bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitamin D and the microbiota connection: understanding its potential to improve COPD outcomes
Authors: Ali Asmaa , Wu Liang , Ali Sameh Samir
Published: March 2024

The mucosa of the respiratory system is an essential site for local vitamin D synthesis, degradation, and signaling. It modulates the inflammatory and immune response by saving the integrity of the mucosal barrier and killing the invading pathogen through the induction of antimicrobial peptides. The proper functioning of the immune system within the respiratory system is influenced by the complex interactions of numerous immune pathways, including the gut-lung axis. Recent research has indicated that the gut microbiota is vital in developing and progressing chronic inflammatory chest conditions, such as asthma and chronic obstructive pulmonary disease (COPD). Furthermore, the immune-modulating function of vitamin D operates through the gut mucosa; hence, the vitamin D receptor is expressed to regulate the antimicrobial peptide. The potential protective role of vitamin D and its correlation with COPD has garnered significant interest. It is currently under exploration as a possible adjuvant therapy to aid in managing frequent exacerbation of COPD. In this review, we explored the connection between vitamin D and the immune system, as well as its relationship with microbiota. We also summarized some novel mechanisms of action of vitamin D supplementation that can impact disease exacerbation.
Farm animals as a critical link between environmental and human health impacts of micro-and nanoplastics
Authors: Aardema Hilde , Vethaak A. Dick , Kamstra Jorke H. , Legler Juliette
Published: March 2024

Plastic pollution is an increasing global health concern, particularly the ever-increasing amount of tiny plastic particles commonly referred to as micro- and nanoplastics (MNPs). Most research to date on MNP exposure and hazards has focused on environmental species such as aquatic organisms and, more recently, humans, leaving impacts on farm animals largely unstudied. MNPs have been detected in all environmental compartments, including agricultural environments, farm animals and food products originating from them. The health of farm animals can be directly affected by MNPs, while humans can be affected by MNPs present in animal-derived food products. In this perspective article, we argue that MNP research should give more attention to farm animals forming a critical link between the environment and human health. Here, we summarize evidence on sources, exposure routes, levels in farm animals, and potential health effects of MNPs on farm animals, and identify knowledge gaps for future research, such as effects of MNPs on reproduction and development. In particular, the bovine embryo model is a promising model to study effects of MNPs on early development of both farm animals and humans. This perspective article signals the need for follow up studies that will increase our understanding of the transfer of MNPs between environment, farm animals, and humans, and the potential of farm animals to serve as an indicator for other animals, including humans.
Plastics in biota: technological readiness level of current methodologies
Authors: Vanavermaete David , Lusher Amy , Strand Jakob , Abad Esteban , Farré Marinella , Kallenbach Emilie , Dekimpe Michael , Verlé Katrien , Primpke Sebastian , Aliani Stefano , De Witte Bavo
Published: March 2024

Plastics are persistent in the environment and may be ingested by organisms where they may cause physical harm or release plastic additives. Monitoring is a crucial mechanism to assess the risk of plastics to the marine and terrestrial ecosystem. Unfortunately, due to unharmonised procedures, it remains difficult to compare the results of different studies. This publication, as part of the Horizon project EUROqCHARM, aims to identify the properties of the available analytical processes and methods for the determination of plastics in biota. Based on a systematic review, reproducible analytical pipelines were examined and the technological readiness levels were assessed so that these methods may eventually (if not already) be incorporated into (harmonised) monitoring programs where biota are identified as indicators of plastic pollution.
Experimental study on the mechanical properties and structural performance of the rapid hardening concrete
Authors: Elfakhrany Mohamed Hussein , Zamrawi Amal , Ibrahim Wael , Sherif Alaa
Published: March 2024

Rapid-hardening concrete (RHC) is becoming more popular as a cast-in-place jointing material in precast concrete bridges and buildings due to its high tensile strength and crack resistance. RHC’s technical properties are highly regarded due to the working conditions of mega projects. The study assessed the impact of modern modifiers on concrete in order to select a composition of rapid-hardening concrete (RHC) with superior mechanical properties. Following an analysis of previous studies by other authors, microsilica and a polycarboxylate ether-based chemical additive was chosen as basic modifiers in the manufacture of RHC. In addition, four reinforced rapid-hardening concrete beams were tested for operational reliability and durability after 3 days of casting. The structural performance of RHC beams was evaluated in comparison to normal concrete beam specimens, and it was determined that crack distribution, load deflection, reinforcement strains, ductility, and toughness were all important factors in the evaluation. RHC beams exhibit higher ductility, toughness, ultimate loads, and deformability than NC beams. The tensile strength analysis revealed a positive impact of RHC, but the shrinkage crack related to heat hydration was crucial.
Restaging With Prostate-Specific Membrane Antigen Imaging in Metastatic Castration-Resistant Prostate Cancer: When Seeing More Is Detrimental to Care
Authors: Madan Ravi A. , Yu Evan Y. , Posadas Edwin M. , Lee Richard J. , Karzai Fatima , Choyke Peter L.
Published: March 2024

#PSMA is amazing new tech but is using it to expedite the call of disease progression helping #ProstateCancer patients?
Investigating the Association of Polygenic Risk Scores With Thyroid Cancer Susceptibility in a Han Chinese Population
Authors: Chen Yi-Hao , Chen I Chieh , Chou Chia-Man , Huang Sheng-Yang
Published: March 2024

Background

Thyroid cancer, the leading endocrine tumor with a rising global incidence, especially in women, is influenced by both genetic and environmental factors. This study examines the relationship between polygenic risk scores (PRS) and thyroid cancer susceptibility in the Han Chinese population, as well as the impact of genetic variants on clinical outcomes.

