bluuebunny/crossref_metadata_2025 huggingface dataset:
178 Adjunctive Use of Preoperative SPECT Imaging for Evaluation of Chronic Cervical and Lumbar Pain
Authors: Howell Sasha , Saccomano Benjamin Woodrow , Harmon Daniel K. , Okor Mamerhi Otaigbe , Godzik Jakub
Published: March 2023

INTRODUCTION:

Radionuclide bone scintigraphy with single photon emission computed tomography (SPECT) has been used to evaluate foci of inflammation within the spinal axis. Studies have reported its use as an tool for recognition of pain foci and spondolytic change. As an adjunctive test SPECT may prove to give valuable insight into areas of focal inflammation within the spinal axis and therefore serve as a tool for guiding operative and nonoperative intervention in patients with degenerative spine disease.

METHODS:

We performed a retrospective case series to identify patients with chronic neck/back pain who underwent SPECT imaging for pre-operative evaluation. Patient demographics, area of uptake, correlation with pain morphology, type of intervention, and degree of symptom resolution were quantified. Patients were excluded if they had prior surgery/intervention at the level corresponding to symptomatology.

RESULTS:

Thirty-two patients underwent SPECT imaging. Patients presented with axial back pain (97%) and radicular pain (42%). Radiotracer uptake was seen in facet and/or disc space at the level of symptomology in 44% of patients, facet alone (22%), disc space alone (22%), and uncovertebral joint (12%). Interventions included facet injections (26 patients), basovertebral plexus ablation (7 patients), and open/minimally-invasive surgery (9 patients). Two patients underwent anterior cervical discectomy and the remainder of our cohort underwent lumbar instrumentation and fusion. All but one surgical patient (97%) reported significant relief of symptoms.

CONCLUSIONS:

SPECT imaging may be useful adjunctive imaging modality to evaluate for focal areas of inflammation not readily observed on MRI or CT. Our experience suggests that SPECT can identify areas of pathology that responsive to various types of intervention.
187 Use of Quantitative Pupillometry in Mild Traumatic Brain Injury to Diagnose and Predict Symptom Severity
Authors: Meister Melissa , Aderman Michael , Hershaw Jamie , Ross Jeremy , Roach Megan , Malvasi Steven , Cameron Kenneth , Dengler Bradley
Published: March 2023

INTRODUCTION:

Concussion screening using the Military Acute Concussion Evaluation (MACE 2) and imaging modalities can be subjective, time intensive, and monopolize scarce resources in a forward deployed environment. The Pupillary light reflex (PLR) has shown recent promise in identifying mild traumatic brain injuries.

METHODS:

Freshman entering a military service academy had baseline PLR measurements (starting pupillary diameter, ending pupillary diameter, average constriction velocity, average dilation velocity, constriction latency, constriction percentage, T75 and pupillary wave form) completed using a Neuroptic PLR-3000. If a subject experienced a concussion they returned for PLR measurements and Sport Concussion Assessment Tool (SCAT) scores within 48 hours of injury.

RESULTS:

Five hundred and fourteen cadets (383 males and 131 females) completed baseline PLR measurements. Sixteen cadets subsequently sustained an mTBI and performed full post-injury assessments. The one-way MANCOVA performed on PLR metrics controlling for symptom severity revealed a marginally significant difference in combined PLR metrics between baseline and post-injury time points [Wilks’ λ = .578, F(8,22) = 2.01, p = .094, partial η = .422]. A significant difference in outcomes between baseline and post-injury were observed for starting pupillary diameter [F(1,29) = 3.10, p = .089, partial η2 = .097], average constriction velocity [F(1,29) = 5.79, p = .023, partial η2 = .167], and maximum constriction velocity [F(1,29) = 4.54, p =.042, partial η2 = .135]. Correlation coefficients demonstrated that post-injury changes in pupillary metrics were strongly associated with post-injury changes in symptom severity, particularly for starting pupillary diameter, constriction percentage, average constriction velocity, maximum constriction velocity, and T75.

CONCLUSIONS:

In this evaluation of service academy cadets there are measurable differences in pupillary dynamics after sustaining an mTBI which correlates with symptom severity.
190 Prion Protein Knockout Leads to Differential RNA Expression Following Head Injury
Authors: Mustroph Christian , Yousuf Seema , Saberian Sepehr , Gimbel David
Published: March 2023

INTRODUCTION:

It is not well understood why repetitive head injury causes the behavioral and pathologic sequelae associated with Chronic Traumatic Encephalopathy. Cellular prion protein (PrPC) is associated with several neurodegenerative diseases including Alzheimer’s disease and Creutzfeldt-Jakob disease and we have previously demonstrated that PrPC is required for the pathology and behavior associated with CTE after TBI. We show that Prpc knockout leads to differential mice cortex gene expression in a murine repetitive head injury model.

METHODS:

Experimental groups consisted of PrPC-knockout (Prnp-/-) and PrPC wild type (WT) mice. Bilateral close head injury consisted of daily impactions over 10 days with appropriate unimpacted control. All animals were allowed to recover for 6 weeks. Mice were sacrificed and brain cortexes rapidly dissected and flash frozen for RNA extraction, sequencing, and quantification.

RESULTS:

We identified 52 upregulated and 134 downregulated genes in WT impacted compared to unimpacted WT mice. 301 genes were upregulated and 85 downregulated in Prnp-/- impacted mice compared to Prnp-/- mice without impactions. We identified 85 upregulated and 86 downregulated genes in Prnp-/- impacted mice compared to WT impacted mice. RNA expression of KLK6 is upregulated by a factor of 2.3 and KChip3 is downregulated by a factor of 1.3 in Prnp-/- impacted mice compared to WT impacted mice.

