Safety of early discharge after elective lumbar spine surgery with subfascial drains and association with significant reduction in length of stay.

OBJECTIVE: After lumbar spine surgery, postoperative drain removal often delays discharge. Whether inpatient drain removal reduces the risk of surgical site infection (SSI) or hematoma remains controversial. Therefore, in patients undergoing elective lumbar spine surgery, the authors sought to determine the impact of inpatient versus outpatient drain removal on the following variables: 1) length of hospital stay (LOS), and 2) postoperative complications. METHODS: A single-center retrospective cohort study in which the authors used prospectively collected data of patients undergoing primary, elective, 1- or 2-level lumbar spine decompression and/or fusion was undertaken between 2016 and 2022. Patients with intraoperative or postoperative CSF leaks were excluded. The primary exposure variable was inpatient versus outpatient drain removal. The primary outcome was LOS, and secondary outcomes were postoperative complications, including 90-day postoperative SSI or hematoma. Multivariable logistic and linear regression were performed, controlling for age, body mass index, instrumentation, number of levels, antibiotics at discharge, and surgeons involved. RESULTS: Of 483 patients included, 325 (67.3%) had inpatient drain removal and 158 (32.7%) had outpatient drain removal. Patients with outpatient drain removal were significantly younger (58.6 ± 12.4 vs 61.2 ± 13.2 years, p = 0.040); more likely to have 1-level surgery (75.9% vs 56.6%, p < 0.001); and less likely to receive instrumentation (50.6% vs 69.5%, p < 0.001). Postoperatively, patients with outpatient drain removal had a shorter LOS (0.7 ± 0.6 vs 2.3 ± 1.6 days, p < 0.001); were more likely to be discharged home (98.1% vs 92.3%, p = 0.015); were more likely to be discharged on antibiotics (76.6% vs 3.1%, p < 0.001); were less likely to be on opioids (32.3% vs 88.3%, p < 0.001); and were more likely to have Jackson-Pratt compared to Hemovac drains (96.2% vs 34.5%, p < 0.001). No difference was found in SSI (3.7% vs 3.8%, p > 0.999) or hematoma (0.9% vs 0.6%, p > 0.999), as well as reoperation or readmission due to SSI or hematoma. On multivariable regression, outpatient drain removal was significantly associated with shorter LOS (ß = -1.15, 95% CI -1.56 to -0.73, p < 0.001). No association was found with SSI/hematoma (p > 0.05). CONCLUSIONS: Outpatient drain removal after elective lumbar spine surgery was associated with a significantly decreased LOS without a significant increase in postoperative SSI or hematoma. Although the choice of drain removal and the LOS may be subject to surgeons' preference, these results may support the feasibility and safety of outpatient drain removal, and the potential cost savings resulting from shortened hospital stays. Drawbacks may exist regarding added burden to the patient and the surgeon's team to accommodate 1-week follow-up appointments for drain removal.

Earlier Radiation Is Associated with Improved 1-Year Survival After Metastatic Spine Tumor Surgery.

OBJECTIVE: In patients undergoing metastatic spine surgery, we sought to 1) report time to postoperative radiation therapy (RT), 2) describe the predictive factors of time to postoperative RT, and 3) determine if earlier postoperative RT is associated with improved local recurrence (LR) and overall survival (OS). METHODS: A single-center retrospective cohort study was undertaken of all patients undergoing spine surgery for extradural metastatic disease and receiving RT within 3 months postoperatively between January 2010 and January 2021. Time to postoperative RT was dichotomized at <1 month versus 1-3 months. The primary outcomes were LR, OS, and 1-year survival. Secondary outcomes were wound complication, Karnofsky Performance Status, and modified McCormick Scale (MMS) score. Regression analyses controlled for age, body mass index, tumor size, preoperative RT, preoperative/postoperative chemotherapy, and type of RT. RESULTS: Of 76 patients undergoing spinal metastasis surgery and receiving postoperative RT within 3 months, 34 (44.7%) received RT within 1 month and 42 (55.2%) within 1-3 months. Patients with larger tumor size (ß = -3.58; 95% confidence interval [CI], -6.59 to -0.57; P = 0.021) or new neurologic deficits (ß = -16.21; 95% CI, -32.21 to -0.210; P = 0.047) had a shorter time to RT. No significant association was found between time to RT and LR or OS on multivariable logistic/Cox regression. However, patients who received RT between 1 and 3 months had a lower odds of 1-year survival compared with those receiving RT within 1 month (odds ratio, 0.18; 95% CI, 0.04-0.74; P = 0.022). Receiving RT within 1 month versus 1-3 months was not associated with wound complications (7.1% vs. 2.9%; P = 0.556) (odds ratio, 4.40; 95% CI, 0.40-118.0; P = 0.266) or Karnofsky Performance Status/modified McCormick Scale score. CONCLUSIONS: Spine surgeons, oncologists, and radiation oncologists should make every effort to start RT within 1 month to improve 1-year survival after metastatic spine tumor surgery.