Methods

Analyzing data from 57 257 participants in the Taiwan Precision Medicine Initiative, the study employed the Affymetrix Genome-Wide TWB 2.0 SNP Array for genotyping. PRS were calculated using single nucleotide polymorphisms (SNPs) from prior genome-wide association studies, specifically PGS000087 and PGS000797, and correlated with clinical parameters like age, sex, comorbidities, and treatment methods.

Results

Among 4063 participants with thyroid tumors (839 malignant, 3224 benign), higher PRS quartiles correlated significantly with increased thyroid cancer incidence. The highest quartile showed a 1.15-fold (PGS000797) and 1.14-fold (PGS000087) greater risk than the lowest quartile. Key findings included an association between higher PRS quartiles and younger onset age, along with a notable link to chronic kidney disease and thyroid hormone levels in specific SNPs.

Conclusion

The study demonstrates PRS's utility in predicting thyroid cancer risk in the Han Chinese population, with higher PRS associated with increased risk and distinct clinical features. While this study focuses on the Han Chinese population, we recognize the importance of comparing PRS performance across different ancestries to fully understand ethnic genetic diversity in cancer risk assessment. Future studies should aim to include such comparative analysis.
101 Glymphatic System Impairment Associated With Neurocognitive Dysfunction and Alzheimers Biomarkers in Moyamoya Disease
Authors: Zeng Chaofan , Zhai Yuanren , Ge Peicong , Zhang Dong , Zhao Jizong
Published: March 2024

INTRODUCTION:

Glymphatic system alterations have been proved to be associated with cognitive dysfunction in Alzheimer’s Disease (AD). The glymphatic pathway has not been elucidated in moyamoya disease (MMD), which was recognized as a chronic hypoperfusion model for AD.

METHODS:

We prospectively recruited 30 MMD patients and 30 matched healthy controls (HC) from October 2022 to March 2023. Participants underwent neurocognition evaluation, and multimodal magnetic resonance imaging (MRI). AD-related serum biomarkers, as well as correlations among these variables were examined. The glymphatic function was assessed by diffusion tensor image analysis along perivascular space (DTI-ALPS). Whole-brain (white matter and grey matter) volumes were calculated by using 3D T1-weighted MRI. Microstructural changes of white matter (intracellular volume fraction, Vic; orientation dispersion index, OD) were evaluated by neurite orientation dispersion and density imaging (NODDI).

RESULTS:

Serum Alzheimer’s biomarkers (ApoE, Aβ40, Aβ42, and tau) were significantly elevated and associated with neurocognitive dysfunction in MMD. Lower periventricular ALPS-index was identified in patients with MMD (P < 0.001). The decreased ALPS-index correlated with declined neurocognitive performance of intelligence quotient, attention, and memory, increased levels of serum ApoE, Aβ40, Aβ42, as well as higher periventricular white matter volume and lower periventricular grey matter volume (P < 0.001). Moreover, MMD patients had significantly lower Vic in the white matter and a lower OD in the cortex than HC.

CONCLUSIONS:

We firstly demonstrated the impaired glymphatic system as assessed by lower ALPS-index in patients with MMD. Glymphatic impairment was associated with AD-related biomarkers and cognitive dysfunction in MMD. These findings suggested that glymphatic disorder may interact with MMD-related pathophysiological processes.
1066 Comparative Outcome Using Expandable Versus Static Cage in Direct Lateral Interbody Fusion for Degenerative Lumbar Disc Disease
Authors: Chieng Lee-Onn , Kanyadike Kim , Chehab Moussa
Published: March 2024

INTRODUCTION:

Subsidence has been a common concern or complication in patients undergoing TLIF with an expandable cage or standalone DLIF with a static cage. It could lead to further complications such as pseudoarthrosis, lumbar kyphosis, and radiculopathy. Recently, expandable technology has emerged in lateral interbody fusion, which could be delivered through the smaller surgical corridors. Therefore we sought to determine the extent of radiological outcome and subsidence rate in patients with expandable cages.

METHODS:

A retrospective review of patients who underwent DLIF was performed. Only patients with degenerative lumbar disc disease were included. Baseline demographic and radiographic outcomes such as cage subsidence, anterior and posterior disc height, foraminal dimensions, and other spinopelvic parameters were collected. The primary endpoint was severe cage subsidence (grade 2 and 3) per level according to the classification by Marchi et al. Multivariate Analysis was performed.

RESULTS:

59 patients underwent DLIF with expandable (n = 25) and static (n = 34) cages respectively. Both expandable and static groups have comparable baseline demographic such as age, gender, BMI, and medical comorbidities. The average follow-up period was 16 months. Both groups also had a comparable rate of the standalone construct (40% vs 68%, p 0.088). Significant higher cage width and length were used in the expandable group. However, there were no statistically significant differences in the restoration of both anterior and posterior disc heights, foraminal height, and central canal diameter. A significantly lower rate of severe subsidence was observed in the expandable group (4% vs 26.5%, p = 0.023) compared to the static group.

CONCLUSIONS:

In our study, expandable cages in DLIF patients were observed to have a significantly lower rate of subsidence when compared to those who received static cages.
1070 Muscle Mechanomyography (MMG) for Peripheral Nerve Monitoring During Lateral Lumbar Fusion: The New Kid on the Block?
Authors: Chine Angel Gabriel , Pressman Elliot , Monsour Molly , Alikhani Puya
Published: March 2024

INTRODUCTION:

The lateral transpsoas approach has become a valuable minimally invasive option in lumbar spine surgery to achieve fusion, decompression, and deformity correction. However, femoral nerve injury during psoas retraction remains a significant concern, especially in the lower spinal levels. A newer alternative to electromyography (EMG), muscle mechanomyography (MMG) measures muscle fiber oscillation during contraction, providing a more specific and quantifiable response with a high signal to noise ratio. These characteristics make MMG an attractive option for intraoperative neuromonitoring (ION) in minimally invasive spine surgery.

