The correlation of cerebral arteriovenous malformation flow measured by quantitative MR angiography on MR-detected arteriovenous malformation microhemorrhage.

OBJECTIVE: The objective of this study was to assess the relationship of arteriovenous malformation (AVM) blood flow measured by quantitative MR angiography (QMRA) in nonruptured AVMs with MR-detected microhemorrhage. METHODS: All patients with unruptured AVMs who received baseline QMRA and gradient echo or susceptibility-weighted MRI were retrospectively reviewed (2004-2022). Imaging data, clinical history, and AVM angioarchitectural and flow features were collected and assessed. AVM flow was calculated from the difference of flow within primary arterial feeders from their contralateral counterparts. A review of the MR images determined the presence of microhemorrhages. Analysis of descriptive statistics, chi-square test, and binomial logistic regression were performed. RESULTS: Of 634 patients with cerebral AVMs at a single center, 89 patients met the inclusion criteria (54 with microhemorrhage and 35 without microhemorrhage). The calculated AVM flow was significantly higher in the group with a microhemorrhage (447.9 ± 193.1 ml/min vs 287.6 ± 235.7 ml/min, p = 0.009). In addition, the presence of venous anomaly, arterial ectasia, and diffuse nidus was significantly associated with microhemorrhage (p = 0.017, p = 0.041, and p = 0.041, respectively). Binary logistic regression found that higher flow predicted the presence of microhemorrhage (OR 1.002, 95% CI 1.000-1.004; p = 0.031). The highest AVM flow quartile significantly predicted the presence of venous anomaly (OR 3.840, 95% CI 1.037-14.213; p = 0.044), diffuse nidus (OR 6.800, 95% CI 1.766-25.181; p = 0.005), and arterial ectasia (OR 13.846, 95% CI 1.905-122.584; p = 0.018). CONCLUSIONS: This study represents the first to examine the association between flow measurements on QMRA with microhemorrhage in unruptured AVMs. Higher AVM flow, venous anomaly, arterial ectasia, and diffuse AVM nidus were related to a higher likelihood of AVM microhemorrhage. Higher AVM flow was present in AVMs with venous anomalies, a diffuse nidus, and arterial ectasia, indicating a possible interaction between these angioarchitectural findings, AVM flow, and microhemorrhage. These findings suggest a relationship between higher AVM flow and the risk of microhemorrhage.

Discharge within 1 day following elective single-level transforaminal lumbar interbody fusion: a propensityscore-matched analysis of predictors, complications, and readmission.

STUDY DESIGN: This was a retrospective case-control study using 8 years of data from a nationwide database of surgical outcomes in the United States. PURPOSE: This study aimed to improve our understanding of the risk factors associated with a length of stay (LOS) >1 day and aid in reducing postoperative hospitalization and complications. OVERVIEW OF LITERATURE: Despite the proven safety of transforaminal lumbar interbody fusion (TLIF), some patients face prolonged postoperative hospitalization. METHODS: Data were collected from the American College of Surgeons National Surgical Quality Improvement Program dataset from 2011 to 2018. The cohort was divided into patients with LOS up to 1 day (LOS ≤1 day), defined as same day or next-morning discharge, and patients with LOS >1 day (LOS >1 day). Univariable and multivariable regression analyses were performed to evaluate predictors of LOS >1 day. Propensity-score matching was performed to compare pre- and postdischarge complication rates. RESULTS: A total of 12,664 eligible patients with TLIF were identified, of which 14.8% had LOS ≤1 day and 85.2% had LOS >1 day. LOS >1 day was positively associated with female sex, Hispanic ethnicity, diagnosis of spondylolisthesis, American Society of Anesthesiologists classification 3, and operation length of >150 minutes. Patients with LOS >1 day were more likely to undergo intraoperative/postoperative blood transfusion (0.3% vs. 4.5%, p<0.001) and reoperation (0.1% vs. 0.6%, p=0.004). No significant differences in the rates of postdischarge complications were found between the matched groups. CONCLUSIONS: Patients with worsened preoperative status, preoperative diagnosis of spondylolisthesis, and prolonged operative time are more likely to require prolonged hospitalization and blood transfusions and undergo unplanned reoperation. To reduce the risk of prolonged hospitalization and associated complications, patients indicated for TLIF should be carefully selected.

