Development of a Metastatic Spinal Tumor Frailty Index (MSTFI) Using a Nationwide Database and Its Association with Inpatient Morbidity, Mortality, and Length of Stay After Spine Surgery

The effectiveness of systemic therapies after surgery for metastatic renal cell carcinoma to the spine: a propensity analysis controlling for sarcopenia, frailty, and nutrition

OBJECTIVE

The effectiveness of starting systemic therapies after surgery for spinal metastases from renal cell carcinoma (RCC) has not been evaluated in randomized controlled trials. Agents that target tyrosine kinases, mammalian target of rapamycin signaling, and immune checkpoints are now commonly used. Variables like sarcopenia, nutritional status, and frailty may impact recovery from spine surgery and are considered when evaluating a patient's candidacy for such treatments. A better understanding of the significance of these variables may help improve patient selection for available treatment options after surgery. The authors used comparative effectiveness methods to study the treatment effect of postoperative systemic therapies (PSTs) on survival.

METHODS

Univariable and multivariable Cox regression analyses were performed to determine factors associated with overall survival (OS) in a retrospective cohort of adult patients who underwent spine surgery for metastatic RCC between 2010 and 2019. Propensity score-matched (PSM) analysis and inverse probability weighting (IPW) were performed to determine the treatment effect of PST on OS. To address confounding and minimize bias in estimations, PSM and IPW were adjusted for covariates, including age, sex, frailty, sarcopenia, nutrition, visceral metastases, International Metastatic RCC Database Consortium (IMDC) risk score, and performance status.

RESULTS

In total, 88 patients (73.9% male; median age 62 years, range 29-84 years) were identified; 49 patients (55.7%) had an intermediate IMDC risk, and 29 (33.0%) had a poor IMDC risk. The median follow-up was 17 months (range 1-104 months) during which 57 patients (64.7%) died. Poor IMDC risk (HR 3.2 [95% CI 1.08-9.3]), baseline performance status (Eastern Cooperative Oncology Group score 3 or 4; HR 2.7 [95% CI 1.5-4.7]), and nutrition (prognostic nutritional index [PNI] first tertile, PNI < 40.74; HR 2.69 [95% CI 1.42-5.1]) were associated with worse OS. Sarcopenia and frailty were not significantly associated with poor survival. PST was associated with prolonged OS, demonstrated by similar effects from multivariable Cox analysis (HR 0.55 [95% CI 0.30-1.00]), PSM (HR 0.53 [95% CI 0.29-0.93]), IPW (HR 0.47 [95% CI 0.24-0.94]), and comparable confidence intervals. The median survival for those receiving PST was 28 (95% CI 19-43) months versus 12 (95% CI 4-37) months for those who only had surgery (log-rank p = 0.027).

CONCLUSIONS

This comparative analysis demonstrated that PST is associated with improved survival in specific cohorts with metastatic spinal RCC after adjusting for frailty, sarcopenia, and malnutrition. The marked differences in survival should be taken into consideration when planning for surgery.

Impacts of Frailty on Prognosis in Lung Cancer Patients: A Systematic Review and Meta-Analysis

Background: Frailty is a common geriatric syndrome and is described as a limited ability to compensate and recover from stressors. Lung cancer is largely diagnosed in old age, when frailty is common and might have predictive value on prognosis. Therefore, we performed a systematic review to evaluate the prognostic role of frailty in lung cancer.

Methods: The online PubMed, Web of Science, CNKI and Wanfang literature databases were searched to identify all related articles that reported the predictive value of frailty for mortality and therapeutic toxicity. Review Manager 5.3 was used to analyze results by standard meta-analysis methodology.

Results: Seven studies were included in this review, and only six studies with 2,359 patients were enrolled in meta-analysis. Patients in two studies received chemotherapy, two studies radiotherapy, two studies surgery, one study not reported. Compared to non-frail patients, frail patients had a higher risk of overall mortality [Hazard Ratio (HR) = 1.57, 95% confidence interval (CI), 1.32–1.87], and therapeutic toxicity [Odds Ratio (OR) = 2.60, 95% CI, 0.82–8.24]. Prefrail patients also showed higher overall mortality and therapeutic toxicity than non-frail patients (HR = 1.20, 95% CI, 1.05–1.38; OR = 1.72, 95% CI, 1.18–2.51, respectively).

Conclusions: Frailty is a powerful predictor of overall mortality and therapeutic toxicity in lung cancer patients.

Inclusion of Frailty Improves Predictive Modeling for Postoperative Outcomes in Surgical Management of Primary and Secondary Lumbar Spine Tumors

BACKGROUND

Malignant spinal tumors are common, continually increasing in incidence as a function of improved survival times for patients with cancer. Using predictive analytics and propensity score matching, we evaluated the influence of frailty on postoperative complications compared with age in patients with malignant neoplasms of the lumbar spine.

METHODS

We used the Nationwide Readmissions Database from 2016 and 2017 to identify patients with malignant neoplasms of the lumbar spine who received a fusion procedure. Patient frailty was queried using the Johns Hopkins Adjusted Clinical Groups. Propensity score matching for age, sex, Charlson Comorbidity Index, surgical approach, and number of levels fused was implemented between frail and nonfrail patients, identifying 533 frail patients and 538 nonfrail patients. The area under the curve (AUC) of each ROC served as a proxy for model performance.