METHODS:

Patients who underwent LLIF between 2018-2021 with MMG ION were included and compared to a historical cohot of patients who underwent LLIF from 2016-2021 with EMG ION. The femoral nerve palsy rate defined by ipsilateral thigh numbness, hip flexor, or quadricep weakness immediately post operatively were collected for both groups. Patients were re-evaluated at 3 month and 1 year follow up intervals.

RESULTS:

The rate of ipsilateral thigh numbness, hip flexor, and quadricep weakness at hospital discharge were 14.6% (6/41), 9.8% (4/41), and 7.3% (3/41) respectively for the MMG group, comparable to 14.8% (9/61), 23% (14/61), and 14.8% (9/61) observed in the EMG control group. Improvement in thigh numbness and leg weakness was observed for both groups at 3 month and 1 year follow up. No patients with leg weakness had less than antigravity strength. There were no statistically significant difference amongst patient demographics for both cohorts.

CONCLUSIONS:

In conclusion, MMG appears to be clinically equivalent to EMG as an intraoperative modality for femoral nerve monitoring in LLIF procedures. Further research is needed to evaluate the additional clinical advantages proposed by mechanomyography, such as low signal interference and quantifiable nerve localization.
1071 Initial Experience Using an Augmented Reality Head-Mounted Display System During Surgical Management of Thoracolumbar Spinal Trauma
Authors: Kann Michael , Ruiz-Cardozo Miguel A. , Brehm Samuel , Carey-Ewend Abigail , Singh Som , Barot Karma , Verastegui Gabriel Trevino , De La Paz Matthew , Hanafy Ahmed , Bui Tim , Joseph Karan , Olufawo Michael O. , Sanchez Paula Alejandra , Patel Rujvee , Yahanda Alexander T. , Perdomo-Pantoja Alexander , Jauregui Julio , Cadieux Magalie , Pennicooke Brenton Henry , Molina Camilo A.
Published: March 2024

INTRODUCTION:

Advancements in trauma medicine can improve the speed and accuracy of care response with a major impact on downstream operative outcomes. Augmented reality using a head-mounted-display (AR-HMD) is a novel technology that may be applied to spine surgery to provide surgeons with a real-time CT-guided 3-dimensional reconstruction of a patient’s spinal anatomy.

METHODS:

We retrospectively reviewed trauma patients who underwent pedicle screw placement guided by AR-HMD or robotic-assisted platforms at an academic tertiary care center between January 1, 2021 and December 31, 2022. Demographic, clinical, cost, and perioperative outcome information was analyzed and outcome profiles were compared using a U test.

RESULTS:

The AR cohort (4 females, 5 males) had a mean age of 66.0 years, BMI of 29.4 kg/m2, Charlson Comorbidity Index (CCI) of 4.11, and Surgical Invasiveness Index (SII) of 8.78. Pedicle screws (77) were placed in the thoracic (51%), lumbar (39%), and sacral spine (10%). Intraoperatively, there was a mean blood loss of 377.78 ml, 0.78 units transfused, 398.33 minutes spent in the operating room, and a 20.00 day LOS. The average 3-month, 6-month, and 12-month ODI scores were 14.25 (n = 8), 15.40 (n = 5), and 12.66 (n = 3). The robotic cohort (5 females, 8 males) had a mean age of 55.6 years, BMI of 27.1 kg/m2, CCI of 3.77, and SII of 14.23. Pedicle screws (128) were placed in the thoracic (59%), lumbar (37%), sacral spine (2%), iliac spine (2%), and pelvis (2%). Intra-operatively, there was a mean blood loss of 431.54 ml, 0.46 units transfused, 330.61 minutes spent in the operating room, and a 10.38 day LOS. The average 3-month, 6-month, and 12-month ODI scores were 22.67 (n = 9), 18.60 (n = 5), and 29.50 (n = 2).

CONCLUSIONS:

This case series demonstrates the utility of AR-HMD in surgical spinal trauma cases by showing operative outcomes comparable to those observed in robotic-assisted surgery.
1076 3-Level ACDF Versus 3-Level Laminectomy and Fusion: Are There Differences in Outcomes? An Analysis of the QOD CSM Cohort
Authors: Kai-Hong Chan Andrew , Ambati Vardhaan Sai , Macki Mohamed , Michalopoulos Giorgos , Le Vivian , Jamieson Alysha , Chou Dean , Shaffrey Christopher I. , Gottfried Oren N. , Bisson Erica Fay , Asher Anthony L.
Published: March 2024

INTRODUCTION:

Prior studies comparing anterior versus posterior approaches for multilevel cervical spondylotic myelopathy (CSM) are limited by the heterogeneity of levels operated.

METHODS:

The prospective QOD CSM cohort was queried for fusions across only three interspaces. Surgeries crossing the cervicothoracic junction were excluded. The cohort was divided into anterior cervical discectomy and fusion (ACDF) and posterior laminectomy-and-fusion. 24-month patient-reported outcomes were compared.

RESULTS:

Of 199 patients (123 ACDF, 76 posterior fusions), 24-month follow-up rates were similar (ACDF: 90.2% vs. 92.1%, p = 0.67). Preoperatively, ACDF were younger (60.8 ± 10.2 vs. 65.0 ± 10.3 yr, p < 0.01), used more private insurance (56.1% vs. 36.8%, p = 0.02), were more often employed (39.8% vs. 22.8%, p = 0.04), and independently ambulatory (14.6% vs. 31.6%, p < 0.01). Otherwise, the cohorts had equivalent baseline mJOA, NDI, NRS Arm-Pain, NRS Neck-Pain, and EQ-5D (p > 0.05). ACDF had shorter hospitalizations (1.6 vs. 3.9 days, p < 0.01) and less non-routine discharge (7.3% vs. 22.8%, p < 0.01) but higher postoperative dysphagia (13.5% vs. 3.5%, p = 0.049). Both groups demonstrated improvements in all outcomes at 24 months (p < 0.05). In multivariable analyses, ACDF was associated with the greatest 24-month NASS Satisfaction (NASS 1)(69.4% vs. 53.7%, OR = 2.44, p = 0.02). Otherwise, the cohorts shared similar 24-month patient-reported outcomes. There were no differences in 3-month readmission (4.1% ACDF vs. 3.9% posterior fusion, p = 0.97) and 24-month reoperation rate (13.5% ACDF vs. 18.6% posterior fusion, p = 0.36).

