Risk of developing glioblastoma following non-CNS primary cancer: a SEER analysis between 2000 and 2018

BACKGROUND

Patients with a prior malignancy are at elevated risk of developing subsequent primary malignancies (SPMs). However, the risk of developing subsequent primary glioblastoma (SPGBM) in patients with a prior cancer history is poorly understood.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database and identified patients diagnosed with non-CNS malignancy between 2000 and 2018. We calculated a modified standardized incidence ratio (M-SIR), defined as the ratio of the incidence of SPGBM among patients with initial non-CNS malignancy to the incidence of GBM in the general population, stratified by sex latency, and initial tumor location.

RESULTS

Of the 5,326,172 patients diagnosed with a primary non-CNS malignancy, 3559 patients developed SPGBM (0.07%). Among patients with SPGBM, 2312 (65.0%) were men, compared to 2,706,933 (50.8%) men in the total primary non-CNS malignancy cohort. The median age at diagnosis of SPGBM was 65 years. The mean latency between a prior non-CNS malignancy and developing a SPGBM was 67.3 months (interquartile range [IQR] 27-100). Overall, patients with a primary non-CNS malignancy had a significantly elevated M-SIR (1.13, 95% CI 1.09-1.16), with a 13% increased incidence of SPGBM when compared to the incidence of developing GBM in the age-matched general population. When stratified by non-CNS tumor location, patients diagnosed with primary melanoma, lymphoma, prostate, breast, renal, or endocrine malignancies had a higher M-SIR (M-SIR ranges: 1.09-2.15). Patients with lung cancers (M-SIR 0.82, 95% CI 0.68-0.99), or stomach cancers (M-SIR 0.47, 95% CI 0.24-0.82) demonstrated a lower M-SIR.

CONCLUSION

Patients with a history of prior non-CNS malignancy are at an overall increased risk of developing SPGBM relative to the incidence of developing GBM in the general population. However, the incidence of SPGBM after prior non-CNS malignancy varies by primary tumor location, with some non-CNS malignancies demonstrating either increased or decreased predisposition for SPGBM depending on tumor origin. These findings merit future investigation into whether these relationships represent treatment effects or a previously unknown shared predisposition for glioblastoma and non-CNS malignancy.

Predictors of spine metastases at initial presentation of pediatric brain tumor patients: a single-institution study

PURPOSE

Given the rarity of disseminated disease at the time of initial evaluation for pediatric brain tumor patients, we sought to identify clinical and radiographic predictors of spinal metastasis (SM) at the time of presentation.

METHODS

We performed a single-institution retrospective chart review of pediatric brain tumor patients who first presented between 2004 and 2018. We extracted information regarding patient demographics, radiographic attributes, and presenting symptoms. Univariate and multivariate logistic regression was used to estimate the association between measured variables and SMs.

RESULTS

We identified 281 patients who met our inclusion criteria, of whom 19 had SM at initial presentation (6.8%). The most common symptoms at presentation were headache (n = 12; 63.2%), nausea/vomiting (n = 16; 84.2%), and gait abnormalities (n = 8; 41.2%). Multivariate models demonstrated that intraventricular and posterior fossa tumors were more frequently associated with SM (OR: 5.28, 95% CI: 1.79-15.59, p = 0.003), with 4th ventricular (OR: 7.42, 95% CI: 1.77-31.11, p = 0.006) and cerebellar parenchymal tumor location (OR: 4.79, 95% CI: 1.17-19.63, p = 0.030) carrying the highest risk for disseminated disease. In addition, evidence of intracranial leptomeningeal enhancement on magnetic resonance imaging (OR: 46.85, 95% CI: 12.31-178.28, p < 0.001) and hydrocephalus (OR: 3.19; 95% CI: 1.06-9.58; p = 0.038) were associated with SM.

CONCLUSIONS

Intraventricular tumors and the presence of intracranial leptomeningeal disease were most frequently associated with disseminated disease at presentation. These findings are consistent with current clinical expectations and offer empirical evidence that heightened suspicion for SM may be prospectively applied to certain subsets of pediatric brain tumor patients at the time of presentation.

Prediction of Discharge Status and Readmissions after Resection of Intradural Spinal Tumors

Objective

Intradural spinal tumors are uncommon and while associations between clinical characteristics and surgical outcomes have been explored, there remains a paucity of literature unifying diverse predictors into an integrated risk model. To predict postresection outcomes for patients with spinal tumors.

Methods

IBM MarketScan Claims Database was queried for adult patients receiving surgery for intradural tumors between 2007 and 2016. Primary outcomes-of-interest were nonhome discharge and 90-day postdischarge readmissions. Secondary outcomes included hospitalization duration and postoperative complications. Risk modeling was developed using a regularized logistic regression framework (LASSO, least absolute shrinkage and selection operator) and validated in a withheld subset.

