bluuebunny/crossref_metadata_2025 huggingface dataset:
317 Pilot Analysis of Surgeon Instrument Utilization Signatures Based on Shannon Entropy for Surgeon Performance Assessment in a Cadaveric Carotid Artery Injury Control Simulation
Authors: Balu Alan , Pangal Dhiraj J. , Kugener Guillaume , Donoho Daniel
Published: March 2023

INTRODUCTION:

Automated video-based feedback for a surgeon’s technical skills would improve patient care and facilitate trainee education, but current feedback methods require the development of task-specific metrics. A generalizable, automated method of surgeon skills assessment with surgeon tool-usage signatures could expedite the development and validation of video-based feedback methods.

METHODS:

Annotated images from the publicly-available SOCAL dataset were used to train an off-the-shelf computer vision model (YOLOv4) which detected surgical instruments. Shannon entropy of unique instruments combinations was calculated from each surgical trial. Logistic regression was used to predict trial success using Shannon entropy.

RESULTS:

Surgeon signatures based on Shannon entropy were created for each trial and each surgeon. Instrument usage patterns demonstrated differences between successful and unsuccessful trials. Shannon entropy of instrument combinations demonstrated significant correlation with trial success (p < 0.001) and predicted success with 97% average precision and 78% accuracy using computer vision detections. Unsuccessful trials displayed a rapid initial peak in entropy which then declined over time. In contrast, successful trials demonstrated slower progression of tool usage with gradually increasing use of a critical, final maneuver.

CONCLUSIONS:

Surgeon signatures based on Shannon entropy predicted task success with acceptable accuracy and revealed patterns between successful and unsuccessful trials. Shannon entropy offers a generalizable and summative signal about surgeon performance, regardless of the task, and can predict outcomes based only on the probabilities of unique instrument combinations. Future efforts will describe the instrument movement signatures.
324 SpineTrak: The First Randomized Control Trial Using the Apple Watch to Objectively Track Spine Surgical Patients
Authors: Leung Christopher , Fatemi Parastou , Yerneni Ketan , Desai Atman , Tompkins-Lane Christy , Zygourakis Corinna Clio
Published: March 2023

INTRODUCTION:

Mobilization after surgery reduces complications and is associated with improved survival and psychological well-being, and decreased length of hospitalization. Current methods for evaluating the outcomes of spine surgery patients rely on patient-reported outcome measures (PROMs). There are numerous wearable activity monitors, including the Apple Watch (AW), that can track and monitor mobility.

METHODS:

Eligibility: Adult patients undergoing elective spine surgery. Patients randomized 1:1 to intervention vs control group. Intervention patients receive AW, download study-specific application to collect health measures from AW. Visual reports are provided to intervention patients and surgeons. All patients complete PROMs pre-operatively and at 6-weeks, 3-months, 6 months, 1-year post-operatively. All patients complete study-specific questionnaire regarding satisfaction and understanding of recovery. Target enrollment is 100 intervention and 100 control patients.

RESULTS:

To date, we have enrolled 163 patients (n = 83 intervention; n = 80 control). Intervention participants (n = 50) have worn AW 91% of the days and for 14.1 hours/day. At 6-week post-operative visits, 67% of patients responded that they were very satisfied with the use of the AW in their spine care and that seeing their AW activity tracking data was helpful. 94% of neurosurgeons agreed that the AW summary helped them understand how their patient was doing post-operatively.

CONCLUSIONS:

Preliminary results of participants indicate patients are compliant with wearing the AW, and both patients and surgeons are satisfied with its use in their spine care. Initial analyses do not show a correlation between PROMs and objective measures, emphasizing the need for a metric that combines objective and subjective measures to track patient's recovery in real-time.
335 Development and Validation of a Predictive Score for Persistent Instability Following Conservative Treatment in Type II Odontoid Fractures
Authors: Page Paul , Ammanuel Simon G. , Brooks Nathaniel P. , Resnick Daniel K.
Published: March 2023

INTRODUCTION:

Odontoid fractures are common cervical spine fractures, however significant controversy exists regarding their treatment. While risk factors for failure of conservative therapy have been identified, no predictive risk score has been developed to aid in decision making regarding surgical intervention or conservative therapy.

METHODS:

A retrospective review was conducted of all patients evaluated at a level one trauma center from 2005 to 2021. Patients identified with Type II Odontoid Fractures as classified by the Anderson D’Alonzo Classification system who were treated with external orthosis were included in analysis. Patients were considered to have failed conservative therapy if they were offered surgical intervention due to nonunion and continued motion on flexion extension x-rays. A machine learning method (RiskSLIM) was then utilized to created a risk stratification score to identify patients at high risk for requiring surgical intervention due to persistent instability.

RESULTS:

In total, 138 patients were identified as presenting with type II odontoid fractures that were treated conservatively. Of these, 38 patients demonstrated persistent instability following conservative therapy with cervical orthosis. The Odontoid Fracture Predictive Model (OFPM) was created using a machine learning algorithm with a five-fold cross validation area under the curve of 0.7389 (95% CI: 0.671 to 0.808) and calibration error of 18.6%. Predictive factors were found to include anterior or posterior displacement, displacement greater than 5 mm, comminution at the fracture base, and history of smoking. The probability of persistent instability was <5% with a score of 0 and 88% with a score of 5.