CONCLUSIONS:

In a cohort limited to 3-level surgeries, ACDF was associated with reduced blood loss, shorter lengths of hospitalization, and higher routine discharge rates; however, posterior cervical fusion resulted in less dysphagia. After controlling for confounders, the ACDF cohort had a significantly higher odds of maximum satisfaction. Patients should be counseled on the risks and benefits of each approach, given relatively comparable outcomes.
1078 Performance of Improved Forms of Demineralized Bone Fiber Allografts in Rabbit Posterolateral Spine Fusion Model
Authors: Scarborough Nelson , Barnes Brian , Khan Safdar
Published: March 2024

INTRODUCTION:

Biologic fusion is often critical for successful spine procedures. Autograft remains the Gold Standard bone graft due to osteogenic properties but has limitations in practice. New bone graft forms that efficiently incorporate autograft or bone marrow aspirate (BMA) and provide osteoinductive and osteoconductive properties were evaluated in the current study. Grafts were made using demineralized bone fibers (DBF) produced by a patented method that provides long fibers that can effectively entangle autograft and be formed into open cylinders (PAK) that contain and prevent autograft migration and absorb BMA.

METHODS:

DBF was produced from rabbit cortical bone using the same processes as human clinical product. Pak grafts were made with 1.5cc Fibers formed into a cylinder with 1.5cc volume. Implants into the rabbit PLF model were harvested after 8 weeks and evaluated for fusion by manual palpation and x-rays.

RESULTS:

All graft forms demonstrated robust new bone formation. Each group demonstrated high fusion rates. Across the groups 10/11 levels were 100% fused (91%) with the remaining 1/11 being 95% reduced motion (functionally fused). Note radiolucency of Group 3 at post-op and appearance of new bone at 8 weeks.

CONCLUSIONS:

The new graft forms demonstrated robust bone formation and fusion in PLF model. The DBF Fibers provided excellent entanglement of autograft to prevent migration. The PAK form eliminated autograft migration, and absorbed BMA providing osteogenesis to the osteoconductive and osteoinductive graft.
1081 Risk Factors for Long Term Opioid Use After Elective Lumbar Spine Surgery: A MSSIC Study
Authors: Telemi Edvin , Mansour Tarek R. , Springer Kylie , Hu Jianhui , Schultz Lonni , Nerenz David , Schwalb Jason M. , Abdulhak Muwaffak , Brennan Matthew , Kim Enoch Gene , Margabandu Pavithra , Chang Victor W.
Published: March 2024

INTRODUCTION:

Long-term opioid use after elective lumbar spine surgery is a significant concern, given the current opioid epidemic and its impact on public health. Identifying risk factors for long-term opioid use after spine surgery is crucial in developing effective interventions to reduce the incidence of opioid dependence in this patient population.

METHODS:

A retrospective analysis of patient data was conducted using the Michigan Spine Surgery Improvement Collaborative (MSSIC) registry. Patients who underwent elective lumbar spine surgery between March 2018, and September 2021, were included, resulting in a total of 3599 patients at one year and 966 patients at two years follow-up. Poisson generalized estimating equation models were used for multivariate analyses.

RESULTS:

A total of 493 (13.7%) and 137 (14.2%) patients were still using opiates at one-year and two-years post-surgery respectively. Discharge morphine milligram equivalents (MMEs), baseline PROMIS PF functional scores, baseline pain scores, age, gender, education level, pre-operative opioid use, and not achieving the minimal clinically important difference (MCID) in PROMIS PF scores at follow-up were significantly associated with long-term opioid use. Specifically, pre-operative opioid use had the strongest association with opioid use at one year (IRR = 2.83, CI: 2.40-3.34, p < 0.001) and two years (IRR = 3.79, CI: 2.53-5.68, p < 0.001). Additionally, not achieving MCID in PROMIS scores at follow-up was strongly associated (IRR = 2.00, CI: 1.72-2.32, p < 0.001 and IRR = 2.18, CI: 1.64-2.91, p < 0.001) with opioid use at both time points (1-year and 2-year respectively).

CONCLUSIONS:

Pre-operative opioid use and not achieving MCID in PROMIS scores at follow-up were the strongest predictors of long-term opioid use after elective lumbar spine surgery. Identifying these risk factors can help clinicians target interventions to reduce opioid use in at-risk patients and improve postoperative outcomes.
1086 Surgical Posture With Microscopic Versus Exoscopic Visualization in Anterior Cervical Procedures
Authors: Kusyk Dorian , Jeong Seung , Fitzgerald Ethan , Williamson Richard Wiley , Kwong-Tak Yu Alexander
Published: March 2024

INTRODUCTION:

Workplace posture has long been associated with back and neck pain, and surgeons are not exempt. Though intraoperative surgeon posture has progressively improved with the visualization of the operative microscope, surgeons nonetheless continue to sustain deviated postures during operations which may result in increased rates of neck and back pain. The surgical exoscope is designed to improve surgical ergonomics. This study aims to quantify the difference in posture during standard anterior cervical spine procedures when performed with the aid of an operative microscope versus an exoscope.

