Association of risk factors with unfavorable outcomes after resection of adult benign intradural spine tumors and the effect of hospital volume on outcomes: an analysis of 18, 297 patients across 774 US hospitals using the National Inpatient Sample (2002−2011)

Procedural volume is linearly associated with mortality, major complications, and readmissions in patients undergoing malignant brain tumor resection

PURPOSE

Improved outcomes have been noted in patients undergoing malignant brain tumor resection at high-volume centers. Studies have arbitrarily chosen high-volume dichotomous cutoffs and have not evaluated volume-outcome associations at specific institutional procedural volumes. We sought to establish the continuous association of volume with patient outcomes and identify cutoffs significantly associated with mortality, major complications, and readmissions. We hypothesized that a linear volume-outcome relationship can estimate likelihood of adverse outcomes when comparing any two volumes.

METHODS

The patient cohort was identified with ICD-10 coding in the Nationwide Readmissions Database(NRD). The association of volume and mortality, major complications, and 30-/90-day readmissions were evaluated in multivariate analyses. Volume was used as a continuous variable with two/three-piece splines, with various knot positions to reflect the best model performance, based on the Quasi Information Criterion(QIC).

RESULTS

From 2016 to 2018, 34,486 patients with malignant brain tumors underwent resection. When volume was analyzed as a continuous variable, mortality risk decreased at a steady rate of OR 0.988 per each additional procedure increase for hospitals with 1-65 cases/year(95% CI 0.982-0.993, p < 0.0001). Risk of major complications decreased from 1 to 41 cases/year(OR 0.983, 95% CI 0.979-0.988, p < 0.0001), 30-day readmissions from 1 to 24 cases/year(OR 0.987, 95% CI 0.979-0.995, p = 0.001) and 90-day readmissions from 1 to 23 cases/year(OR 0.989, 95% CI 0.983-0.995, p = 0.0003) and 24-349 cases/year(OR 0.9994, 95% CI 0.999-1, p = 0.01).

CONCLUSION

In multivariate analyses, institutional procedural volume remains linearly associated with mortality, major complications, and 30-/90-day readmission up to specific cutoffs. The resulting linear association can be used to calculate relative likelihood of adverse outcomes between any two volumes.

A guide to selecting upper thoracic versus lower thoracic uppermost instrumented vertebra in adult spinal deformity correction

PURPOSE

Operative treatment of adult spinal deformity (ASD) has been shown to improve patient health-related quality of life (HRQOL). Selection of the uppermost instrumented vertebra (UIV) in either the upper thoracic (UT) or lower thoracic (LT) spine is a pivotal decision with effects on operative and postoperative outcomes. This review overviews the multifaceted decision-making process for UIV selection in ASD correction.

METHODS

PubMed was queried for articles using the keywords "uppermost instrumented vertebra", "upper thoracic", "lower thoracic", and "adult spinal deformity".

RESULTS

Optimization of UIV selection may lead to superior deformity correction, better patient-reported outcomes, and lower risk of proximal junctional kyphosis (PJK) and failure (PJF). Patient alignment characteristics, including preoperative thoracic kyphosis, coronal deformity, and the magnitude of sagittal correction influence surgical decision-making when selecting a UIV, while comorbidities such as poor body mass index, osteoporosis, and neuromuscular pathology should also be taken in to account. Additionally, surgeon experience and resources available to the hospital may also play a role in this decision. Currently, it is incompletely understood whether postoperative HRQOLs, functional and radiographic outcomes, and complications after surgery differ between selection of the UIV in either the UT or LT spine.

CONCLUSION

The correct selection of the UIV in surgical planning is a challenging task, which requires attention to preoperative alignment, patient comorbidities, clinical characteristics, available resources, and surgeon-specific factors such as experience.

Socioeconomic and Racial Disparities Affect Access to High-Volume Centers During Meningioma Treatment

BACKGROUND

Studies examining the relationship among hospital case volume, socioeconomic determinants of health, and patient outcomes are lacking. We sought to evaluate these associations in the surgical management of intracranial meningiomas.

METHODS

We queried the National Inpatient Sample (NIS) database for patients who underwent craniotomy for the resection of meningioma in 2013. We categorized hospitals into high-volume centers (HVCs) or low-volume centers (LVCs). We compared outcomes in 2016 to assess the potential impact of the Affordable Care Act on health care equity. Primary outcome measures included hospital mortality, length of stay, complications, and disposition.