CONCLUSIONS:

The OFPM model is a quick and accurate tool to assist in clinical decision making in patients with type II odontoid fractures.
339 Mineral Coated Micropaarticles Delivering Chondroitinase ABC mRNA Improves Motor Function After Spinal Cord Injury in Rats
Authors: Hanna Amgad S. , Hellenbrand Daniel , Khalil Andrew , Murphy William
Published: March 2023

INTRODUCTION:

Currently, there are no treatments to help regain a significant amount of the function that is lost after spinal cord injury (SCI). A primary reason for the lack in functional recovery is the glial scar, which forms after SCI and inhibits axonal regeneration. Chondroitinase ABC (ChABC), a bacterial enzyme, digests one of the main axonal inhibitors in the glial scar, chondroitin sulfate proteoglycans (CSPGs), and results in axonal regeneration and functional recovery. However, ChABC is not thermally stable and quickly becomes inactive at body temperature. Recently, messenger RNA (mRNA) delivery has emerged as an attractive strategy for non-virally producing proteins in vivo with higher activity than recombinant proteins and a more desirable safety profile than viral gene delivery.

METHODS:

ChABC mRNA synthesis was designed in Benchling Molecular Biology Suite and ordered as-synthesized plasmid (Genscript). Mineral coatings were grown on hydroxyapatite microparticles and lipoplexes with mRNA were bound to the coatings. Rat spinal cords were contused at the T10 level and the glial scar was allowed to form. Seven days post-injury MCMs with ChABC mRNA were injected into the epicenter of the injury. Rat Hindlimb function was assessed for seven weeks before the rats were harvested. Lastly, immunohistochemistry was used to assess CSPG digestion and axonal sprouting.

RESULTS:

MCMs delivering ChABC mRNA forced local overexpression of ChABC and significantly digested CSPGs after SCI, resulting in axonal sprouting and a significant improvement in hindlimb function.

CONCLUSIONS:

MCMs efficiently delivered ChABC mRNA to digest CSPGs in the glial scar after SCI.
342 Predicting Early Disease Progression in Tectal Plate Gliomas
Authors: Bauman Megan , Giesken Max , Naylor Ryan M. , Daniels David J.
Published: March 2023

INTRODUCTION:

Tectal gliomas are slow-growing tumors of the midbrain. Due to their indolent nature, treatment mainly consists of observation and management of hydrocephalus. However, a subset of tectal gliomas may exhibit tumor enlargement and disease progression. Currently, there are no established guidelines for predicting future progression of tectal gliomas. Further, given the rarity of these tumors, studies in the literature are limited to <50 patients.

METHODS:

We performed a retrospective chart review of 172 patients diagnosed with tectal glioma. In addition to descriptive statistics, we performed univariate analysis using Student’s t-test and Chi-squared testing to determine if significant differences exist between patients with tumor progression versus those without progression.

RESULTS:

The median patient age was 24 years (range: 0-73 years); of these, 69 were pediatric (≤18 years). Hydrocephalus was present in 64% of cases. Lesions were incidentally detected in 37% of the cohort and were only present in the adult population. Of the patients that had > 1 year follow-up (n = 145), 26 experienced radiological progression (18%) with 19 requiring tumor-directed treatment (13%). Predictors of progression included younger age at diagnosis (p = 0.005), expansion of the lesion beyond the tectum on initial imaging (p < 0.001), moderate T1 signal (p < 0.001), and mild or moderate contrast enhancement (p = 0.011 and p < 0.001, respectively). At most recent follow-up, 92% had stable disease, 3% had progressive disease, 1% died from tumor progression, and 3% died of other causes.

CONCLUSIONS:

Certain characteristics of radiographic imaging may be predictive of future disease progression. In patients with progression, excellent survival can be achieved if progression is detected early and appropriate treatment is initiated.
354 Decreasing Blood Transfusions with a Multidisciplinary Intra-Operative Algorithm in Open Craniosynostosis Surgery
Authors: Drapeau Annie Isabelle , Valenti Olivia , Khansa Ibrahim , Pearson Gregory , Alalade Emmanuel , Smith Ashley
Published: March 2023

INTRODUCTION:

Blood transfusions are common in craniosynostosis surgery. Lack of an intra-operative transfusion protocol is a known risk factor for increased transfusion in these surgeries.

METHODS:

Quality improvement methodology was used (Institute for Healthcare Improvement model). A multidisciplinary team proceeded with a survey of anesthesiology teams to evaluate readiness for change; creation of an intra-operative algorithm (guiding decision making, timing of measuring hemoglobin, administration of fluid resuscitation, and indications for blood transfusion); and integration of the algorithm into the surgery time out. No modifications were made regarding the type of general anesthesia and surgical technique (1 neurosurgeon, 2 plastic surgeons). Data collected: use of the intra-operative algorithm, administration of blood products, lowest hemoglobin recorded during admission, and other relevant surgical details. Minimally invasive surgeries were excluded.

RESULTS:

Eighty-two surgeries were included in three cohorts: baseline (2018, n = 6), project initiation (2019-2020, n = 44), and post-intervention (2021-2022, n = 32). After implementation, the algorithm was used in all cases. Transfusions given in stable patients with a hemoglobin >7.5 g/dL decreased from a baseline of 40.0% to 0% (p < 0.01). This improvement was demonstrated with a centerline shift on a statistical process control chart (Aggregate Point Rule). Overall transfusion rate decreased from a baseline of 100% to 59.4% post-intervention (p = 0.07). Those receiving a transfusion did not require more than 1 unit of packed red blood cells. No transfusions were required beyond post-operative day 1.