IL-8 Instructs Macrophage Identity in Lateral Ventricle Contacting Glioblastoma.

Adult IDH-wildtype glioblastoma (GBM) is a highly aggressive brain tumor with no established immunotherapy or targeted therapy. Recently, CD32+ HLA-DRhi macrophages were shown to have displaced resident microglia in GBM tumors that contact the lateral ventricle stem cell niche. Since these lateral ventricle contacting GBM tumors have especially poor outcomes, identifying the origin and role of these CD32+ macrophages is likely critical to developing successful GBM immunotherapies. Here, we identify these CD32+ cells as M_IL-8 macrophages and establish that IL-8 is sufficient and necessary for tumor cells to instruct healthy macrophages into CD32+ M_IL-8 M2 macrophages. In ex vivo experiments with conditioned medium from primary human tumor cells, inhibitory antibodies to IL-8 blocked the generation of CD32+ M_IL-8 cells. Finally, using a set of 73 GBM tumors, IL-8 protein is shown to be present in GBM tumor cells in vivo and especially common in tumors contacting the lateral ventricle. These results provide a mechanistic origin for CD32+ macrophages that predominate in the microenvironment of the most aggressive GBM tumors. IL-8 and CD32+ macrophages should now be explored as targets in combination with GBM immunotherapies, especially for patients whose tumors present with radiographic contact with the ventricular-subventricular zone stem cell niche.

Comparison of Outcomes in Patients with Cervical Spine Metastasis After Different Surgical Approaches: A Single-Center Experience.

OBJECTIVE: In patients undergoing cervical spine surgery for metastatic spine disease, we sought to 1) compare perioperative and oncologic outcomes among 3 different operative approaches, 2) report fusion rates, and 3) compare different types of anterior vertebral body replacement. METHODS: A single-center retrospective cohort study of patients undergoing extradural cervical/cervicothoracic spine metastasis surgery between February 2010 and January 2021 was conducted. Operative approaches were anterior-alone, posterior-alone, or combined anterior-posterior, and the grafts/cages used in the anterior fusions were cortical allografts, static cages, or expandable cages. All cages were filled with autograft/allograft. Outcomes included perioperative/postoperative variables, along with fusion rates, functional status, local recurrence (LR), and overall survival (OS). RESULTS: Sixty-one patients underwent cervical spine surgery for metastatic disease, including 11 anterior (18.0%), 28 posterior (45.9%), and 22 combined (36.1%). New postoperative neurologic deficit was the highest in the anterior approach group (P = 0.038), and dysphagia was significantly higher in the combined approach group (P = 0.001). LR (P > 0.999), OS (P = 0.655), and time to both outcomes (log-rank test, OS, P = 0.051, LR, P = 0.187) were not significantly different. Of the 51 patients alive at 3 months, only 19 (37.2%) obtained imaging ≥3 months. Fusion was seen in 11/19 (57.8%) at a median of 8.3 months (interquartile range, 4.6-13.7). Among the anterior corpectomies, the following graft/cage was used: 6 allografts (54.5%), 4 static cages (36.3%), and 1 expandable cage (9.0%), with no difference found in outcomes among the 3 groups. CONCLUSIONS: The only discernible differences between operative approaches were that patients undergoing an anterior approach had higher rates of new postoperative neurologic deficit, and the combined approach group had higher rates of postoperative dysphagia.

Pediatric neurosurgical-oncology scope and management paradigms in Sub-Saharan Africa: a collaboration among 7 referral hospitals on the subcontinent.