RESULTS

A total of 10,270 encounters were studied (LVC, n = 5730 [55.8%]; HVC, n = 4340 [44.2%]). Of LVC patients, 62.9% identified as white compared with 70.2% at HVCs (P < 0.01). A higher percentage of patients at LVCs came from the lower 2 quartiles of median household income than did patients at HVCs (49.9% vs. 44.2%; P < 0.001). Higher mortality (1.3% vs. 0.9%; P = 0.041) was found in LVCs. Multivariable regression analysis showed that LVCs were significantly associated with increased complication (odds ratio, 1.36; 95% confidence interval, 1.30-1.426, P<0.001) and longer hospital length of stay (odds ratio, -0.05; 95% confidence interval, -0.92 to -0.45; P <0.001). There was a higher proportion of white patients at HVCs in 2016 compared with 2013 (67.9% vs. 72.3%). More patients from top income quartiles (24.2% vs. 40.5%) were treated at HVCs in 2016 compared with 2013.

CONCLUSIONS

This study found notable racial and socioeconomic disparities in LVCs as well as access to HVCs over time. Disparities in meningioma treatment may be persistent and require further study.

Hospital Frailty Risk Score and Healthcare Resource Utilization After Surgery for Primary Spinal Intradural/Cord Tumors

OBJECTIVE

The Hospital Frailty Risk Score (HFRS) is a metric that measures frailty among patients in large national datasets using ICD-10 codes. While other metrics have been utilized to demonstrate the association between frailty and poor outcomes in spine oncology, none have examined the HFRS. The aim of this study was to investigate the impact of frailty using the HFRS on complications, length of stay, cost of admission, and discharge disposition in patients undergoing surgery for primary tumors of the spinal cord and meninges.

METHODS

A retrospective cohort study was performed using the Nationwide Inpatient Sample database from 2016 to 2018. Adult patients undergoing surgery for primary tumors of the spinal cord and meninges were identified using ICD-10-CM codes. Patients were categorized into 2 cohorts based on HFRS score: Non-Frail (HFRS<5) and Frail (HFRS≥5). Patient characteristics, treatment, perioperative complications, LOS, discharge disposition, and cost of admission were assessed.

RESULTS

Of the 5955 patients identified, 1260 (21.2%) were Frail. On average, the Frail cohort was nearly 8 years older (P < .001) and experienced more postoperative complications (P = .001). The Frail cohort experienced longer LOS (P < .001), a higher rate of non-routine discharge (P = .001), and a greater mean cost of admission (P < .001). Frailty was found to be an independent predictor of extended LOS (P < .001) and non-routine discharge (P < .001).

CONCLUSION

Our study is the first to use the HFRS to assess the impact of frailty on patients with primary spinal tumors. We found that frailty was associated with prolonged LOS, non-routine discharge, and increased hospital costs.

Effect of race, sex, and socioeconomic factors on overall survival following the resection of intramedullary spinal cord tumors

INTRODUCTION

Intramedullary spinal cord tumors (IMSCTs) account for 2-4% of all primary CNS tumors. Given their low prevalence and the intricacy of their diagnosis and management, it is critical to address the surrounding racial and socioeconomic factors that impact the care of patients with IMSCTs. This study aimed to investigate the association between race and socioeconomic factors with overall 5 year mortality following the resection of IMSCTs.

METHODS

The study used the National Cancer Database to retrospectively analyze patients who underwent resection of IMSCTs from 2004 to 2017. Patients were divided into four cohorts by race/ethnicity, facility type, insurance, median income quartiles, and living area. The primary outcome of interest was 5 year survival, and secondary outcomes included postoperative length of stay and 30 day readmission. Descriptive and multivariable analyses were used to identify independent factors associated with mortality, with statistical significance assessed at a 2-sided p < 0.05.

RESULTS

We evaluated the patient characteristics and outcomes for 8,028 patients who underwent surgical treatment for IMSCTs between 2004 and 2017. Most patients were white males (52.4%) with a mean age of 44 years where 7.17% of patients were Black, 7.6% were Hispanic, and 3% were Asian. Most were treated in an academic/research program (72.4%) and had private insurance (69.2%). Black patients had a higher odd of 5 year mortality (OR 1.4; 95% CI 1.1 to 1.77; p = 0.04) compared to white patients, while no significant differences in mortality were observed among other races. Factors associated with lower odds of mortality included being female (OR 0.89; 95% CI 0.78 to 1.02; p < 0.01), receiving treatment in an academic/research program (OR 0.51; 95% CI 0.33 to 0.79; p = 0.04), having private insurance (OR 0.65; 95% CI 0.45 to 0.93; p = 0.02), and having higher income quartiles (OR 0.77; 95% CI 0.62 to 0.96; p = 0.02).

CONCLUSION

Our study sheds light on the healthcare disparities that exist in the surgical management of IMSCTs. Our findings indicate that race, sex, socioeconomic status, and treatment facility are independent predictors of 5 year mortality, with Black patients, males, those with lower socioeconomic status, and those treated at non-academic centers experiencing significantly higher mortality rates. These alarming disparities underscore the urgent need for policymakers and researchers to address the underlying factors contributing to these discrepancies and provide equal access to high-quality surgical care for patients with IMSCTs.