RESULTS

Frail patients reported significantly higher inpatient lengths of stay, costs, infection, posthemorrhagic anemia, and urinary tract infections (P < 0.05). In addition, frail patients were more often discharged to skilled nursing facilities and short-term hospitals compared with nonfrail patients (P < 0.0001). Regression models for mortality (AUC = 0.644), nonroutine discharge (AUC = 0.600), and acute infection (AUC = 0.666) were improved when using frailty as the primary predictor. These models were also improved using frailty when predicting 30-day readmission and 90-day hardware failure.

CONCLUSIONS

Frailty demonstrated a significant relationship with increased postoperative patient complications, length of stay, costs, and acute complications in patients receiving fusion following resection of a malignant neoplasm of the lumbar spine region. Frailty demonstrated better predictive validity of outcomes compared with patient age.

Frailty adversely affects outcomes of patients undergoing spine surgery: a systematic review

BACKGROUND

With an aging population, there are an increasing number of elderly patients undergoing spine surgery. Recent literature in other surgical specialties suggest frailty to be an important predictor of outcomes.

PURPOSE

The aim of this review was to examine the association between frailty and outcomes after spine surgery.

STUDY DESIGN

A systematic review was performed.

PATIENT SAMPLE

Electronic databases from 1946 to 2020 were searched to identify articles on frailty and spine surgery.

OUTCOME MEASURES

The primary outcome was adverse events. Secondary outcomes included other measures of morbidity, mortality, and patient outcomes.

METHODS

Sample size, mean age, age limitation, data source, study design, primary pathology, surgical procedure performed, follow-up period, assessment of frailty used, surgical outcomes, and impact of frailty on outcomes were extracted from eligible studies. Quality and bias were assessed using the PRISMA 27-point item checklist and the QUADAS-2 tool.

RESULTS

Thirty-two studies were selected for review, with a total of 127,813 patients. There were eight different frailty indices/measures. Regardless of how frailty was measured, frailty was associated with an increased risk of adverse events, mortality, extended length of stay, readmission, and nonhome discharge.

CONCLUSION

There is strong evidence that frailty is associated with an increased risk of morbidity and mortality in patients who received spine surgery. However, it remains inconclusive whether frailty impacts patient outcomes and quality of life after surgery.

The influence of modifiable risk factors on short-term postoperative outcomes following cervical spine surgery: A retrospective propensity score matched analysis

BACKGROUND

Modifiable risk factors (MRFs) represent patient variables associated with increased complication rates that may be prevented. There exists a paucity of studies that comprehensively analyze MRF subgroups and their independent association with postoperative complications in patients undergoing cervical spine surgery. Therefore, the purpose of this study is to compare outcomes between patients receiving cervical spine surgery with reported MRFs.

METHODS

Retrospective analysis of the Nationwide Readmissions Database (NRD) from the years 2016 and 2017, a publicly available and purchasable data source, to include adult patients undergoing cervical fusion. MRF cohorts were separated into three categories: substance abuse (alcohol, tobacco/nicotine, opioid abuse); vascular disease (hypertension, dyslipidemia); and dietary factors (malnutrition, obesity). Three-way nearest-neighbor propensity score matching for demographics, hospital, and surgical characteristics was implemented.

FINDINGS

We identified 9601 with dietary MRFs (D-MRF), 9654 with substance abuse MRFs (SA-MRF), and 9503 with vascular MRFs (V-MRF). Those with d-MRFs had significantly higher rates of medical complications (9.3%), surgical complications (8.1%), and higher adjusted hospital costs compared to patients with SA-MRFs and V-MRFs. Patients with d-MRFs (16.3%) and V-MRFs (14.0%) were independently non-routinely discharged at a significantly higher rate compared to patients with SA-MRFs (12.6%) (p<0.0001 and p = 0.0037). However, those with substance abuse had the highest readmission rate and were more commonly readmitted for delayed procedure-related infections.

INTERPRETATION

A large proportion of patients who receive cervical spine surgery have potential MRFs that uniquely influence their postoperative outcomes. A thorough understanding of patient-specific MRF subgroups allows for improved preoperative risk stratification, tailored patient counseling, and postoperative management planning.

FUNDING

None.

A Systematic Review and Meta-Analysis of Preoperative Frailty Instruments Derived From Electronic Health Data

BACKGROUND

Frailty is a strong predictor of adverse outcomes in the perioperative period. Given the increasing availability of electronic medical data, we performed a systematic review and meta-analysis with primary objectives of describing available frailty instruments applied to electronic data and synthesizing their prognostic value. Our secondary objectives were to assess the construct validity of frailty instruments that have been applied to perioperative electronic data and the feasibility of electronic frailty assessment.

METHODS

Following protocol registration, a peer-reviewed search strategy was applied to Medline, Excerpta Medica dataBASE (EMBASE), Cochrane databases, and the Comprehensive Index to Nursing and Allied Health literature from inception to December 31, 2019. All stages of the review were completed in duplicate. The primary outcome was mortality; secondary outcomes included nonhome discharge, health care costs, and length of stay. Effect estimates adjusted for baseline illness, sex, age, procedure, and urgency were of primary interest; unadjusted and adjusted estimates were pooled using random-effects models where appropriate or narratively synthesized. Risk of bias was assessed.

RESULTS

Ninety studies were included; 83 contributed to the meta-analysis. Frailty was defined using 22 different instruments. In adjusted data, frailty identified from electronic data using any instrument was associated with a 3.57-fold increase in the odds of mortality (95% confidence interval [CI], 2.68-4.75), increased odds of institutional discharge (odds ratio [OR], 2.40; 95% CI, 1.99-2.89), and increased costs (ratio of means, 1.54; 95% CI, 1.46-1.63). Most instruments were not multidimensional, head-to-head comparisons were lacking, and no feasibility data were reported.

