Pain Outcomes Following Endoscopic Microvascular Decompression for Trigeminal Neuralgia Based on Vascular Compression Type

Background  Arterial compression of the trigeminal nerve at the root entry zone has been the long-attributed cause of compressive trigeminal neuralgia despite numerous studies reporting distal and/or venous compression. The impact of compression type on patient outcomes has not been fully elucidated. Objective  We categorized vascular compression (VC) based on vessel and location of compression to correlate pain outcomes based on compression type. Methods  A retrospective video review of 217 patients undergoing endoscopic microvascular decompression for trigeminal neuralgia categorizing VC into five distinct types, proximal arterial compression (VC1), proximal venous compression (VC2), distal arterial compression (VC3), distal venous compression (VC4), and no VC (VC5). VC type was correlated with postoperative pain outcomes at 1 month ( n  = 179) and last follow-up (mean = 42.9 mo, n  = 134). Results  At 1 month and longest follow-up, respectively, pain was rated as "much improved" or "very much improved" in 89 69% of patients with VC1, 86.6 and 62.5% of patients with VC2, 100 and 87.5% of patients with VC3, 83 and 62.5% of patients with VC4, and 100 and 100% of patients with VC5. Multivariate analysis demonstrated VC4 as a significant negative of predictor pain outcomes at 1 month, but not longest follow-up, and advanced age as a significant positive predictor. Conclusion  The degree of clinical improvement in all types of VC was excellent, but at longest follow-up VC type was not a significant predictor out outcome. However distal venous compression was significantly associated with worse outcomes at 1 month.

Incidental Durotomy Repair in Lumbar Spine Surgery: Institutional Experience and Review of Literature

STUDY DESIGN

: Retrospective Chart Review.

OBJECTIVES

Incidental durotomies (IDs) are common spine surgery complications. In this study, we present a review on the most commonly utilized management strategies, report our institutional experience with case examples, and describe a stepwise management algorithm.

METHODS

A retrospective review was performed of the electronic medical records of all patients who underwent a thoracolumbar or lumbar spine surgery between March 2017 and September 2019. Additionally, a literature review of the current management approaches to treat IDs and persistent postoperative CSF leaks following lumbar spine surgeries was performed.

RESULTS

We looked at 1133 patients that underwent posterior thoracolumbar spine surgery. There was intraoperative evidence of ID in 116 cases. Based on our cohort and the current literature, we developed a progressive treatment algorithm for IDs that begins with a primary repair, which can be bolstered by dural sealants or a muscle patch. If this fails, the primary repair can be followed by a paraspinal muscle flap, as well as a lumbar drain. If the patient cannot be weaned from temporary CSF diversion, the final step in controlling postoperative leak is longterm CSF diversion via a lumboperitoneal shunt. In our experience, these shunts can be weaned once the patient has no further clinical or radiographic signs of CSF leak.

CONCLUSIONS

There is no standardized management approach of IDs and CSF leaks in the literature. This article intends to provide a progressive treatment algorithm and contribute to the development process of a treatment consensus.

The Device for Intraventricular Entry guide: a novel solution to a perpetual problem

OBJECTIVE

The authors designed a low-profile device for reliable ventricular access and prospectively studied its safety, efficacy, and accuracy at a large academic center.

METHODS

A novel device for ventricular entry, the Device for Intraventricular Entry (DIVE) guide, was designed and created by the first and senior authors. Fifty patients undergoing external ventricular drainage (EVD) or shunt placement were prospectively enrolled for DIVE-assisted catheter placement at a single academic center. The primary outcome was the catheter tip location on postprocedural CT. Secondary outcomes included number of catheter passes, clinically significant hemorrhages, and procedure-related infections.

RESULTS

Fifty patients were enrolled. Indications included subarachnoid hemorrhage, intraventricular hemorrhage, traumatic brain injury, hydrocephalus, pseudotumor, and postsurgical wound drainage. In total, 76% (38/50) of patients underwent right-sided placement and 24% (12/50) underwent left-sided placement. All 100% (50/50) of patients had successful cannulation with an average of 1.06 passes. Postprocedural head CT confirmed ipsilateral frontal horn or third ventricle placement (Kakarla grade 1) in 92% (46/50) of patients and placement in the contralateral lateral ventricle in 8% (4/50) (Kakarla grade 2). There were no clinically significant track hemorrhages or procedural infections.

CONCLUSIONS

This single-center prospective study investigated the safety and efficacy of DIVE-assisted ventricular access. In total, 100% of procedures had successful ventricular cannulation, with 92% achieving Kakarla grade 1, with an average of 1.06 passes without any clinical complications.

