Dana A. Leonard

Modeling 1-year survival after surgery on the metastatic spine.

BACKGROUND CONTEXT Choosing appropriate surgical patients in the setting of spinal metastases can be challenging. Existing scoring systems focus primarily on patient selection or operative techniques. These scores are limited in their capacity to predict postoperative survival. PURPOSE The aim was to model survival after spine surgery for metastastic disease. STUDY DESIGN This was a retrospective multicenter study. PATIENT SAMPLE All patients who had undergone surgery for the treatment of metastatic spinal disease at one of four tertiary care centers between 2007 and 2013 were included. OUTCOME MEASURE The outcome measure was 1-year survival after surgery. METHODS Demographic, medical, oncologic, surgical, and survival data were abstracted from medical records. The effect of predictor variables on survival was evaluated alone and in combination using stepwise logistic regression. Multivariable logistic regression was subsequently used to adjust for confounders. A predictive score was then developed and compared against that of the modified Bauer score alone in terms of prognosticating 1-year survival after surgery. RESULTS In the time period under investigation, 318 patients underwent surgical intervention for metastastic disease involving the spine, with 307 having data available for analysis. The survival rate at 1 year was 48% (n=142), with a median survival of 10 months. In final adjusted analysis, preoperative modified Bauer score (odds ratio [OR] 3.00; 95% confidence interval [CI] 1.80-5.01; p<.001), ambulatory status (OR 2.47; 95% CI 1.48-4.14; p=.001), and serum albumin (OR 2.80; 95% CI 1.66-4.72; p<.001) were all independent predictors of 1-year survival. The most parsimonious model weighted the modified Bauer score with 2 points and intact ambulatory status and normal serum albumin level with 1 point each, with a ceiling score of 3. The final model using the predictive score was able to explain 74% of the variation in 1-year survival. In contrast, the modified Bauer score alone was only able to explain 64% of the variation in 1-year survival. CONCLUSIONS This study demonstrates the importance of including factors related to the overall health of a patient, in addition to parameters surrounding their cancer diagnosis, to better prognosticate survival. Our predictive score performed better than the modified Bauer alone and may be used to predict survival after surgical intervention for metastatic disease. LEVEL OF EVIDENCE III.

Assessing the utility of a clinical prediction score regarding 30-day morbidity and mortality following metastatic spinal surgery: the New England Spinal Metastasis Score (NESMS)

BACKGROUND CONTEXT The New England Spinal Metastasis Score (NESMS) was recently proposed to help predict 1-year survival following surgery for spinal metastases. Its ability to predict short-term outcomes, including 30-day morbidity, mortality, and hospital length of stay, has not been evaluated. PURPOSE Assess the capacity of NESMS to predict 30-day morbidity and mortality, as well as hospital length of stay, following surgery for spinal metastases. STUDY DESIGN Validation study. PATIENT SAMPLE All patients who had undergone spinal surgery with a history of metastatic spinal disease within the National Surgical Quality Improvement Program (NSQIP; 2007-2013). OUTCOME MEASURE Mortality, complications, failure to rescue, and length of stay. METHODS Demographic, oncologic, laboratory, and surgical data were obtained from the NSQIP. All patients were assigned an NESMS score (0-3). The effect of the NESMS score on the outcomes of interest was assessed using multivariable logistic regression and negative binomial regression that controlled for confounders. Final model discrimination and calibration were assessed using the c-statistic and Hosmer-Lemeshow test, respectively. Internal validation was performed using a bootstrapping procedure. RESULTS NSQIP data on 776 patients were included in this analysis. The 30-day mortality rate was 11% (N=87), and 51% of patients (N=395) sustained one or more complications. The final adjusted model demonstrated that the NESMS was a statistically significant predictor of 30-day mortality (p<.001), major systemic complications (p<.001), and failure to rescue (p=.03) following metastatic spinal surgery. Patients with an NESMS score of 3 had an 89% reduction in mortality (95% confidence interval [CI]: 0.04, 0.31), a 74% reduction in major systemic complications (95% CI: 0.11, 0.62), and an 88% reduction in failure to rescue (95% CI: 0.03, 0.47) as compared with those with a score of 0. The final model explained 71% of the variation in 30-day mortality. Findings were unchanged in the bootstrap analysis performed among 77,600 patient replicates. CONCLUSION This study demonstrates the clinical accuracy of the NESMS score for predicting short-term major morbidity and mortality following metastatic spinal surgery. The success of this score in an independent cohort of patients collected from centers across the United States indicates its potential for translation to clinical practice.

Predictors of 30- and 90-Day Survival Following Surgical Intervention for Spinal Metastases: A Prognostic Study Conducted at Four Academic Centers.