CONCLUSIONS

Frailty status derived from electronic data provides prognostic value as it is associated with adverse outcomes, even after adjustment for typical risk factors. However, future research is required to evaluate multidimensional instruments and their head-to-head performance and to assess their feasibility and clinical impact.

Performance assessment of the metastatic spinal tumor frailty index using machine learning algorithms: limitations and future directions

OBJECTIVE

Frailty is recognized as an important consideration in patients with cancer who are undergoing therapies, including spine surgery. The definition of frailty in the context of spinal metastases is unclear, and few have studied such markers and their association with postoperative outcomes and survival. Using national databases, the metastatic spinal tumor frailty index (MSTFI) was developed as a tool to predict outcomes in this specific patient population and has not been tested with external data. The purpose of this study was to test the performance of the MSTFI with institutional data and determine whether machine learning methods could better identify measures of frailty as predictors of outcomes.

METHODS

Electronic health record data from 479 adult patients admitted to the Massachusetts General Hospital for metastatic spinal tumor surgery from 2010 to 2019 formed a validation cohort for the MSTFI to predict major complications, in-hospital mortality, and length of stay (LOS). The 9 parameters of the MSTFI were modeled in 3 machine learning algorithms (lasso regularization logistic regression, random forest, and gradient-boosted decision tree) to assess clinical outcome prediction and determine variable importance. Prediction performance of the models was measured by computing areas under the receiver operating characteristic curve (AUROCs), calibration, and confusion matrix metrics (positive predictive value, sensitivity, and specificity) and was subjected to internal bootstrap validation.

RESULTS

Of 479 patients (median age 64 years [IQR 55-71 years]; 58.7% male), 28.4% had complications after spine surgery. The in-hospital mortality rate was 1.9%, and the mean LOS was 7.8 days. The MSTFI demonstrated poor discrimination for predicting complications (AUROC 0.56, 95% CI 0.50-0.62) and in-hospital mortality (AUROC 0.69, 95% CI 0.54-0.85) in the validation cohort. For postoperative complications, machine learning approaches showed a greater advantage over the logistic regression model used to develop the MSTFI (AUROC 0.62, 95% CI 0.56-0.68 for random forest vs AUROC 0.56, 95% CI 0.50-0.62 for logistic regression). The random forest model had the highest positive predictive value (0.53, 95% CI 0.43-0.64) and the highest negative predictive value (0.77, 95% CI 0.72-0.81), with chronic lung disease, coagulopathy, anemia, and malnutrition identified as the most important predictors of postoperative complications.

CONCLUSIONS

This study highlights the challenges of defining and quantifying frailty in the metastatic spine tumor population. Further study is required to improve the determination of surgical frailty in this specific cohort.

Interhospital transfer status for spinal metastasis patients in the United States is associated with more severe clinical presentations and higher rates of inpatient complications

OBJECTIVE

In patients with metastatic spinal disease (MSD), interhospital transfer can potentially impact clinical outcomes as the possible benefits of transferring a patient to a higher level of care must be weighed against the negative effects associated with potential delays in treatment. While the association of clinical outcomes and transfer status has been examined in other specialties, the relationship between transfer status, complications, and risk of mortality in patients with MSD has yet to be explored. The purpose of this study was to examine the impact of transfer status on in-hospital mortality and clinical outcomes in patients diagnosed with MSD.

METHODS

The National (Nationwide) Inpatient Sample (NIS) database was retrospectively queried for adult patients diagnosed with vertebral pathological fracture and/or spinal cord compression in the setting of metastatic disease between 2012 and 2014. Demographics, baseline characteristics (e.g., metastatic spinal cord compression [MSCC] and paralysis), comorbidities, type of intervention, and relevant patient outcomes were controlled in a multivariable logistic regression model to analyze the association of transfer status with patient outcomes.

RESULTS

Within the 10,360 patients meeting the inclusion and exclusion criteria, higher rates of MSCC (50.2% vs 35.9%, p < 0.001) and paralysis (17.3% vs 8.4%, p < 0.001) were observed in patients transferred between hospitals compared to those directly admitted. In univariable analysis, a higher percentage of transferred patients underwent surgical intervention (p < 0.001) when compared with directly admitted patients. After controlling for significant covariates and surgical intervention, transferred patients were more likely to develop in-hospital complications (OR 1.34, 95% CI 1.18-1.52, p < 0.001), experience prolonged length of stay (OR 1.33, 95% CI 1.16-1.52, p < 0.001), and have a discharge disposition other than home (OR 1.70, 95% CI 1.46-1.98, p < 0.001), with no significant difference in inpatient mortality rates.

CONCLUSIONS

Patients with MSD who were transferred between hospitals demonstrated more severe clinical presentations and higher rates of inpatient complications compared to directly admitted patients, despite demonstrating no difference in in-hospital mortality rates.

Cost and Health Care Resource Utilization Differences After Spine Surgery for Bony Spine versus Primary Intradural Spine Tumors

OBJECTIVE

The aim of this study was to compare complication rates, length of stay (LOS), and hospital costs after spine surgery for bony spine tumors and intradural spinal neoplasms.

METHODS

A retrospective cohort study was performed using the National Inpatient Sample database from 2016 to 2017. All adult inpatients who underwent surgical intervention for a primary intradural spinal tumor or primary/metastatic bony spine tumor were identified using International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis/procedural coding systems. Patient demographics, comorbidities, intraoperative variables, complications, LOS, discharge disposition, and total cost of hospitalization were assessed. Backward stepwise multivariable logistic regression analyses were used to identify independent predictors of perioperative complication, extended LOS (≥75th percentile), and increased cost (≥75th percentile).