Incidence, Management, and Outcomes of Adult Spinal Chordoma Patients in the United States.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Spinal chordomas are rare primary malignant neoplasms of the primitive notochord. They are slow growing but locally aggressive lesions that have high rates of recurrence and metastasis after treatment. Gold standard treatment remains en-bloc surgical resection with questionable efficacy of adjuvant therapies such as radiation and chemotherapy. Here we provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with spinal chordoma. METHODS: Patients with diagnosis codes specific for chordoma of spine, sacrum, and coccyx were queried from the National Cancer Database (NCDB) during the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: 1,548 individuals were identified with a diagnosis of chordoma, 60.9% of which were at the sacrum or coccyx and 39.1% at the spine. The mean overall survival of patients in our cohort was 8.2 years. Increased age, larger tumor size, and presence of metastases were associated with worsened overall survival. 71.2% of patients received surgical intervention and both partial and radical resection were associated with significantly improved overall survival (P < 0.001). Neither radiotherapy nor chemotherapy administration improved overall survival; however, amongst patients who received radiation, those who received proton-based radiation had significantly improved overall survival compared to traditional radiation. CONCLUSION: Surgical resection significantly improves overall survival in patients with spinal chordoma. In those patients receiving radiation, those who receive proton-based modalities have improved overall survival. Further studies into proton radiotherapy doses are required.

Clinical and radiographic benefits of skipping C7 instrumentation in posterior cervicothoracic fusion: a retrospective analysis.

Background: C7 instrumentation during posterior cervicothoracic fusion can be challenging because it requires additional work of either placing side connectors to a single rod or placing two rods. Our clinical observations suggested that skipping instrumentation at C7 in a multi-level posterior cervicothoracic fusion will result in minimal intraoperative complications and decreased blood-loss while still maintaining sagittal balance parameters of cervical fusion. The objective of this study is to determine the clinical and radiographic outcomes of skipping C7 instrumentation compared to instrumenting the C7 vertebra in posterior cervicothoracic fusion. Methods: This is a retrospective chart review of 314 consecutive patients who underwent multilevel posterior cervical fusion (PCF) at our institution. Out of 314 patients, 19 were instrumented at C7 serving as the control group, while the remaining 295 patients were not. Evaluation of efficacy was based on intraoperative complications, operative time, estimated blood loss (EBL), significant long-term complications, and radiographic evidence of fusion. Results: Skipping the C7 level resulted in a significant reduction in EBL (488±576 vs. 822±1,137; P=0.007); however, operative time was similar between groups (174±95 vs. 184±86 minutes; P=0.844). Complications were minimal in both groups and not statistically significant. Radiographic analysis revealed C7 bridge patients had a significantly increased postoperative sagittal vertical axis (SVA) (29.3±13.1 vs. 20.2±3.1 mm; P=0.008); however, there was no significant difference between groups in SVA correction (-0.3±16.2 vs. -16.1±16.0 mm; P=0.867), T1 slope correction (3.4°±9.9° vs. 3.2°±5.5°; P=0.127), or cervical cobb angle correction (-5.7°±14.2° vs. -7.0°±12.2°; P=0.519). There were no significant long-term complications in either group. Conclusions: Skipping instrumentation at C7 in a multilevel posterior cervicothoracic fusion is associated with significantly reduced operative blood loss without loss of radiographic correction. This study demonstrates the clinical benefits of skipping C7 instrumentation in posterior cervicothoracic fusion with maintenance of radiographic correction parameters.

Current Trends and Socioeconomic Disparities in the Utilization of Spine Augmentation for Patients With Osteoporotic Vertebral Compression Fracture: A Nationwide Inpatient Sample Analysis From 2012 to 2016.