CONCLUSIONS:

Implementation of a multidisciplinary intra-operative transfusion algorithm for open craniosynostosis surgery led to meaningful decrease in blood transfusions. This was achieved without changing surgical technique or introducing complex adjuncts.
378 RAGE Ablation Attenuates Glioma Progression and Enhances Tumor Immune Responses by Suppressing Galectin-3 Expression
Authors: Dayyani Mojtaba , Zhang Ian , Liu Shunan , Zhang Leying , Liang Rongrui , Fang Qinxiao , Zhao Jie , Ren Lyuzhi , Medina Eric , Filippov Aleksandr , Bonjoc Kimberley-Jane , Chaudhry Ammar , Bild Andrea , Badie Behnam
Published: March 2023

INTRODUCTION:

Malignant gliomas consist of heterogenous cellular components that have adopted multiple overlapping escape mechanisms that overcome both targeted and immune-based therapies. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that is activated by diverse proinflammatory ligands present in the tumor microenvironment (TME). Activation of RAGE by its ligands stimulates multiple signaling pathways that are important in tumor growth, invasion, and immune escape.

METHODS:

We evaluated genetic ablation of RAGE on the tumorigenicity of two syngeneic murine glioma models. RAGE expression was inhibited in the GL261 and K-Luc gliomas by shRNA and CRSPR/Cas9 techniques prior to intracranial implantation. Tumor growth, invasion, and inflammatory responses were examined by immunohistochemistry, qPCR, ELISA, western blotting, NanoString, flow cytometry, and in vivo survival analysis.

RESULTS:

Intracellular RAGE ablation abrogated glioma growth and invasion by suppressing AKT and ERK1/2 activities and by downregulating MMP9 expression. Interestingly, RAGE inhibition also enhanced tumor inflammatory responses by downregulating the expression of galectin-3, rendered the immunotherapy resistant K-Luc gliomas responsive to immune checkpoint blockade therapy, and significantly increased survival.

CONCLUSIONS:

This study is the first to link RAGE expression with galactin-3 as an immune modulator in glioblastoma and revealed that the effect of glioma RAGE expression on TME was mediated through downregulation of Gal-3 and subsequent polarization of Tumor-associated macrophages. The therapeutic significance of RAGE downregulation was demonstrated by sensitizing a highly invasive and immune-resistant glioma model to immune checkpoint blockade and strongly supports the development of RAGE ablation as a complementary treatment strategy for malignant gliomas.
381 Repeated Opening of the Blood-Brain Barrier With the Skull-implantable SonoCloud-9 (SC9) Device: Phase 1 Trial of Nab-Paclitaxel and SC9 in Recurrent Glioblastoma
Authors: Sonabend Adam M. , Gould Andrew , Luan Yu , Hou Ye , Chen Le , Kobayashi Mikoto , Castro Brandyn , Zhang Daniel , Korobova Farida , Amidei Christina , Youngblood Mark William , Bebawy John Patrick , Liu Benjamin P. , Horbinski Craig , Desseaux Carole , Helenowski Irene , Zhang Hui , Muzzio Miguel , Yue Feng , Caney Michael , Stupp Roger
Published: March 2023

INTRODUCTION:

The blood-brain barrier (BBB) is a major impediment to pharmacological treatment of gliomas, as these infiltrate the brain. Low-intensity pulsed ultrasound with concomitant intravenous microbubbles (LIPU/MB), opens the BBB.

METHODS:

To perform LIPU/MB-based BBB opening prior to ABX infusions, we used a novel 6 x 6 cm device with 9 ultrasound emitters (SC9) that is implanted in a skull window after tumor resection. A Phase 1 dose-escalation trial using Bayesian adaptive design was initiated at our institution (NCT04528680). Patients with recurrent operable glioblastoma, a WHO PS ≤ 2 and normal bone marrow and organ function were eligible. After tumor resection and implantation of SC9, repeated cycles of BBB opening by LIPU/MB immediately followed by ABX, were performed Q3W. Intraoperative LIPU/MB and low dose ABX was given prior to tumor resection for pharmacokinetic studies.

RESULTS:

Seventeen patients were enrolled, and dose levels 40-260 mg/m2 were investigated. At dose of 260 mgm2, a grade 3 reversible taxane-associated encephalopathy was observed in one patient, considered a dose-limiting toxicity. The patient continued treatment at a lower dose in subsequent cycles. A second patient exhibited encephalopathy on cycle 2. Pharmacokinetic studies showed that ABX tissue concentrations in non-enhancing peri-tumoral brain were increased 3.7-fold after LIPU/MB. sc-RNA-sequencing showed transcriptional dysregulation of membrane transporters, pathways related to trans-cytosis as well as cell-cell and cell-matrix adhesion. Ultrastructural analysis of brain capillaries revealed that LIPU/MB led to time-dependent emergence of vesicles in endothelial cells

CONCLUSIONS:

The LIPU/MB using skull-implantable ultrasound enhances the penetration of ABX in large regions of the brain, a procedure that can be performed repeatedly and safely. LIPU-based BBB opening leads to ultrastructural transcriptional alterations in brain endothelium.

Funding:

NIH/NCI 1R01CA245969-01A1, CarThera (SC9 devices), BMS/Celgene (Abraxane®).
387 ICU Utilization in Elective Endovascular Treatment of Unruptured Intracranial Aneurysms
Authors: Padmanaban Varun , Cohrs Austin , Jareczek Francis , Hazard Sprague , Zacko Chris Christopher , Church Ephraim W. , Simon Scott Douglas , Cockroft Kevin M. , Leslie Douglas , Wilkinson D. Andrew
Published: March 2023

INTRODUCTION:

Evidence suggests routine post-operative intensive care unit (ICU) admission in high-risk neurosurgical procedures, including endovascular treatment of unruptured intracranial aneurysms (UIA), may be unnecessary, though current practice patterns are undescribed. We sought to evaluate trends in ICU utilization in patients undergoing elective endovascular repair of UIA in the United States.