RESULTS

A total of 9855 adult patients were included in the study; 3850 (39.1%) were identified as having a primary intradural spinal tumor and 6005 (60.9%) had a primary or metastatic bony spine tumor. Those treated for bony tumors had more comorbidities (≥3, 67.8% vs. 29.2%) and more commonly experienced ≥1 complications (29.9% vs. 7.9%). Multivariate analyses also showed those in the bony spine cohort had a higher odds of experiencing ≥1 complications (odds ratio [OR], 4.26; 95% confidence interval [CI], 3.04-5.97; P < 0.001), extended LOS (OR, 2.44; 95% CI, 1.75-3.38; P < 0.001), and increased cost (OR, 5.32; 95% CI, 3.67-7.71; P < 0.001).

CONCLUSIONS

Relative to patients being treated for primary intradural tumors, those undergoing spine surgery for bony spine tumors experience significantly higher risk for perioperative complications, extended LOS, and increased cost of hospital admission. Further identification of patient and treatment characteristics that may optimize management of spine oncology may reduce adverse outcomes, improve patient care, and reduce health care resources.

The Impact of Frailty on Spine Surgery: Systematic Review on 10 years Clinical Studies

Frailty is a condition characterized by a high vulnerability to low-power stressor. Frailty increases with age and is associated with higher complications and mortality. Several indexes have been used to quantify frailty. Spine diseases, both degenerative and oncologic, frequently require surgery which is related to complications and mortality. Aim of the present systematic review was to collect the most frequently used frailty indexes in clinics to predict surgical outcomes in patients affected by spine diseases, taking into account gender differences. Three databases were employed, and 29 retrospective clinical studies were included in this systematic review. The identified spine pathologies were primary and metastatic spine tumors, adult spine deformity (ASD), degenerative spine disease (DSD), cervical deformity (CD) and other pathologies that affected lumbar spine or multiple spine levels. Eleven indexes were identified: modified Frailty Index (mFI), Adult spinal deformity frailty index (ASD-FI), mFI-5, Metastatic Spinal Tumor Frailty Index (MSTFI), Fried criteria, Cervical deformity frailty index (CD-FI), Spinal tumor frailty index (STFI), Frailty Phenotype criteria (FP), Frailty Index (FI), FRAIL scale and Modified CD-FI (mCD-FI). All these indexes correlated well with minor and major postoperative complications, mortality and length of stay in hospital. Results on gender differences and frailty are still conflicting, although few studies show that women are more likely to develop frailty and more complications in the post-operative period than men. This systematic review could help the surgeon in the adoption of frailty indexes, before the operation, and in preventing complications in frail patients.

Spinal laser interstitial thermal therapy: single-center experience and outcomes in the first 120 cases

OBJECTIVE

The objective of this study was to present the results of a consecutive series of 120 cases treated with spinal laser interstitial thermal therapy (sLITT) to manage epidural spinal cord compression (ESCC) from metastatic tumors.

METHODS

The electronic records of patients treated from 2013 to 2019 were analyzed retrospectively. Data collected included demographic, pathology, clinical, operative, and imaging findings; degree of epidural compression before and after sLITT; length of hospital stay; complications; and duration before subsequent oncological treatment. Independent-sample t-tests were used to compare means between pre- and post-sLITT treatments. Survival was estimated by the Kaplan-Meier method. Multivariate logistic regression was used to analyze predictive factors for local recurrence and neurological complications.

RESULTS

There were 110 patients who underwent 120 sLITT procedures. Spinal levels treated included 5 cervical, 8 lumbar, and 107 thoracic. The pre-sLITT Frankel grades were E (91.7%), D (6.7%), and C (1.7%). The preoperative ESCC grade was 1c or higher in 92% of cases. Metastases were most common from renal cell carcinoma (39%), followed by non-small cell lung carcinoma (10.8%) and other tumors (35%). The most common location of ESCC was in the vertebral body (88.3%), followed by paraspinal/foraminal (7.5%) and posterior elements (4.2%). Adjuvant radiotherapy (spinal stereotactic radiosurgery or conventional external beam radiation therapy) was performed in 87 cases (72.5%), whereas 33 procedures (27.5%) were performed as salvage after radiotherapy options were exhausted. sLITT was performed without need for spinal stabilization in 87 cases (72.5%). Post-sLITT Frankel grades were E (85%), D (10%), C (4.2%), and B (0.8%); treatment was associated with a median decrease of 2 ESCC grades. The local control rate at 1 year was 81.7%. Local control failure occurred in 25 cases (20.8%). The median progression-free survival was not reached, and overall survival was 14 months. Tumor location in the paraspinal region and salvage treatment were independent predictors of local recurrence, with hazard ratios of 6.3 and 3.3, respectively (p = 0.01). Complications were observed in 22 cases (18.3%). sLITT procedures performed in the lumbar and cervical spine had hazard ratios for neurological complications of 15.4 and 17.1 (p < 0.01), respectively, relative to the thoracic spine.

CONCLUSIONS

sLITT is safe and provides effective local control for high-grade ESCC from vertebral metastases in the thoracic spine, particularly when combined with adjuvant radiotherapy. The authors propose considering sLITT as an alternative to open surgery in selected patients with spinal metastases.

A Novel Clinical Scoring System for Perioperative Morbidity in Metastatic Spinal Tumor Surgery: The Spine Oncology Morbidity Assessment Score

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate a scoring system to predict morbidity for patients undergoing metastatic spinal tumor surgery (MSTS).