Should I See You Again Soon? A Multispecialty Assessment of the Impact and Burden of Preoperative History and Physical Update Visits

BACKGROUND

Federal regulations require a history and physical (H&P) update performed ≤30 days before a planned procedure. We evaluated the utility and burdens of H&P update visits by determining impact on operative management, suitability for telehealth, and visit time and travel burden.

STUDY DESIGN

We identified H&P update visits performed in our health system during 2019 for 8 surgical specialties. As available, up to 50 visits per specialty were randomly selected. Primary outcomes were a) interval changes in history, exam, or operative plan between the initial and updated H&P notes and b) visit suitability for telehealth, as determined by two independent physician reviewers. Clinic time was captured, and round-trip driving time and distance between patients' home and clinic ZIP codes were estimated.

RESULTS

We identified 8,683 visits and 362 were randomly selected for review. Documented changes were most commonly identified in histories (60.8%), but rarely in physical exams (11.9%) and operative plans (11.6%). 99.2% of visits were considered suitable for telehealth. Median clinic time was 52 minutes (IQR:33.8-78), driving time was 55.6 minutes (IQR:35.5-85.5), and driving distance was 20.2 miles (IQR:8.5-38.4). At the health system level, patients spent an estimated aggregate 7,000 hours (including 4,046 hours of waiting room and travel time) and drove 142,273 miles to attend in-person H&P update visits in 2019.

CONCLUSION

Given their minimal impact on operative management, regulatory requirements for in-person H&P updates should be reconsidered. Flexibility in update timing and modality might help defray the substantial burdens these visits impose on patients.

Multi-institutional Analysis of Endoscopic Sellar Surgical Volumes During the COVID-19 Pandemic

OBJECTIVE

We sought to quantify trends in operative volumes and complications of endoscopic sellar surgery before and after the COVID-19 pandemic onset.

STUDY DESIGN

We performed a retrospective analysis.

SETTING

TriNetX database analysis.

METHODS

All adults undergoing neuroendoscopy for resection of pituitary tumor (Current Procedural Terminology code 62165) with diagnosis of benign/malignant neoplasm of pituitary gland (D35.2/C75.1) or benign/malignant neoplasm of craniopharyngeal duct (D35.3/C75.2) were included using the TriNetX database for 2 years before (pre-COVID group) and 2 years after (post-COVID group) February 17, 2020.

RESULTS

A total of 1238 patients in the pre-COVID group and 1186 patients in the post-COVID group were compared. Age, gender, and race were statistically similar between the groups (P > .05). Surgical volume decreased by 6% in the post-COVID group. In 2020 Q2, operative volume decreased by 19%, and in 2021 Q4 (peak COVID-19 caseload in the United States), operative volumes decreased by 29% compared to 2 years prior. Postoperative complications including meningitis (P = .49), cerebrospinal fluid leak (P = .36), visual field deficits (P = .07), postoperative pneumonia or respiratory failure (P = .42), and 30-day readmission rates (P = .89) were similar between the 2 groups.

CONCLUSION

Overall, endoscopic sellar surgery may continue to fluctuate with increased COVID-19 outbreaks. Patient outcomes do not appear to be worsened by decreased operative volumes or delays in nonurgent surgeries.

Large Language Model-Based Neurosurgical Evaluation Matrix: A Novel Scoring Criteria to Assess the Efficacy of ChatGPT as an Educational Tool for Neurosurgery Board Preparation

INTRODUCTION

Technological advancements are reshaping medical education, with digital tools becoming essential in all levels of training. Amidst this transformation, the study explores the potential of ChatGPT, an artificial intelligence model by OpenAI, in enhancing neurosurgical board education. The focus extends beyond technology adoption to its effective utilization, with ChatGPT's proficiency evaluated against practice questions from the Primary Neurosurgery Written Board Exam.

METHODS

Using the Congress of Neurologic Surgeons (CNS) Self-Assessment Neurosurgery (SANS) Exam Board Review Prep questions, we conducted 3 rounds of analysis with ChatGPT. We developed a novel ChatGPT Neurosurgical Evaluation Matrix (CNEM) to assess the output quality, accuracy, concordance, and clarity of ChatGPT's answers.

RESULTS

ChatGPT achieved spot-on accuracy for 66.7% of prompted questions, 59.4% of unprompted questions, and 63.9% of unprompted questions with a leading phrase. Stratified by topic, accuracy ranged from 50.0% (Vascular) to 78.8% (Neuropathology). In comparison to SANS explanations, ChatGPT output was considered better in 19.1% of questions, equal in 51.6%, and worse in 29.3%. Concordance analysis showed that 95.5% of unprompted ChatGPT outputs and 97.4% of unprompted outputs with a leading phrase were aligned.