METHODS:

This is a prospective cohort study utilizing the MetaWare MetaMotion S device placed at the surgeon’s cervicothoracic junction to measure Euler angles of upper thoracic spine during each case. Primary outcome was the percentage of time spent with greater than 10deg deviation from a surgeon’s baseline posture while using either the microscope or the exoscope. Additional metrics were analyzed for average deviation from baseline for each axis, as well was percentage of operative time spent with the microscope or the exoscope.

RESULTS:

Overall, 37 anterior cervical procedures were recorded, 18 performed with an exoscope and 19 with a microscope. Surgeons spent significantly more time in a deviated posture with the operative microscope than with the exoscope (32% vs 8% with x-axis >10 deg, p < 0.005; 20% vs 6% with y-axis >10 deg, p < 0.05). This is also reflected with significant differences in the average deviation in the x- and y- axis while under scope.

CONCLUSIONS:

Utilizing the exoscope for anterior cervical spine procedures allowed for less time spent in deviated posture.
111 Interspinous Process Device Utilization and Reimbursement Vary by Provider Specialty and Care Setting
Authors: Jiang Kelly , Gong Jung Ho , Azad Tej D.
Published: March 2024

INTRODUCTION:

Interspinous process devices (IPDs) are a popular less invasive treatment option for lumbar degenerative disease. Studies suggest they may yield initial symptomatic relief but are not better than traditional surgery in improving function or quality of life and may increase reoperation and costs. Ideal indications remain contested.

METHODS:

Centers for Medicare and Medicaid Services Physician/Supplier Procedure Summary data sets (2017-2020) were queried by CPT codes for lumbar interlaminar/interspinous process stabilization/distraction devices without fusion. Utilization rates were normalized per 10,000 lumbar fusions.

RESULTS:

IPD utilization increased by 329% from 2017-2020. Percutaneous IPD utilization increased to 31.8 (+1,267%), while open procedures decreased to 4.4 (-27%). Pain management/anesthesia placed the majority of IPDs and increased utilization the most (27.4, +1,387%). Physical medicine and rehabilitation (PM&R) had the second-highest rate of utilization (3.5, +1,492%). Neurosurgery (2.3, -15%) and orthopedics (0.7, -63%) decreased utilization. Ambulatory surgical centers (ASCs) increased utilization the most (25.8, +907%). Outpatient procedures increased (9.2, +162%), while inpatient procedures decreased (1.2, -49%). IPD reimbursements decreased to $400 (-44.6%), with decreasing trends in percutaneous ($364, -28.6%) and open placement ($776, -6.8%). Reimbursements were highest for orthopedics ($800, +0.6%) and lowest for pain management/anesthesiology ($362, -26.7%). Reimbursements decreased across all settings, especially outpatient (-48.8%) and inpatient (-35.9%).

CONCLUSIONS:

Despite uncertainty of indications for IPDs, utilization increased by 329% when normalized to lumbar fusions to account for changes in disease prevalence. IPDs are increasingly placed by PM&R and pain management in ASCs and outpatient settings. Utilization does not seem to be driven by reimbursement rates. It is unknown how the rapid increase in IPDs has affected clinical outcomes. Given the magnitude of increased utilization and limited data on the safety and efficacy of IPDs, closer examination of indications is warranted.
112 Impact of COVID-19 on Neurosurgical Utilization and Reimbursement
Authors: Rallo Michael Stephen , Nanda Anil , Menger Richard P.
Published: March 2024

INTRODUCTION:

The COVID-19 pandemic required significant adaptations in healthcare operations to preserve limited resources and mitigate viral spread. This included the postponement of non-emergent services, including elective surgical procedures, in the Spring/Summer of 2020. Additionally, patients may have avoided or delayed medical care even after the mandatory postponement due to fear of infection.

METHODS:

We analyzed public data summarizing neurosurgical services provided to Medicare beneficiaries. Annual number of services rendered, beneficiaries treated, and payments received by neurosurgeons were compared between 2019 and 2020 via Students’ T-test and Wilcoxon Rank-Sum tests. Procedures were categorized by location, pathology, and/or approach to identify patterns in the types of procedures most heavily impacted. Pearson's linear regression was used to determine the relationship between the stringency of Covid-19 restrictions and the change in services.

RESULTS:

From 2019 to 2020, there was a 12.27% decrease in the aggregate number of services rendered by neurosurgeons corresponding to a 12.48% decrease in total Medicare payment. In a matched cohort of 4,649 neurosurgeons active in both 2019 and 2020, the average number of annual services per neurosurgeon declined by 12.40% with a concomitant decrease in payment by 12.77%. This corresponded to an average per-neurosurgeon loss of $17,455.43 in Medicare-related income. Nationally, functional, sellar/parasesellar, and open cerebrovascular surgeries exhibited the largest reduction in volume (all >20%). In contrast, endovascular procedures only declined by 5.5%. There was a weak but significant trend toward larger reduction in volume in states with more stringent Covid-19 restrictions (R = -0.357, p = 0.010).

CONCLUSIONS:

Neurosurgeons experienced significant reductions in case volume and income during the first year of the Covid-19 pandemic. The magnitude of impact appears to be influenced, at least in part, by the stringency of state-level restrictions.
1130 Anatomical Features Predicting Outcome From Stereotactic Laser Amygdalohippocampotomy
Authors: Zajner Chris , Lau Jonathon , Isbaine Faical , Laxpati Nealen , Gross Robert E.
Published: March 2024

INTRODUCTION:

Stereotactic laser amygdalohippocampotomy (SLAH) is a novel procedure which is effective and safe for the treatment of temporal lobe epilepsy. Optimal operative ablation location and extent, however, is uncertain, as are the neuroanatomical features guiding successful ablations.