CONCLUSIONS:

Deletion of PrPc in a murine model of CTE leads to differential expression of multiple gene clusters. Deletion of Prpc in impacted mice upregulates KLK6 and downregulates KCHip3 which have been implicated in neurodegenerative processes and neuroinflammation including Alzheimer’s disease. We have previously demonstrated that Prpc is required for cognitive deficits and standard histologic pathology following head injury who's biochemical mechanism may implicate KLK6 and KCHip3.
203 Novel Adeno-Associated Viral (AAV) Vectors for Preferential Targeting of Peripheral Nerve Tumors
Authors: Greven Alexander Craig McConnell , Lei Kecheng , Nagarajan Purva , Carneiro Ana , Schafer David , Boulis Nicholas M.
Published: March 2023

INTRODUCTION:

Definitive treatment for peripheral nerve tumors by surgical excision is associated with significant morbidity. Gene therapy with adeno-associated viral (AAV) vectors is emerging as a promising therapy for these tumors. Directed evolution is a technique that involves applying selective pressure to large libraries of mutated cap genes to bioengineer AAV vectors that selectively bind to and transduce schwannoma tissue.

METHODS:

Tumor samples were harvested from 8 patients and divided for cell culture. Cultures were infected with novel AAV vector C1, novel AAV vector C5, AAV1, AAV2, and AAV6 at MOIs of 2500, 5000, and 10000 for 3-, 7-, and 14-day periods. GFP fluorescence was used to quantify transduction efficiency of each vector. Statistical analysis was performed with one-way ANOVA and student t test.

RESULTS:

AAV2 had significantly higher transduction efficiency at 65% +/- 11 compared to all other vectors (p < 0.001). The remaining order of highest transduction efficiency was novel AAV vector C2 at 21% +/- 4, novel AAV vector C5 at 12% +/- 3, AAV1 at 7% +/- 2, and AAV6 at 6% +/- 2. Higher transduction efficiencies were seen at higher MOIs (2500 vs. 5000 vs. 10000) with no significant difference in cell count (2500: 74.25 +/- 25.59. 5000: 105.50 +/- 15.93, 10000: 90.75 +/- 5.74, p = 0.094). Longer post-infection incubation periods (3-day vs. 7-day vs. 14-day) led to higher transduction efficiencies.

CONCLUSIONS:

AAV2 remains the gold standard for delivery of gene therapy to peripheral nerve tissue. Higher MOIs and longer incubation periods can better differentiate transduction efficiency when comparing multiple AAV vectors without having detrimental effects on cell culture.
213 A Positive Impact on Patterns of Relapse in Diffuse Intrinsic Pontine Glioma after Convection-Enhanced Delivery of Omburtamab
Authors: Bander Evan D. , Garton Andrew L.A. , Pasquini Luca , Yildirim Onur , Ilica Ahmet , Freret Morgan E. , Donzelli Maria , Haque Sofia , Souweidane Mark M.
Published: March 2023

INTRODUCTION:

Diffuse intrinsic pontine glioma (DIPG) carries a high mortality rate secondary to its aggressive molecular characteristics, infiltrative nature, and lack of effective treatment options. Overall survival is only 9-11 months and median time to progression after radiotherapy is 5-6 months. Convection-enhanced delivery (CED) has demonstrated safety in phase-1 trials, but efficacy is indeterminate.

METHODS:

Sixty-three children with DIPG treated between 2010-2022 were retrospectively reviewed for first radiographic progression. All were treated using conventional external beam radiation (EBRT) and 31 (49%) were treated with CED of radiolabeled 124-Iodine-Omburtamab following EBRT (NCT01502917). Progression was codified by independent neuroradiologists according to anatomic location (local, contiguous, medulla, midbrain, middle cerebellar peduncle (MCP), and/or distant). Overall survival (OS) was assessed with Kaplan-Meier methodology and cumulative incidence of progression at each anatomic site was assessed in a cause-specific competing risk analysis with death as a competing event and were stratified based on CED treatment.

RESULTS:

Mean age at diagnosis was 7.1 (+/-3.4 years) with a median OS of 1.22 years for the cohort. Patients receiving CED demonstrated higher rates of progression in general, when considering progression at all anatomical sites (HR 1.79, p = 0.047) and no statistically significant difference was found in OS when stratified by CED treatment (p = 0.22). However, CED treatment was associated with significantly lower cumulative incidence of pontine and medullary progression (HR 0.43, p = 0.03; HR 0.15, p = 0.01, respectively) relative to non-CED treated patients. No statistically significant differences in progression were identified at other sites (contiguous, midbrain, MCP, or distant).

CONCLUSIONS:

MR-defined patterns of relapse provide evidence for locoregional control in children with DIPG treated with radioimmunotherapy administered by CED. These results prompt a consideration for modifying the design of future clinical trials by supplementing brain stem CED with whole neuroaxis treatment.
306 Post-Hemorrhagic Stroke Scar Components in the Rat Intracerebral Hemorrhage Model
Authors: Koduri Sravanthi , Okauchi Masanobu , Keep Richard , Pandey Aditya S. , Xi Guohua
Published: March 2023

INTRODUCTION:

Intracerebral hemorrhage (ICH) has long been known to be a cause of significant morbidity and mortality with few medical or surgical treatment options. Though various studies have investigated hematoma evacuation and iron chelation in acute ICH management, there has been minimal study regarding the components of the scar cavity following ICH.