Background: Understanding of the epidemiology and biology of pediatric CNS tumors has advanced dramatically over the last decade; however there remains a discrepancy in the understanding of epidemiologic data and clinical capacity between high- and lower-income countries. Objective: We collected and analyzed hospital-level burden and capacity-oriented data from pediatric neurosurgical oncology units at 7 referral hospitals in Sub-Saharan Africa (SSA). Methods: A cross sectional epidemiological survey was conducted using REDCap at the 7 SSA sites, capturing 3-month aggregate data for patients managed over a total of 9 months. Descriptive statistical analyses for the aggregate data were performed. Results: Across the neurosurgical spectrum, 15% of neurosurgery outpatient and 16% of neurosurgery operative volume was represented by pediatric neuro-oncology across the 7 study sites. Eighty-six percent and 87% of patients who received surgery underwent preoperative CT scan and/or MRI respectively. Among 312 patients evaluated with a CNS tumor, 211 (68%) underwent surgery. Mean surgery wait time was 26.6 ± 36.3 days after initial presentation at the clinic. The most common tumor location was posterior fossa (n=94, 30%), followed by sellar/suprasellar region (n=56, 18%). Histopathologic analysis was performed for 189 patients (89%). The most common pathologic diagnosis was low grade glioma (n=43, 23%), followed by medulloblastoma (n=37, 20%), and craniopharyngioma (n=31, 17%). Among patients for whom adjuvant therapy was indicated, only 26% received chemotherapy and 15% received radiotherapy. Conclusion: The histopathologic variety of pediatric brain and spinal tumors managed across 7 SSA referral hospitals was similar to published accounts from other parts of the world. About two-thirds of patients received a tumor-directed surgery with significant inter-institutional variability. Less than a third of patients received adjuvant therapy when indicated. Multi-dimensional capacity building efforts in neuro-oncology are necessary to approach parity in the management of children with brain and spinal tumors in SSA.

Palliative Care Consultation Utilization Among Patient Undergoing Surgery for Metastatic Spinal Tumors.

OBJECTIVE: In patients undergoing surgery for spinal metastasis, we sought to: (1) describe patterns of palliative care consultation, (2) evaluate the factors that trigger palliative care consultation, and (3) determine the association of palliative care consultation on longer-term outcomes. METHODS: A single-center, retrospective, case-control study was conducted for patients undergoing spinal metastasis surgery from February 2010 to January 2021. The primary outcome was receiving a palliative care consultation, and the timing of consultation was divided into same hospital stay consultation, preoperative versus postoperative consultation, and early (

Clinical tool for prognostication of discharge outcomes following craniotomy for meningioma.

BACKGROUND: Patients' comorbidities might affect the immediate postoperative morbidity and discharge disposition after surgical resection of intracranial meningioma. OBJECTIVE: To study the impact of comorbidities on outcomes and provide a web-based application to predict time to favorable discharge. METHODS: A retrospective review of the prospectively collected national inpatient sample (NIS) database was conducted for the years 2009-2013. Time to favorable discharge was defined as hospital length of stay (LOS). A favorable discharge was defined as a discharge to home and a non-home discharge destination was defined as an unfavorable discharge. Cox proportional hazards model was built. Full model for time to discharge and separate reduced models were built. RESULTS: Of 10,757 patients who underwent surgery for meningioma, 6554 (60%) had a favorable discharge. The median hospital LOS was 3 days (interquartile range [IQR] 2-5). In the full model, several clinical and socioeconomic factors were associated with a higher likelihood of unfavorable discharge. In the reduced model, 13 modifiable comorbidities were negatively associated with a favorable discharge except for drug abuse and obesity, which are not associated with discharge. Both models accurately predicted time to favorable discharge (c-index:0.68-0.71). CONCLUSION: We developed a web application using robust prognostic model that accurately predicts time to favorable discharge after surgery for meningioma. Using this tool will allow physicians to calculate individual patient discharge probabilities based on their individual comorbidities and provide an opportunity to timely risk stratify and address some of the modifiable factors prior to surgery.

Does Low-Grade Versus High-Grade Bilsky Score Influence Local Recurrence and Overall Survival in Metastatic Spine Tumor Surgery?