SUMMARY OF BACKGROUND DATA

Multiple scoring systems exist to predict survival for patients with spinal metastasis. The potential benefits and risks of surgery need to be evaluated for patients with disseminated cancer and limited life expectancy. Few scoring systems exist to predict perioperative morbidity after MSTS.

METHODS

We reviewed records of patients who underwent MSTS at our institution between 2013 and 2019. All perioperative complications occurring within 30 days were recorded. A clinical scoring system consisting of five variables (age ≥ 70 yr, hypoalbuminemia, poor preoperative functional status [Karnofsky ≤ 40], Frankel Grade A-C, and multilevel disease ≥2 continuous vertebral bodies) was evaluated as a predictive tool for morbidity; every parameter was assigned a value of 0 if absent or 1 if present (total possible score = 5). The effect of the scoring system on morbidity was evaluated using stepwise multiple logistic regression. Model accuracy was calculated by receiver operating characteristic analysis.

RESULTS

One hundred and five patients were identified, with a male prevalence of 58.1% and average age at surgery of 61 years. The overall 30-day complication rate was 36.2%. The perioperative morbidity was 4.6%, 30.0%, 53.9%, and 64.7% for patients with scores of 0, 1, 2, and ≥3 points, respectively (P < 0.001). On multiple logistic regression analysis controlling for covariates not present in the model, the scoring system was significantly associated with 30-day morbidity (OR 3.11; 95% CI, 1.72-5.59; P < 0.001). The model's accuracy was estimated at 0.75.

CONCLUSION

Our proposed model was found to accurately predict perioperative morbidity after MSTS. The Spine Oncology Morbidity Assessment (SOMA) score may prove useful for risk stratification and possibly decision-making, though further validation is needed.Level of Evidence: 4.

To operate, or not to operate? Narrative review of the role of survival predictors in patient selection for operative management of patients with metastatic spine disease

Accurate prediction of patient survival is an essential component of the preoperative evaluation of patients with spinal metastases. Over the past quarter of a century, a number of predictors have been developed, although none have been accurate enough to be instituted as a staple of clinical practice. However, recently more comprehensive survival calculators have been published that make use of larger data sets and machine learning to predict postoperative survival among patients with spine metastases. Given the glut of calculators that have been published, the authors sought to perform a narrative review of the current literature, highlighting existing calculators along with the strengths and weaknesses of each. In doing so, they identify two "generations" of scoring systems-a first generation based on a priori factor weighting and a second generation comprising predictive tools that are developed using advanced statistical modeling and are focused on clinical deployment. In spite of recent advances, the authors found that most predictors have only a moderate ability to explain variation in patient survival. Second-generation models have a greater prognostic accuracy relative to first-generation scoring systems, but most still require external validation. Given this, it seems that there are two outstanding goals for these survival predictors, foremost being external validation of current calculators in multicenter prospective cohorts, as the majority have been developed from, and internally validated within, the same single-institution data sets. Lastly, current predictors should be modified to incorporate advances in targeted systemic therapy and radiotherapy, which have been heretofore largely ignored.

A National Surgical Quality Improvement Program Analysis of Postoperative Major and Minor Complications in Patients with Spinal Metastatic Disease

BACKGROUND

Major complications after spine metastasis surgery are prioritized in the literature with little consideration of the more frequent minor events such as pneumonia or urinary tract infection. We analyzed incidence and risk factors of postsurgical complications in patients with spinal metastasis extracted from the National Surgical Quality Improvement Program (NSQIP). We also developed a useful predictive model to estimate the probability of occurrence of complications.

METHODS

A total of 1176 patients diagnosed with spinal metastasis were extracted from NSQIP. Variables screened included age, sex, tumor location, patient's functional status, comorbidities, laboratory values, and case urgency. Two multivariate logistic regression models were designed to evaluate risk factors and likelihood of event occurrence.

RESULTS

Minor events occurred twice as frequently compared with major complications (36% vs. 18% of patients). The most common major event was death (10%); the most frequent minor event was need for postoperative transfusion (29.4%). In the multivariate analysis, elderly age, emergency case, preoperative leukocytosis, and smoking status retained significance for major complications; American Society of Anesthesiologists classes 4-5, low hematocrit levels, and intradural extramedullary location of the tumor retained significance for minor complications. The predictive models designed explained 72% of the variability in major complications occurrence and 67% for minor events.

CONCLUSIONS

Smoking status and emergent surgery were found to be the strongest independent predictors of major complications, whereas higher American Society of Anesthesiologists class showed a greater association with minor events. The predictive models produced can be a useful aid for surgeons to identify those patients who are at greater risk of developing postoperative adverse events.

Rates, Risk Factors, and Complications of Red Blood Cell Transfusion in Metastatic Spinal Tumor Surgery: An Analysis of a Prospective Multicenter Surgical Database

OBJECTIVE

To identify rates, risks, and complications of red blood cell (RBC) transfusion in metastatic spinal tumor surgery.

METHODS

The multicenter prospective American College of Surgeons National Quality Improvement Program database was queried for the years 2012-2016. Adult patients with disseminated cancer who underwent metastatic spinal tumor surgery were identified. Transfusion was defined as having received at least 1 intraoperative/postoperative RBC transfusion within the first 72 hours of surgery start time. A stepwise multiple logistic regression model with backward elimination was used.