METHODS:

To investigate this further, our group injected 100 µL of autologous blood into the right basal ganglia of 18-month-old male Fisher 344 rats and euthanized the rats for histological brain analysis at 2 months following injection.

RESULTS:

Study of these brains revealed that the post-hemorrhagic scar cavity had increased fluorescence with GFAP, a marker of astrogliosis following injury, with a reduction in DARPP-32, a protein enriched in dopamine-innervated areas and involved with neurotransmission, which indicates neuronal loss. It was also noted that there was a statistically significant increase in Olig2+ oligodendrocyte cells within the scar cavity compared to similar regions in the contralateral hemisphere or in control animals. Interestingly, when stained with CC1, a marker of mature oligodendrocytes, the scar cavity contained a mix of both mature and precursor oligodendrocytes, indicating that this increase is likely proliferative in nature rather than due to a migration phenomenon.

CONCLUSIONS:

The role of these Olig2+ cells, how they are affected by deferoxamine administration and whether they are functional and contributing to the recovery of this injured region is currently under investigation. As oligodendrocytes provide support and insulation to the axons of the central nervous system, this proliferation within the scar cavity may indicate a form of healing and be the first understanding of the delayed recovery that takes placed after ICH.
320 Deep-Learning Cortical Thickness Analysis as Predictor for Shunt Surgery Effectiveness in Possible iNPH Patients
Authors: Piccolo Daniele , Fabbro Sara , Bagatto Daniele , De Colle Maria Cristina , Belgrado Enrico , Skrap Miran , Tuniz Francesco
Published: March 2023

INTRODUCTION:

While optimal treatment for iNPH is quite known, diagnosis remains a topic of debate, with different procedures suggested as potential predictors for shunt surgery effectiveness. Various tests, biomarkers, and neuroimaging techniques can be used; however, the diagnostic accuracy is below optimal when performed with neuroimaging techniques alone and not always cost-effective when achieved with CSF biomarkers. Quantitative computational methods for cortical thickness analysis have become available in the last decade, and they only require regularly available T1-weighted brain MR images.

METHODS:

We analyzed 294 total patients referred to our clinic from January 2015 until December 2021. After exclusion criteria, the final sample consisted of 98 possible iNPH patients: 64 were diagnosed as probable iNPH and underwent VPS surgery, while 34 did not receive a surgical indication after diagnostic procedures. We investigated differences in cortical thickness for all possible iNPH patients using a public deep-learning based neuroimaging pipeline composed by an advanced semantic segmentation neural network architecture and automated surface-based cortical thickness analysis.

RESULTS:

In 38 total patients with a negative CSFTT or not responsive to shunt surgery, a significant localized cortical thinning was seen in the lateral surface of the frontal and parietal lobes (bilateral superior and middle frontal gyrus, bilateral pars opercularis, bilateral superior parietal gyrus, bilateral supramarginal gyrus, left inferior parietal gyrus, bilateral precuneus).

CONCLUSIONS:

Preoperative cortical thickness is a feasible analysis that might be useful in defining the optimal therapeutic plan for possible iNPH patients. A large multicentric study is encouraged to elucidate specific patterns and ratios of cortical thickness that might be used as potential predictors for shunt surgery effectiveness.
321 Automated Development of a Spine Registry (Autoregistry) using an Interpretable Surgeon-Written Regular Expression Classifier
Authors: Cheung Alexander , Laufer Ilya , Pacione Donato R. , Lau Darryl , Frempong-Boadu Anthony , Kondziolka Douglas S. , Golfinos John G. , Oermann Eric
Published: March 2023

INTRODUCTION:

Clinical registries are critical for modern surgery and underpin outcomes research, reimbursement negotiations, device monitoring, and trial development. Existing approaches to registry construction are labor intensive, costly, and prone to user error. Natural language processing (NLP) techniques combined with broad electronic health record (EHR) datasets can theoretically automate the building and maintenance of registries.

METHODS:

We utilized a Hadoop datalake consisting of the EHR, billing systems, imaging systems, and other data representing all information generated by an AMC. Using this database and SQL queries, we retrieved every operative note written in the department of neurosurgery over the last decade. Operative notes were parsed using regular expressions constructed by the operative surgeons themselves. A random subset of 100 notes was selected for manual review and analysis.

RESULTS:

31,139 operative cases were identified and downloaded. An operative note processor was written by the operating surgeons and required three days of development time with approximately two weeks of validation. In 100 random cases, the regex classifier was on average 98.6% accurate at identifying whether a particular procedure was performed and correctly identified the entire list of defined surgical procedures in 88% of patients. Most errors (64.2%) occurred during the identification of the involved vertebral levels. Operative notes from ancillary specialties for assistive approaches or closures also led to false-positive results.

CONCLUSIONS:

This study demonstrates the feasibility of automatically generating a spine surgery registry (“autoregistry”) using a Hadoop EHR datalake combined with an interpretable and customizable surgeon-written natural language processing algorithm, which may reduce labor costs and other pitfalls associated with manual registry development.
322 Distributed Vector Representations of Neurosurgical Admission Notes Predict Discharge Disposition
Authors: Khanna Arjun , Coumans Jean-Valery
Published: March 2023

INTRODUCTION:

Natural language processing (NLP) aims to extract information from unstructured language input for use in machine learning, without the need for laborious manual review of text to retrieve data of potential interest. An NLP-based model utilizing term frequency-inverse document frequency (TF-IDF) vectoral representations of pre-operative clinical notes has previously been shown to predict discharge disposition following meningioma resection. The TF-IDF vectorization scheme is based on word counts across documents but does not account for word order or semantic information. An alternative algorithm, paragraph vectorization, utilizes an unsupervised neural network to learn document vector representations.