Impact of Racial Disparities on All-Cause Mortality in Patients With Tumors of the Spinal Cord or Spinal Meninges: A Propensity-Score Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The influence that race has on mortality rates in patients with spinal cord tumors is relatively unknown. The aim of this study was to investigate the influence of race on the outcomes of patients with primary malignant or nonmalignant tumors of the spinal cord or spinal meninges.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) Registry was used to identify all patients with a code for primary malignant or nonmalignant tumor of the spinal cord (C72.0) or spinal meninges (C70.1) from 1973 through 2016. Racial groups (African-American/Black vs. White) were balanced using propensity-score (PS) matching using a non-parsimonious 1:1 nearest neighbor matching algorithm. Overall survival (OS) estimates were obtained using the Kaplan-Meier method and compared across non-PS-matched and PS-matched groups using log-rank tests. Associations of survival with clinical variables was assessed using doubly robust Cox proportional-hazards (CPH) regression analysis.

RESULTS

There were a total of 7,498 patients identified with 648 (6.8%) being African American. African-American patients with primary intradural spine tumors were more likely to die of all causes than were White patients in both the non-PS-matched [HR: 1.26, 95% CI: (1.04, 1.51), P = 0.01] and PS-matched cohorts [HR: 1.64, 95% CI: (1.28, 2.11), P < 0.0001]. On multivariate CPH regression analysis age at diagnosis [HR: 1.03, 95% CI: (1.02, 1.05), P < 0.0001], race [HR: 1.82, 95% CI: (1.22, 2.74), P = 0.004), and receipt of RT [HR: 2.62, 95% CI: (1.56, 4.37), P = 0.0002) were all significantly associated with all-cause mortality, when controlling for other demographic, tumor, and treatment variables.

CONCLUSIONS

Our study provides population-based estimates of the prognosis for patients with primary malignant or nonmalignant tumors of the spinal cord or spinal meninges and suggests that race may impact all-cause mortality.

Machine Learning Models for Predicting Postoperative Outcomes following Skull Base Meningioma Surgery

Objective  While predictive analytic techniques have been used to analyze meningioma postoperative outcomes, to our knowledge, there have been no studies that have investigated the utility of machine learning (ML) models in prognosticating outcomes among skull base meningioma patients. The present study aimed to develop models for predicting postoperative outcomes among skull base meningioma patients, specifically prolonged hospital length of stay (LOS), nonroutine discharge disposition, and high hospital charges. We also validated the predictive performance of our models on out-of-sample testing data. Methods  Patients who underwent skull base meningioma surgery between 2016 and 2019 at an academic institution were included in our study. Prolonged hospital LOS and high hospital charges were defined as >4 days and >$47,887, respectively. Elastic net logistic regression algorithms were trained to predict postoperative outcomes using 70% of available data, and their predictive performance was evaluated on the remaining 30%. Results  A total of 265 patients were included in our final analysis. Our cohort was majority female (77.7%) and Caucasian (63.4%). Elastic net logistic regression algorithms predicting prolonged LOS, nonroutine discharge, and high hospital charges achieved areas under the receiver operating characteristic curve of 0.798, 0.752, and 0.592, respectively. Further, all models were adequately calibrated as determined by the Spiegelhalter Z -test ( p >0.05). Conclusion  Our study developed models predicting prolonged hospital LOS, nonroutine discharge disposition, and high hospital charges among skull base meningioma patients. Our models highlight the utility of ML as a tool to aid skull base surgeons in providing high-value health care and optimizing clinical workflows.

Assessment of Frailty Indices and Charlson Comorbidity Index for Predicting Adverse Outcomes in Patients Undergoing Surgery for Spine Metastases: A National Database Analysis

OBJECTIVE

The aim of this study was to assess the predictive ability of Metastatic Spinal Tumor Frailty Index (MSTFI) and the Modified 5-Item Frailty Index (mFI-5) on adverse outcomes, compared with the known Charlson Comorbidity Index (CCI).

METHODS

A retrospective cohort study was performed using National Surgical Quality Improvement Program database from 2011 to 2019. All adult patients undergoing various procedures for extradural spinal metastases were identified. Patients were stratified into frail and nonfrail cohorts based on CCI, mFI-5, and MSTFI scores. A multivariate logistic regression analysis was used to identify independent predictors of prolonged length of stay, nonroutine discharge, adverse events, and unplanned readmission.

RESULTS

Of the 1613 patients included in this study, 21.4% had a CCI >0, 56.6% had an mFI-5 >0, and 76.7% of patients had an MSTFI >0. On multivariate analysis, all 3 indices were found to be predictive of nonroutine discharge (CCI: adjusted odds ratio [aOR], 1.41 vs. mFI-5: aOR, 1.37 vs. MSTFI: aOR, 1.5) and adverse events (CCI: aOR, 1.53 vs. mFI-5: aOR, 1.23 vs. MSTFI: aOR, 1.43). High CCI (adjusted relative risk, 1.67) and MSTFI (adjusted relative risk, 1.14), but not mFI-5, were also associated with a prolonged length of stay, whereas MSTFI was found to be the only significant predictor of unplanned readmission (aOR, 1.22).