METHODS:

This is a retrospective cohort study utilizing commercial claims from a nationwide longitudinal database of multiple payors in the U.S. (MarketScan) to evaluate ICU use in patients undergoing elective, endovascular repair of UIA between 2005 and 2019. Our initial cohort was defined using diagnosis codes and CPT procedural codes. Patients with ruptured aneurysms were excluded, and the remaining unruptured patients were separated by ICU revenue codes to identify those who were likely admitted to the ICU post-operatively. A combination of diagnosis codes and procedural codes were utilized to evaluate demographics, pre-operative comorbidities, post-procedural complications, and discharge status. Cost analysis was also performed.

RESULTS:

Of 6218 patients who underwent elective endovascular treatment of UIA, 78.6% (4890) of patients were placed in the ICU post-operatively, and this percentage remained stable over the study period. No differences in age, sex, comorbidity scores, or smoking history were found between patients admitted to the ICU versus those admitted to the floor. ICU utilization was more common in urban locations (p < 0.001). The average total payment was higher in patients admitted to the ICU post-operatively ($46,429 versus $40,552, p < 0.0001).

CONCLUSIONS:

Almost 80% of patients undergoing elective endovascular repair of UIA are admitted to the ICU postoperatively, despite multiple studies suggesting this practice is unnecessary. Costs are significantly higher in patients utilizing the ICU. Reducing routine ICU use in this subgroup of patients may reduce costs and resource utilization in a safe manner.
392 A Morphological Study of Non-Stenotic Carotid Atheromas Causing Recurrent Strokes: Chronicle of Disruption and Stabilization
Authors: Madhani Sarosh Irfan , Larco Jorge Arturo , Abbasi Mehdi , Liu Yang , Shahid Adnan , Reade Quinton , Seibel Eric , Savastano Luis
Published: March 2023

INTRODUCTION:

Symptomatic non-stenotic carotid (SyNC) artery disease is a recognized etiology of ischemic strokes with a putative thromboembolic mechanism. To date, the structural phenotypes expressed at the lumen/wall interface of these lesions are not completely understood resulting in misdiagnosis and hindering the development of targeted therapies.

METHODS:

After IRB approval, en block endarterectomy specimen were obtained from patients with recurrent strokes from SyNC (n=9). Additionally, segments of superficial temporal artery (STA) of patients undergoing cerebral artery bypass surgeries were obtained as controls (n=3). The endovascular surfaces of the samples were imaged with laser microangioscopy and scanning electron microscopy (SEM). Images were benchmarked with histological sections and immunohistochemistry (IHC).

RESULTS:

Normal endothelial surfaces in STA were light pink, smooth and homogenous by angioscopy with typical cobblestone endothelial pattern. Features recognized as those associated with plaque disruption and thrombosis were de-endothelialization, inflammatory infiltrates within and under the endothelium, delamination (flaps oriented to the flow) with superficial intimal hemorrhages, plaque erosion and disruption of the fibrous cap with fissuring, ulceration, excavation and plaque hemorrhage. Additionally, cellular and acellular structures actively involved in plaque stabilization, seen on SEM and confirmed with histology and IHC, were also identified including activated platelets, fibrin band, bridges and webs, neutrophil extracellular traps and endothelial progenitor cells.

CONCLUSIONS:

This ultrastructural study of the vascular surface of SyNC specimens reveals concurrent phenotypes of flow-dependent disruption and stabilization that could become new imaging biomarkers and enable the development of targeted therapies.
395 The “Hub-Spoke” Telemedicine Model in a Large Cohort of Stroke Patients
Authors: El Naamani Kareem , Herial Nabeel , Abbas Rawad , Sioutas Georgios Georgios , Amllay Abdelaziz , Munoz Alfredo , Morse Charles , Moylan Daniel , Joffe Daniel , Knapp Michael , Tjoumakaris Stavropoula I. , Gooch Michael Reid , lRosenwasser Robert H. , Jabbour Pascal
Published: March 2023

INTRODUCTION:

Stroke is a leading cause of death and disability worldwide. According to the World Health Organization, stroke patients should be treated in dedicated stroke units. However, stroke units require multidisciplinary stroke expertise which is usually scarce in rural areas.

METHODS:

This is a retrospective single-center study encompassing patients suffering from strokes and receiving pre-hospital and in-hospital tele-stroke expertise based on a spoke/hub stroke network. Data from 38 hospital networks between December 2014 and January 2018 were collected.

RESULTS:

The study cohort consisted of 9702 patients. The majority were females (n = 3556, 55.3%) and the mean age was 67 (67 +16.7, 66.7 - 67.4, 26 -122). Of all patients, tissue plasminogen activator (tPA) was recommended in 1313 (16.3%) patients, and from these, 810 (61.7%) patients were actually given tPA. As for endovascular intervention, only 187 (2.3%) patients underwent mechanical thrombectomy at our institution.

CONCLUSIONS:

Tele-stroke networks have proven to be a pivotal development in the treatment of strokes, especially those that are remote. With the additional expertise and the shorter duration from onset to diagnosis to treatment, these networks have substantially improved patient care and decreased healthcare costs, avoiding unnecessary transfers from spoke hospitals to hub.
398 Towards Catheter-Clot Engagement Detection Via Classification of Vacuum and Motion Signature During Aspiration Thrombectomy
Authors: Veliky Madison , Lawson Jared , Chitale Rohan V. , Simaan Nabil
Published: March 2023

INTRODUCTION:

While acute ischemic stroke caused by large vessel occlusion is effectively treated with aspiration thrombectomy, procedural success depends on the quality of engagement between the catheter tip and the thrombus. Currently, there is no method to identify whether the catheter tip is truly in contact with the clot surface. Poor thrombus engagement can result in failure of recanalization.