METHODS:

We analyzed 7,122 admission notes. We trained a neural network to derive paragraph vector representations of notes and trained a classifier to predict home vs non-home discharge disposition based on these representations. Out-of-sample performance was assessed on a held-out testing set. We repeated the analysis using TF-IDF document representations to compare the two approaches. Performance was quantified using area under the receiver operating characteristic curve (ROC-AUC).

RESULTS:

Model performance increased with vector dimensionality. A 200-dimensional distributed document vectorization was highly predictive of nonhome discharge with an ROC-AUC of 0.82 ± 0.01 (mean ± standard error over 5-fold nested cross-validation). When the dimensionality of the embedding vector space was relatively low (e.g. <100), learned paragraph vectors predicted discharge disposition better than TF-IDF vectors.

CONCLUSIONS:

Natural language processing of admission notes via neural network-learned distributed vectoral representations is a viable strategy of information extraction from neurosurgical clinical documentation. This embedding scheme overcomes some of the limitations of TF-IDF and encodes more information in lower-dimensional embedding vector spaces. It holds promise as a method of using free text to train machine learning algorithms for prediction of clinically relevant outcomes.
329 Acute Cognitive Symptom Cluster Predicts Return-to-Learn Duration Following a Sport-Related Concussion
Authors: Tang Alan Ruigang , Davis Philip , Neitz Kristen , Grusky Alan , Hajdu Katherine , Hou Brian , Yengo-Kahn Aaron Michael , Zuckerman Scott L. , Terry Douglas
Published: March 2023

INTRODUCTION:

Adolescents sustaining sport-related concussion (SRC) often experience difficulties with the return-to-learn (RTL) process. While initial symptom burden has predicted prolonged RTL, no studies have established a relationship between acute cognitive symptoms and RTL duration.

METHODS:

A retrospective single-institution cohort study of adolescent athletes 12-23-years-old evaluated within 5 days of a diagnosed SRC from 11/2017-10/2020 was conducted. Athletes missing cognitive symptom ratings and RTL data were excluded. The primary exposure variable was cognitive symptom score, consisting of 4 symptoms for a total possible score of 24. Primary and secondary outcomes were time-to-RTL and total length-of-care, respectively. Multivariable Cox proportional hazards modeling was used to assess the effect of Cognitive Symptom Ratio (CSR), defined as cognitive symptom score divided by Post-Concussion Symptom Scale (PCSS) score, on RTL duration.

RESULTS:

Of 653 athletes evaluated within 5 days of their concussion, 343 patients were included in the final cohort. Athletes reported a median initial PCSS score of 21 (IQR 6-37) and a median cognitive symptom score of 4 (IQR 0-9). Most patients endorsed some degree of “difficulty concentrating” (n = 212, 61.3%). Median CSR was 0.18 (IQR 0.00-0.27). On multivariable regression analysis, higher CSR was associated with prolonged RTL duration (HR 0.30, 95% CI 0.13-0.69, p = .004). When initial PCSS was added to the model, the previously significant association between CSR and RTL was no longer significant (HR 0.67, 95% CI 0.29-1.59, p = .367). When dichotomized based on frequency distribution, a higher proportion of low CSR patients achieved RTL by 7 days post-injury (82.2% vs. 69.9%, p = .007), a difference not seen at 14 days (92.2% vs. 87.3%, p = .133).

CONCLUSIONS:

Acute cognitive symptom scores can predict who may be at increased risk for prolonged RTL and which patients with normal PCSS scores may experience difficulties once resuming school activities.
332 Estimation of Intracranial Pressure Using Non-Invasive Monitor and Machine Learning
Authors: Habboub Ghaith , Hassett Catherine , Kondylis Efstathios , Gomes Joao
Published: March 2023

INTRODUCTION:

Several non-invasive technologies have attempted to utilize surrogate markers of cerebral hemodynamics to infer intracranial pressure (ICP). Successful clinical application of these methods have been limited by hesitancy to rely upon surrogate data and inferences about ICP, in lieu of directly measured ICP. One newer method utilizes a mechanical extensometer to detect subtle, dynamic skull deformations can yield a non-invasive ICP waveform. This data has been validated to provide important information about intracranial dynamics, including inferences on the cerebral compliance. This method does not provide an absolute intracranial pressure and thus questions about clinical application remain.

METHODS:

High frequency (326 Hz) arterial blood pressure, non-invasive and invasive ICP measurements were collected from 5 patients. Samples were collected over 30 minutes. The first 15 minutes were used for training and last 15 minutes were used for testing. Facebook Prophet was used to perform signal analysis and forecasting. Switch-point analysis tools were also used to identify shifts in ICP measurements.

RESULTS:

Model per patient was generated from the 5 patients. Trend and seasonality analysis were then performed using Facebook Prophet modeling. Arterial blood pressure and non-invasive measurement were used as regressor to invasive intracranial pressure measurement. Mean absolute error of the testing samples of all models ranged from 0.8–2.4 mmHg.

CONCLUSIONS:

More closely and reliably estimating invasive intracranial pressure measurement from non-invasive measurements and arterial blood pressure is feasible using sequence analysis and machine learning. This will aid the clinical applicability of non-invasive monitoring and perhaps provide the pathway to replacing invasive measurement altogether. Further study of the applications of this clinical tool is warranted with the goal of intervening early to improve neurologic outcomes following acute brain injuries.
352 Prevalence and Charactersitics of Moyamoya Syndrome in Patients With Down Syndrome
Authors: Ritz Caitlin , Malik Noor , Wilkinson C. Corbett , Graber Sarah
Published: March 2023

INTRODUCTION:

Moyamoya arteriopathy can be idiopathic (moyamoya disease, MMD) or associated with other diseases, i.e., Down syndrome (moyamoya syndrome, MMS). The prevalence of Down syndrome in patients admitted for moyamoya has been estimated using the National Inpatient Sample to be 3.8%. However, the prevalence of moyamoya in Down Syndrome is not well-quantified.