INTRODUCTION: Osteoporotic vertebral compression fracture (OVCF) is a growing health care problem in today's aging population. Since the advent of kyphoplasty and vertebroplasty, these interventions have been commonly utilized in the treatment of symptomatic OVCF. However, the use of these interventions varies because there is not a standard of care for the management of OVCF. There remain disparities in the use of these procedures as treatment for OVCFs in the United States. METHODS: The 2012 to 2016 Nationwide Inpatient Sample was queried for all patients admitted for OVCF. These patients were then grouped based on whether they received conservative vs surgical (kyphoplasty/vertebroplasty) management and compared with respect to various socioeconomic factors including race, insurance coverage, income quartile, hospital control, and geography. Propensity score matching was utilized to control for potential baseline confounders as well as the influence of other endpoints. RESULTS: The search criteria identified 35,199 patients admitted with OVCF, of whom 7900 (22.4%) received spine augmentation. Blacks/African Americans (risk ratios [RR] = 0.79, P < 0.001), Hispanics/Latinos (RR = 0.82, P < 0.001), Asians/Pacific Islanders (RR = 0.81, P = 0.048), and unknown/other races (RR = 0.88, P = 0.037) were less likely to receive surgical management than whites/Caucasians. When compared with Medicare patients, those with Medicaid (RR = 0.76, P < 0.001) were less likely to receive surgery while privately insured patients were more likely (RR = 1.06, P = 0.42). Patients in the West (RR = 0.90, P < 0.001) were less likely to receive surgery for OVCF than those in the Northeast. CONCLUSIONS: A wide variety of socioeconomic disparities exists in the use of spinal augmentation for the management of OVCF in the United States, limiting patient access to a potentially beneficial procedure. CLINICAL RELEVANCE: Retrospective Analysis.

Thrombocytopenia as an Independent Prognostic Indicator Following Extradural Spinal Tumor Resection.

OBJECTIVE: Few studies have examined the prognosis for patients with baseline thrombocytopenia undergoing extradural spine tumor resection. Our objective was to evaluate mortality, readmission, and other 30-day outcomes in patients with varying degrees of preoperative thrombocytopenia undergoing osseous extradural tumor excision. METHODS: A multicenter registry was queried for patients treated from 2011-2019. Patients were categorized according to baseline preoperative platelet count, in 25,000/µL increments: 125,000-149,000/µL, 100,000-125,000/µL, 75,000-100,000/µL, and <75,000/µL. These were compared to a control group with platelet count >150,000/µL. Outcomes in each cohort were analyzed using multivariate logistic regression analysis. RESULTS: The database search revealed 3574 patients undergoing extradural tumor resection; 2171 (60.7%) patients with platelets 125,000-149,000/µL, 114 (3.2%) with 100,000-125,000/µL, 43 (1.2%) with 75,000-100,000/µL, and 42 (1.2%) with <75,000/µL. Platelet counts <100,000/µL was associated with perioperative blood transfusion, cardiac complications, non-home discharge, and 30-day mortality. On subgroup analysis for mortality, an interaction was present between individuals with moderate/severe thrombocytopenia and cervical tumors. CONCLUSIONS: In patients undergoing surgery for extradural spine tumor, degree of baseline thrombocytopenia-rather than presence alone-is an independent predictor of several adverse events. Wherever possible, optimization of preoperative platelet count to at least 100,000/µL may improve outcomes.

Chordoma of the Skull Base: A National Cancer Database Analysis of Current Practice Patterns and Outcomes.

BACKGROUND: Chordomas of the skull base are aggressive locally destructive tumors that arise from the remnants of the fetal notochord. Current guidelines recommend maximal safe surgical resection followed by adjuvant radiation therapy. However, because of the rarity of these tumors, the optimal radiotherapeutic regimen regarding dose and modality is unclear. METHODS: The National Cancer Database (NCDB) was queried from 2004 to 2016. Data from adult patients were extracted, including tumor characteristics, comorbidity indices, and details of treatment (surgery, radiation, and chemotherapy). The primary outcome of interest was overall survival (OS), which was evaluated for specific treatment cohorts using Cox univariate and multivariate regression constructs along with associated survival curves. RESULTS: We identified 798 patients with a diagnosis of skull base chordoma. Mean OS in this cohort was 9.57 years. Most patients received surgical resection (89.1%), with 53.9% receiving radiotherapy and 6.5% receiving chemotherapy. After adjusting for baseline characteristics using multivariate regression, advanced age and increased tumor size were associated with decreased OS. Surgical resection was associated with increased OS, whereas neither radiotherapy nor chemotherapy was associated with OS. However, in patients who did receive radiation, dosage >6000 cGy was associated with increased OS (hazard ratio, 0.51; P = 0.038); OS did not vary significantly between traditional and proton-based methods. CONCLUSIONS: Our multi-institutional analysis supports the use of partial and radical surgical resection to improve survival in patients with skull base chordomas. Among patients who receive radiotherapy, higher radiation dose is associated with improved survival.

Cannabis Abuse and Perioperative Complications Following Inpatient Spine Surgery in the United States.

MINI: Due to its complicated legal status, the effects of cannabis on elective spine surgery patients have not been well studied. In this nationwide analysis, we find that cannabis abuse is associated with higher perioperative thromboembolism and neurologic complications, respiratory complications, sepsis, length of stay, hospital charges, and rates of unfavorable discharge disposition.