Results

A total of 5,060 adult patients were included. Most surgeries utilized a posterior approach (n=5,023, 99.3%) and tumors were most commonly found in the thoracic region (n=1,941, 38.4%), followed by the lumbar (n=1,781, 35.2%) and cervical (n=1,294, 25.6%) regions. Compared to models using only tumor-specific or patient-specific features, our integrated models demonstrated better discrimination (area under the curve [AUC] [nonhome discharge] = 0.786; AUC [90-day readmissions] = 0.693) and accuracy (Brier score [nonhome discharge] = 0.155; Brier score [90-day readmissions] = 0.093). Compared to those predicted to be lowest risk, patients predicted to be highest-risk for nonhome discharge required continued care 16.3 times more frequently (64.5% vs. 3.9%). Similarly, patients predicted to be at highest risk for postdischarge readmissions were readmitted 7.3 times as often as those predicted to be at lowest risk (32.6% vs. 4.4%).

Conclusion

Using a diverse set of clinical characteristics spanning tumor-, patient-, and hospitalization-derived data, we developed and validated risk models integrating diverse clinical data for predicting nonhome discharge and postdischarge readmissions.

Surgical Outcomes of Human Immunodeficiency Virus-positive Patients Undergoing Lumbar Degenerative Surgery

STUDY DESIGN

This was a retrospective cohort studying using a national administrative database.

OBJECTIVE

The objective of this study was to determine the postoperative complications and quality outcomes of the human immunodeficiency virus (HIV)-positive patients undergoing surgical management for lumbar degenerative disease (LDD).

METHODS

This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether they were HIV positive at the time of surgery. Multivariate regression was utilized to reduce the confounding of baseline covariates. Patients who underwent 3 or more levels of surgical correction were under the age of 18 years, or those with any prior history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.

RESULTS

A total of 120,167 patients underwent primary lumbar degenerative surgery, of which 309 (0.26%) were HIV positive. In multivariate regression analysis, the HIV-positive cohort was more likely to be readmitted at 30 days [odds ratio (OR)=1.9, 95% confidence interval (CI): 1.2-2.8], 60 days (OR=1.7, 95% CI: 1.2-2.5), and 90 days (OR=1.5, 95% CI: 1.0-2.2). The HIV-positive cohort was also more likely to experience any postoperative complication (OR=1.7, 95% CI: 1.2-2.3). Of the major drivers identified, HIV-positive patients had significantly greater odds of cerebrovascular disease and postoperative neurological complications (OR=3.8, 95% CI: 1.8-6.9) and acute kidney injury (OR=3.4, 95% CI: 1.3-7.1). Costs of index hospitalization were not significantly different between the 2 cohorts ($30,056 vs. $29,720, P=0.6853). The total costs were also similar throughout the 2-year follow-up period.

CONCLUSION

Patients who are HIV positive at the time of LDD surgery are at a higher risk for postoperative central nervous system and renal complications and unplanned readmissions.

Outcome Measures of Medicare Patients With Diabetes Mellitus Undergoing Thoracolumbar Deformity Surgery

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

The objective of this study was to identify the impact of diabetes on postoperative outcomes in Medicare patients undergoing adult spinal deformity (ASD) surgery.

METHODS

We queried the MarketScan Medicare database to identify patients who underwent ASD surgery from 2007 to 2016. Patients were then stratified based on diabetes status at the time of the index operation. Patients not enrolled in the Medicare dataset and those with any prior history of trauma or tumor were excluded from this study.

RESULTS

A total of 2564 patients met the inclusion criteria of this study, of which n=746 (29.1.%) were diabetic. Patients with diabetes had a higher rate of postoperative infection than nondiabetic patients (3.1% vs. 1.7%, P<0.05) within 90 days. Renal complications were also more elevated in the diabetic cohort (3.2% vs. 1.3%, P<0.05). Readmission rates were significantly higher in the diabetes cohort through of 60 days (15.2% vs. 11.8%, P<0.05) and 90 days (17.0% vs. 13.4%, P<0.05). When looking specifically at the outpatient payments, patients with diabetes did have a higher financial burden at 60 days ($8147 vs. $6956, P<0.05) and 90 days ($10,126 vs. $8376, P<0.05).

CONCLUSIONS

In this study, diabetic patients who underwent ASD surgery had elevated rates of postoperative infection, outpatient costs, and rates of readmissions within 90 days. Further research should investigate the role of poor glycemic control on spine surgery outcomes.

Risk Factors for Revision Surgery After Primary Adult Thoracolumbar Deformity Surgery

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim was to identify the risk factors for revision surgery within 2 years of patients undergoing primary adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

Previous literature reports estimate 20% of patients undergoing thoracolumbar ASD correction undergo reoperation within 2 years. There is limited published data regarding specific risk factors for reoperation in ASD surgery in the short term and long term.