METHODS:

This retrospective study used the Sie Center for Down Syndrome and Stroke Program databases at Children’s Hospital Colorado to identify moyamoya patients aged 30 days to 18 years at diagnosis. Demographics, clinical presentation, treatment, and outcome were compared among patients with DS, those with idiopathic MMD, and the entire group.

RESULTS:

Sixty-five patients (30 idiopathic, 14 MMS with DS, 21 MMS without DS). Prevalence of MMS in the DS population was 0.4%. Gender and age at presentation did not differ significantly between populations. 47% of idiopathic moyamoya patients initially presented with transient ischemic attacks (TIAs) versus 14% of DS patients (P < 0.05). This is compared to 34% of the total population that presented with TIAs. DS patients were more likely to present with stroke (57%) compared to idiopathic (37%) and total patient populations (40%) although these results were not significant. 23% of idiopathic patients presented with basal ganglia strokes compared to 7% in the DS population (P < 0.05).

CONCLUSIONS:

In this study, the prevalence of moyamoya in DS was 0.4%. Patients with DS were less likely to present with TIAs and more likely to present with stroke, with different stroke locations, than were other moyamoya populations.
358 Biomechanical Analysis of the Structural Stability of the Lumbar Spine Following the Extent of Endoscopic Lumbar Foraminotomy and Laminotomy: A Finite Element Analysis
Authors: Liu Yanting , Kim Jin-sung , Lee Jeong Hyeon , Lee Sung Jae
Published: March 2023

INTRODUCTION:

Facetectomy as the standard surgical option performed to relieve the patient's symptoms. Recently, endoscopic lumbar foraminotomy shows an alternative to secure space for the spinal nerve to pass through the foramen. However, the biomechanical research on the postoperative structure stability of the spine after endoscopic surgery remains unknown.

METHODS:

Six types of models were constructed following the graded removal L4 left side of the superior articular process with or without lamina: Type 1: intact model; Type 2: foraminotomy of left-superior dorsal corner of the superior articular process; Type 3: extended foraminotomy of left superior ventral side of the superior articular process; Type 4: left side total facetectomy; Type 5: left side facetectomy and unilateral laminectomy; Type 6: left side facetectomy and laminectomy.

RESULTS:

From the changes of experiment data in our finite element analysis of simulated endoscopic surgery, the extent of facet removal increases, the mobility and stress distribution of the surgical segment increases. In all loading conditions, the increase rate of the range of motion was the highest in Type 6 in L3-L4 compared to the intact model. The measured increase rate of von Mises s tresses was highest in left lateral bending in types 5 and 6. Furthermore, under other modes of movement, there was no peak von Mises stress differences on Type 1 to Type 4.

CONCLUSIONS:

In symptomatic lumbar foraminal stenosis, the impact of endoscopic foraminotomy on the stability may be less than those of total facetectomy. There is no significant difference between the standard and extended endoscopic foraminotomy on stability of the lumbar spine.
359 Sacroiliac Joint Fusion – A Shift Towards Variant Anatomy and Their Clinical Implications
Authors: Wessell Jeffrey Ernest , Saway Brian Fabian , Glaser John , Patel Sunil J. , Kalhorn Stephen P.
Published: March 2023

INTRODUCTION:

Sacroiliac joint (SIJ) dysfunction is a common cause of low back pain, estimated to account for 14-22%. Currently, a limited amount is known about risk factors predicting surgical outcomes. Few studies have evaluated the prevalence of variant SIJ anatomy, while none have investigated this in the pathologic SIJ. Furthermore, the impact SIJ morphology on outcomes is unknown.

METHODS:

We performed a retrospective review of patients undergoing SIJ fusion at our institution between 2014 and 2021. Inclusion criteria included patients 18 years or older, diagnosed with SIJ dysfunction refractory to conservative management. Clinical and sociodemographic information was collected from chart review. Two separate study team members independently reviewed CT and MRI studies, categorizing anatomic subtypes based on Prassopoulos et. al’s classification system. Disagreement was resolved by consensus for the final data analysis.

RESULTS:

A total of 77 joints were instrumented across 67 patients. Postoperative VAS significantly improved from preoperative VAS of 2 (0-5) and 6.6 (5.5-8) respectively (p < .001). Interestingly, median percent improvement and interquartile range (IQR) for smokers was 77.8 (50-100) compared to 57.1 (14.3-83.3) for non-smokers (p = 0.04). There were significantly fewer normal SIJs than previously reported (p < 0.05). There were differences in outcomes between anatomic subtypes, though this failed to reach statistical significance.

CONCLUSIONS:

SIJ fusion leads to significant improvement in patients with refractory SIJ pathology. The distribution across anatomic joint subtypes is markedly different in the pathologic SIJ. There appears to be differences in clinical outcomes between these subtypes. Further research is needed to power these results. These changes may further understanding on SIJ dysfunction pathophysiology and prompt additional investigations into differences in clinical outcomes.
362 Transforaminal Versus Interlaminar Endoscopic Lumbar Discectomy for Lumbar Disc Herniation: a Systematic Review and Meta-Analysis
Authors: Jitpakdee Khanathip , Liu Yanting , Kotheeranurak Vit , Kim Jin-sung
Published: March 2023

INTRODUCTION:

The endoscopic lumbar discectomy can be divided into two main approaches, transforaminal (TELD) and interlaminar endoscopic lumbar discectomy (IELD). However, results of comparative studies between these techniques have been inconsistent, and consensus on the decision making to select which approach has not been reached.