Retrospective cohort analysis of a nationwide administrative database. The aim of this study was to analyze the association between cannabis abuse and serious adverse events following elective spine surgery. Cannabis is the most popular illicit drug in the United States, and its use has been increasing in light of state efforts to decriminalize and legalize its use for both medical and recreational purposes. Its legal status has long precluded extensive research into its adverse effects, and to date, little research has been done on the sequelae of cannabis on surgical patients, particularly in spine surgery. The 2012­2015 Nationwide Inpatient Sample was queried for all patients undergoing common elective spine surgery procedures. These patients were then grouped by the presence of concurrent diagnosis of cannabis use disorder and compared with respect to various peri- and postoperative complications, all-cause mortality, discharge disposition, length of stay, and hospitalization costs. Propensity score matching was utilized to control for potential baseline confounders. A total of 423,978 patients met inclusion/exclusion criteria, 2393 (0.56%) of whom had cannabis use disorder. After controlling for baseline characteristics and comorbid tobacco use, these patients similar inpatient mortality, but higher rates of perioperative thromboembolism (odds ratio [OR] 2.2; 95% confidence interval [CI] 1.2­4.0; P  = 0.005), respiratory complications (OR 2.0; 95% CI 1.4­2.9; P  < 0.001), neurologic complications such as stroke and anoxic brain injury (OR 2.9; 95% CI 1.2­7.5; P  = 0.007), septicemia/sepsis (OR 1.5; 95% CI 1.0 to 2.5; P  = 0.031), and nonroutine discharge ( P  < 0.001), as well as increased lengths of stay (7.1 vs. 5.2 days, P  < 0.001) and hospitalization charges ($137,631.30 vs. $116,112.60, P  < 0.001). Cannabis abuse appears to be associated with increased perioperative morbidity among spine surgery patients. Physicians should ensure that a thorough preoperative drug use history is taken, and that affected patients be adequately informed of associated risks. Level of Evidence: 3.

Predictors of Extended Hospitalization and Early Reoperation After Elective Lumbar Disc Arthroplasty.

BACKGROUND: Lumbar disc arthroplasty (LDA) has emerged as a motion-sparing alternative to lumbar fusion. Although LDA may be amenable to the ambulatory surgical setting, to date no study has identified the factors predisposing patients to extended hospital stay. METHODS: A national surgical quality improvement database was queried from 2011 to 2019 for patients undergoing elective, single-level, primary LDA. Univariate and multivariate logistic regression analyses were performed to elucidate predictors of length of stay (LOS) at or above the 90th percentile of the study population (3 days). Secondary study endpoints included rates of complications, as well as predictors and reasons for unplanned reoperation within 30 days. RESULTS: A total of 630 patients met eligibility criteria for the study, of whom 517 (82.1%) had LOS <3 days and 113 (17.9%) had LOS ≥3 days. Multivariate logistic regression revealed associations between prolonged hospitalization and postoperative diagnosis of degenerative disk disease, obesity, Hispanic identity, and operation length >120 minutes. Before discharge, patients with LOS ≥3 days were more likely to have venous thromboembolisms, pneumonia, surgical site infections, and reoperations. Independent predictors of reoperation were wound infections, diabetes, and smoking. CONCLUSIONS: Complications following elective single-level LDA are relatively rare, with few extended hospitalizations being attributable to any specific complication. Risk factors for prolonged LOS appear to be related to diagnosis and surgical time rather than to modifiable preoperative comorbidities. Conversely, unplanned reoperations within 30 days are associated with optimizable perioperative factors such as smoking, diabetes, and surgical site infection.

Fenestrated Pedicle Screws in Spinal Oncology: Technique and Comparative Retrospective Analysis.