BACKGROUND AND OBJECTIVES: Spinal cord compression caused by spinal tumors is measured using the epidural spinal cord compression scale, also known as the Bilsky score. Whether Bilsky score predicts short-/long-term outcomes remains unknown. The objectives were to determine the correlation of Bilsky score 0-1 vs 2-3 with regards to (1) preoperative presentation, (2) perioperative variables, and (3) long-term outcomes. METHODS: A single-center, retrospective evaluation of a cohort of patients undergoing metastatic spine surgery was performed between 01/2010 and 01/2021. Multivariable logistic/linear/Cox regression were performed controlling for age, body mass index, race, total decompressed levels, tumor size, other organ metastases, and postoperative radiotherapy/chemotherapy. RESULTS: Of 343 patients with extradural spinal metastasis, 92 (26.8%) were Bilsky 0-1 and 251 (73.2%) were Bilsky 2-3. Preoperatively, patients with Bilsky 2-3 lesions were older ( P = .008), presented more with sensory deficits ( P = .029), and had worse preoperative Karnofsky Performance Scale (KPS) ( P = .002). Perioperatively, Bilsky 2-3 patients had more decompressed levels ( P = .005) and transpedicular decompression ( P < .001), with similar operative time ( P = .071) and blood loss ( P = .502). Although not statistically significant, patients with Bilsky 2-3 had more intraoperative neuromonitoring changes ( P = .412). Although rates of complications ( P = .442) and neurological deficit ( P = .852) were similar between groups, patients with Bilsky 2-3 lesions had a longer length of stay ( P = .007) and were discharged home less frequently ( P < .001). No difference was found in 90-day readmissions ( P = .607) and reoperation ( P = .510) Long-term: LR ( P =.100) and time to LR (log-rank; P =0.532) were not significantly different between Bilsky 0-1 and Bilsky 2-3 lesions. However, patients with Bilsky 2-3 lesions had worse postoperative KPS ( P < .001), worse modified McCormick scale score ( P = .003), shorter overall survival (OS) (log-rank; P < .001), and worse survival at 1 year ( P = .012). Bilsky 2-3 lesions were associated with shorter OS on multivariable Cox regression (hazard ratio = 1.78, 95% CI = 1.27-2.49, P < .001), with no significant impact on time to LR (hazard ratio = 0.73, 95% CI = 0.37-1.44, P = .359). CONCLUSION: Bilsky 2-3 lesions were associated with longer length of stay, more nonhome discharge, worse postoperative KPS/modified McCormick scale score, shorter OS, and reduced survival at 1 year. Higher-grade Bilsky score lesions appear to be at a higher risk for worse outcomes. Efforts should be made to identify metastatic spine patients before they reach the point of severe spinal cord compression..

Neurological Examination Frequency and Time-to-Delirium After Traumatic Brain Injury.

BACKGROUND: Frequent neurological examinations in patients with traumatic brain injury (TBI) disrupt sleep-wake cycles and potentially contribute to the development of delirium. OBJECTIVE: To evaluate the risk of delirium among patients with TBI with respect to their neuro-check frequencies. METHODS: A retrospective study of patients presenting with TBI at a single level I trauma center between January 2018 and December 2019. The primary exposure was the frequency of neurological examinations (neuro-checks) assigned at the time of admission. Patients admitted with hourly (Q1) neuro-check frequencies were compared with those who received examinations every 2 (Q2) or 4 (Q4) hours. The primary outcomes were delirium and time-to-delirium. The onset of delirium was defined as the first documented positive Confusion Assessment Method for the Intensive Care Unit score. RESULTS: Of 1552 patients with TBI, 458 (29.5%) patients experienced delirium during their hospital stay. The median time-to-delirium was 1.8 days (IQR: 1.1, 2.9). Kaplan-Meier analysis demonstrated that patients assigned Q1 neuro-checks had the greatest rate of delirium compared with the patients with Q2 and Q4 neuro-checks ( P < .001). Multivariable Cox regression modeling demonstrated that Q2 neuro-checks (hazard ratio: 0.439, 95% CI: 0.33-0.58) and Q4 neuro-checks (hazard ratio: 0.48, 95% CI: 0.34-0.68) were protective against the development of delirium compared with Q1. Other risk factors for developing delirium included pre-existing dementia, tobacco use, lower Glasgow Coma Scale score, higher injury severity score, and certain hemorrhage patterns. CONCLUSION: Patients with more frequent neuro-checks had a higher risk of developing delirium compared with those with less frequent neuro-checks.

An immunosuppressed microenvironment distinguishes lateral ventricle-contacting glioblastomas.

Radiographic contact of glioblastoma (GBM) tumors with the lateral ventricle and adjacent stem cell niche correlates with poor patient prognosis, but the cellular basis of this difference is unclear. Here, we reveal and functionally characterize distinct immune microenvironments that predominate in subtypes of GBM distinguished by proximity to the lateral ventricle. Mass cytometry analysis of isocitrate dehydrogenase wild-type human tumors identified elevated T cell checkpoint receptor expression and greater abundance of a specific CD32+CD44+HLA-DRhi macrophage population in ventricle-contacting GBM. Multiple computational analysis approaches, phospho-specific cytometry, and focal resection of GBMs validated and extended these findings. Phospho-flow quantified cytokine-induced immune cell signaling in ventricle-contacting GBM, revealing differential signaling between GBM subtypes. Subregion analysis within a given tumor supported initial findings and revealed intratumor compartmentalization of T cell memory and exhaustion phenotypes within GBM subtypes. Collectively, these results characterize immunotherapeutically targetable features of macrophages and suppressed lymphocytes in GBMs defined by MRI-detectable lateral ventricle contact.