METHODS:

An in vitro arterial occlusion was modeled with Tygon tubing representing the blood vessel and a synthetic thrombus made from TrueClot simulants. A 6Fr microcatheter was controllably inserted into the mock vessel until it contacted the synthetic thrombus. A motorized syringe and pressure sensor were connected proximally to the catheter to precisely control and measure the cyclic vacuum excitation in the catheter. The cyclic vacuum excitation was performed with a stroke of ±0.5 mm at 2 Hz, 4 Hz, and 8 Hz at catheter-clot distances of 150 mm, 20 mm, 10 mm, 5 mm, and in contact on 17 different clot models. Control and sensing data was collected at 1000 Hz frequency. For each catheter-clot distance, 1000 vacuum measurements were collected and pressure traces were saved. The change in the pressure mean per a change in insertion depth of the catheter was used to train a support vector machine (SVM) classifier that confirms clot contact.

RESULTS:

Using 30% of the clot model samples to train the SVM classifier and the remaining samples for validation, the quality of classification was determined. The accuracy (and F1 score) of clot detection at 2 Hz, 4 Hz, and 8 Hz were 98.31% (95.65%), 100% (100%), and 93.22% (80.00%) respectively.

CONCLUSIONS:

Accurate detection of catheter-clot contact is feasible via small excitation of the aspiration syringe and concurrent measurement of vacuum pressure.
409 Effect of Social Determinants of Health on Post-Discharge Adverse Outcomes After Surgical Resection of Meningioma
Authors: Wong Gunther , Tang Alan Ruigang , Guidry Bradley , Grisham Candace , McDermott Jake , Morone Peter J. , Thompson Reid C. , Chambless Lola Blackwell , Chotai Silky
Published: March 2023

INTRODUCTION:

Understanding the role of social determinants of health (SDoH) is critical in informing preoperative care and postoperative follow-up for meningioma patients undergoing surgery.

METHODS:

A retrospective cohort study of adults presenting for meningioma resection from 1999-2020 was conducted. Primary outcomes included recurrence, readmission, and LTF (6-month and total). The main exposure of interest was Area Deprivation Index (ADI), a composite score of socioeconomic disadvantages. Additional SDoH factors analyzed included drive time to the hospital, insurance, and race. Multivariable logistic regression analyses for LTF and Cox regression for recurrence- and readmission-free survival were conducted. Covariates included age, WHO grade, and extent of resection.

RESULTS:

In total, 736 patients were included. Recurrence was observed in 90 patients, and 99 patients were readmitted following discharge. 121 patients missed initial and 6-month follow-up, but 107 of those eventually followed-up after six months. Fourteen patients were entirely LTF. ADI (OR = 1.11 per 10-point increase, 95% CI 1.02-1.21, p = 0.017) and drive time (OR = 1.03 per 30-minute increase, 95% CI 1-1.06, p = 0.022) predicted 6-month LTF. Drive time predicted complete LTF (OR = 1.04 per 30-minute increase, 95% CI 1-1.07, p = 0.017). Medicare/Military insurance predicted lower recurrence risk (HR = 0.43, 95% CI 0.23-0.81, p = 0.009) and higher readmission risk (HR = 2.00, 95% CI 1.17-3.41, p = 0.011). Other SDoH factors were not associated with recurrence or readmission. Lower WHO grade predicted lower recurrence risk (HR = 0.5, 95% CI 0.33-0.78, p = 0.002), while age (HR = 0.75 per 10-year increase, 95% CI 0.62-0.89, p < 0.001) and gross total resection (HR = 0.56, 95% CI 0.35-0.9, p = 0.016) predicted lower readmission risk.

CONCLUSIONS:

Socioeconomically disadvantaged neighborhoods and further distance from the hospital were barriers to follow-up after meningioma resection. Other SDoH associated with readmission and recurrence are reported. Individualized follow-up plans should consider these SDoH to ensure care continuity and improve outcomes.
410 Treatment of Idiopathic Normal Pressure Hydrocephalus With a Novel Programmable Valve With Gravitational Unit: Prospective Evaluation of Efficacy, Safety and Costs
Authors: Reis Rodolfo , Yamashita Renata , Fontoura Solla Davi Jorge , Ramin Laís , Almeida de Oliveira Teixeira Manoel Jacobsen , Gomes Pinto Fernando Campos
Published: March 2023

INTRODUCTION:

Programmable valves provide an equal or superior neurological outcome when compared to fixed pressure ones, with fewer complications, in treating idiopathic normal pressure hydrocephalus (iNPH) patients. Long-term costs of these treatments have not been properly compared in literature.

METHODS:

A prospective cohort of iNPH patients treated with programmable valve between January 2018 and May 2020 was compared to a historical cohort of iNPH patients treated with fixed pressure valve from January 2016 through December 2017. Our primary outcome was the mean cost of treating iNPH up to one year. Cost variables assessed included number of surgeries, length of ICU and hospital stay, and number of imaging tests. Efficacy in treating iNPH, measured by mean NPH Japanese Scale, and safety, measured by complications rates, were assessed as secondary outcomes.