CONCLUSIONS

Our study evaluated the performance of ChatGPT in neurosurgical board education by assessing its accuracy, clarity, and concordance. The findings highlight the potential and challenges of integrating AI technologies like ChatGPT into medical and neurosurgical board education. Further research is needed to refine these tools and optimize their performance for enhanced medical education and patient care.

Developing the surgeon-machine interface: using a novel instance-segmentation framework for intraoperative landmark labelling

Introduction

The utilisation of artificial intelligence (AI) augments intraoperative safety, surgical training, and patient outcomes. We introduce the term Surgeon-Machine Interface (SMI) to describe this innovative intersection between surgeons and machine inference. A custom deep computer vision (CV) architecture within a sparse labelling paradigm was developed, specifically tailored to conceptualise the SMI. This platform demonstrates the ability to perform instance segmentation on anatomical landmarks and tools from a single open spinal dural arteriovenous fistula (dAVF) surgery video dataset.

Methods

Our custom deep convolutional neural network was based on SOLOv2 architecture for precise, instance-level segmentation of surgical video data. Test video consisted of 8520 frames, with sparse labelling of only 133 frames annotated for training. Accuracy and inference time, assessed using F1-score and mean Average Precision (mAP), were compared against current state-of-the-art architectures on a separate test set of 85 additionally annotated frames.

Results

Our SMI demonstrated superior accuracy and computing speed compared to these frameworks. The F1-score and mAP achieved by our platform were 17% and 15.2% respectively, surpassing MaskRCNN (15.2%, 13.9%), YOLOv3 (5.4%, 11.9%), and SOLOv2 (3.1%, 10.4%). Considering detections that exceeded the Intersection over Union threshold of 50%, our platform achieved an impressive F1-score of 44.2% and mAP of 46.3%, outperforming MaskRCNN (41.3%, 43.5%), YOLOv3 (15%, 34.1%), and SOLOv2 (9%, 32.3%). Our platform demonstrated the fastest inference time (88ms), compared to MaskRCNN (90ms), SOLOV2 (100ms), and YOLOv3 (106ms). Finally, the minimal amount of training set demonstrated a good generalisation performance -our architecture successfully identified objects in a frame that were not included in the training or validation frames, indicating its ability to handle out-of-domain scenarios.

Discussion

We present our development of an innovative intraoperative SMI to demonstrate the future promise of advanced CV in the surgical domain. Through successful implementation in a microscopic dAVF surgery, our framework demonstrates superior performance over current state-of-the-art segmentation architectures in intraoperative landmark guidance with high sample efficiency, representing the most advanced AI-enabled surgical inference platform to date. Our future goals include transfer learning paradigms for scaling to additional surgery types, addressing clinical and technical limitations for performing real-time decoding, and ultimate enablement of a real-time neurosurgical guidance platform.

Protocol for human brain organoid transplantation into a rat visual cortex to model neural repair

Human stem-cell-derived organoids represent a promising substrate for transplantation-based neural repair. Here, we describe a protocol for transplanting forebrain organoids into an injured adult rat visual cortex. This protocol includes surgical details for craniectomy, aspiration injury, organoid transplantation, and cranioplasty. This platform represents a valuable tool for investigating the efficacy of organoids as structured grafts for neural repair. For complete details on the use and execution of this protocol, please refer to Jgamadze et al.1.

Preoperative Predictors of Survival in Patients With Spinal Metastatic Disease

BACKGROUND

There remains a number of factors thought to be associated with survival in spinal metastatic disease, but evidence of these associations is lacking. In this study, we examined factors associated with survival among patients undergoing surgery for spinal metastatic disease.

METHODS

We retrospectively examined 104 patients who underwent surgery for spinal metastatic disease at an academic medical center. Of those patients, 33 received local preoperative radiation (PR) and 71 had no PR (NPR). Disease-related variables and surrogate markers of preoperative health were identified, including age, pathology, timing of radiation and chemotherapy, mechanical instability by spine instability neoplastic score, American Society of Anesthesiologists (ASA) classification, Karnofsky performance status (KPS), and body mass index (BMI). We performed survival analyses using a combination of univariate and multivariate Cox proportional hazards models to assess significant predictors of time to death.