RESULTS

Of 1601 patients identified, 623 patients (38.9%) received a RBC transfusion. Independent predictors of RBC transfusion included higher American Society of Anesthesiologists class (odds ratio [OR] = 1.54), preoperative anemia (OR = 3.10), instrumentation (OR = 1.63), and longer operative time (OR = 1.52). The overall complication rate was significantly higher in patients who received a transfusion compared with patients who did not receive a transfusion (22.3% vs. 15.0%, P < 0.001). Individual complications that were more common in patients who received a transfusion were sepsis (3.5% vs. 1.9%, P = 0.050), deep vein thrombosis (6.1% vs. 3.3%, P = 0.007), and prolonged ventilation (3.9% vs. 1.3%, P = 0.001). RBC transfusion (OR = 1.65), hypoalbuminemia (OR = 1.53), and anterior/anterolateral approaches for corpectomy (OR = 2.11) were independent risk factors for developing a postoperative complication.

CONCLUSIONS

RBC transfusion after metastatic spinal tumor surgery may increase the risk of early postoperative complications. Future research into preoperative patient optimization and decreasing intraoperative blood loss is needed.

The immense heterogeneity of frailty in neurosurgery: a systematic literature review

The aim of this study was to review and analyze the neurosurgery body of literature to document the current knowledge of frailty within neurosurgery, standardizing terminology and how frailty is defined, including the different levels of frailty, while determining what conclusions can be drawn about frailty's impact on neurosurgical outcomes. While multiple studies on frailty in neurosurgery exist, no literature reviews have been conducted. Therefore, we performed a literature review in order to organize, tabulate, and present findings from the data to broaden the understanding about what we know from frailty and neurosurgery. We performed a PubMed search to identify studies that evaluated frailty and neurosurgery. The terms "frail," "frailty," "neurosurgery," "spine surgery," "craniotomy," and "neurological surgery" were all used in the query. We then organized, analyzed, and summarized the comprehensive frailty and neurosurgical literature. The literature contained 25 published studies analyzing frailty in neurosurgery between December 2015 and December 2018. Five of these studies were cranial neurosurgical studies, the remaining studies focused on spinal neurosurgery. Over 100,000 surgical cases were analyzed among the 25 studies. Of these, 18 studies demonstrated that increasing frailty was associated with increased rate of complications, 10 studies showed that frailty was associated with higher mortality rates, 11 studies demonstrated an association between frailty and increased hospital length of stay, and 5 studies noted that higher frailty was associated with discharge to a higher level of care. The current body of literature repeatedly demonstrates that frailty is associated with worse outcomes across the neurosurgical subspecialties.

Sarcopenia, but not frailty, predicts early mortality and adverse events after emergent surgery for metastatic disease of the spine

BACKGROUND CONTEXT

Frailty and sarcopenia variably predict adverse events (AEs) in a number of surgical populations.

PURPOSE

The aim of this study was to investigate the ability of frailty and sarcopenia to independently predict early mortality and AEs following urgent surgery for metastatic disease of the spine.

STUDY DESIGN

A single institution, retrospective cohort study.

PATIENT SAMPLE

One hundred eight patients undergoing urgent surgery for spinal metastases from 2009 to 2015.

OUTCOME MEASURES

The incidence of AEs including 1- and 3-month mortality.

METHODS

Sarcopenia was defined using the L3 Total Psoas Area/Vertebral body Area (L3-TPA/VB) technique on CT. The modified Frailty Index (mFI), Metastatic Frailty Index (MSTFI) and the Bollen prognostic scales were calculated for each patient. Additional data included demographics, tumor type and burden, neurological status, the extent of surgical treatment and the use of radiation-therapy. Spearman correlation test, logistic regression and Kaplan-Meier were used to study the relation between the outcomes measures and potential predictors (L3-TPA/VB, MSTFI, mFI, and the Bollen prognostic scales).

RESULTS

Eighty-five percent of patients had at least one acute AE. Sarcopenia predicted the occurrence of at least one postop AE (L3-TPA/VB, 1.07±0.40 vs. 1.25±0.52; p=.031). Sarcopenia (L3-TPA/VB) and the degree of neurological impairment were predictive of postoperative AE but MFI or MSTFI were not. Sarcopenia predicted 3-month mortality, independent of primary tumor type (L3-TPA/VB: 0.86±0.27 vs. 1.12±0.41; p<.001). Kaplan-Meyer analysis showed L3-TPA/VB and the Bollen Scale to significantly discriminate patient survival.

CONCLUSIONS

Sarcopenia, easily measured by the L3-TPA/VB on conventional CT, predicts both early postoperative mortality and adverse events in patients undergoing urgent surgery for spinal metastasis, thus providing a practical tool for timely therapeutic decision-making in this complex patient population.

Timing of Prophylactic Anticoagulation and Its Effect on Thromboembolic Events After Surgery for Metastatic Tumors of the Spine

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To investigate the effect of timing of initiation of prophylactic anticoagulation (AC) on the incidence of venous thromboembolism (VTE) after surgery for metastatic tumors of the spine.

SUMMARY OF BACKGROUND DATA

VTE is a known complication in patients undergoing surgery for metastatic spine disease. However, there is limited data on the use of prophylactic AC in this population and its impact on the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE), as well as the risk of epidural hematoma.

METHODS

A retrospective review of our institutional neurosurgical spine database for the years 2012 through 2018 was performed. Patients who underwent surgery for metastatic tumors were identified. The development of VTE within 30 days was examined, as well as the occurrence of epidural hematoma. The incidence of VTE was compared between patients receiving "early" (within postoperative days 1-3) and "delayed" prophylactic AC (on or after postoperative day 4).