Study Design. A retrospective review. Objective. We sought to use data from 4 tertiary medical centers to explore surgical, medical, and demographic factors that influence survival within the first 90 days following surgery for spinal metastases. Summary of Background Data. Over the last 2 decades, patients with spinal metastases have become more likely to receive surgical intervention. The impact of surgical intervention and its potential benefits must be weighed against the risk of complications and peri-operative mortality. Risk factors that elevate the risk of mortality in the acute postoperative period are not well understood. Methods. All records of patients who underwent surgery for metastatic spinal disease at 1 of 4 academic medical centers in New England from 2007 to 2013 were obtained. Patient demographics, tumor characteristics, medical comorbidities, nutritional and functional status, as well as surgical variables were abstracted. Mortality was assessed for patients at 30 and 90 days following the procedure. Factors predictive of survival were assessed using bivariate logistic regression. Those factors with P values < 0.20 in the bivariate assessment were included in a final multivariable model that adjusted for confounders. Results. Between 2007 and 2013, 318 patients received surgical intervention for metastatic disease involving the spine. Cancer type did not influence the odds of survival at 30 days, while nutritional status and ambulatory capacity increased survival. Lung cancer significantly decreased the odds of survival at 90 days following surgery (odds ratio 0.36; 95% confidence interval 0.18–0.72), while ambulatory function and nutritional status remained significantly associated with improved survival. Conclusion. This effort is one of the first to identify predictors of acute postoperative survival in a large series of patients treated for spinal metastases. Improved nutritional status and ambulatory function may enhance postoperative survival among individuals who undergo surgical intervention for spinal metastases. Level of Evidence: 3

The effect of chronic liver disease on acute outcomes following cervical spine trauma

BACKGROUND CONTEXT The adverse impact of chronic liver diseases, including chronic hepatitis and cirrhosis, on outcomes following orthopedic surgery has been increasingly recognized in recent years. The impact of these conditions on acute outcomes following spinal trauma remains unknown. STUDY DESIGN This is a cohort control study that uses patient records in the Massachusetts Statewide Inpatient Dataset (2003-2010). PURPOSE The study aimed to evaluate whether chronic liver disease increased the odds of mortality, complications, failure to rescue (FTR), reoperation, and hospital length of stay (LOS) following cervical spine trauma. PATIENT SAMPLE The sample is composed of 10,841 patients with cervical spine trauma. OUTCOME MEASURES Posttreatment morbidity, mortality, reoperation, and LOS were the outcome measures. METHODS Differences between patients with and without chronic liver disease were evaluated using chi-square or Wilcoxon rank-sum tests. Logistic and negative binomial regression techniques were used to adjust for confounders, including whether a surgical intervention was performed. Receiver operator characteristic curves were used to assess final model discrimination. RESULTS There were 117 patients with chronic liver disease identified in the cohort. The rate of surgical intervention for cervical trauma was not significantly different between patients with and without chronic liver disease (odds ratio [OR]: 0.82, 95% confidence interval [CI]: 0.52-1.29). Mortality (OR: 2.12, 95% CI: 1.23-3.66), FTR (OR: 2.86, 95% CI: 1.34-6.11), complications (OR: 1.65, 95% CI: 1.12-2.45), and LOS (regression coefficients: 0.31, 95% CI: 0.14-0.48) were all significantly increased for patients with chronic liver disease in final adjusted models that controlled for differences in case-mix and whether a surgical procedure was performed. Final models explained approximately 72% of the variation in mortality and FTR. CONCLUSIONS Our novel findings indicate that patients with chronic liver disease may be at elevated risk of posttreatment morbidity and mortality following cervical spine trauma. Medical comanagement in the acute period following injury and optimization before surgery may diminish the potential for adverse events.

The importance of fluency of terminology in the applicability of imaging findings

COMMENTARY ON Fu MC, Webb ML, Buerba RA, Neway WE, Brown JE, Trivedi M, et al. Comparison of agreement of cervical spine degenerative pathology findings in magnetic resonance imaging studies. Spine J 2016:16:42-8 (in this issue).

Validation of Multisociety Combined Task Force Definitions of Abnormal Disk Morphology

Fifty-four patients underwent classification of lumbar disk herniations during preoperative MRI and surgery using the new multisociety classification. Disagreement as to classification based on MRI studies occurred in only 1 instance and agreement of preoperative classification with operative findings was 70%. The authors believe that though this level of agreement is reasonable, differences exist between what neuroradiologists see on imaging and what surgeons encounter. BACKGROUND AND PURPOSE: The multisociety task force descriptively defined abnormal lumbar disk morphology. We aimed to use their definitions to provide a higher level of evidence for the validation of MR imaging in the evaluation of this pathology in patients who have undergone diskectomy by retrospectively classifying their preoperative MRI. MATERIALS AND METHODS: This retrospective, institutional review board–approved study included 54 of 86 consecutive patients (47 men; average age, 44 years) enrolled in an ongoing prospective trial of surgically treated lumbar disk herniation who had preoperative MRI and documented intraoperative classification of the abnormal disk as protrusion, extrusion, or sequestration by the treating surgeon. Preoperative MRI was classified by 2 blinded radiologists; discrepancies were resolved by a third reader. Statistical analysis of interobserver agreement and imaging compared with surgical findings was performed. RESULTS: The readers disagreed on only 1 of the 54 cases. The third reader resolved the disagreement. Eight protrusions and 46 extrusions were found on imaging, with no sequestrations. At surgery, there were 13 protrusions and 40 extrusions, with 2 of the extrusions also containing sequestrations; the remaining case had only sequestration. There were 16 discrepancies between imaging and surgery, resulting in 70% agreement. CONCLUSIONS: This study, which was intended to validate the multisociety combined task force definitions of abnormal disk morphology by using MR imaging with a surgical criterion standard, found 70% agreement between imaging diagnosis and surgical findings. Although reasonable, this finding highlights differences that often exist between intraoperative and preoperative imaging findings of lumbar disk herniation.