RESULTS

Local PR (Hazard Ratio [HR] = 1.84, P = 0.034), mechanical instability (HR = 1.11, P = 0.024), and melanoma (HR = 3.60, P = 0.010) were significant predictors of survival on multivariate analysis when controlling for confounders. PR vs NPR cohorts exhibited no statistically significant differences in preoperative age (P = 0.22), KPS (P = 0.29), BMI (P = 0.28), or ASA classification (P = 0.12). NPR patients had more reoperations for postoperative wound complications (11.3% vs 0%, P < 0.001).

CONCLUSIONS

In this small sample, PR and mechanical instability were significant predictors of postoperative survival, independent of age, BMI, ASA classification, and KPS and in spite of fewer wound complications in the PR group. It is possible that PR was a surrogate of more advanced disease or poor response to systemic therapy, independently portending a worse prognosis. Future studies in larger, more diverse populations are crucial for understanding the relationship between PR and postoperative outcomes to determine the optimal timing for surgical intervention.

CLINICAL RELEVANCE

These findings are clinically relevent as they provide insight into factors associated with survival in metastatic spinal disease.

LEVEL OF EVIDENCE: 3

Endoscopic fenestration of an enlarging giant occipital arachnoid cyst

This case demonstrates an endoscopic fenestration of an enlarging giant occipital arachnoid cyst. The patient is a 42-year-old woman presenting with headache, progressive vision loss, and nausea and vomiting. MRI demonstrates a large, nonenhancing cystic lesion in the right occipital lobe measuring up to 8.3 cm, consistent with an arachnoid cyst. This surgical video illustrates the technique for an endoscopic fenestration into the native ventricular system utilizing stereotactic MRI-guided stealth navigation. Postoperatively, the patient had full recovery with improvement of headaches and vision and was discharged on postoperative day 1 without complications.

The video can be found here: https://stream.cadmore.media/r10.3171/2023.1.FOCVID22129

Navigated lumbar drain placement: A description of technique and case example

Background:

Lumbar drain (LD) placement can be a difficult procedure leading to postprocedure complications, particularly in patients with persistent cerebrospinal fluid leaks or a large body habitus. The objective of this technical case report is to describe the use of Medtronic’s SureTrak Navigation system for navigated LD placement.

Case Description:

The patient was an 18-year-old morbidly obese male who initially underwent a suboccipital craniectomy with duraplasty and a C1 laminectomy for Chiari Malformation. Postoperatively, he developed a pseudomeningocele and was taken to the operating room for wound revision, duraplasty repair, and LD placement. Medtronic’s SureTrak Navigation system was used for LD placement before wound revision. Successful LD placement was achieved in a single pass using the SureTrak Navigation. The patient did well postoperatively, and LD removal occurred on postoperative day 6. The patient was discharged in good condition without evidence of a cerebral spinal fluid leak.

Conclusion:

Navigation using the SureTrak system is a reasonable option to use in patients with a high body mass index and a persistent cerebrospinal fluid leak. When the patient is already undergoing an operative procedure, it can aid in an efficient low-risk intervention completed in a single prone positioning.

The Influence of Radiologist Practice Setting on Identification of Vascular Compression from Magnetic Resonance Imaging in Trigeminal Neuralgia

OBJECTIVE

Preoperative magnetic resonance imaging (MRI) studies are routinely ordered for trigeminal neuralgia (TN), though with contested reliability in contemporary literature. A potential reason for this disagreement is inconsistency in MRI reading methodologies. Here, we compare the rate of reported neurovascular compression on preoperative MRI by radiologists employed in community or private practice settings and academic neuroradiologists.

METHODS

A retrospective review was conducted on patients who underwent endoscopic microvascular decompression for TN with intraoperatively visualized neurovascular compression and primary read by a non-academic or community radiologist. Patient imaging was then re-read by a board-certified neuroradiologist practicing in an academic setting, who was blinded to the initial read and the side of TN symptoms.

RESULTS

Non-academic radiologists reported vascular compression in 26.0% (20/77) of all patients, and mention was rarely made of the non-pathological side (sensitivity = 26.0%). On academic neuroradiologist re-reads, vascular compression was noted in 87.0% (67/77) of patients on the pathological side and in 57.1% (44/77) on the non-pathological side (sensitivity = 87.0%, specificity = 42.9%). Isotropic/near isotropic 3-dimensional steady state or heavily T2-weighted sequences were read with 92.3% sensitivity and 36.9% specificity, compared to 58.3% sensitivity and 66.7% specificity using routine T2 weighted sequences.