RESULTS

Sixty-five consecutive patients were identified (mean age 57, 62% male). The overall rate of VTE was 16.9%-all of whom had DVTs with a 3.1% rate of nonfatal PE (two patients also developed PE). From the overall cohort, 36 of 65 (56%) received prophylactic AC in addition to mechanical prophylaxis-22 in the early group (61.1%) and 14 in the delayed group (38.9%). The risk of VTE was 9.1% in the early group and 35.7% in the delayed group (26.6% absolute risk reduction; P = 0.049); there was one case of epidural hematoma (1.5%). On multivariate analysis, delayed prophylactic AC was found to significantly increase the odds of VTE development (OR 6.43; 95% CI, 1.01-41.2; P = 0.049).

CONCLUSION

The findings of this study suggest that administration of prophylactic AC between days 1 and 3 after surgery for metastatic tumors of the spine may significantly reduce the risk of postoperative thromboembolic events.

LEVEL OF EVIDENCE

4.

The modified Frailty Index does not correlate with survival in surgically-treated patients with metastatic spine disease

With the increasing burden of metastatic spinal disease there is ever-more pressure on the health system to provide optimal management. Multiple treatment modalities, including surgical intervention, are available. Multiple prognostic scoring systems have been developed to aid both clinician and patient in making the best decision for each individual. The modified Frailty Index (mFI) has not been assessed for its correlation with survival in patients treated for metastatic spine disease. A retrospective review of a patients undergoing surgery for metastatic spine disease at a tertiary referral centre was performed and a comparison was made between the mFI and previously established disease-specific prognostic scores (revised Tokuhashi, modified Bauer and Tomita scores and the Oswestry Spine Risk Index). 41 patients were included over a 5-year period. 38 deceased by the end of the study period with a 30-day mortality of 14.6% and a 1-year mortality of 73.2%. The mFI poorly correlated with survival. Out of the four established scoring system, the OSRI had the best correlation. The mFI did not correlate with survival in this cohort of surgically treated patients with metastatic spinal disease and is best used as a selection tool for surgery. Dedicated prognostic tools can be selected appropriate to the institution experience and set-up.

Malnutrition in patients who underwent surgery for spinal metastases

Background

Malnutrition is common among cancer patients and has been associated with increased morbidity and mortality. The primary objective of this study was to evaluate the nutritional status of patients who underwent surgical treatment for spinal metastases. In addition, the association between nutritional status and length of stay, health related quality of life (HRQOL), the occurrence of adverse events and survival was investigated.

Methods

A single center prospective observational cohort study including patients with spinal metastases who underwent surgical treatment was performed. Demographic, diagnostic, treatment, and HRQOL (SOSGOQ2.0 and EQ-5D-3L) data were prospectively collected at baseline and 12 weeks post-treatment. Nutritional status was evaluated with the Patient-Generated Subjective Global Assessment (PG-SGA).

Results

A total of 39 patients were included. Malnutrition as determined by the PG-SGA was present in 36 (92%) of the patients, of whom 32 (82%) were moderately malnourished and 4 (10%) were severely malnourished. Malnourishment was associated with lower baseline SOSGOQ2.0 total scores, SOSGOQ2.0 physical function, mental health and social functioning scores, EQ-5D total scores and EQ-5D mobility scores. No association between malnutrition and survival could be determined.

Conclusions

The prevalence of malnutrition among surgically treated patients with spinal metastases is high. Malnutrition demonstrated to be associated with lower baseline HRQOL scores. Future larger studies are needed to further investigate the prognostic significance of malnutrition.

Hypoalbuminemia as an Independent Risk Factor for Perioperative Complications Following Surgical Decompression of Spinal Metastases

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Malnutrition has been shown to be a risk factor for poor perioperative outcomes in multiple surgical subspecialties, but few studies have specifically investigated the effect of hypoalbuminemia in patients undergoing operative treatment of metastatic spinal tumors. The aim of this study was to assess the role of hypoalbuminemia as an independent risk factor for 30-day perioperative mortality and morbidity after surgical decompression of metastatic spinal tumors using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2011 to 2014.

METHODS

We identified 1498 adult patients in the ACS-NSQIP database who underwent laminectomy and excision of metastatic extradural spinal tumors. Patients were categorized into normoalbuminemic and hypoalbuminemic (ie, albumin level <3.5 g/dL) groups. Univariate and multivariate regression analyses were performed to examine the association between preoperative hypoalbuminemia and 30-day perioperative mortality and morbidity. Subgroup analysis was performed in the hypoalbuminemic group to assess the dose-dependent effect of albumin depletion.

RESULTS

Hypoalbuminemia was associated with increased risk of perioperative mortality, any complication, sepsis, intra- or postoperative transfusion, prolonged hospitalization, and non-home discharge. However, albumin depletion was also associated with decreased risk of readmission. There was an albumin level-dependent effect of increasing mortality and complication rates with worsening albumin depletion.

CONCLUSIONS

Hypoalbuminemia is an independent risk factor for perioperative mortality and morbidity following surgical decompression of metastatic spinal tumors with a dose-dependent effect on mortality and complication rates. Therefore, it is important to address malnutrition and optimize nutritional status prior to surgery.

30-day Mortality Following Surgery for Spinal Epidural Abscess: Incidence, Risk Factors, Predictive Algorithm, and Associated Complications

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To determine incidence and timing of mortality following surgery for spinal epidural abscess (SEA), identify risk factors for mortality, and identify complications associated with mortality.

SUMMARY OF BACKGROUND DATA

SEA is a serious condition with potentially devastating sequelae. There is a paucity of literature characterizing mortality following surgery for SEA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was used. Patients with a diagnosis of SEA were included. A Cox proportional hazards model identified independent risk factors for 30-day mortality. A predictive model for mortality was created. Multivariate models identified postoperative complications associated with mortality.