BACKGROUND: The use of spinal stabilization with decompression has been shown to improve survival, spinal stability, and ambulatory status in patients with metastatic spinal tumors. However, the poor bone quality typically seen in these patients can prevent adequate stabilization. Fenestrated pedicle screws permit augmented fixation via injection of bone cement into the vertebral body upon screw placement, potentially mitigating the difficulties in achieving adequate stabilization in these patients. OBJECTIVE: To compare surgical outcomes of posterior spinal fusion in patients with cancerous spinal lesions between polymethyl methacrylate cement-augmented fenestrated screws and standard pedicle screws. METHODS: A total of 19 consecutive patients with cancerous spinal lesions receiving posterior spinal fusion (PSF) with pedicle screws from a single surgeon were retrospectively reviewed for demographic information, comorbidities, surgical parameters, and outcomes. RESULTS: Ten patients underwent PSF with cement augmentation, whereas 9 underwent standard PSF. There was no significant difference in demographics, comorbidities, or surgical characteristics. Operative time was significantly greater in the cement-augmented group (302 ± 100 minutes vs 203 ± 55 minutes; P = .015). There was no significant difference in rates of operation or readmission between the cohorts nor was there any significant difference in discharge disposition. There was 1 case of surgical site infection (in a patient with a fenestrated screw) and no cases of cement extravasation. No instances of mechanical hardware failure were recorded. CONCLUSIONS: Fenestrated screws confer similar risk profiles as nonfenestrated screws for posterior spinal fusion in patients with spinal cancer. However, fenestrated screws may affect operative time, radiation exposure, and impose risk of cement extravasation. Cement-augmented fenestrated pedicle screws may be a viable option for patients with poor bone quality associated with metastatic disease without significantly increased rates of surgical complications. LEVEL OF EVIDENCE: 3.

Outcomes and Patterns of Care in Elderly Patients with Glioblastoma Multiforme.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in adults, with an increased incidence among the elderly. However, the optimal treatment strategy in elderly patients remains unclear. This study seeks to investigate the effect of patient selection and treatment strategies on survival trends in these patients. METHODS: Patients with diagnosis codes specific for GBM were queried from the National Cancer Database during 2004-2016. Univariate and multivariate Cox regression analysis was performed to investigate outcomes. Survival curves and 5-year survival were also generated based on patient-specific factors. RESULTS: Among 104,456 patients with GBM identified, elderly patients were less likely to receive radiotherapy (61.3% vs. 77.8%; P < 0.001) or chemotherapy (47.2% vs. 62.9%; P < 0.001) or to undergo surgical resection (68.3% vs. 81.8; P < 0.001). Mean overall survival was 9.1 months (standard deviation, 10.0) and 5-year survival was 5.3%. Multivariate analysis showed age 75-84 years (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.12-1.73; P = 0.003) and lower Karnofsky Performance Status (50-70: HR, 1.68, 95% CI, 1.35-2.08, P < 0.001; ≤40: HR, 1.79, 95% CI 1.18-2.72, P = 0.006) were associated with decreased overall survival, whereas surgical resection (subtotal resection: HR, 0.52, 95% CI, 0.38-0.71, P < 0.001; gross total resection: HR, 0.29, 95% CI, 0.21-0.41, P < 0.001), radiotherapy (HR, 0.65; 95% CI, 0.47-0.91; P = 0.012), and chemotherapy (HR, 0.65; 95% CI, 0.48-0.88; P = 0.006) were associated with increased overall survival in elderly patients. CONCLUSIONS: In an analysis of 104,456 patients with GBM, all treatment modalities were found to be used less frequently in elderly patients. Increasing age and poor performance status were associated with worsened survival. Gross total resection was associated with the greatest survival benefit, and chemotherapy and radiotherapy also improved survival outcomes. These treatment options improved outcomes regardless of performance status. Although maximal treatment strategies may improve survival in elderly patients with GBM, these treatment strategies must be balanced against patient-specific factors and quality-of-life concerns.

High-Grade Spinal Hemangioma: A National Cancer Database Analysis.

BACKGROUND: Spinal hemangiomas are common primary tumors of the vertebrae. Although these tumors are most frequently benign and asymptomatic, they can rarely exhibit aggressive growth and invasion into neighboring structures. Treatment for these aggressive variants is controversial, often involving surgery, chemotherapy, and/or radiotherapy. This study sought to investigate current trends affecting overall survival (OS) using the National Cancer Database (NCDB) and to formulate treatment recommendations. METHODS: The National Cancer Database was queried for spinal hemangiomas between 2004 and 2016. A Cox proportional hazards model was used to perform multivariate regression analysis of survival. Survival curves for comparative visualization of demographic and treatment factors were generated using a semiparametric Cox approach. RESULTS: A cohort of 102 patients with histologically confirmed spinal hemangiomas was identified in the database. Mean OS was 1.94 years. Administered treatments included partial surgical resection (n = 17), radical resection (n = 14), chemotherapy (n = 34), and radiotherapy (n = 56). Multivariate analysis revealed associations between decreased OS and advanced age (>65 years) and presence of metastasis. Cox survival analysis further revealed improved OS in patients who received surgical treatment and higher radiation dose. CONCLUSIONS: This retrospective analysis finding that treatment with surgical resection and/or radiotherapy is associated with increased OS constitutes the largest cohort of patients with aggressive vertebral hemangiomas to date. Given that the mean OS of the study cohort was 1.94 years, our findings suggest that the optimal treatment regimen to maximize survival should consist of early surgical resection with adjuvant high-dose radiotherapy.