RESULTS:

A total of 19 patients were analyzed in each group (mean age 75 years, the majority male). Comorbidities and clinical presentation were similar between groups. Both fixed pressure and programmable valve patients had neurological improvement over time (p < 0.001), but no difference was seen between groups (p = 0.104). The fixed pressure valve group had more complications than programmable valve group (52.6% vs 10.5%, respectively, p = 0.013). Annual treatment cost per patient was US$ 3,820 ± 2,231 in the fixed pressure valve group and US$ 3,108 ± 553 in the programmable valve group. Mean difference was US$712 (95% CI, 393 – 1,805) in favor of the programmable valve group.

CONCLUSIONS:

The novel programmable valve with gravitational unit had one-year treatment cost not higher than that of fixed-pressure valve, and resulted in similar efficacy and fewer complications.
414 Competitive Advantage: An Analysis of Matched and Unmatched United States Neurological Surgery Residency Applicants From 2009-2021
Authors: Goldman Liam , Iyer Ankitha Mahesh , Barpujari Awinita , Rogers James Louis , Reddy Vamsi , Johnson Jeremiah N.
Published: March 2023

INTRODUCTION:

National Resident Matching Program releases a detailed report of residency match statistics for each specialty. Securing a training position in a United States neurological surgery residency program is notoriously competitive, and the subspecialty has long maintained a match rate much lower than other specialties. There remains a paucity of recently studied longitudinal trends in academic and extracurricular characteristics of successfully matched neurological surgery residency applicants.

METHODS:

Residency applicant self-reported data, obtained from the American Association of Medical Colleges Electronic Residency Application Service, were collected from yearly “Results and Data: Main Residency Match” (2009-2021) and biennial “Charting Outcomes in the Match” (2009-2020) National Residency Match Program summary reports.

RESULTS:

From 2009-2021, the number of neurological surgery residency programs and positions increased from 97 to 115 and 191 to 234, respectively. Matched applicants’ average United States Medical Licensing Exam (USMLE) Step 1 scores significantly increased (239 to 248; p = 0.01332), while average USMLE Step 2 Clinical Knowledge scores rose (237 to 252; p = 0.05682) during the study period. Average number of distinct research experiences among matched applicants increased (3.3 to 6.1; p = 0.5398), while the average number of abstracts, presentations, and publications increased from 7.8 to 23.4 (p = 0.0746). Lastly, Alpha Omega Alpha (AOA) membership (p = 0.00077) and percentage graduating from a top National Institutes of Health-funded medical school (p = 0.00396) significantly differed between matched and unmatched neurological surgery residency applicants.

CONCLUSIONS:

Matched neurological surgery residency applicants had significantly fewer average number of distinct specialties ranked, higher USMLE Step 1 scores, greater AOA membership, and more frequently graduated from top 40 NIH-funded medical schools than their unmatched counterparts. Additional research considering applicant-level intersectional data is warranted to further understand the match process.
415 Gender Differences in Operative Autonomy Using the Surgical Autonomy Program
Authors: Kirsch Elayna P. , Suarez Alexander , Venkatraman Vishal , Murphy Kelly Ryan , McDaniel Kate , Dharmapurikar Rajeev , Lad Nandan P. , Haglund Michael M.
Published: March 2023

INTRODUCTION:

While efforts to recruit females into surgical fields have increased, gender differences in surgical training exist.

METHODS:

The SAP divides a surgical case into four parts, or zones of proximal development (ZPD). For each ZPD, residents are evaluated on a 4-tier autonomy scale (TAGS scale). Using logistic regression analysis, we evaluated neurosurgery residents at Duke University Hospital from July 2017-July 2021 to compare differences in male and female trainee autonomy as rated by both attendings and residents.

RESULTS:

There were a total of 4,441 cases logged by 26 different residents and 30 attendings. 69% of residents were male (n = 18) and 31% (n = 8) were female. An ordinal regression analysis showed that female residents were given less autonomy than males by attendings (OR 0.59, 0.51-0.69 95% CI, p < 0.001). Females were also less likely to focus on a more complex ZPD (OR 0.53, 95% CI 0.46-0.61, p < 0.001). Based on self-evaluation, female residents rated their autonomy lower than males (OR 0.71, 0.61-0.82 95% CI, p < 0.001). Faculty provided greater intraoperative feedback in cases with female residents (84%, n = 539) compared to male residents (79%, n = 1,875) (X2 = 7.52, df = 1, p < 0.01). Female and male residents were fully autonomous on a similar proportion of cases in post-graduate year seven (73% and 72%, respectively).

CONCLUSIONS:

Female residents were given less autonomy compared to their male counterparts for index neurosurgical cases and were less likely to focus on a more complex portion of a case. Female residents were more self-critical, though received greater significant intraoperative feedback. Nonetheless, females and males were fully autonomous on a similar number of cases in their final residency year. Increased efforts are needed to address the gender gap within surgical education.
422 Utilizing Situational Judgment Test in Neurosurgery Residency Online Interviews
Authors: Feng Rui , Subramaniam Varun , Mocco J D. , Kellner Christopher P. , Shrivastava Raj K.
Published: March 2023

INTRODUCTION:

Neurosurgery residency selection is heavily reliant on pre-residency factors and unstructured interviews. These metrics, however, have not been shown to reliably predict residency performance, and have potential to introduce bias and discrimination. Outside of medicine, the science of selection is much better developed, and methods such as structured interviews, situational judgment tests (SJT), and personality assessments are routinely used with robust evidence for efficacy and reliability at predicting job performance.

METHODS:

We designed a set of 4 SJT questions mimicking common situations a neurosurgery resident would encounter during residency. Each question had individualized grading rubrics scored on a scale of 1 to 4. For the 2021 residency application cycle, our program incorporated these SJT questions as part of the online interview process. Four volunteer faculty interview pairs delivered one question each for every candidate, and recorded the scores. Other traditional evaluation metrics from the candidate’s application and interview were also collected post interview.