CONCLUSIONS

Our study suggests that MSTFI frailty index may be more sensitive than both CCI and mFI-5 in identifying adverse outcomes after spine surgery for metastases.

A Population-Based Study of Patients with Sleep-Wake Disorders Undergoing Elective Instrumented Spinal Surgery

BACKGROUND

Sleep-wake disorders are associated with multisystemic pathologies, but the clinical risk that such disorders carry for spinal surgery patients is not well understood. This population-based study comprehensively evaluates the significance of sleep-related risk factors on instrumented spinal surgery outcomes.

METHODS

National Inpatient Sample data for hospitalizations of patients undergoing elective instrumented spine surgery between 2008 and 2014 was analyzed using national estimates. Cohorts were defined as those admissions with or without a coexisting sleep-wake disorder diagnosis identified by ICD-9 codes. Postoperative complications, mortality rate, length of stay, discharge status, and total cost of admission were compared between groups using bivariate and multivariate analyses.

RESULTS

A coexisting sleep-wake disorder existed in 234,640 (10.8%) of 2,171,167 instrumented spinal surgery hospitalizations. Multivariate binary logistic regression accounting for these variables confirmed that a sleep-wake disorder is a significant risk factor for postoperative complication (OR 1.160, 95% CI 1.140-1.179, p<0.0001), length of stay above the 75^th percentile (OR 1.303, 95% CI 1.288-1.320, p<0.0001), non-routine discharge (OR 1.147, 95% CI 1.131-1.163, p<0.0001), and death (OR 1.533, 95% CI 1.131-2.078, p<0.01), but not for total charges above the 75^th percentile (OR 0.975, 95% CI 0.962-0.989, p<0.001).

CONCLUSIONS

Sleep-wake disorders confer increased risk of morbidity and mortality in elective instrumented spine surgery. Understanding the specific contributions of sleep-wake disorders to postoperative morbidity and mortality can help physicians implement prophylactic measures to reduce complications and improve postoperative patient recovery.

Predicting High-Value Care Outcomes After Surgery for Non-Skull Base Meningiomas

OBJECTIVE

A need exists to better understand the prognostic factors that influence high-value care outcomes after meningioma surgery. The goal of the present study was to develop predictive models to determine the patients at risk of experiencing an extended hospital length of stay (LOS), nonroutine discharge disposition, and/or a 90-day hospital readmission after non-skull base meningioma resection.

METHODS

In the present study, we analyzed the data from 396 patients who had undergone surgical resection of non-skull base meningiomas at a single institution between January 1, 2005 and December 31, 2020. The Mann-Whitney U test was used for bivariate analysis of the continuous variables and the Fisher exact test for bivariate analysis of the categorical variables. A multivariate analysis was conducted using logistic regression models.

RESULTS

Most patients had had a falcine or parasagittal meningioma (66.2%), with the remainder having convexity (31.8%) or intraventricular (2.0%) tumors. Nonelective surgery (P < 0.0001) and an increased tumor volume (P = 0.0022) were significantly associated with a LOS >4 days on multivariate analysis. The independent predictors of a nonroutine discharge disposition included male sex (P = 0.0090), nonmarried status (P = 0.024), nonelective surgery (P = 0.0067), tumor location within the parasagittal or intraventricular region (P = 0.0084), and an increased modified frailty index score (P = 0.039). Hospital readmission within 90 days was independently associated with nonprivate insurance (P = 0.010) and nonmarried status (P = 0.0081). Three models predicting for a prolonged LOS, nonroutine discharge disposition, and 90-day readmission were implemented in the form of an open-access, online calculator (available at: https://neurooncsurgery3.shinyapps.io/non_skull_base_meningiomas/).

CONCLUSIONS

After external validation, our open-access, online calculator could be useful for assessing the likelihood of adverse postoperative outcomes for patients undergoing surgery of non-skull base meningioma.

Race Is an Independent Predictor for Nonroutine Discharges After Spine Surgery for Spinal Intradural/Cord Tumors

OBJECTIVE

The aim of this study was to determine if race was an independent predictor of extended length of stay (LOS), nonroutine discharge, and increased health care costs after surgery for spinal intradural/cord tumors.

METHODS

A retrospective cohort study was performed using the National Inpatient Sample database from 2016 to 2017. All adult (>18 years old) inpatients who underwent surgical intervention for a benign or malignant spinal intradural/cord tumor were identified using International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis and procedural coding systems. Patients were then categorized based on race: White, African American (AA), Hispanic, and other. Postoperative complications, LOS, discharge disposition, and total cost of hospitalization were assessed. A backward stepwise multivariable logistic regression analysis was used to identify independent predictors of extended LOS and nonroutine discharge disposition.