METHODS

The authors queried the MarketScan database in order to identify patients who were diagnosed with a spinal deformity and underwent ASD surgery from 2007 to 2015. Patient-level factors and revision risk were investigated during 2 years after primary ASD surgery. Patients under the age of 18 years and those with any prior history of trauma or tumor were excluded from this study.

RESULTS

A total 7422 patients underwent ASD surgery during 2007-2015 in the data set. Revision rates were 13.1% at 90 days, 14.5% at 6 months, 16.7% at 1 year, and 19.3% at 2 years. In multivariate multiple logistic regression analysis, obesity [adjusted odds ratio (OR): 1.58, P<0.001] and tobacco use (adjusted OR: 1.38, P=0.0011) were associated with increased odds of reoperation within 2 years. Patients with a combined anterior-posterior approach had lower odds of reoperation compared with those with posterior only approach (adjusted OR: 0.66, P=0.0117).

CONCLUSIONS

Obesity and tobacco are associated with increased odds of revision surgery within 2 years of index ASD surgery. Male sex and combined surgical approach are associated with decreased odds of revision surgery.

The impact of osteoporosis on adult deformity surgery outcomes in Medicare patients

OBJECTIVE

To identify the impact of osteoporosis (OS) on postoperative outcomes in Medicare patients undergoing ASD surgery.

BACKGROUND

Patients with OP and advanced age experience higher than average rates of ASD. However, poor bone density could undermine the durability of a deformity correction.

METHODS

We queried the MarketScan Medicare Supplemental database to identify patients Medicare patients who underwent ASD surgery from 2007 to 2016.

RESULTS

A total of 2564 patients met the inclusion criteria of this study, of whom n = 971 (61.0%) were diagnosed with osteoporosis. Patients with OP had a similar 90-day postoperative complication rates (OP: 54.6% vs. non-OP: 49.2%, p = 0.0076, not significant after multivariate regression correction). This was primarily driven by posthemorrhagic anemia (37.6% in OP, vs. 33.1% in non-OP). Rates of revision surgery were similar at 90 days (non-OP 15.0%, OP 16.8%), but by 2 years, OP patients had a significantly higher reoperation rate (30.4% vs. 22.9%, p < 0.0001). In multivariate regression analysis, OP increased odds for revision surgery at 1 year (OR 1.4) and 2 years (OR 1.5) following surgery (all p < 0.05). OP was also an independent predictor of readmission at all time points (90 days, OR 1.3, p < 0.005).

CONCLUSION

Medicare patients with OP had elevated rates of complications, reoperations, and outpatient costs after undergoing primary ASD surgery.

Anterior Cervical Discectomy and Fusion Versus Laminoplasty for Multilevel Cervical Spondylotic Myelopathy: A National Administrative Database Analysis

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is effective for the treatment of single-level cervical spondylotic myelopathy (CSM). However, the data surrounding multilevel CSM have remained controversial. One alternative is laminoplasty, although evidence comparing these strategies has remained sparse. In the present report, we retrospectively reviewed the readmission and reoperation rates for patients who had undergone ACDF or laminoplasty for multilevel CSM from a national longitudinal administrative claims database.

METHODS

We queried the MarketScan Commercial Claims and Encounters database to identify patients who had undergone ACDF or laminoplasty for multilevel CSM from 2007 to 2016. The patients were stratified by operation type. Patients aged <18 years, patients with a history of tumor or trauma, and patients who had undergone anteroposterior approach were excluded from the present study.

RESULTS

A total of 5445 patients were included, of whom 1521 had undergone laminoplasty. A matched cohort who had undergone ACDF was identified. The overall 90-day postoperative complication rate was greater in the laminoplasty cohort (odds ratio, 1.48; 95% confidence interval, 1.18-1.86; P < 0.0001). The mean length of stay and 90-day readmission rates were greater in the laminoplasty cohort. The hospital and total payments of the index hospitalization were greater in the ACDF cohort, as were the total payments for ≤2 years after the index hospitalization.

CONCLUSIONS

In the present administrative claims database study, no difference was found in the reoperation rate between ACDF and laminoplasty. ACDF resulted in fewer complications and readmissions compared with laminoplasty but was associated with greater costs. Additional prospective research is required to investigate the factors driving the higher costs of ACDF in this population and the long-term clinical outcomes.

A Comparative Analysis of Patients Undergoing Fusion for Adult Cervical Deformity by Approach Type

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To provide insight into postoperative complications, short-term quality outcomes, and costs of the surgical approaches of adult cervical deformity (ACD).

METHODS

A national database was queried from 2007 to 2016 to identify patients who underwent cervical fusion for ACD. Patients were stratified by approach type-anterior, posterior, or circumferential. Patients undergoing anterior and posterior approach surgeries were additionally compared using propensity score matching.