RESULTS

There were 1094 patients included, with 40 cases of mortality (3.7%), the majority of which occurred within 2 weeks postoperatively (70%). Independent risk factors for 30-day mortality were age>60 years (hazard ratio [HR]: 2.147, P = 0.027), diabetes (HR: 2.242, P = 0.015), respiratory comorbidities (HR: 2.416, P = 0.037), renal comorbidities (HR: 2.556, P = 0.022), disseminated cancer (HR: 5.219, P = 0.001), and preoperative thrombocytopenia (HR: 3.276, P = 0.001). A predictive algorithm predicts a 0.3% mortality for zero risk factors up to 37.5% for 4 or more risk factors. A ROC area under curve (AUC) was 0.761, signifying a fair predictor (95% CI: 0.683-0.839, P < 0.001). Cardiac arrest (adjusted odds ratio [aOR]: 72.240, 95% confidence interval [CI]: 27.8-187.721, P < 0.001), septic shock (aOR: 15.382, 95% CI: 7.604-31.115, P < 0.001), and pneumonia (aOR: 2.84, 95% CI: 1.109-7.275, P = 0.03) were independently associated with mortality.

CONCLUSION

The 30-day mortality rate following surgery for SEA was 3.7%. Of the mortalities that occurred within 30 days of surgery, the majority occurred within 2 weeks. Independent risk factors for mortality included older age, diabetes, hypertension, respiratory comorbidities, renal comorbidities, metastatic cancer, and thrombocytopenia. Risk for mortality ranged from 0.3% to 37.5% based on number of risk factors. Septic shock, cardiac arrest, and pneumonia were associated with mortality.

LEVEL OF EVIDENCE

3.

The impact of frailty and sarcopenia on postoperative outcomes in adult spine surgery. A systematic review of the literature

STUDY DESIGN

Systematic review.

OBJECTIVES

To identify currently used measures of frailty and sarcopenia in the adult spine surgery literature. To assess their ability to predict postoperative outcomes including mortality, morbidity, in-hospital length of stay (LOS), and discharge disposition. To determine which is the best clinical measure of frailty and sarcopenia in predicting outcome after spine surgery.

SUMMARY OF BACKGROUND DATA

Frailty and sarcopenia have been identified as predictors of mortality and adverse-events (AEs) in numerous nonsurgical and nonspine populations. This topic is an emerging area of interest and study in patients undergoing spinal surgery.

METHODS

A systematic literature review using the PRISMA methodology of MEDLINE, PubMed, Ovid, EMBASE, and Cochrane databases was performed from January 1950 to August 2017. Included studies consisted of those that examined measures of frailty or sarcopenia in adult patients undergoing any spinal surgery. The literature was synthesized and recommendations are proposed based on the GRADE system.

RESULTS

The initial search yielded 210 results, 11 of which met our complete inclusion criteria. Seven reported on measures of frailty and four reported on measures of sarcopenia. Frailty, assessed using a variety of measurement tools, was a consistent predictor of mortality, major and minor morbidity, prolonged in-hospital LOS, and discharge to a center of higher care for adult patients undergoing spinal surgery. The relationship between sarcopenia and postoperative outcomes was inconsistent due to the lack of consensus regarding the definition, measurement tools, and wide variability in sarcopenia measured in the spinal population.

CONCLUSIONS

Frailty is predictive of AEs, mortality, in-hospital LOS, and discharge disposition in a number of distinct spinal surgery populations. The impact of sarcopenia on postoperative outcomes is equivocal given the current state of the literature. The relationship between spinal pathology, frailty, sarcopenia, and how they interact to yield outcome remains to be clarified. Frailty and sarcopenia are potentially useful tools for risk stratification of patients undergoing spinal surgery. This systematic review was registered with PROSPERO, registration number 85096.

Risk factors for wound-related reoperations in patients with metastatic spine tumor

OBJECTIVE

Resection of metastatic spine tumors can improve patients’ quality of life by addressing pain or neurological compromise. However, resections are often complicated by wound dehiscence, infection, instrumentation failures, and the need for reoperation. Moreover, when reoperations are needed, the most common indication is surgical site infection and wound breakdown. In turn, wound reoperations increase morbidity as well as the length and cost of hospitalization. The aim of this study was to examine perioperative risk factors associated with increased rate of wound reoperations after metastatic spine tumor resection.

METHODS

A retrospective study of patients at a single institution who underwent metastatic spine tumor resection between 2003 and 2013 was conducted. Factors with a p value < 0.200 in a univariate analysis were included in the multivariate model.

RESULTS

A total of 159 patients were included in this study. Karnofsky Performance Scale score > 70, smoking status, hypertension, thromboembolic events, hyperlipidemia, increasing number of vertebral levels, and posterior approach were included in the multivariate analysis. Thromboembolic events (95% CI 1.19–48.5, p = 0.032) and number of levels involved were independently associated with increased wound reoperation rates in the multivariate model. For each additional spinal level involved, the risk for wound reoperations increased by 21% (95% CI 1.03–1.43, p = 0.018).

CONCLUSIONS

Although wound complications and subsequent reoperations are potential risks for all patients with metastatic spine tumor, due to adjuvant radiotherapy and other medical comorbidities, this study identified patients with thromboembolic events or those requiring a larger incision as being at the highest risk. Measures intended to decrease the occurrence of perioperative venous thromboembolism and to improve wound care, especially for long incisions, may decrease wound-related revision surgeries in this vulnerable group of patients.