RESULTS

Of 3595 patients identified, there were 2620 (72.9%) whites (W), 310 (8.6%) AAs/blacks, 275 (7.6%) Hispanic (H), and 390 (10.8%) other (O). Postoperative complication rates were similar among the cohorts (P = 0.887). AAs had longer mean (W, 5.4 ± 4.2 days vs. AA, 8.9 ± 9.5 days vs. H, 5.9 ± 3.9 days vs. O, 6.1 ± 3.9 days; P = 0.014) length of hospitalizations than the other cohorts. The overall incidence of nonroutine discharge was 55% (n = 1979), with AA race having the highest rate of nonroutine discharges (W, 53.8% vs. AA, 74.2% vs. H, 45.5% vs. O, 43.6%; P = 0.016). On multivariate regression analysis, AA race was the only significant racial independent predictor of nonroutine discharge disposition (odds ratio, 3.32; confidence interval, 1.67-6.60; P < 0.001), but not extended LOS (P = 0.209).

CONCLUSIONS

Our study indicates that AA race is an independent predictor of nonroutine discharge disposition in patients undergoing surgical intervention for a spinal intradural/cord tumor.

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.

Predicting High-Value Care Outcomes After Surgery for Skull Base Meningiomas

BACKGROUND

Although various predictors of adverse postoperative outcomes among patients with meningioma have been established, research has yet to develop a method for consolidating these findings to allow for predictions of adverse health care outcomes for patients diagnosed with skull base meningiomas. The objective of the present study was to develop 3 predictive algorithms that can be used to estimate an individual patient's probability of extended length of stay (LOS) in hospital, experiencing a nonroutine discharge disposition, or incurring high hospital charges after surgical resection of a skull base meningioma.

METHODS

The present study used data from patients who underwent surgical resection for skull base meningiomas at a single academic institution between 2017 and 2019. Multivariate logistic regression analysis was used to predict extended LOS, nonroutine discharge, and high hospital charges, and 2000 bootstrapped samples were used to calculate an optimism-corrected C-statistic. The Hosmer-Lemeshow test was used to assess model calibration, and P < 0.05 was considered statistically significant.

RESULTS

A total of 245 patients were included in our analysis. Our cohort was mostly female (77.6%) and white (62.4%). Our models predicting extended LOS, nonroutine discharge, and high hospital charges had optimism-corrected C-statistics of 0.768, 0.784, and 0.783, respectively. All models showed adequate calibration (P>0.05), and were deployed via an open-access, online calculator: https://neurooncsurgery3.shinyapps.io/high_value_skull_base_calc/.

CONCLUSIONS

After external validation, our predictive models have the potential to aid clinicians in providing patients with individualized risk estimation for health care outcomes after meningioma surgery.

Associations Between Perioperative Crystalloid Volume and Adverse Outcomes in Five Surgical Populations

BACKGROUND

Optimal administration of fluids is an important part of enhanced recovery after surgery (ERAS) protocols. We sought to examine the relationship between perioperative crystalloid volume and adverse outcomes in five common types of surgical procedures with ERAS fluid guidelines in place where large randomized controlled trials have not been conducted: breast reconstruction, bariatric, major urologic, gynoncologic, and head and neck oncologic procedures.

METHODS

This retrospective cohort study included patients who had undergone any one of the aforementioned procedures within any facility in a large multihospital alliance (Premier, Inc, Charlotte, NC) between 2008 and 2014. We used multivariable generalized additive models to examine relationships between the total crystalloid volume (TCV) on the day of surgery and a composite adverse outcome of prolonged (>75th percentile) hospital or intensive care unit stay or in-hospital mortality. Models were constructed separately within each surgical category and adjusted for demographic, clinical, and hospital characteristics. Informed consent requirements were waived because deidentified data were used.

RESULTS

We identified 83,685 patients within 312 US hospitals undergoing breast reconstruction (n = 8738), bariatric surgery (n = 8067), major urologic surgery (n = 28,654), gynoncologic surgery (n = 34,559), and head/neck oncology surgery (n = 3667). There was significant patient-independent variation in TCV. Probabilities of adverse outcomes increased at a TCV below 3 L and above 6 L for all types of surgeries except bariatric surgery, where larger volumes were associated with progressively better outcomes.

CONCLUSIONS AND RELEVANCE

Relationships between TCV and adverse outcomes were generally J shaped with higher volumes (>6 L) associated with increased risk. As per current ERAS guidelines, it is important to avoid excessive crystalloid volume in most surgical procedures except for bariatric surgery.

Hospital teaching status associated with reduced inpatient mortality and perioperative complications in surgical neuro-oncology

PURPOSE

Studies have demonstrated that higher surgical volumes correlate with improved neurosurgical outcomes yet none exist evaluating the effects of hospital teaching status on the surgical neuro-oncology patient. We present the first analysis comparing brain tumor surgery perioperative outcomes at academic and non-teaching centers.