METHODS:

Three electronic databases were searched for reported outcomes following TELD and IELD. Oswestry Disability Index (ODI), visual analog scale of back (VASB) and leg pain (VASL), and MacNab criteria were evaluated. Operative time, hospital stays, radiation exposure, and complications were investigated. Odds ratio (OR) and mean differences (MD) with 95% confidence intervals (CI) were calculated using random and fixed-effect models.

RESULTS:

Total of 1,948 patients from 18 studies were included, consisting of 1,006 patients (51.6%) in TELD group and 942 (48.4%) patients in IELD group. TELD had slightly better improvement of postoperative ODI (MD = 1.26; 95% CI: 0.07–2.16; P = 0.04), postoperative VASB (MD = -0.23; 95% CI: -0.40 to -0.05; P = 0.01) and last follow-up VASB (MD = -0.25; 95% CI: -0.41 to -0.09; P = 0.002), but with longer operative time (MD = 10.1 mins; 95% CI: 1.925–18.77; P < 0.00001) and more fluoroscopic time (SMD = 4.12; 95% CI: 3.22–5.03; P < 0.00001), especially in L5-S1 operation. Postoperative bed rest time was significantly longer in IELD. However, there was no difference in VASL, hospital stays, or complication.

CONCLUSIONS:

We found comparable clinical outcomes in terms of ODI, VAS, patient satisfaction, hospital stays, and complication between both techniques. TELD required more radiation exposure and longer operative time at L5-S1 level than IELD. Our study provided helpful results to consider which approach is suitable for selected patients and informed consent of benefits from each approach.
366 Micro-Endoscopic Posterior Cervical Foraminotomy and Discectomy is Health Economically Dominant to Anterior Cervical Discectomy and Fusion for Unilateral Cervical Radiculopathy
Authors: Hani Ummey , Monk Steve Hubert , Pfortmiller Deborah , Kim Paul Keetae , Bohl Michael , Holland Christopher Michael , Smith Mark D. , Adamson Tim E. , McGirt Matthew J.
Published: March 2023

INTRODUCTION:

Micro-endoscopic posterior cervical foraminotomy and discectomy (MPCF) has served as a minimally invasive, motion sparing alternative to ACDF for unilateral cervical radiculopathy for decades. While growing data suggests similar effectiveness, the cost effectiveness and potentially superior healthcare value of MPCF vs ACDF remains largely unstudied.

METHODS:

The National Quality Outcomes Database (QOD) was queried for 323 consecutive ASA 1-3 patients (201 ACDF, 122 MPCF) performed at the authors' single institution for unilateral cervical radiculopathy at our ambulatory surgical center (ASC). Propensity-matching yielded 222 patients. Resource utilization, missed workdays, and EQ5D quality adjusted life year (QALY) gains were assessed over a one-year period. Direct cost (resource use x unit costs based on Medicare national allowable payment amounts) and indirect cost (missed workdays x average US daily wage) were recorded and incremental cost-effectiveness ratio (ICER) was calculated.

RESULTS:

Estimated blood loss, and length of surgery were less for MPCF vs. ACDF (p < 0.001). All other safety measures and patient-reported outcomes were similar between cohorts. MPCF vs. ACDF demonstrated reduction in total one-year costs of $6,709 (Medicare) and $13,061 (private payers) (p < 0.001), and comparable QALYs gained. ACDF vs. MPCF had a cost ineffective ICER of $91,773/QALY-gained and $178,668/QALY for Medicare and private payer patients, respectively.

CONCLUSIONS:

MPCF is a health-economically dominant option to ACDF for unilateral cervical radiculopathy given the increased healthcare costs despite comparable safety, outcome, and QALY gains associated with ACDF.
367 Microendoscopic Posterior Cervical Foraminotomy in the Ambulatory Setting: A Longitudinal Experience
Authors: Monk Steve Hubert , Zeitouni Daniel , Cowan David , Rossi Vincent , Smith Mark D. , Kim Paul Keetae , Adamson Tim E.
Published: March 2023

INTRODUCTION:

Posterior cervical foraminotomy (PCF) is a motion-sparing surgical option for unilateral cervical radiculopathy caused by foraminal stenosis. The evolution of microendoscopic (MED) techniques makes it an ideal procedure for the outpatient setting. There are few studies to date that report the safety and efficacy of this procedure specifically in the ambulatory setting.

METHODS:

This study was a retrospective case series of all patients who underwent MED-PCF at a single ambulatory surgery center over a 6-year period. Standard demographic and perioperative data were collected. Outcome measures included visual analog scale (VAS) pain scores, postoperative complications, 30-day readmission, and need for reoperation at the index or adjacent levels.

RESULTS:

A total of 825 patients underwent MED-PCF during the 6-year study period. Mean age was 56.5 years. Most patients underwent decompression at C5-6 (260, 31.5%) or C6-7 (426, 51.6%). Eighty-five patients (10.3%) underwent surgery at multiple levels. Mean operative time was 38.0 minutes for single-level cases and 53.1 minutes for multilevel cases. There were no intraoperative or immediate postoperative complications. All patients were discharged home with an approximate length of stay of 3 hours (mean 182.7 ± 44.8 minutes). The vast majority of patients (85.7%) experienced improved VAS pain scores postoperatively and achieved a good or excellent clinical outcome (75.8%) according to the Odom criteria. Almost half (43.5%) had complete resolution of their preoperative pain (ie. postoperative VAS pain score of 0). Very few patients (5, 0.6%) were readmitted within 30 days. Only 46 patients (5.6%) required reoperation at the index level (35, 4.2%), adjacent level (16, 1.9%), or both (5, 0.6%). Mean follow-up was 13.4 months.