METHODS:

Patients treated with SLAH for MTS at Emory University between 2011 and 2019 (n = 65) were considered in this retrospective study. Post-procedure T1 MRI scans of patients were used to create manual segmentations of the ablation region of each patient. Ablations were assessed in relation to 1) whether they crossed the coronal plane of the lateral mesencephalic sulcus (LMS), 2) the extent to which the ablation extended posterior to the LMS, and 3) extent of ablation of the uncus. Wilcoxon ranked-sign test was performed for each variable between groups of patients with Engel score 1 versus Engel score 2-4.

RESULTS:

Distance of ablation past the LMS was not different between Engel class 1 (mean 6.32 ± 4.16 mm), and Engel class 2-4 (7.93 ± 3.75 mm) (p = 0.099). Ratio of ablations extending posterior to the LMS was 0.82 (SD = 0.39) in Engel 1, and 0.90 (SD = 0.30) in Engel 2-4 (p = 0.370). Volume of ablation showed little correlation with outcome, with average ablation of Engel 1 = 6064 ± 2128 mm3, Engel 2-4 = 5828 ± 3031 mm3, and no significant difference with Wilcoxon ranked-sign test (p = 0.239). Ablation of the uncus showed a strong association with better surgical outcome, with ratio of uncus ablation for Engel 1 at 0.71(SD = 0.31), and Engel 2-4 at 0.37 (SD = 0.36); p < 0.001).

CONCLUSIONS:

Larger ablation alone was not associated with better surgical outcomes. Ablation of the uncus was shown to result in better outcomes. Contrary to current practice, extension of SLAH ablation posterior to the lateral mesencephalic sulcus did not demonstrate improved post-operative outcomes.
114 Compliance with Federal Price Transparency Rules at US Hospitals With Neurosurgical Training Programs
Authors: Larsen Alexandra Giantini , Pandey Abhinav , Tata Nalini , Newman W. Christopher
Published: March 2024

INTRODUCTION:

The Centers for Medicare & Medicaid Services implemented federal requirements on January 1st, 2021 that require hospitals to provide a list of payer-negotiated prices in a machine-readable file.

METHODS:

We performed a cross-sectional analysis in March of 2023 of 116 US hospitals associated with a neurosurgical training program to assess compliance with the new federal requirements by searching “price transparency” or “standard charges” with associated hospital on the internet to download machine readable files. The payer-negotiated price for 11 common neurosurgical procedures based on CPT codes for 4 insurance companies were collected (Aetna,Anthem/BCBS,United,Medicare). Pricing using DRG codes were excluded given the range of neurosurgical procedures that are encompassed by a specific DRG code.

RESULTS:

92/116 (79.3%) hospitals were compliant with the requirement for machine-readable file with payer-negotiated prices. 45/92 (48.9%) used DRG codes. For the common neurosurgical procedures, hospitals had negotiated price available for at least one insurance company with average private insurance cost and average Medicare costs as follows: ventriculoperitoneal shunt (21/92;$10,698;$1,919), lumbar laminectomy (20/92;$10,343;$4,460), lumbar microdiscectomy (31/92;$9,374;$5,026), anterior cervical discectomy and fusion (28/92;$11,544;$9,859), deep brain stimulator with microelectrode recording (15/92;$10,510;$3,616), craniotomy for tumor (14/92;$6,951;$2,361), stereotactic radiosurgery for brain (18/92;$22,409;$7,362) and spine (14/92;$14,242;$3,306), intrathecal pump placement (31/92;$7,139;$5,064), intracranial aneurysm endovascular treatment (14/92;$9,452;$3352), and diagnostic angiogram (46/92;$11,295;$5,867).

CONCLUSIONS:

While hospital compliance with federal requirement for machine readable files with payer-negotiated prices was high, availability of payer-negotiated prices for 4 major insurance types across 11 common neurosurgical procedures based on CPT code was sparce. Overall, meaningful conclusions on procedural related cost for elective procedures will be difficult for patients to make due to the unintelligible format of data and a lack of reporting of cost per CPT code in a comprehensive manner.
117 Standardizing Wearable-based Real-life Physical Activity Monitoring in Patients Undergoing Surgery for Degenerative Lumbar Disorders
Authors: Maldaner Nicolai , Tang Megan , Leung Christopher , Desai Atman , Tomkins-Lane Christy , Zygourakis Corinna Clio
Published: March 2024

INTRODUCTION:

Assessment of function in patients with degenerative thoracolumbar disorders (DTD) has traditionally relied solely on the patient’s subjective perception of disability. There is a clear need to better understand an objective measure of physical activity impairment in this patient cohort.

METHODS:

This analysis is part of the Stanford SpineTrak study, a RCT to assess the feasibility of using a commercially available smartwatch (AppleWatch) to monitor outcome in patients with DTD. Mean preoperative physical activity 2 weeks before surgery was expressed as raw step count, as well as in standardized z-scores that wre referenced to age- and sex-specific values of a control population from a large public database. Step counts were assessed for convergent validity with established patient-reported outcome measures (PROMs) and impairment in activity was stratified into performance groups based on z-score cut-off values.

RESULTS:

Of 67 patients with DTD, 65 patients (62% female) with a mean age (SD) of 63.8 (12.8) years were available for analysis with a mean (SD) daily step count of 5215 (3868). Physical activity showed significant correlation with the ODI (r = 0.28, 95% CI -0.49-0.03), SF36-PCS (r = -0.34, 95% CI 0.11-0.54) and PROMIS-PF (r = -0.48, 95% CI 0.27-0.65). No, Mild, moderate, and severe impairment in activity performance were defined as corresponding z-scores of >0, 0 to -0.99, -1 to -1.99 and = -2, accounting for 20%, 29%, 43% and 8% of the study population. Each 1-step increase in activity impairment resulted in increased subjective disability as measured by the ODI, SF36-PCS and PROMIS-PF (all < 0.05).