Outcomes and Patterns of Care in Adult Skull Base Chondrosarcoma Patients in the United States.

BACKGROUND: Chondrosarcomas of the skull base are rare intracranial tumors of chondroid origin. The rarity of these lesions has made it difficult to form a consensus on optimal treatment regimens. The aim of this study was to provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with chondrosarcoma of the skull base. METHODS: Patients with diagnosis codes for chondrosarcoma of the skull base were queried from the National Cancer Database for the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: A total of 718 patients with chondrosarcoma of the skull base were identified. Mean overall survival (OS) in these patients was 10.7 years. Older age and presence of metastases were associated with worsened OS. Of patients, 83.3% received surgical intervention, and both partial resection and radical resection were associated with significantly improved OS (P < 0.001). Neither radiotherapy nor chemotherapy improved OS; however, patients who received proton-based radiation and patients who received high-dose radiation (≥6000 cGy) had significantly improved OS compared with patients who received traditional radiation. CONCLUSIONS: In the largest study to our knowledge of skull base chondrosarcoma to date, both partial resection and radical resection significantly improved OS, thus supporting the goal of maximal safe resection to preserve vital neurovascular structures without sacrificing outcome. In patients who received radiotherapy, proton-based modalities and high-dose radiation were associated with increased OS.

Assessing the Clinical Safety Profile of Computer-Assisted Navigation for Posterior Cervical Fusion: A Propensity-Matched Analysis of 30-Day Outcomes.

BACKGROUND: Computer-assisted navigation (CAN) has been shown to improve accuracy of screw placement in procedures involving the posterior cervical spine, but whether the addition of CAN affects complication rates, neurologic or otherwise, is presently unknown. The objective of this study is to determine the effect of spinal CAN on short-term clinical outcomes following posterior cervical fusion. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2011 to 2018. Patients receiving posterior cervical fusion were identified and separated into CAN and non-CAN cohorts on the basis of a propensity score matching algorithm to select similar patients for comparison. Rates of 30-day unplanned readmission, reoperation, and other complications were evaluated. A separate matching algorithm was used to generate a subgroup of patients undergoing C1-C2 or occiput-C2 fusion for comparison of the same outcomes. RESULTS: A total of 12,578 patients met inclusion criteria, of which 689 received CAN and 11,889 did not. After adjusting for baseline differences, patients receiving CAN experienced longer operations and had higher total relative value units associated with care. There were no significant differences in 30-day complication, readmission, or revision rates. At the occipitocervical junction, there were more hardware revisions in the non-CAN group, but this effect did not reach statistical significance (2 vs. 0; P = 0.155). CONCLUSIONS: Surgeons should embrace navigation in the cervical spine at their own discretion, as use of CAN does not appear to be associated with increased rates of surgical complications or readmissions despite longer operative time.

Incidence, Management, and Outcomes of Adult Patients with Spinal Chondrosarcoma in the United States.

OBJECTIVE: Spinal chondrosarcomas are rare primary malignant neoplasms composed of cartilage-producing cells. They are slow-growing but locally aggressive lesions that have high rates of recurrence and progression after treatment. We provide the largest comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with spinal chondrosarcoma using a large, prospectively collected national database. METHODS: Patients with diagnosis codes specific for chondrosarcoma of the spine, sacrum, and coccyx were queried from the National Cancer Database (NCDB) during 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: A total of 1843 individuals were identified with a diagnosis of chondrosarcoma, 82.1% of which were at the sacrum or coccyx and 17.9% at the spine. The mean overall survival of patients in our cohort was 7.91 years. Increased age, larger tumor, dedifferentiated histology, and presence of metastases were associated with worsened overall survival. Regarding management, 77.7% of patients received surgical intervention and both partial and radical resection were associated with significantly improved overall survival (P < 0.001). Neither radiotherapy nor chemotherapy administration improved overall survival; however, among patients who received radiation, those who received higher-dose radiation had significantly improved overall survival compared with those who received lower-dose radiation. CONCLUSIONS: Surgical resection significantly improves overall survival in patients with spinal chondrosarcoma. In those patients receiving radiation, those who receive high doses have improved overall survival compared with those who receive lower doses. Further studies into optimal radiation modality and doses are required.