CONCLUSIONS:

MED-PCF can be performed safely in the ambulatory setting with excellent efficacy and low reoperation rates.
368 Development, Outcome and Costs of a Simulation-Based Neurosurgery Bootcamp at the National Level
Authors: Bakhshi Saqib , Ahmad Rida , Hussain Merchant Asma Altaf , Noorali Ali Aahil , Rahim Komal Abdul , Qadeer Namra , Afzal Noreen , Ali Lakhdil Maryam Piyar , Shamim Shahzad M. , Haider Adil Hussain
Published: March 2023

INTRODUCTION:

With a growing interest in simulation-based training to develop clinical proficiency, bootcamps have been utilized for imparting basic skills to medical trainees. Some research on the topic has been published from high income countries, with considerable costs of the course. No such neurosurgical teaching standards have been employed in Low-and Middle-Income Countries

METHODS:

It was a cross-sectional study. Twenty two participants hailing from 6 institutes attended 12 lectures, and practiced 12 hands-on skills. Burr-holes and craniotomies were done on 3D printed skulls. Lumbar drain insertion was practiced on a lumbar puncture mannequin. For laminectomy, we used an indigenously designed simulator. Knowledge was assessed via a pre and post study design using a validated tool, while the modified Objective Structured Assessment of Technical Skills tool was utilized for skills Assessment. Feedback from faculty and residents was collected via a standard 5-point Likert scale.

RESULTS:

Only one participant (4.55%) had previously attended a neurosurgical skills workshop. Comparison of knowledge assessment scores of the participants on topics taught showed significant improvement (p value = 0.034). Comparison of outcomes on 1st and 3rd attempts of cranial and spinal skills showed a significant improvement in all 14 domains assessed. Positive feedback was received ranging from 3.9 up to 4.8 on a 5 point Likert scale. Overall cost per participant culminated to $145, significantly lower than previously reported data.

CONCLUSIONS:

Our findings report the effectiveness of sustainable, low-cost training models which can be easily reproduced elsewhere. This indigenously designed inexpensive simulator can be modified for variable difficulty level and serve as an effective educational strategy in improving learners’ skills, knowledge and confidence.
372 IPSC-Derived NK cells Exhibit Potent In Vitro and In Vivo Tumorcidal Activity Against Patient-Derived Glioblastoma Stem Cells (GSCs)
Authors: Ning Jianfang , Davis Zachary , Cichocki Frank , Wang Hongbo , Tuininga Katie , Bjordahl Ryan , Lee Tom , Miller Jeffrey , Chen Clark C C.
Published: March 2023

INTRODUCTION:

Natural Killer (NK) cells play pivotal roles in cancer immune surveillance and harbor potent anti-tumor activities. We have engineered an induced pluripotent stem cells (iPSCs) derived, NK cell (termed FT538) that express 1) a high-affinity non-cleavable CD16 Fc receptor to facilitate antibody engagement 2) a membrane-bound IL-15/IL-15 receptor fusion to enhance NK activity and persistence and 3) a knock-out of CD38 to enhance NK metabolic fitness. FT538 is produced in a GMP-compliant manner as an off-the-shelf immunotherapy. Clinical experiences with FT538 have shown evidence of durable anti-tumor immunity after single administration in select lymphoma patients.

METHODS:

Laboratory characterization and murine modeling.

RESULTS:

Without specific antibody to engage CD16, FT538 exhibited potent in vitro activity against ∼80% of a panel of isocitrate dehydrogenase wild-type patient derived xenograft (PDX) glioblastoma lines, including MGG8. When directly injected into the murine brain, 50% of the FT538 persisted for >2 weeks without addition of exogenous cytokine. Moreover, the mice exhibited no evidence of neurologic compromise, and brains harvested after injection show no signs of FT538 activation. In vivo intratumoral injection of FT538 into an orthotopically established MGG8 glioblastoma caused an ∼20 fold increase in granzyme B release by FT538, with a comparable increase of cleaved Caspase 3 in the tumor proper. In independent experiments, >90% of mice orthotopically implanted MGG8 survived beyond 100 days after intra-tumoral FT538 while all mice treated with mock injection died by 60 days. For glioblastoma PDX refractory to FT538, such as MGG4, tumoricidal activity of FT583 can be induced in vitro and in vivo by the addition of a tri-specific engager targeting B7H3, a surface protein highly expressed in glioblastomas.

CONCLUSIONS:

Our results suggest that FT538 great promise as a glioblastoma therapy, with plans for translation into a first-in-human clinical trial.
377 Evaluating Large-Scale Brain Networks Patients With Brain Tumors: A Machine Learning Analysis of 100 Consecutive Patients
Authors: Morell Alexis Andres , Eichberg Daniel Green , Shah Ashish Harish , Luther Evan , Lu Victor M. , Merenzon Martin , Kader Michael , Higgins Dominique , Patel Nitesh Vijay , Komotar Ricardo Jorge , Ivan Michael E.
Published: March 2023

INTRODUCTION:

Large-scale brain networks and higher cognitive functions are frequently altered in neuro-oncology patients, but comprehensive non-invasive brain mapping is difficult to achieve in the clinical setting.