RESULTS

A total of 6575 patients underwent multilevel cervical fusion for ACD correction. Circumferential fusion had the highest postoperative complication rate (46.9% vs posterior: 36.7% vs anterior: 18.5%, P < .0001). Anterior fusion patients more commonly required reoperation compared with posterior fusion patients (P < .0001), and 90-day readmission rate was highest for patients undergoing circumferential fusion (P < .0001). After propensity score matching, the complication rate remained higher in the posterior, as compared to the anterior fusion group (P < .0001). Readmission rate also remained higher in the posterior fusion group; however, anterior fusion patients were more likely to require reoperation. At index hospitalization, posterior fusion led to 1.5× higher costs, and total payments at 90 days were 1.6× higher than their anterior fusion counterparts.

CONCLUSION

Patients who undergo posterior fusion for ACD have higher complication rates, readmission rates, and higher cost burden than patients who undergo anterior fusion; however, posterior correction of ACD is associated with a lower rate of reoperation.

Differences in treatment patterns and overall survival between grade II and anaplastic pleomorphic xanthoastrocytomas

INTRODUCTION

Pleomorphic xanthoastrocytomas (PXAs) are classified as a grade II neoplasm, typically occur in children, and have favorable prognoses. However, their anaplastic counterparts remain poorly understood and vaguely characterized. In the present study, a large cohort of grade II PXA patients were compared with primary anaplastic PXA (APXA) patients to characterize patterns in treatment and survival.

METHODS

Data were collected from the National Cancer Institute's SEER database. Univariate and multivariate Cox regressions were used to evaluate the prognostic impact of demographic, tumor, and treatment-related covariates. Propensity score matching was used to balance baseline characteristics. Kaplan-Meier curves were used to estimate survival.

RESULTS

A total of 346 grade II PXA and 62 APXA patients were identified in the SEER database between 2000 and 2016. Kaplan-Meier analysis revealed substantially inferior survival for APXA patients compared to grade II PXA patients (median survival: 51 months vs. not reached) (p < 0.0001). After controlling across available covariates, increased age at diagnosis was identified as a negative predictor of survival for both grade II and APXA patients. In multivariate and propensity-matched analyses, extent of resection was not associated with improved outcomes in either cohort.

CONCLUSIONS

Using a large national database, we identified the largest published cohort of APXA patients to date and compared them with their grade II counterparts to identify patterns in treatment and survival. Upon multivariate analysis, we found increased age at diagnosis was inversely associated with survival in both grade II and APXA patients. Receipt of chemoradiotherapy or complete surgical resection was not associated with improved outcomes in the APXA cohort.

First reported use of real-time intraoperative computed tomography angiography image registration using the Machine-vision Image Guided Surgery system: illustrative case

BACKGROUND

Vertebral artery injury is a devastating potential complication of C1–2 posterior fusion. Intraoperative navigation can reduce the risk of neurovascular complications and improve screw placement accuracy. However, the use of intraoperative computed tomography (CT) increases radiation exposure and operative time, and it is unable to image vascular structures. The Machine-vision Image Guided Surgery (MvIGS) system uses optical topographic imaging and machine vision software to rapidly register using preoperative imaging. The authors presented the first report of intraoperative navigation with MvIGS registered using a preoperative CT angiogram (CTA) during C1–2 posterior fusion.

OBSERVATIONS

MvIGS can register in seconds, minimizing operative time with no additional radiation exposure. Furthermore, surgeons can better adjust for abnormal vertebral artery anatomy and increase procedure safety.

LESSONS

CTA-guided navigation generated a three-dimensional reconstruction of cervical spine anatomy that assisted surgeons during the procedure. Although further study is needed, the use of intraoperative MvIGS may reduce the risk of vertebral artery injury during C1–2 posterior fusion.

Postoperative Complication Burden, Revision Risk, and Health Care Use in Obese Patients Undergoing Primary Adult Thoracolumbar Deformity Surgery

STUDY DESIGN

This is a retrospective cohort study using a nationally representative administrative database.

OBJECTIVE

To identify the impact of obesity on postoperative outcomes in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery.

BACKGROUND

The obesity rate in the United States remains staggering, with approximately one-third of all Americans being overweight or obese. However, the impact of elevated body mass index on spine surgery outcomes remains unclear.

METHODS

We queried the MarketScan database to identify patients who were diagnosed with a spinal deformity and underwent ASD surgery from 2007 to 2016. Patients were then stratified by whether or not they were diagnosed as obese at index surgical admission. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between obese and nonobese patients. Patients <18 years and those with any prior history of trauma or tumor were excluded from this study. Baseline demographics and comorbidities, postoperative complication rates, and short- and long-term reoperation rates were determined.