Association of Neurosurgical Work Relative Value Units with Objective Markers of Operative Complexity.

OBJECTIVE: Relative value units (RVUs) form the backbone of health care service reimbursement calculation in the United States. However, it remains unclear how well RVUs align with objective measures of procedural complexity within neurosurgery. METHODS: The 2018 American College of Surgeons National Surgical Quality Improvement Program database was queried for neurosurgical procedures with >50 patients, using Current Procedural Terminology (CPT) codes. Length of stay (LOS), operative time, mortality, and readmission and reoperation rates were collected for each code and a univariate correlation analysis was performed, with significant predictors entered into a multivariate logistic regression model, which generated predicted work RVUs, which were compared with actual RVUs to identify undervalued and overvalued procedures. RESULTS: Among 64 CPT codes, LOS, operative time, mortality, readmission, and reoperation were significant independent predictors of work RVUs and together explained 76% of RVU variance in a multivariate model (R2 = 0.76). Using a difference of >1.5 standard deviations from the mean, procedures associated with greater than predicted RVU included surgery for intracranial carotid circulation aneurysms (CPTs 61697 and 61700; residual RVU = 12.94 and 15.07, respectively), and infratemporal preauricular approaches to middle cranial fossa (CPT 61590; residual RVU = 15.39). Conversely, laminectomy/foraminotomy for decompression of additional spinal cord, cauda equina, and/or nerve root segments (CPT 63048; residual RVU = -21.30), transtemporal craniotomy for cerebellopontine angle tumor resection (CPT 61526; residual RVU = -9.95), and brachial plexus neuroplasty (CPT 64713; residual RVU = -11.29) were associated with lower than predicted RVU. CONCLUSIONS: Work RVUs for neurosurgical procedures are largely predictive of objective measures of surgical complexity, with few notable exceptions.

Endoscopic Versus Open Laminectomy for Lumbar Spinal Stenosis: An International, Multi-Institutional Analysis of Outcomes and Adverse Events.

STUDY DESIGN: Retrospective cohort study and systematic review. OBJECTIVES: Endoscopic decompression offers a minimally invasive alternative to traditional, open laminectomy. However, comparison of these surgical techniques has been largely limited to small, single-center studies. In this study, we perform the first international, multicenter comparison of both with regard to their associated rates of mortality, complications, readmissions, and reoperations. METHODS: The 2017 American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database, containing data from over 650 hospitals internationally, was queried to evaluate the effect of endoscopic guidance on adverse events. Operative time, length of stay, readmission and reoperation rates, as well as the incidence of peri- and postoperative complications, were compared between endoscopic and open groups. The PubMed/MEDLINE database was queried for studies comparing the techniques. RESULTS: A total of 10 726 single-level lumbar decompression patients were identified and included in this study, 34 (0.32%) of whom were operated upon endoscopically. Apart from 2 (5.88%) readmissions, among which only 1 was unplanned, there were no reported surgical complications within the endoscopic group. The mean length of stay for these patients was 0.86 ± 1.44 days, with procedures lasting an average of 91.89 ± 46.72 minutes. However, these endpoints did not differ significantly from the open group. On literature review, 16 studies met the inclusion criteria, and largely consisted of single-center, retrospective analyses. CONCLUSIONS: Endoscopically guided approaches to single-level lumbar decompression did not reduce the incidence of adverse events, length of stay or operative time, perhaps due to advances among certain nonendoscopic techniques, such as microsurgery.

Incidence, Management, and Outcomes of Spinal Giant Cell Tumor of Bone in Adult Patients: A National Cancer Database Analysis.