RESULTS:

All 44 interview candidates applying to our program during the 2021 cycle were assessed. Due to time constraints, the number of questions each candidate responded to varied from 2 to 3. The average score was 3.6 (SD 0.44, range 2-4). The SJT score was not associated with USMLE Step 1 score (p = 0.31), number of publications (p = 0.42), or letter of recommendation score (p = 0.21). The SJT scores had a moderate positive correlation with personality on interview (r = 0.42, p < 0.01), and overall interview score (r = 0.30, p = 0.04).

CONCLUSIONS:

It is feasible to incorporate SJT questions into the neurosurgery resident online interview process. They may provide objective metrics independent of academic and research abilities. Further investigations with long term follow up is needed to see if SJT can be validated and correlated with residency performance.
431 An Observational Analysis of Randomized Controlled Trials (RCTs) Discontinuation and Non-Publication in Spine Disease
Authors: Tiefenbach Jakov , Demetriades Andreas K. , Park Jay
Published: March 2023

INTRODUCTION:

Incompleteness and non-publication of Randomized Controlled Trials (RCTs) have been increasingly reported in the literature. This is a significant concern as RCTs demand monumental amounts of healthcare resources leading to wastage. Most importantly, both under-reporting and non-publication distorts evidence landscape and obscures rationale behind clinical decisions.

METHODS:

A list of RCTs was obtained from the U.S National Library of Medicine ClinicalTrials.gov database from January 1st, 2013, to December 31st, 2020. Two independent authors excluded all non-RCTs, trials unrelated to spinal diseases, and trials that are in or before the recruitment phase. We extracted the progress status, sources of funding, number of centers, type of intervention, principal investigator’s department affiliation, publication status, location, reason for discontinuation, publication date, and subtopics.

RESULTS:

A total of 112 trials were included in the study. Twenty-five (22%) trials were discontinued early, with slow recruitment being the major reason (38%). Only fifty-six (50%) of the trials were published in peer-reviewed journals. Trial discontinuation was much higher in trials registered in the United States (US) compared to other countries (P = 0.009). There were 11 (23.4%) industry-sponsored and 14 (21.5%) non-industry-sponsored studies that remained uncompleted. Over the study period, only 20% of the trials were fully compliant with the FDA reporting requirements.

CONCLUSIONS:

Nearly a quarter of all trials in spinal disorders were discontinued. Half of the trials were unpublished. These rates remain worrisome from an ethical and financial perspective. Both under-reporting and non-publication adversely affect patient safety and waste valuable healthcare resources. An organized effort is needed to address this important issue and improve the rates of trial completion and publication.
436 Transforaminal Endoscopic Decompression for Foraminal Stenosis: Single-Arm Meta-Analysis and Systematic Review
Authors: Liu Yanting , Van Isseldyk Facundo , Kotheeranurak Vit , Kim Jin-sung , Chul Choi Kyung , Bae Jun Seok , Quillo-Olvera Javier
Published: March 2023

INTRODUCTION:

The objective of this single-arm systematic review was to assess the effectiveness of transforaminal endoscopic foraminal decompression (TEFD) in patients with symptomatic LFS.

METHODS:

The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The Medicine, PubMed, Web of Science, and Embase databases were searched from inception to February 20, 2022. Primary research results were Visual Analog Scale (VAS) scores, Oswestry Disability Index scores (ODI), MacNab Criteria (MNC) scores, and reported adverse events (AEs). Subgroup analyses were performed on the primary outcome to evaluate the potential effects of several clinical factors that affected the results.

RESULTS:

Of the 2020 studies identified, nine met the inclusion criteria, and 316 participants were eligible for meta-analysis. The meta-analysis results found that transforaminal endoscopic surgery for the treatment of LFS was associated with a significant improvement in postoperative 12-month clinical indicators: 8 studies reported improvements in VAS scores: -5.38, ODI scores: -40.44, and MNC scores: OR (odds ratio) = 0.86; 8 studies reported 11.53% AEs occurred in a total of 295 patients, and the most commonly reported event was transient postoperative dysesthesia, which occurred in 26 patients in a total of six studies with 240 patients (10.83%).

CONCLUSIONS:

Transforaminal endoscopic surgery positively affects postoperative LFS patients' clinical indicators; however, high-level literature with randomized controlled trials is needed to confirm this technique's applicability in LFS.
440 10 kHz Spinal Cord Stimulation (SCS) Provides Significant, Durable Pain Relief for Patients with Painful Diabetic Neuropathy (PDN): 24-Month Results
Authors: Petersen Erika A. , Stauss Thomas , Scowcroft James , Jaasma Michael , White Judith , Sills Shawn , Amirdelfan Kasra , Guirguis Maged , Xu Jijun , Yu Cong , Nairizi Ali , Patterson Denis , Creamer Michael , Galan Vincent , Bundschu Richard , Mehta Neel , Sayed Dawood , Lad Nandan P. , DiBenedetto David , Sethi Khalid Ahmed , Wu Paul , Argoff Charles , Nasr Christian , Taylor Rod , Caraway David , Mekhail Nagy
Published: March 2023

INTRODUCTION:

Approximately 37 million Americans have diabetes, 1 with 25-30% experiencing PDN. 2 High-frequency (10 kHz) SCS has been shown to provide substantial symptom relief for PDN, 3 and here we report durability of these outcomes to 24 months (24M).