Unplanned Readmission Is Associated With Decreased Overall Survival and Performance After Metastatic Spine Surgery.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: In a cohort of patients undergoing metastatic spine surgery, we sought to: (1) identify risk factors associated with unplanned readmission, and (2) determine the impact of an unplanned readmission on long-term outcomes. SUMMARY OF BACKGROUND DATA: Factors affecting readmission after metastatic spine surgery remain relatively unexplored. MATERIALS AND METHODS: A single-center, retrospective, case-control study was undertaken of patients undergoing spine surgery for extradural metastatic disease between 02/2010 and 01/2021. The primary outcome was 3-month unplanned readmission. Preoperative, perioperative, and tumor-specific variables were collected. Multivariable Cox regression was performed, controlling for tumor size, other organ metastasis, and preoperative/postoperative radiotherapy/chemotherapy. RESULTS: A total of 357 patients underwent surgery for spinal metastases with a mean follow-up of 538.7±648.6 days. Unplanned readmission within 3 months of surgery occurred in 64/357 (21.9%) patients, 37 (57.8%) were medical, 27 (42.2%) surgical, and 21 (77.7%) were related to their spine surgery. No significant differences were found regarding demographics and preoperative variables, except for insurance, where most readmitted patients had private insurance compared with nonreadmitted patients ( P =0.021). No significant difference was found in preoperative radiotherapy/chemotherapy. Regarding perioperative exposure variables, readmitted patients had a higher rate of postoperative complications (68.8% vs. 24.2%, P <0.001) and worse postoperative Karnofsky Performance Score ( P =0.021) and Modified McCormick Scale ( P =0.015) at the time of first follow-up. On multivariate logistic regression, postoperative complications were associated with increased readmissions (odds ratio=1.38, 95% CI=1.25-1.52, P <0.001). Regarding the impact of unplanned readmission on long-term tumor control, unplanned readmission was associated with shorter time to local recurrence (log-rank; P =0.029) and reduced overall survival (OS) (log-rank; P <0.001). On multivariate Cox regression, other organ metastasis [hazard ratio (HR)=1.48, 95% CI=1.13-1.93, P =0.004] and 3-month readmission (HR=1.75, 95% CI=1.28-2.39, P <0.001) were associated with worsened OS, with no impact on LR. Postoperative chemotherapy was significantly associated with longer OS (HR=0.59, 95% CI=0.45-0.77, P <0.001). CONCLUSIONS: Postoperative complications were associated with unplanned readmission following metastatic spine surgery. Furthermore, 3-month unplanned readmission was associated with a shorter time to local recurrence and decreased OS. These results help surgeons understand the drivers of readmissions and the impact of readmissions on patient outcomes. LEVEL OF EVIDENCE: 3.

Conditional Recurrence-Free Survival After Surgical Resection of Meningioma.

BACKGROUND: Recurrence after meningioma resection warrants serial surveillance imaging, but little evidence guides the optimal time interval between imaging studies/surveillance duration. OBJECTIVE: To describe recurrence-free survival (RFS) after meningioma resection, conditioned to short-term RFS. METHODS: A retrospective cohort study for adults presenting for meningioma resection from 2000 to 2018 was conducted. The primary outcome was postoperative follow-up RFS. Conditional RFS Kaplan-Meier analysis was performed at 1, 2, 3, 5, and 10 years, conditioned to 6-month and 12-month RFS. RFS probabilities conditioned to 6-month RFS were estimated in subgroups, stratified by World Health Organization grade, extent of resection, and need for postoperative radiation. RESULTS: In total, 723 patients were included. Median age at surgery was 57.4 years (IQR = 47.2-67.2). Median follow-up was 23.5 months (IQR = 12.3-47.8). Recurrence was observed in 90 patients (12%), with median time to recurrence of 14.4 months (IQR = 10.3-37.1). Conditioned to 6-month postoperative RFS, patients had 90.3% probability of remaining recurrence-free at 2 years and 69.4% at 10 years. Subgroup analysis conditioned to 6-month RFS demonstrated grade 1 meningiomas undergoing gross total resection (GTR) had 96.0% probability of RFS at 1 year and 82.8% at 5 years, whereas those undergoing non-GTR had 94.5% and 79.9% probability, respectively. RFS probability was 78.8% at 5 years for non-grade 1 meningiomas undergoing GTR, compared with 69.7% for non-grade 1 meningiomas undergoing non-GTR. Patients with non-grade 1 meningiomas undergoing upfront radiation had a 1-year RFS of 90.1% and 5-year RFS of 51.7%. CONCLUSION: Recurrence risk after meningioma resection after an initial recurrence-free period is reported, with high-risk subgroups identified. These results can inform objective shared decision-making for optimal follow-up.