METHODS

Brain tumor surgeries in the Nationwide Inpatient Sample (NIS) from 1998 to 2014 were identified. A teaching hospital, defined by the NIS, must have ≥ 1 Accreditation Council of Graduate Medical Education (ACGME) approved residency programs, Council of Teaching Hospitals membership, or have a ratio ≥ 0.25 of full-time residents to hospital beds. Annual treatment trends were stratified by hospital teaching status, assessing yearly caseload with linear regression. Multivariable logistic regression determined predictors of inpatient mortality/complications. Hospitals were further divided into quartiles by case volume and teaching status was compared in each.

RESULTS

Teaching hospitals (THs) exhibited an average annual increase in brain tumor surgeries (+ 1057/year, p < 0.0001). In multivariable analysis, teaching status was associated with decreased risk of mortality (OR 0.82, p = 0.0003) and increased likelihood of discharge home (OR 1.21, p < 0.0001). In subgroup analysis, within the highest hospital quartile by caseload, higher mortality rates and lower routine discharges were again seen at non-teaching hospitals (NTHs) (p = 0.0002 and p = 0.0016, respectively).

CONCLUSION

THs are performing more brain tumor surgeries over time with lower rates of inpatient mortality and perioperative complications even after controlling for hospital case volume. These results suggest a shift in neuro-oncology practice patterns favoring THs to optimize patient outcomes especially at the highest volume centers.

Does Hospital Volume Affect Outcomes in Spine Surgeries? A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To assess the impact of hospital volume on postoperative outcomes in spine surgery.

SUMMARY OF BACKGROUND DATA

Several strategies have recently been proposed to optimize provider outcomes, such as regionalization to higher volume centers and setting volume benchmarks.

MATERIALS AND METHODS

We performed a systematic review examining the association between hospital volume and spine surgery outcomes. To be included in the review, the study population had to include patients undergoing a primary or revision spinal procedure. These included anterior/posterior cervical fusions, anterior/posterior lumbar fusions, laminectomies, discectomies, spinal deformity surgeries, and surgery for spinal malignancies. We searched the Pubmed, OVID MEDLINE (1966-2018), Google Scholar, and Web of Science (1900-2018) databases in January 2018 using the search criteria ("Hospital volume" OR "volume" OR "volume-outcome" OR "volume outcome") AND ("spine" OR "spine surgery" OR "lumbar" OR "cervical" OR "decompression" OR "deformity" OR "fusions"). There were no restrictions placed on study design, publication date, or language. The studies were evaluated with respect to the quality of methodology as outlined by the Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

Twelve studies were included in the review. Studies were variable in defining hospital volume thresholds. Higher hospital volume was associated with statistically significant lower risks of postoperative complications, a shorter length of stay, lower cost of hospital stay, and a lower risk of readmissions and reoperations/revisions.

CONCLUSIONS

Our findings suggest a trend toward better outcomes for higher volume hospitals; however, further study needs to be carried out to define objective volume thresholds for specific spine surgeries for hospitals to use as a marker of proficiency.

Age Stratification of 30-Day Postoperative Outcomes Following Excisional Laminectomy for Extradural Cervical and Thoracic Tumors

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To evaluate age as an independent predictive factor for perioperative morbidity and mortality in patients undergoing surgical decompression for metastatic cervical and thoracic spinal tumors using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2011 to 2014.

METHODS

We identified 1673 adult patients undergoing excisional laminectomy of cervical and thoracic extradural tumors. Patients were stratified into quartiles based on age, with Q1 including patients aged 18 to 49 years, Q2 including patients aged 50 to 60 years, Q3 including patients aged 61 to 69 years, and Q4 including patients ≥70 years. Univariate and multivariate regression analyses were performed to examine the association between age and 30-day perioperative morbidity and mortality.

RESULTS

Age was an independent risk factor for 30-day venous thromboembolism (VTE) and reoperation. Patients in Q3 for age had nearly a 4 times increased risk of VTE than patients in Q1 (odds ratio [OR] 3.97; 95% CI 1.91-8.25; P < .001). However, there was no significant difference in VTE between patients in Q4 and Q1 (P = .069). Patients in Q2 (OR 1.99; 95% CI 1.06-3.74; P = .032) and Q4 (OR 2.18; 95% CI 1.06-4.52; P = .036) for age had a 2 times increased risk of reoperation compared with patients in Q1.

CONCLUSIONS

Age was an independent predictive factor for perioperative VTE and reoperation, but there was no clear age-dependent relationship between increasing age and the risk of these perioperative complications.

Healthcare Resource Utilization and Patient-Reported Outcomes Following Elective Surgery for Intradural Extramedullary Spinal Tumors

BACKGROUND

Healthcare resource utilization and patient-reported outcomes (PROs) for intradural extramedullary (IDEM) spine tumors are not well reported.