RESULTS

A total of 7423 patients met the inclusion criteria of this study, of whom 597 (8.0%) were obese. Initially, patients with obesity had a higher 90-day postoperative complication rate than nonobese patients (46.1% vs 40.8%, P < .05); however, this difference did not remain after PSM. Revision surgery rates after 2 years were similar across the 2 groups following primary surgery (obese, 21.4%, vs nonobese, 22.0%; P = .7588). Health care use occurred at a higher rate among obese patients through 2 years of long-term follow-up (obese, $152 930, vs nonobese, $140 550; P < .05).

CONCLUSION

Patients diagnosed with obesity who underwent ASD surgery did not demonstrate increased rates of complications, reoperations, or readmissions. However, overall health care use through 2 years of follow-up after index surgery was higher in the obesity cohort.

Medical malpractice in spine surgery: a review

Medical malpractice is an important but often underappreciated topic within neurosurgery, particularly for surgeons in the early phases of practice. The practice of spinal neurosurgery involves substantial risk for litigation, as both the natural history of the conditions being treated and the operations being performed almost always carry the risk of permanent damage to the spinal cord or nerve roots, a cardiopulmonary event, death, or other dire outcomes. In this review, the authors discuss important topics related to medical malpractice in spine surgery, including tort reform, trends and frequency of litigation claims in spine surgery, wrong-level and wrong-site surgery, catastrophic outcomes including spinal cord injury and death, and ethical considerations.

Adverse Events and Bundled Costs after Cranial Neurosurgical Procedures: Validation of the LACE Index Across 40,431 Admissions and Development of the LACE-Cranial Index

OBJECTIVE

Anticipating postdischarge complications after neurosurgery remains difficult. The LACE index, based on 4 hospitalization descriptors, stratifies patients by risk of 30-day postdischarge adverse events but has not been validated in a procedure-specific manner in neurosurgery. Our study sought to explore the usefulness of the LACE index in a population undergoing cranial neurosurgery and to develop an enhanced model, LACE-Cranial.

METHODS

The OptumClinformatics Database was used to identify cranial neurosurgery admissions (2004-2017). Procedures were grouped as trauma/hematoma/intracranial pressure, open vascular, functional/pain, skull base, tumor, or endovascular. Adverse events were defined as postdischarge death/readmission. LACE-Cranial was developed using a logistic regression framework incorporating an expanded feature set in addition to the original LACE components.

RESULTS

A total of 40,431 admissions were included. Predictions of 30-day readmissions was best for skull base (area under the curve [AUC], 0.636) and tumor (AUC, 0.63) admissions but was generally poor. Predictive ability of 30-day mortality was best for functional/pain admissions (AUC, 0.957) and poorest for trauma/hematoma/intracranial pressure admissions (AUC, 0.613). Across procedure types except for functional/pain, a high-risk LACE score was associated with higher postdischarge bundled payment costs. Incorporating features identified to contribute independent predictive value, the LACE-Cranial model achieved procedure-specific 30-day mortality AUCs ranging from 0.904 to 0.98. Prediction of 30-day and 90-day readmissions was also improved, with tumor and skull base cases achieving 90-day readmission AUCs of 0.718 and 0.717, respectively.

CONCLUSIONS

Although the unmodified LACE index shows inconsistent classification performance, the enhanced LACE-Cranial model offers excellent prediction of short-term postdischarge mortality across procedure groups and significantly improved anticipation of short-term postdischarge readmissions.

Predictors of 2-year reoperation in Medicare patients undergoing primary thoracolumbar deformity surgery

OBJECTIVE

This was a retrospective cohort study in which the authors used a nationally representative administrative database. Their goal was to identify the risk factors for reoperation in Medicare patients undergoing primary thoracolumbar adult spinal deformity (ASD) surgery. Previous literature reports estimate that 20% of patients undergoing thoracolumbar ASD correction undergo revision surgery within 2 years. Most published data discuss risk factors for revision surgery in the general population, but these have not been explored specifically in the Medicare population.

METHODS

Using the MarketScan Medicare Supplemental database, the authors identified patients who were diagnosed with a spinal deformity and underwent ASD surgery between 2007 and 2015. The interactions of patient demographics, surgical factors, and medical factors with revision surgery were investigated during the 2 years following primary ASD surgery. The authors excluded patients without Medicare insurance and those with any prior history of trauma or tumor.

RESULTS

Included in the data set were 2564 patients enrolled in Medicare who underwent ASD surgery between 2007 and 2015. The mean age at diagnosis with spinal deformity was 71.5 years. A majority of patients (68.5%) were female. Within 2 years of follow-up, 661 (25.8%) patients underwent reoperation. Preoperative osteoporosis (OR 1.58, p < 0.0001), congestive heart failure (OR 1.35, p = 0.0161), and paraplegia (OR 2.41, p < 0.0001) independently increased odds of revision surgery. The use of intraoperative bone morphogenetic protein was protective against reoperation (OR 0.71, p = 0.0371). Among 90-day postoperative complications, a wound complication was the strongest predictor of undergoing repeat surgery (OR 2.85, p = 0.0061). The development of a pulmonary embolism also increased the odds of repeat surgery (OR 1.84, p = 0.0435).