OBJECTIVE: Giant cell tumors (GCTs) constitute 5% of all primary bone tumors with spinal GCTs (SGCTs) accounting for 2%-15% of all GCTs. The standard of care for SGCT has been maximal surgical resection. However, many adjuvant therapies have been used owing to the difficulty in achieving gross total resection combined with the high local recurrence rate. The purpose of the present study was to analyze the incidence, management, and outcomes of SGCT. METHODS: Patients with diagnosis codes specific for SGCT were queried from the National Cancer Database from 2004 to 2016. The outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization. RESULTS: The search criteria identified 92 patients in the NCDB dataset from 2004 to 2016 with a diagnosis of SGCT. Of the 92 patients, 64.1% had undergone surgical intervention, 24.8% had received radiotherapy, and 15.2% had received immunotherapy. Univariate analysis revealed that age ≥55 years and tumor location in the sacrum/coccyx were associated with worsened overall survival (OS) and that surgical resection was associated with improved OS. On multivariate analysis, age 55-64 years was associated with worsened OS, and radical surgical resection was associated with improved OS. The survival analysis revealed improved OS with surgery but not with radiotherapy, chemotherapy, or immunotherapy. CONCLUSION: SGCT is a rare primary bone tumor of the vertebral column. The standard of care has been surgical resection with the goal of gross total resection; however, adjuvant therapies have often been used. Our study found that surgical resection significantly improved OS and that immunotherapy neared significance in improving OS.

Risk Factors for Hyponatremia and Perioperative Complications With Malignant Intracranial Tumor Resection in Adults: An Analysis of the Nationwide Inpatient Sample from 2012 to 2015.

BACKGROUND: The present study aims to study the incidence and risk factors for developing hyponatremia and associated perioperative outcomes in adult patients admitted for malignant brain tumor resection. METHODS: The 2012-2015 Nationwide Inpatient Sample was queried for all patients undergoing surgical resection of malignant brain tumors. These patients were then grouped by the presence of concurrent diagnosis of hyponatremia, and compared with respect to various clinical features, perioperative and postoperative complications, all-cause mortality, discharge disposition, length of stay, and hospitalization costs. Propensity score matching was utilized to control for appropriate baseline confounders and the influence of other endpoint variables. RESULTS: The search criteria identified 12,480 adult patients admitted for malignant brain tumor resection, of whom 1162 (9.3%) developed hyponatremia in the perioperative period. Patients with obstructive hydrocephalus (risk ratio [RR] = 1.23, P < 0.001), diabetes (RR = 1.14, P = 0.014), hypertension (RR = 1.15, P < 0.001), and depression (RR = 1.24, P < 0.002) were more likely to develop hyponatremia. Tumor location was not associated with risk of developing hyponatremia. Patients with hyponatremia were more likely to require ventriculostomy (RR = 1.23, P < 0.001), ventriculoperitoneal shunt (RR = 1.34, P < 0.001), and lumbar puncture (RR = 1.25, P < 0.001), and were also more likely to be discharged to short-term hospital (RR = 1.25, P < 0.001) or rehabilitation (RR = 1.21, P < 0.001), as well as have longer hospital stay (P < 0.001) and increased hospital charges (P < 0.001). CONCLUSIONS: Patients with obstructive hydrocephalus, diabetes, hypertension, and depression were more likely to develop perioperative hyponatremia. Hyponatremia was associated with increased morbidity following malignant brain tumor resection.

Early versus late surgical intervention for central cord syndrome: A nationwide all-payer inpatient analysis of length of stay, discharge destination and cost of care.

OBJECTIVE: Central cord syndrome (CCS) is the most common incomplete spinal cord injury (SCI), resulting in various degrees of neurologic compromise below the level of the affected cervical cord. The management of CCS is controversial regarding not only whether to surgically intervene, but also when surgery should occur. In this study, we conduct the largest multi-center study to date examining differences in inpatient outcomes, general discharge disposition, length of stay, and cost associated with early versus late surgical intervention for CCS. PATIENTS AND METHODS: The National Inpatient Sample (NIS) was queried for years 2012-2015 for patients who underwent surgery with a primary diagnosis of CCS. The median interval between admission and intervention was noted. Patients operated upon prior to this timepoint were placed in the early surgery group, and others into the later surgery group. The groups were then compared, while using 1:1 propensity score matching to control for baseline presentation, with respect to mortality, discharge disposition, length of stay, and total charges. RESULTS: A total of 422 patients met inclusion and exclusion criteria. The median time from admission to intervention was 2 days. Patients with higher initial severity of injury were more likely to undergo early surgery. Upon controlling for severity of initial presentation, earlier intervention did not appear to affect mortality or post-operative length of stay. However, patients operated upon earlier had more favorable discharge destinations (p = 0.025) and a lower associated cost of care ($198,050.70 vs. $243,048.10, p = 0.009). CONCLUSION: Earlier surgical intervention for CCS may result in better patient disposition and less total charges. LEVEL OF EVIDENCE: III.