OBJECTIVE

To analyze the PROs, costs, and resource utilization 1 year following surgical resection of IDEM tumors.

METHODS

Patients undergoing elective spine surgery for IDEM tumors and enrolled in a single-center, prospective, longitudinal registry were analyzed. Baseline and postoperative 1-year PROs were recorded. One-year spine-related direct and indirect healthcare resource utilization was assessed. One-year resource use was multiplied by unit costs based on Medicare national payment amounts (direct cost). Patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost).

RESULTS

A total of 38 IDEM tumor patients were included in this analysis. There was significant improvement in quality of life (EuroQol-5D), disability (Oswestry and Neck Disability Indices), pain (Numeric rating scale pain scores for back/neck pain and leg/arm pain), and general physical and mental health (Short-form-12 health survey, physical and mental component scores) in both groups 1 year after surgery (P < .0001). Eighty-seven percent (n = 33) of patients were satisfied with surgery. The 1-year postdischarge resource utilization including healthcare visits, medication, and diagnostic cost was $4111 ± $3596. The mean total direct cost was $23 717 ± $7412 and indirect cost was $5544 ± $4336, resulting in total 1-year cost $29 177 ± $9314.

CONCLUSION

Surgical resection of the IDEM provides improvement in patient-reported quality of life, disability, pain, general health, and satisfaction at 1 year following surgery. Furthermore, we report the granular costs of surgical resection and healthcare resource utilization in this population.

Proposing a validated clinical app predicting hospitalization cost for extracranial-intracranial bypass surgery

OBJECT

United States healthcare reforms are focused on curtailing rising expenditures. In neurosurgical domain, limited or no data exists identifying potential modifiable targets associated with high-hospitalization cost for cerebrovascular procedures such as extracranial-intracranial (ECIC) bypass. Our study objective was to develop a predictive model of initial cost for patients undergoing bypass surgery.

METHODS

In an observational cohort study, we analyzed patients registered in the Nationwide Inpatient Sample (2002-2011) that underwent ECIC bypass. Split-sample 1:1 randomization of the study cohort was performed. Hospital cost data was modelled using ordinary least square to identity potential drivers impacting initial hospitalization cost. Subsequently, a validated clinical app for estimated hospitalization cost is proposed (https://www.neurosurgerycost.com/calc/ec-ic-by-pass).

RESULTS

Overall, 1533 patients [mean age: 45.18 ± 19.51 years; 58% female] underwent ECIC bypass for moyamoya disease [45.1%], cerebro-occlusive disease (COD) [23% without infarction; 12% with infarction], unruptured [12%] and ruptured [4%] aneurysms. Median hospitalization cost was $37,525 (IQR: $16,225-$58,825). Common drivers impacting cost include Asian race, private payer, elective admission, hyponatremia, neurological and respiratory complications, acute renal failure, bypass for moyamoya disease, COD without infarction, medium and high volume centers, hospitals located in Midwest, Northeast, and West region, total number of diagnosis and procedures, days to bypass and post-procedural LOS. Our model was validated in an independent cohort and using 1000-bootstrapped replacement samples.

CONCLUSIONS

Identified drivers of hospital cost after ECIC bypass could potentially be used as an adjunct for creation of data driven policies, impact reimbursement criteria, aid in-hospital auditing, and in the cost containment debate.

Minimally Invasive Microsurgical Resection of Primary, Intradural Spinal Tumors is Feasible and Safe: A Consecutive Series of 83 Patients

BACKGROUND

To date, the traditional approach to intraspinal tumors has been open laminectomy or laminoplasty followed by microsurgical tumor resection. Recently, however, minimally invasive approaches have been attempted by some.

OBJECTIVE

To investigate the feasibility and safety of minimally invasive surgery (MIS) for primary intradural spinal tumors.

METHODS

Medical charts of 83 consecutive patients treated with MIS for intradural spinal tumors were reviewed. Patients were followed up during the study year, 2015, by either routine history/physical examination or by telephone consultation, with a focus on tumor status and surgery-related complications.

RESULTS

Mean age at surgery was 53.7 yr and 52% were female. There were 49 schwannomas, 18 meningeomas, 10 ependymomas, 2 hemangioblastomas, 1 neurofibroma, 1 paraganglioma, 1 epidermoid cyst, and 1 hemangiopericytoma. The surgical mortality was 0%. In 87% of cases, gross total resection was achieved. The complication rate was 11%, including 2 cerebrospinal fluid leakages, 1 asymptomatic pseudomeningocele, 2 superficial surgical site infections, 1 sinus vein thrombosis, and 4 cases of neurological deterioration. There were no postoperative hematomas, and no cases of deep vein thrombosis or pulmonary embolism. Ninety-three percent of patients were ambulatory and able to work at the time of follow-up.