CONCLUSIONS:

This study establishes a new wearable-based objective measure of real-life physical activity as well as corresponding standard scores that allow for a direct comparison of test results between individual patients and different study populations.
120 Outcome Related Thresholds of Near Infrared Spectroscopy Based Cerebrovascular Reactivity Metrics in Moderate Severe TBI: A Canadian High Resolution-TBI (CAHR-TBI) Cohort Study
Authors: Gomez Alwyn Titus , Tas Jeanette , Aries Marcel , Griesdale Donald , Froese Logan , Thelin Eric , Raj Rahul , Gallagher Clare Naomi , Bernard Francis , Kramer Andreas H. , Zeiler Frederick
Published: March 2024

INTRODUCTION:

Dysfunctional cerebrovascular reactivity (CVR)/autoregulation contributes to secondary injury following traumatic brain injury (TBI). Currently, monitoring of CVR relies on intracranial pressure (ICP) monitoring and has known thresholds at which outcomes worsen. Interest has shifted to less invasive near infrared spectroscopic (NIRS) regional cerebral oxygen saturation (rSO2) based measures of CVR. However, threshold levels at which outcomes worsen have not yet been determined for these indices.

METHODS:

A retrospective multi-institutional cohort study utilizing the CAnadian High Resolution TBI (CAHR-TBI) Research Collaborative database was performed. The cohort included TBI patients with ICP, arterial blood pressure (ABP), and rSO2 monitoring treated in adult intensive care units (ICU). COx (using rSO2 and cerebral perfusion pressure) as well as COx_a (using rSO2 and ABP) were calculated for each subject as the rSO2 based indices of CVR. 2 x 2 tables were created grouping patients by alive/dead and favorable/unfavorable outcomes at various thresholds of COx and COx_a as well as rSO2 itself. Chi-square values were calculated and the threshold producing the highest value was identified as providing the best discriminative value.

RESULTS:

A total of 129 patients were included. For both COx and COx_a an optimal threshold value of 0.2 was identified for both survival (χ2 = 9.57, p = 0.0020; χ2 = 13.04, p = 0.0003 respectively) and favorable outcomes (χ2 = 5.98, p = 0.0145; χ2 = 8.94, p = 0.0028 respectively) with values above this associated with worse outcomes. Notably, there was no identifiable threshold for raw rSO2 values at which outcomes were identified to worsen.

CONCLUSIONS:

In this multi-institutional cohort study, COx and COx_a were found to have a uniform threshold of 0.2, above which clinical outcomes worsened. This study lays the groundwork to transition to less invasive means of continuously measuring CVR.
1229 Leveraging Machine Learning for Pre-operative Prediction of Supralesional Ablation in Laser Interstitial Thermal Therapy (LITT) for Brain Tumors
Authors: Bhatia Shovan , Merenzon Martin Andres , Levy Adam , Rivera Cameron , Lu Victor M. , Chand Daggubati Lekhaj , Luther Evan , Shah Ashish H. , Komotar Ricardo Jorge , Ivan Michael E.
Published: March 2024

INTRODUCTION:

Although maximizing the extent of ablation (EOA) following laser interstitial thermal therapy (LITT) can improve outcomes in patients with brain tumors, the pre-operative factors that predict a supralesional ablation (EOA >100%) remain unclear.

METHODS:

A retrospective study of patients with glioblastoma, metastasis, or radiation necrosis receiving LITT at a tertiary care referral center between 2013 to 2023 was conducted. Using the EOA >100% as a primary outcome, several clinical and radiographic pre-operative factors were evaluated. Five ML models, Decision Trees, Random Forest, Gradient Boosting, XGBoost, and AdaBoost, were trained using an 80/20 training/testing split and 5-fold cross validation. The models were optimized using hyperparameter tuning and evaluated against traditional logistic regression. The area under the receiver operating characteristic curve (AUC-ROC) was used to evaluate model performance. The optimal pre-operative volume cutoff for constituting an EOA >100% was also explored.

RESULTS:

201 patients were included in the final cohort. Multivariate logistic regression showed that lower pre-operative volume (p < 0.001) and deep-seated lesions (p = 0.041) have a greater likelihood to undergo a supralesional ablation. Of the five ML models analyzed, Random Forest had the highest F1-score of 0.889, and XGBoost had the highest AUC-ROC of 0.74. Additionally, Random Forest (p = 0.02), Gradient Boosting (p < 0.001) and XGBoost (p = 0.01) showed statistically improved predictive performance compared to logistic regression. Features of importance were pre-operative volume, deep-seated lesions, and ellipsoid ratio. The pre-operative lesion volume cutoff for achieving an EOA >100% was 4.38 cc.

CONCLUSIONS:

This study shows the improved predictive ability of ML models over a traditional regression model in determining pre-operative factors for a supralesional ablation of brain tumors following LITT. Notably, the ML models identified pre-operative tumor volume, deep-seated tumors, and ellipsoid tumors as important factors, which could optimize treatment decisions and patient outcomes.
1236 Skull-Derived Myeloid Cells Augment T Cell Responses and Suppress Glioblastoma Growth
Authors: Lad Meeki , Young Jacob , Lui Austin , Salha Diana , Aghi Manish Kumar
Published: March 2024

INTRODUCTION:

Recent studies have implicated skull marrow as a functional myeloid reservoir in CNS pathology. However, its contribution to malignancy remains unexplored.

METHODS:

Fluorescently labeled calvarial flaps were transplanted onto syngeneic glioblastoma-bearing mice, followed by flow cytometric profiling of tumor-infiltrative leukocytes. To assay SDMC function, tumor-bearing C57BL/6 mice were treated with preemptive calvarial ablation (13 Gy irradiation), or conversely intracalvarial AMD3100 to augment myeloid egress from marrow niches. Tumor burden was monitored via survival and bioluminescent imaging.