CONCLUSIONS

Approximately one-quarter of Medicare patients with ASD who underwent surgery required an additional spinal surgery within 2 years. Baseline comorbidities such as osteoporosis, congestive heart failure, and paraplegia, as well as short-term complications such as pulmonary embolism and wound complications significantly increased the odds of repeat surgery.

Single- versus dual-attending strategy for spinal deformity surgery: 2-year experience and systematic review of the literature

OBJECTIVE

Adult spinal deformity (ASD) surgery is complex and associated with high morbidity and complication rates. There is growing evidence in the literature for the beneficial effects of an approach to surgery in which two attending physicians rather than a single attending physician perform surgery for and oversee the surgical care of a single patient in a dual-attending care model. The authors developed a dual-attending care collaboration in August 2017 in which a neurosurgeon and an orthopedic surgeon mutually operated on patients with ASD.

METHODS

The authors recorded data for 2 years of experience with ASD patients operated on by dual attending surgeons. Analyses included estimated blood loss (EBL), transfusions, length of stay (LOS), discharge disposition, complication rates, emergency room visits and readmissions, subjective health status improvement, and disability (Oswestry Disability Index [ODI] score) and pain (visual analog scale [VAS] score) at last follow-up. In addition, the pertinent literature for dual-attending spinal deformity correction was systematically reviewed.

RESULTS

The study group comprised 19 of 254 (7.5%) consecutively operated patients who underwent thoracolumbar fusion during the period from January 2017 to June 2019 (68.4% female; mean patient age 65.1 years, ODI score 44.5, VAS pain score 6.8). The study patients were matched by age, sex, anesthesia risk, BMI, smoking status, ODI score, VAS pain score, prior spine surgeries, and basic operative characteristics (type of interbody implants, instrumented segments, pelvic fixation) to 19 control patients (all p > 0.05). There was a trend toward less EBL (mean 763 vs 1524 ml, p = 0.059), fewer intraoperative red blood cell transfusions (mean 0.5 vs 2.3, p = 0.079), and fewer 90-day readmissions (0% vs 15.8%, p = 0.071) in the dual-attending group. LOS and discharge disposition were similar, as were the rates of any < 30-day postsurgery complications, < 90-day postsurgery emergency room visits, and reoperations, and ODI and VAS pain scores at last follow-up (all p > 0.05). At last follow-up, 94.7% vs 68.4% of patients in the dual- versus single-attending group stated their health status had improved (p = 0.036). In the authors' literature search of prior articles on spinal deformity correction, 5 of 8 (62.5%) articles reported lower EBL and 6 of 8 (75%) articles reported significantly lower operation duration in dual-attending cases. The literature contained differing results with regard to complication- or reoperation-sparing effects associated with dual-attending cases. Similar clinical outcomes of dual- versus single-attending cases were reported.

CONCLUSIONS

Establishing a dual-attending care management platform for ASD correction was feasible at the authors' institution. Results of the use of a dual-attending strategy at the authors' institution were favorable. Positive safety and outcome profiles were found in articles on this topic identified by a systematic literature review.

Stem cell therapies for acute spinal cord injury in humans: a review

Recent advances in stem cell biology present significant opportunities to advance clinical applications of stem cell-based therapies for spinal cord injury (SCI). In this review, the authors critically analyze the basic science and translational evidence that supports the use of various stem cell sources, including induced pluripotent stem cells, oligodendrocyte precursor cells, and mesenchymal stem cells. They subsequently explore recent advances in stem cell biology and discuss ongoing clinical translation efforts, including combinatorial strategies utilizing scaffolds, biogels, and growth factors to augment stem cell survival, function, and engraftment. Finally, the authors discuss the evolution of stem cell therapies for SCI by providing an overview of completed (n = 18) and ongoing (n = 9) clinical trials.

Designer, injectable gels to prevent transplanted Schwann cell loss during spinal cord injury therapy

Transplantation of patient-derived Schwann cells is a promising regenerative medicine therapy for spinal cord injuries; however, therapeutic efficacy is compromised by inefficient cell delivery. We present a materials-based strategy that addresses three common causes of transplanted cell death: (i) membrane damage during injection, (ii) cell leakage from the injection site, and (iii) apoptosis due to loss of endogenous matrix. Using protein engineering and peptide-based assembly, we designed injectable hydrogels with modular cell-adhesive and mechanical properties. In a cervical contusion model, our hydrogel matrix resulted in a greater than 700% improvement in successful Schwann cell transplantation. The combination therapy of cells and gel significantly improved the spatial distribution of transplanted cells within the endogenous tissue. A reduction in cystic cavitation and neuronal loss were also observed with substantial increases in forelimb strength and coordination. Using an injectable hydrogel matrix, therefore, can markedly improve the outcomes of cellular transplantation therapies.