Association between preoperative hematologic markers and aggressive behavior in meningiomas.

INTRODUCTION: Meningiomas have varying degrees of aggressive behavior. Some systemic hematologic makers are associated with malignancy, but their value in predicting aggressive meningioma behavior is not fully understood. OBJECTIVE: To evaluate the association between preoperative markers such as neutrophil-lymphocyte ratio (NLR), neutrophil-monocyte ratio (NMR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), and prognostic nutritional index (PNI), and diagnostic and prognostic factors including WHO grade, proliferation index, presence of edema on preoperative MRI, and tumor recurrence. METHODS: A retrospective review of patients treated between 2000 and 2019 with a preoperative complete blood count (CBC) differential lab draw before intracranial meningioma resection was conducted. All preoperative steroid dosages were converted to dexamethasone equivalents. Primary outcomes included presence/absence of perilesional edema, WHO grade, Ki-67/MIB-index, and recurrence. Univariate and multivariable regression analyses were conducted. RESULTS: A total of 209 meningioma patients were included. Of these, 143 (68 %) were WHO grade I, 61 (29 %) grade II and 5 (2 %) were grade III. Recurrence was reported in 19 (9.1 %) tumors. No hematologic markers were associated with recurrence. In separate multivariable logistic analyses, no biomarkers were associated with perilesional edema or WHO grade. MLR was associated with higher MIB-index (p = 0.018, OR 6.57, 95 % CI 1.37-30.91). CONCLUSION: Most hematologic markers were not associated with meningioma invasiveness, grade, proliferative index, or aggressiveness. Preoperative MLR was associated with high proliferation index in patients undergoing surgery for intracranial meningioma. Higher MLR could be a surrogate for meningioma proliferation and has potential to be used as an adjunct for risk-stratifying meningiomas.

Role of Chiari Decompression in Managing Spinal Deformity Associated with Chiari I Malformation and Syringomyelia.

CM-I-associated syringomyelia is a risk factor for scoliosis where a larger syrinx size is more likely to be associated with scoliosis. Therefore, the effect of syrinx on scoliosis progression may be alleviated by PFD. There is no difference in the need for fusion surgery between patients undergoing PFD with duraplasty vs. those undergoing extradural decompression; however, PFD with duraplasty is associated with an improvement in curve magnitude compared to extradural decompression alone. Further study on the comparison of PFD techniques for this cohort of patients is needed. PFD is a durable surgical option for patients with CM-I, syrinx, and scoliosis. Early decompression of CM-I in younger patients and those with smaller scoliosis curves at presentation is recommended as there is a higher likelihood of halting curve progression.

Methods and Impact for Using Federated Learning to Collaborate on Clinical Research.

BACKGROUND: The development of accurate machine learning algorithms requires sufficient quantities of diverse data. This poses a challenge in health care because of the sensitive and siloed nature of biomedical information. Decentralized algorithms through federated learning (FL) avoid data aggregation by instead distributing algorithms to the data before centrally updating one global model. OBJECTIVE: To establish a multicenter collaboration and assess the feasibility of using FL to train machine learning models for intracranial hemorrhage (ICH) detection without sharing data between sites. METHODS: Five neurosurgery departments across the United States collaborated to establish a federated network and train a convolutional neural network to detect ICH on computed tomography scans. The global FL model was benchmarked against a standard, centrally trained model using a held-out data set and was compared against locally trained models using site data. RESULTS: A federated network of practicing neurosurgeon scientists was successfully initiated to train a model for predicting ICH. The FL model achieved an area under the ROC curve of 0.9487 (95% CI 0.9471-0.9503) when predicting all subtypes of ICH compared with a benchmark (non-FL) area under the ROC curve of 0.9753 (95% CI 0.9742-0.9764), although performance varied by subtype. The FL model consistently achieved top three performance when validated on any site's data, suggesting improved generalizability. A qualitative survey described the experience of participants in the federated network. CONCLUSION: This study demonstrates the feasibility of implementing a federated network for multi-institutional collaboration among clinicians and using FL to conduct machine learning research, thereby opening a new paradigm for neurosurgical collaboration.

Unplanned Readmission After Surgery for Cervical Spine Metastases.