CONCLUSION

This study both demonstrates that it is feasible and safe to remove select, primary intradural spinal tumors using MIS, and augments the previous literature in favor of MIS for these tumors.

Surgical Resection of Intradural Extramedullary Spinal Tumors: Patient Reported Outcomes and Minimum Clinically Important Difference

STUDY DESIGN

Analysis of prospectively collected longitudinal web-based registry data.

OBJECTIVE

To determine relative validity, responsiveness, and minimum clinically important difference (MCID) thresholds in patients undergoing surgery for intradural extramedullary (IDEM) spinal tumors.

SUMMARY OF BACKGROUND DATA

Patient-reported outcomes (PROs) are vital in establishing the value of care in spinal pathology. There is limited availability of prospective, quality studies reporting PROs for IDEM spine tumors.

METHODS

. A total of 40 patients were analyzed. Baseline, postoperative 3-month, and 12-month PROs were recorded: Oswestry Disability Index or Neck disability Index (ODI/NDI), Quality of life EuroQol-5D (EQ-5D), Short Form-12 (SF-12), Numeric Rating Scale (NRS)-pain scores. Responders were defined as those who achieved a level of improvement one or two, after surgery, on health transition index (HTI) of SF-36. Receiver-operating characteristic curves were generated to assess the validity of PROs, and the difference between standardized response means (SRMs) in responders versus nonresponders was utilized to determine the relative responsiveness of each PRO measure. MCID thresholds were derived using previously reported minimal detectable change approach.

RESULTS

A significant improvement across all PROs at 3-months and 12-months follow up was noted. The derived MCID thresholds were 13.9 points: ODI/NDI, 0.14 quality adjusted life years: EQ-5D, 2.8 points: SF-12PCS and 10.7 points: SF-12MCS, 1.9 points: NRS-back/neck pain, and 1.8 points: NRS-leg/arm pain. SF-12PCS was most accurate discriminator of meaningful improvement (area under the curve, AUC-0.83) and most responsive (SRM-1.36) to postoperative improvement. EQ-5D, ODI/NDI, NRS-pain scores were all accurate discriminator (AUC-0.7-0.8) and responsive measures (0.97-0.67) of meaningful postoperative improvement. SF-12MCS was neither a valid discriminator (AUC-0.48) nor a responsive measure (SRM: -1.5) of outcome.

CONCLUSION

Surgical resection of IDEM spinal tumors provides significant and sustained improvement in quality of life, general health, disability, and pain at 12-month after surgery. The surgically resected IDEM-specific clinically meaningful thresholds are reported. All the PROs reported in this study can accurately discriminate responders and nonresponder based on SF-36 HTI index except for SF-12 MCS.

LEVEL OF EVIDENCE

3.

Growth dynamics of intramedullary spinal tumors in patients with neurofibromatosis type 2

OBJECTIVES

Volumetric data on the natural growth of intramedullary tumors in patients with neurofibromatosis type 2 (NF2) are rare, but crucial for long-term disease monitoring. Our aim was to evaluate the growth rates and growth patterns of these tumors.

PATIENTS AND METHODS

Patient records from the regional neurofibromatosis referral center were evaluated for inclusion in this analysis. Magnetic resonance images of the spine were collected and digitized as necessary. Tumor volumes were determined by volumetric extrapolation after segmentation in datasets (iPlan Net software, BrainLAB, Munich) if the tumors met the following inclusion criteria: sagittal T2-weighted MRI scans had to be available from at least two investigations and tumors had to be visible on at least two slices. All tumors that had undergone previous therapy, such as surgery, radiation or bevacizumab treatment were excluded from this study.

RESULTS

Suitable MR images of the spine were available from 51 patients (20 males, 31 females) with NF2. The median follow-up time per patient was 54 months (range 0-190 months). 23 patients (15 females, 11 males) of the 51 patients with spinal imaging harbored intramedullary tumors. Across this cohort, there was an aggregate of 68 tumors at baseline. Over the course of follow-up, the patients developed 19 additional tumors, resulting in a total of 87 tumors. A final set of 42 tumors from 19 patients met the inclusion criteria and was included in the growth analysis. The median follow-up time per tumor was 44 months (range 9-122 months). 23 of the tumors were located in the cervical spine; 19 of them were located in the thoracic spine. The median tumor size±standard deviation (SD) after 5 years was 136±71.0% compared to baseline. The median time to ≥20% tumor growth was 24 months. Overall, 30 tumors (71.4%) grew, 8 (19.1%) remained stable and 4 (9.52%) decreased in size. The most common growth pattern was saltatory growth.

CONCLUSION

Intramedullary spinal cord tumors are present in about half of patients with NF2. The majority of these tumors grow over time, albeit slowly. Given the confines of the spinal medulla and the limited scope for functional recovery after symptomatic tumor expansion, NF2 patients should be under continual surveillance in order to rapidly identify intramedullary spinal tumors that may require microsurgical resection.