METHODS:

We retrospectively included patients who underwent surgery for brain tumor resection at our Institution. Preoperative MRI with T1-weighted and DTI sequences were uploaded into the Quicktome platform. We categorized the integrity of nine large-scale brain networks: language, sensorimotor, visual, ventral attention, central executive, default mode, dorsal attention, salience and limbic. Networks were correlated with preoperative clinical data.

RESULTS:

One-hundred patients were included in the study. The most affected network was the central executive network (49%), followed by the default mode network (42%) and dorsal attention network (33%). Patients with preoperative deficits showed a significantly higher number of altered networks before the surgery (3.44 vs 2.16, p < .001), compared to patients without deficits. Furthermore, we found that patients without neurologic deficits had an average 2.16 networks affected and 1.56 networks at risk, with most of them being related to non-traditional eloquent areas (p = .014).

CONCLUSIONS:

Our results show that large-scale brain networks are frequently affected in patients with brain tumors, even when presenting without evident neurologic deficits. In our study, the most commonly affected brain networks were related to non-traditional eloquent areas. Integrating non-invasive brain mapping machine-learning techniques into the clinical setting may help elucidate how to preserve higher-order cognitive functions associated with those networks.
390 Real World Analysis of Outcomes After Revascularization Surgery for Symptomatic Non-stenotic Carotid (SyNC) Artery Disease
Authors: Madhani Sarosh Irfan , Alvi Mohammed Ali , Oushy Soliman , Borg Nicholas , Pando Alejandro , Alotaibi Naif M. , Savastano Luis
Published: March 2023

INTRODUCTION:

Symptomatic non-stenotic carotid (SyNC) artery disease is emerging as one of the primary causes of embolic stroke of unknown source. The optimal secondary prevention strategies including medical therapy and revascularization (Carotid Endarterectomy (CEA) versus Carotid Artery Stenting (CAS)) continue to be controversial.

METHODS:

The National Surgical Quality Improvement Program (NSQIP) targeted dataset for CEA and CAS was queried for symptomatic patients with <50% stenosis of the ipsilateral carotid artery undergoing CEA and CAS between 2012-2019. Data analysis for continuous and categorical variables was carried out.

RESULTS:

A total of 363 symptomatic patients with <50% stenosis of the ipsilateral carotid artery were identified of which 22 underwent CAS and 341 underwent CEA. Statistical analysis showed that patients undergoing CEA were more likely to be male as compared to those undergoing CAS (68% vs 54.5%, p < 0.001). Additionally, patients in the CAS group were more likely to present with high-risk anatomy features compared to patients in the CEA group (31.8% vs 11.7%, p = 0.007) whereas patients undergoing CEA were more likely to have <50% stenosis contralateral ICA stenosis when compared to patients undergoing CAS (65.1% vs 36.4%, p = 0.001). Furthermore, patients undergoing CAS were more likely to experience post procedural stroke at 30 days compared to those undergoing CEA (13.6% vs 3.8%, p = 0.03). Upon multivariable analysis, CEA was associated with lower odds of post procedural stroke as compared to CAS (OR = 0.17, 95% CI 0.033-0.82, p = 0.027).

CONCLUSIONS:

Carotid revascularization for SyNC is being performed despite current guidelines and CEA is associated with lower odds of post-procedural stroke compared to CAS.
393 Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Extra-to-Intracranial Bypass: Early Multicenter Experience of 44 Cases
Authors: Salem Mohamed M. , Ravindran Krishnan , Hoang Alex Nguyen , Doron Omer , Esparza Rogelio , Raper Daniel , Jankowitz Brian T. , Tanweer Omar , Lopes Demetrius K. , Langer David J. , Nossek Erez Zeev , Burkhardt Jan-Karl
Published: March 2023

INTRODUCTION:

The new sonolucent cranioplasty implant (clear polymethyl methacrylate, PMMA) adds functionality besides reconstruction during and after surgery. One possible application uses transcranioplasty ultrasound (TCUS) technique after PMMA cranioplasty to assess graft patency of extracranial-intracranial (EC-IC) bypass procedures.

METHODS:

Multicenter analysis of consecutive EC-IC bypass patients from 5 US centers between 2019-2022 with closure post bypass using the translucent PMMA cranioplasty implant.

RESULTS:

Forty-four patients (median-age 53, 68.2% females) were included. The most common indication for bypass was Moyamoya disease/syndrome (77.3%) and superficial temporal artery to middle cerebral artery (STA-MCA) bypass was the most common procedure (79.5%). Pre-treatment modified Rankin Scale of 0 and 1-2 was noted in 11.4% and 59.1% of the patients, respectively, with hypertension being the most common comorbidity (72.7%). Intraoperative imaging for bypass patency involved utilizing combination of modalities in all patients, with intraoperative doppler being the most commonly utilized monitoring modality (90.9%) followed by indocyanine green (ICG) and catheter angiography (86.4% and 61.4%, respectively). Qualitative TCUS assessment of the graft patency was feasible in all cases without technical difficulties. Post-operative inpatient TCUS confirmation of the bypass patency was recorded in 56.8% of the cases, and outpatient TCUS surveillance for monitoring bypass patency through the implant was recorded in 22.7% of the patients. There were no cases of bypass failure noted in this cohort necessitating retreatment. Similarly, no implant-related complications were encountered in the cohort. Major complications requiring additional surgery occurred in 2 patients (4.6%) including epidural hematoma requiring surgical evacuation (2.3%) and post-operative surgical site infection (2.3%) that was unrelated to the implant.

CONCLUSIONS:

This multicenter study supports the safety and feasibility of using the sonolucent PMMA implant in the setting of EC-IC bypass surgery with the goal to monitor bypass patency using TCUS.