Racial and socioeconomic correlates of treatment and survival among patients with meningioma: a population-based study

BACKGROUND

Though meningioma is the most common primary brain tumor, there is a paucity of epidemiologic studies investigating disparities in treatment and patient outcomes. Therefore, we sought to explore how sociodemographic factors are associated with rates of gross total resection (GTR) and radiotherapy as well as survival.

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database was queried to identify adult patients with meningioma diagnosed between 2005 and 2015. Socioeconomic status (SES) was determined using a validated composite index in which patients were stratified into tertiles and quintiles. Multivariable logistic regression and Cox proportional hazards analyses were used to identify predictors of treatment and survival, respectively.

RESULTS

71,098 patients met our inclusion criteria. Low SES quintile was associated with reduced odds of receiving GTR (OR 0.76, 95% CI 0.69-0.83, p < 0.0001) and radiotherapy (OR 0.83, 95% CI 0.76-0.91, p < 0.0001) as well as worse survival (HR 1.48, 95% CI 1.41-1.56) as compared to the highest SES quintile. Black patients had reduced odds of GTR (OR 0.74, 95% CI 0.67-0.71, p < 0.0001) and worse survival (HR 1.23, 95% CI 1.18-1.29, p < 0.0001) as compared to white patients.

CONCLUSIONS

This national study of patients with meningioma found socioeconomic status and race to be independent inverse correlates of likelihood of GTR, radiotherapy, and survival. Limited access to care may underlie these disparities in part, and future studies are warranted to identify specific causes for these findings.

Children with epilepsy demonstrate macro- and microstructural changes in the thalamus, putamen, and amygdala

PURPOSE

Despite evidence for macrostructural alteration in epilepsy patients later in life, little is known about the underlying pathological or compensatory mechanisms at younger ages causing these alterations. The aim of this work was to investigate the impact of pediatric epilepsy on the central nervous system, including gray matter volume, cerebral blood flow, and water diffusion, compared with neurologically normal children.

METHODS

Inter-ictal magnetic resonance imaging data was obtained from 30 children with epilepsy ages 1-16 (73% F, 27% M). An atlas-based approach was used to determine values for volume, cerebral blood flow, and apparent diffusion coefficient in the cerebral cortex, hippocampus, thalamus, caudate, putamen, globus pallidus, amygdala, and nucleus accumbens. These values were then compared with previously published values from 100 neurologically normal children using a MANCOVA analysis.

RESULTS

Most brain volumes of children with epilepsy followed a pattern similar to typically developing children, except for significantly larger putamen and amygdala. Cerebral blood flow was also comparable between the groups, except for the putamen, which demonstrated decreased blood flow in children with epilepsy. Diffusion (apparent diffusion coefficient) showed a trend towards higher values in children with epilepsy, with significantly elevated diffusion within the thalamus in children with epilepsy compared with neurologically normal children.

CONCLUSION

Children with epilepsy show statistically significant differences in volume, diffusion, and cerebral blood flow within their thalamus, putamen, and amygdala, suggesting that epilepsy is associated with structural changes of the central nervous system influencing brain development and potentially leading to poorer neurocognitive outcomes.

Risks, costs, and outcomes of cerebrospinal fluid leaks after pediatric skull fractures: a MarketScan analysis between 2007 and 2015

OBJECTIVE

Skull fractures are common after blunt pediatric head trauma. CSF leaks are a rare but serious complication of skull fractures; however, little evidence exists on the risk of developing a CSF leak following skull fracture in the pediatric population. In this epidemiological study, the authors investigated the risk factors of CSF leaks and their impact on pediatric skull fracture outcomes.

METHODS

The authors queried the MarketScan database (2007–2015), identifying pediatric patients (age < 18 years) with a diagnosis of skull fracture and CSF leak. Skull fractures were disaggregated by location (base, vault, facial) and severity (open, closed, multiple, concomitant cerebral or vascular injury). Descriptive statistics and hypothesis testing were used to compare baseline characteristics, complications, quality metrics, and costs.

RESULTS

The authors identified 13,861 pediatric patients admitted with a skull fracture, of whom 1.46% (n = 202) developed a CSF leak. Among patients with a skull fracture and a CSF leak, 118 (58.4%) presented with otorrhea and 84 (41.6%) presented with rhinorrhea. Patients who developed CSF leaks were older (10.4 years vs 8.7 years, p < 0.0001) and more commonly had skull base (n = 183) and multiple (n = 22) skull fractures (p < 0.05). These patients also more frequently underwent a neurosurgical intervention (24.8% vs 9.6%, p < 0.0001). Compared with the non–CSF leak population, patients with a CSF leak had longer average hospitalizations (9.6 days vs 3.7 days, p < 0.0001) and higher rates of neurological deficits (5.0% vs 0.7%, p < 0.0001; OR 7.0; 95% CI 3.6–13.6), meningitis (5.5% vs 0.3%, p < 0.0001; OR 22.4; 95% CI 11.2–44.9), nonroutine discharge (6.9% vs 2.5%, p < 0.0001; OR 2.9; 95% CI 1.7–5.0), and readmission (24.7% vs 8.5%, p < 0.0001; OR 3.4; 95% CI 2.5–4.7). Total costs at 90 days for patients with a CSF leak averaged $81,206, compared with $32,831 for patients without a CSF leak (p < 0.0001).