METHODS:

This prospective, multicenter, RCT evaluated 10 kHz SCS with these key inclusion criteria: PDN symptoms ≥12 M refractory to medications, lower limb pain intensity ≥5 cm (0-10 cm visual analog scale [VAS]), and hemoglobin A1c ≤ 10%. Patients (n = 216) were randomized 1:1 to 10 kHz SCS plus CMM or CMM alone, with optional crossover at 6M.

RESULTS:

At 6M, patients receiving 10 kHz SCS experienced average pain relief of 76.1% (95% CI: 70.5–81.6%), which increased to 82.0% (95% CI: 77.3–86.6%) at 24M. At 24M, 10 kHz SCS patients experienced 70% decreases in pain-associated sleep disturbance and interference with mood and daily activities. At 24M, neurological improvements were observed in 72% of patients receiving 10 kHz SCS. After 6M, 93% of eligible CMM patients elected to cross over to 10 kHz SCS, while zero 10 kHz patients crossed over. With 10 kHz SCS, both groups experienced similar, significant reductions in pain and pain-associated interference. There were zero device explants due to lack of efficacy and eight (5.2%) procedure-related infections (n = 3 resolved with antibiotics; n=5 explanted), which is within the range reported for SCS in non-diabetic patients (2.5-10%).4

CONCLUSIONS:

This is the largest RCT to date for SCS management of PDN. The 24M results support that 10 kHz SCS can provide safe, durable pain and symptom relief for PDN.

REFERENCES:

1 CDC. National Diabetes Statistics Report; 2022. 2 Finnerup et al. Lancet Neurol 2015; 14(2):162-73. 3 Petersen et al. Diabetes Care; 45(1):e3-e6. 4 Eldabe et al. Pain Med 2016; 17(2):325-36.
442 Reversible Cognitive Dysfunction and Neuropsychiatric Symptoms in Patients With Chiari Malformation Type I
Authors: Henry Luke , McDowell Michael Maurice , Stephenson Tina , Crittenden J. Bret , Bird Amy , Fernandez-de Thomas Ricardo Jose , Strick Peter , Friedlander Robert Max
Published: March 2023

INTRODUCTION:

Chiari malformation type I (CMI) is a congenital/acquired structural condition where the cerebellar tonsils herniate through the foramen magnum, resulting in cerebellar and lower medulla/upper cervical spinal cord compression. Symptoms typically include occipital headaches, however, additional symptoms have been reported by symptomatic patients. We have observed a proportion reporting cognitive dysfunction and neuropsychiatric symptoms, which appear to improve following posterior fossa decompression (PFD).

METHODS:

Patients completed comprehensive neuropsychological evaluations, including a 90-minute standardized assessment of cognitive function across multiple domains and a self-reported assessment of neuropsychiatric symptoms, pre- and approximately 6-months post-surgery.

RESULTS:

This prospective study included patients with CMI who opted to undergo PFD surgery and reported cognitive or neuropsychiatric impairment between 2015 to 2021. All patients completed a comprehensive pre-operative neuropsychological assessment. A parallel assessment was completed at 6-month post-operative follow-up. 112 patients (Mage = 35.1 years; SD = 10.4) were included in pre-operative analyses, and of these, 31 patients (Mage = 32.5 years; SD = 10.5) were included in paired pre-post-operative analyses. Pre-operatively, CMI patients performed significantly worse than a standard norm on measures of executive function, attention, visuospatial memory, verbal memory, and neuropsychiatric symptoms.

CONCLUSIONS:

This is the first study to 1) demonstrate significant impairments in cognitive function and neuropsychiatric symptoms in CMI patients pre-operatively, and 2) show significant improvements in these domains at post-operative follow-up. This work calls attention to a significant proportion of CMI patients who suffer debilitating and life altering symptoms and provides compelling evidence for a role of the cerebellum in such conditions. In addition to CMI, cerebellar pathology should be considered as potential neuroanatomical site for patients with cognitive and neuropsychiatric impairment from other etiologies.
444 Extraction and Analysis of Speech Features to Understand Audio Phenotypes of Pain
Authors: Duey Akiro , Rana Aakanksha , Hussein Helweh , Siddi Francesca , Onnela J.P. , Smith Timothy R.
Published: March 2023

INTRODUCTION:

Pain evaluation of spine patients remains largely a subjective assessment in practice, but artificial intelligence provides the potential for objective pain assessment tools.

METHODS:

This study enrolled spine patients from a general neurosurgical clinic. Patients were asked to download the Beiwe smartphone application and prompted to complete pain surveys at home once per day and speech recordings once per week during the study. The pain surveys asked patients to rate their pain on a scale from 0 to 10. For the speech recordings, patients were asked to read a passage from a well-known novel. Patients were included in the study if they completed at least one speech recording and pain survey within 24 hours of each other. Audio features were extracted from the speech recordings using the Parselmouth library, and 13 Mel-frequency cepstral coefficients (MFCCs) were extracted using the Librosa package. The mean MFCC values were calculated for each speech recording. These speech features were then analyzed using a linear mixed model with pain as the model output and a random intercept for each patient.

RESULTS:

In total, there were 384 speech recordings from 60 patients. The linear mixed model was significantly associated with two MFCCs – MFCC 2 (Coef: 0.552; 95% CI: [0.254, 0.850]; p < 0.001) and MFCC 12 (Coef: -0.286; 95% CI: [-0.538, -0.034]; p = 0.026). However, we observed that none of the other available audio features were significantly associated with pain scores.

CONCLUSIONS:

This preliminary study shows that MFCCs 2 and 12 are of potential interest for phenotyping speech and objective pain assessment.