OBJECTIVE: Patients undergoing surgery for cervical spine metastases are at risk for unplanned readmission due to comorbidities and chemotherapy/radiation. Our objectives were to: 1) report the incidence of unplanned readmission, 2) identify risk factors associated with unplanned readmission, and 3) determine the impact of an unplanned readmission on long-term outcomes. METHODS: A single-center, retrospective, case-control study was undertaken of patients undergoing cervical spine surgery for metastatic disease between 02/2010 and 01/2021. The primary outcome of interest was unplanned readmission within 6 months. Survival analysis was performed for overall survival (OS) and local recurrence (LR). RESULTS: A total of 61 patients underwent cervical spine surgery for metastatic disease with the following approaches: 11 (18.0%) anterior, 28 (45.9%) posterior, and 22 (36.1%) combined. Mean age was 60.9 ± 11.2 years and 38 (62.3%) were males. A total of 9/61 (14.8%) patients had an unplanned readmission, 3 for surgical reasons and 6 for medical reasons. No difference was found in demographics, preoperative Karnofsky Performance Scale (P = 0.992), motor strength (P = 0.477), or comorbidities (P = 0.213) between readmitted patients versus not. Readmitted patients had a higher rate of preoperative radiation (P = 0.009). No statistical differences were found in operative time (P = 0.893), estimated blood loss (P = 0.676), length of stay (P = 0.720), discharge disposition (P = 0.279), and operative approach (P = 0.450). Furthermore, no difference was found regarding complications (P = 0.463), postoperative Karnofsky Performance Scale (P = 0.535), and postoperative Modified McCormick Scale (P = 0.586). Lastly, unplanned readmissions were not associated with OS (log-rank; P = 0.094) or LR (log-rank; P = 0.110). CONCLUSIONS: In patients undergoing cervical spine metastasis surgery, readmission occurred in 15% of patients, 33% for surgical reasons, and 67% for medical reasons. Preoperative radiotherapy was associated with an increased rate of unplanned readmissions, yet readmission had no association with OS or LR.

Comparison of supratentorial meningioma resection outcomes by dural reconstruction technique.

OBJECTIVE: Excision of intracranial meningiomas often requires resection or coagulation of the dura mater. The choice of dural closure technique is individualized and based on surgeon preference. The objective of this study was to determine outcomes following various dural closure techniques for supratentorial meningiomas. METHODS: A retrospective, single-center cohort study was performed for patients who underwent excision of supratentorial meningiomas from 2000 to 2019. Outcomes including operative time, postoperative in-hospital complications, readmission, causes of readmission including surgical site infection, pseudomeningocele, need for shunt surgery, and imaging appearance of pseudomeningocele on long-term follow-up imaging were compared. Univariate and multivariable analyses were conducted. RESULTS: A total of 353 patients who had complete clinical and operative data available for review were included. Of these patients, 227 (64.3%) had nonsutured dural graft reconstruction and 126 (35.7%) had sutured dural repair, including primary closure, artificial dura, or pericranial graft. There was significant variability in using nonsutured dural reconstruction compared with sutured dural repair technique among surgeons (p < 0.001). Tumors with sagittal sinus involvement were more likely to undergo nonsutured closure (n = 79, 34.8%) than dural repair (n = 26, 20.6%) (p = 0.003). There were no other differences in preoperative imaging findings or WHO grade. Frequency of surgical site infection and pseudomeningocele, need for shunt surgery, and recurrence were similar between those undergoing nonsutured and those undergoing sutured dural repair. The mean operative time for the study cohort was 234.9 (SD 106.6) minutes. The nonsutured dural reconstruction group had a significantly shorter mean operative time (223.9 [SD 99.7] minutes) than the sutured dural repair group (254.5 [SD 115.8] minutes) (p = 0.015). In a multivariable linear regression analysis, after controlling for tumor size and sinus involvement, nonsutured dural graft reconstruction was associated with a 36.8-minute reduction (95% CI -60.3 to -13.2 minutes; p = 0.002) in operative time. CONCLUSIONS: Dural reconstruction using a nonsutured graft and sutured dural repair exhibit similar postoperative outcomes for patients undergoing resection for supratentorial meningiomas. Although sutured grafts may sometimes be necessary, nonsutured graft reconstruction for most supratentorial meningioma resections may suffice. The decreased operative time associated with nonsutured grafts may ultimately result in cost savings. These findings should be taken into consideration when selecting a dural reconstruction technique for supratentorial meningioma.

Assessment of safety and effectiveness of non-neurosurgical management for minimal traumatic brain injury (TBI).