CONCLUSIONS

The authors found that CSF leaks occurred in 1.46% of pediatric patients with skull fractures and that skull fractures were associated with significantly increased rates of neurosurgical intervention and risks of meningitis, hospital readmission, and neurological deficits at 90 days. Pediatric patients with skull fractures also experienced longer average hospitalizations and greater healthcare costs at presentation and at 90 days.

Simulating Costs for Episode-Based Bundled Payments for Cranial Neurosurgical Procedures

INTRODUCTION

Episode-based bundled payments were introduced by Medicare in 2013 as the Bundled Care Improvement Initiative (BPCI) in order to improve care coordination and cost efficiency. BPCI has been implemented for orthopedic, cardiac, and spine procedures, but has not yet been applied to cranial neurosurgical procedures. We project the cost of episode-based bundled payments for cranial neurosurgical procedures.

METHODS

We performed a large retrospective observational study using the MarketScan administrative database to project bundled payment costs for common cranial neurosurgical procedures. Operations were classified into 4 groups: craniotomy for unruptured aneurysm, craniotomy for meningioma, craniotomy for malignant glioma, and craniotomy for metastasis. We project 30-, 60-, and 90-d bundle payments for each category, and analyze the contributions of postdischarge costs to total bundle payments at each time point.

RESULTS

We identified 15 276 procedures that met our inclusion criteria. We observed significant variability between groups, with 90-d bundle projected costs ranging from $58,200 for craniotomy for meningioma to $102,073 for craniotomy for malignant glioma. We also found significant variability in projected bundled payments within each class of operation. On average, payment for the index hospitalization accounted for 85% of projected costs for a 30-d bundle and 70.5% of projected costs for a 90-d bundle. Multivariate analysis showed that medical comorbidities, adjuvant therapies, and payer status significantly contributed to projected cranial bundle costs.

CONCLUSION

For the first time in our knowledge, we report projected costs of 30-, 60-, and 90-d episode-based bundled payments for common elective vascular and tumor cranial operations. As previously identified in the orthopedic literature, there is significant cost variability in total bundle payments within each cranial procedure. Compared to spine and orthopedic procedures, postdischarge costs significantly impact total bundle payments in cranial neurosurgery.

Grade II Spondylolisthesis: Reverse Bohlman Procedure with Transdiscal S1-L5 and S2 Alar Iliac Screws Placed with Robotic Guidance

BACKGROUND

Grade II spondylolisthesis remains a complex surgical pathology for which there is no consensus regarding optimal surgical strategies. Surgical strategies vary regarding extent of reduction, use of instrumentation/interbody support, and anterior versus posterior approaches with or without decompression. Here we provide the first report on the efficacy of robotic spinal surgery systems in support of the treatment of grade II spondylolisthesis.

METHODS

Using 2 illustrative cases, we provide a technical report describing how robotic spinal surgery platform can be used to treatment grade II spondylolisthesis with a novel instrumentation strategy.

RESULTS

We describe how the "reverse Bohlman" technique to achieve a large anterior fusion construct spanning the pathological level and buttressed by the adjacent level above, coupled with a novel, high-fidelity posterior fixation scheme with transdiscal S1-L5 and S2 alar iliac (S2AI) screws placed in a minimally invasive fashion with robot guidance allows for the best chance of fusion in situ.

CONCLUSIONS

The reverse Bohlman technique coupled with transdiscal S1-L5 and S2AI screw fixation accomplishes the surgical goals of creating a solid fusion construct, avoiding neurologic injury with aggressive reduction, and halting the progression of anterolisthesis. The use of robot guidance allows for efficient placement of these difficult screw trajectories in a minimally invasive fashion.

Axon degeneration: molecular mechanisms of a self-destruction pathway

Axon degeneration is a characteristic event in many neurodegenerative conditions including stroke, glaucoma, and motor neuropathies. However, the molecular pathways that regulate this process remain unclear. Axon loss in chronic neurodegenerative diseases share many morphological features with those in acute injuries, and expression of the Wallerian degeneration slow (WldS) transgene delays nerve degeneration in both events, indicating a common mechanism of axonal self-destruction in traumatic injuries and degenerative diseases. A proposed model of axon degeneration is that nerve insults lead to impaired delivery or expression of a local axonal survival factor, which results in increased intra-axonal calcium levels and calcium-dependent cytoskeletal breakdown.