine discharge) within thirty days; predictors screened included patient demographics, comorbidities, American Society of Anesthesiologists (ASA) classification, functional status, comorbidities, preoperative laboratory values, and case urgency. Independent predictors were utilized to build a predictive scale, which was validated using the 2014 NSQIP release.
Results: Among the 1,853 patients in the study population, the thirty-day mortality rate was 6.2%, a major complication occurred in 15.2% and a nonroutine hospital discharge in 21.6% of patients. The NSQIP intracranial metastasis scale was constructed: one point was assigned for ASA class 3 designation, insulin-dependent diabetes mellitus, emergent surgery, age 56-65 years, and mild anemia (hematocrit 30-40%); two points for dependent functional status, severe anemia (hematocrit < 30%), and preoperative intubation; and three points for ASA class 4-5 designation and age greater than 65 years. In the validation population, increased score was associated with higher odds of an adverse event (OR=1.31, 95% CI=1.21-1.42, p<0.001, C-statistic=0.63); greater score was also associated with increased odds of thirty-day mortality, any complication, a major medical complication, and nonroutine hospital discharge (all p<0.001, C-statistic=0.60-0.65).
Conclusions: The NSQIP intracranial metastasis scale identifies preoperative clinical variables that impact the thirty-day postoperative outcomes, and may be an adjunct when risk-stratifying patients preoperatively. Future studies combining these surgical predictors with oncologic variables may augment decision analysis regarding treatment of intracranial metastases.
Patient Care: This NSQIP analysis identifies predictors of adverse events among patients undergoing craniotomy for intracranial metastases. Additionally, the predictive scale may be used to risk-stratify patients preoperatively, as well as provide a platform for future predictive analytics.
Learning Objectives: By the conclusion of the session, participants should be able to 1) identify the thirty-day cumulative incidence of mortality, complications, and adverse events after craniotomy for intracranial metastases; 2) describe the predictors of adverse events included in the NSQIP intracranial metastases scale; and 3) discuss the utility and limitations to the use of the scale for preoperative risk-stratification.