BACKGROUND: Patients with mild traumatic brain injury (TBI) and intracranial hemorrhage often receive neurosurgical consultation. However, only a small proportion of patients require intervention. Our hypothesis is that low-risk minimal TBI patients managed without immediate neurosurgical consultation will have a reasonable safety and effectiveness outcome profile. METHODS: A non-neurosurgical management protocol for adult minimal TBI was implemented at a level I trauma center as an interdisciplinary quality-improvement initiative in November 2018. Minimal TBI was defined as Glasgow Coma Scale (GCS) of 15 secondary to blunt mechanism, without anticoagulant or antiplatelet therapy, and isolated pneumocephalus and/or traumatic subarachnoid hemorrhage on head CT imaging. Safety was assessed by in-hospital mortality, neurosurgical interventions, and ED revisits within two weeks of discharge. Effectiveness was assessed by neurosurgical consult rate and length of stay. Outcomes were compared 8-months pre- and post-protocol implementation. RESULTS: A total of 97 patients were included, of which 49 were pre-protocol and 48 were post-protocol There was no difference in rates of in-hospital mortality [0 (0%) vs 0 (0%)], neurosurgical procedure [1 (2.1%) vs 0 (0%)], operations [0 (0%) vs 0 (0%)], and ED revisits [1 (2.0%) vs 2 (4.2%), p = 0.985] between the periods. There was a significant reduction in neurosurgical consults post-protocol implementation (92% vs 29%, p<0.001). CONCLUSION: A protocol for minimal TBI patients effectively reduced neurosurgical consultation without changes in safety profile. Such an interdisciplinary management protocol for low-risk neurotrauma can effectively utilize the neurosurgery consult services by stratifying neurologically stable TBI patient.

Review of Intraoperative Adjuncts for Maximal Safe Resection of Gliomas and Its Impact on Outcomes.

Maximal safe resection is the mainstay of treatment in the neurosurgical management of gliomas, and preserving functional integrity is linked to favorable outcomes. How these modalities differ in their effectiveness on the extent of resection (EOR), survival, and complications remains unknown. A systematic literature search was performed with the following inclusion criteria: published between 2005 and 2022, involving brain glioma surgery, and including one or a combination of intraoperative modalities: intraoperative magnetic resonance imaging (iMRI), awake/general anesthesia craniotomy mapping (AC/GA), fluorescence-guided imaging, or combined modalities. Of 525 articles, 464 were excluded and 61 articles were included, involving 5221 glioma patients, 7(11.4%) articles used iMRI, 21(36.8%) used cortical mapping, 15(24.5%) used 5-aminolevulinic acid (5-ALA) or fluorescein sodium, and 18(29.5%) used combined modalities. The heterogeneity in reporting the amount of surgical resection prevented further analysis. Progression-free survival/overall survival (PFS/OS) were reported in 18/61(29.5%) articles, while complications and permanent disability were reported in 38/61(62.2%) articles. The reviewed studies demonstrate that intraoperative adjuncts such as iMRI, AC/GA mapping, fluorescence-guided imaging, and a combination of these modalities improve EOR. However, PFS/OS were underreported. Combining multiple intraoperative modalities seems to have the highest effect compared to each adjunct alone.

Matched case-control analysis of outcomes following surgical resection of incidental meningioma.

PURPOSE: The management of incidentally discovered meningioma remains controversial. We sought to compare outcomes following surgical resection of incidental meningioma to a matched cohort of symptomatic meningiomas. METHODS: A retrospective single-center case-control study was conducted for patients undergoing resection of incidental meningioma from 2000 to 2019. A 1:1 case-control matching for incidental and symptomatic meningioma was performed using the following variables: age at initial visit, gender, tumor location/size, and presence of peritumoral edema. Primary outcomes included (1) WHO grading/histopathological subtype/MIB-1 index, (2) extent of resection (gross total resection or subtotal resection), and (3) recurrence. Outcomes were compared between groups using descriptive/bivariate analyses. RESULTS: A total of 91 incidental meningiomas were analyzed. Trauma was the most common reason (n = 19, 21%) to obtain imaging, and tumor size the leading reason to operate (n = 37, 41%). Median time-to-surgery from initial clinical encounter was 5-months (Q1:3, Q3:16.5). More incidental meningioma patients (n = 47, 52%) were privately insured compared to their matched symptomatic cohort (n = 30, 33%) (P = 0.006). Patients with incidental meningioma had significantly higher mean Karnofsky Performance Scale at time-of-surgery (93.2, SD:11.1 vs. 81.4, SD:12.7) (P < 0.001). There were no significant differences in primary/secondary outcomes between the groups. Incidental meningioma was not associated with recurrence on Cox proportional hazards analysis (HR: 0.795, 95%CI: 0.3-2.1, P = 0.637). CONCLUSION: Matched case-control analysis demonstrated no significant differences in clinical, histopathological, and functional outcomes following resection of incidental and symptomatic meningioma. While non-operative management with close follow-up and serial imaging is preferred for incidental meningiomas, those undergoing resection when indicated can anticipate similar safety and efficacy as symptomatic meningiomas.