RESULTS:

72 h following CMFDA-stained calvarial transplantation into tumor-bearing Balb/C mice, 40.3% of tumor-infiltrative myeloid cells were fluorescent and thus skull-derived; transplantation in an alternative longitudinal model (GFP+ flaps, C57BL/6) validated that SDMCs were robust and viable at 3 weeks post-operatively. As MHCII+ cells were disproportionately enriched among SDMCs (87.9% vs 67.3%, p = 0.012), we interrogated the immunogenicity of these cells through targeted ablation. Indeed, skull-ablated mice had reduced aggregate infiltration by antigen-presenting cells than controls (cDCs: 1.1% vs 4.5%, p = 0.002; macrophages: 14.4% vs 36.6%, p < 0.001) and 6-fold greater necrosis (67.7% vs 13.5% apoptotic, p < 0.001), suggesting an impaired ability to mount a controlled, adaptive immune response. The stimulatory role of SDMCs was further demonstrated via intracalvarial AMD3100 administration, which through its promotion of myeloid precursor egress (0.26% vs 0.02%, p < 0.001) and cDC2 infiltration (10.4% vs 3.0%, p = 0.003) yielded robust CD4+ T cell activation and effector memory differentiation. These differences were clinically meaningful, as skull irradiation accelerated tumor growth and attenuated survival compared to controls, while the opposite was observed with AMD3100 treatment (median OS: 17d vs 22d, p < 0.001; 26.5 d vs 22 d, p = 0.006).

CONCLUSIONS:

The preferential polarization of SDMCs into immunostimulatory APCs warrants the continued exploration of local marrow-targeting agents (e.g., AMD3100) as therapeutic modalities.
1239 Trends in Geospatial Availability of Neuro-oncology Clinical Trials in the United States Over Two Decades
Authors: Naik Anant , Smith Emily Jean , Germano Isabelle M.
Published: March 2024

INTRODUCTION:

Advances in brain tumors treatments rely on successful neuro-oncology (NO) clinical trials. To date, data on NO trials completion in the US is scarce. Understanding these factors could help improve access to and the design of future clinical trials.

METHODS:

NO clinical trials registered in the US were analyzed (2000-2019). Univariate and multivariate analysis were used to compare success rates among trials. Geospatial analysis was performed to determine the trial density and failure rates across different states. Trial density was estimated by the number of trials/state population.

RESULTS:

A total of 2,610 neuro-oncology clinical trials were registered in the US during the study period, of which 1,257 met a primary endpoint – completion or trial failure. North Dakota had the highest trial density (6.03 trials/100,000 residents), followed by South Dakota (5.83) and several Northeastern states (3.90-5.60). The change in trial failure rates did not correlate with trial density by state (p = 0.777). The states with the greatest increase in trial failure rates were Nevada (23.1%), West Virginia, Alaska, and Idaho (all three at 20.0%). Florida showed a trend towards a statistically significant increase in failure rates to 10.9% (p = 0.09).

CONCLUSIONS:

The results of this study highlight the variations in success rates and geographic distribution of neuro-oncology clinical trials in the United States. Factors beyond trial density may be critical to trial success. The significant geographic variations in trial density and failure rates across states emphasize the need for targeted efforts to improve access participation to trials in certain regions. Further studies aimed at identifying the factors contributing to the increase in trial failure rates are needed to develop strategies to improve trial enrollment.
1242 Metabologenomic Characterization Uncovers Heterogeneity Amongst IDH Mutant Gliomas
Authors: Ajisebutu Andrew A. , Mamatjan Yasin , Nassiri Farshad , Nejad Romina , Patil Vikas , Wang Justin Z. , Liu Jeff , Zadeh Gelareh
Published: March 2024

INTRODUCTION:

Mutations in isocitrate dehydrogenase (IDH) enzymes are recognised to drive the molecular footprint of diffuse gliomas through the accumulation of oncometabolite R-2-hydroxyglutarate which drives the widespread restructuring of the DNA methylome; however, beyond R-2-hydroxyglutarate, a comprehensive metabologenomic characterization of IDH-mutant gliomas has yet to be performed.

METHODS:

Glioma samples from a cohort of 154 patients underwent multiplatform molecular analysis, including metabolomic studies, genome-wide DNA methylation profiling and bulk RNA sequencing. A integrative analysis was performed, including hierarchical clustering and principal component analysis of identified metabolites, differentially methylated probes, copy number alteration and bulk mRNA data. Survival analysis as well as multivariable hazard ratios for clinical variables were calculated by fitting Cox Proportional Hazards Models.

RESULTS:

We discovered a group of IDH-mutant gliomas whose metabolic profile highly resembled IDH wildtype tumors. Notably, these IDH-mutant gliomas with dysregulated metabolism were distinguished from their IDH-mutant counterparts by significantly shorter overall survival (median OS 118.9 months vs 173.6 months, p=0.048). The IDH-mutant tumors with dysregulated metabolism harbored distinct epigenetic alterations that converged to drive proliferative and stem-like transcriptional profiles. The prognostic relevance of dysregulated metabolism complements, but was not wholly explained by canonically recognized prognostic classifications in IDH-mutant gliomas including 1p/19q codeletion, glioma CpG Island Hypermethylator (GCIMP) status and CDKN2A homozygous deletion.

CONCLUSIONS:

Utilizing a cross-platform analysis we have uncovered a novel subtyping of IDH-mutant gliomas with dysregulated cellular metabolism with similar survival to IDH-wildtype tumors. The metabolic profile provides unique information on glioma phenotypes, which may facilitate a more comprehensive understanding of glioma biology, and provide a window to target novel dependencies.