CONCLUSIONS

The frequency of vascular compression reported by non-academic radiologists is much lower than what is reported by academic neuroradiologists reading the same MRI scans. These results highlight the effect of practice setting on the predictive power of neuroimaging. Future studies are indicated to further investigate these relationships, as well as to trial newer imaging modalities.

Structural and functional integration of human forebrain organoids with the injured adult rat visual system

Brain organoids created from human pluripotent stem cells represent a promising approach for brain repair. They acquire many structural features of the brain and raise the possibility of patient-matched repair. Whether these entities can integrate with host brain networks in the context of the injured adult mammalian brain is not well established. Here, we provide structural and functional evidence that human brain organoids successfully integrate with the adult rat visual system after transplantation into large injury cavities in the visual cortex. Virus-based trans-synaptic tracing reveals a polysynaptic pathway between organoid neurons and the host retina and reciprocal connectivity between the graft and other regions of the visual system. Visual stimulation of host animals elicits responses in organoid neurons, including orientation selectivity. These results demonstrate the ability of human brain organoids to adopt sophisticated function after insertion into large injury cavities, suggesting a translational strategy to restore function after cortical damage.

Implementation of a Streamlined Care Pathway to Reduce Cost and Length of Stay for Patients Undergoing Endoscopic Transsphenoidal Pituitary Surgery

BACKGROUND

We implemented a streamlined care pathway for patients undergoing endoscopic transsphenoidal (TSA) pituitary surgery. Select patients are recovered in the postanesthesia care unit and transferred to a step-down unit for intermediate neurologic care (INCU), with clinicians trained to manage cerebrospinal fluid leak, diabetes insipidus (DI), and other complications.

METHODS

We evaluated all TSA surgeries performed at 1 academic medical center from 7^th January, 2017 to 30^th March, 2020, collecting patient factors, tumor characteristics, cost variables, and outcomes. The INCU pathway was implemented on 7^th January 2018. Pathway patients were compared with nonpathway patients across the study period. Outcomes were assessed using multivariate regression, adjusting for patient and surgical characteristics, including intraoperative cerebrospinal fluid leak, postoperative DI, and tumor dimensions.

RESULTS

One hundred eighty-seven patients were identified. Seventy-nine were on the INCU pathway. Mean age was 53.5 years. Most patients were male (66%), privately insured (62%), and white (66%). Mean total cost of admission was $27,276. Mean length of stay (LOS) was 3.97 days. Use of the INCU pathway was associated with total cost reduction of $6376.33 (P < 0.001, 95% confidence interval [CI]: $3698.21-$9054.45) and LOS reduction by 1.27 days (P = 0.008, 95% CI: 0.33-2.20). In-hospital costs were reduced across all domains, including $1964.87 in variable direct labor costs (P < 0.001, 95% CI: $1142.08-$2787.64) and $1206.52 in variable direct supply costs (P < 0.001, 95% CI: $762.54-$1650.51). Pathway patients were discharged earlier despite a higher rate of postoperative DI (25% vs. 11%, P = 0.011), with fewer readmissions (0% vs. 6%, P = 0.021).

CONCLUSIONS

A streamlined care pathway following TSA surgery can reduce in-hospital costs and LOS without compromising patient outcomes.

Multi-layer approach to complex traumatic anterior skull base fracture repair: A case report

Background

Anterior skull base fractures represent a unique challenge for neurosurgical repair due to the potential for orbital injury and the proximity to the air sinuses, yielding increased possibility for infection, and persistent cerebrospinal fluid (CSF) leak. While multiple techniques are available for the repair of anterior skull base defects, there exists a paucity of robust, long-term clinical data to guide the optimal surgical management of these fractures.

Case Description

We present the case of a complex, traumatic penetrating anterior skull base fracture, and describe a multi-layered approach for successful repair - namely, with the use of a temporally-based pericranial flap, split-thickness frontal bone graft, and autogenous abdominal fat graft. The patient was followed for nine months postoperatively, over which time she experienced no significant complications.

Conclusion

The goal of successful anterior skull base repair involves creating a durable, watertight separation between intra and extracranial compartments to prevent CSF leak, protect intracranial structures, and minimize infection risk. The temporally-based pericranial flap, split-thickness frontal bone graft, and autogenous abdominal fat graft represent safe and efficacious approaches to achieve lasting repair.

Intraoperative Hypotension Is Not Correlated With Acute Kidney Injury During Spinal Fusion Surgery

BACKGROUND

Intraoperative hypotension (IOH) has been found to be associated with organ damage, including cardiac injury and acute kidney injury (AKI). However, to our knowledge, this relationship has not been studied in a neurosurgery-specific patient population. In this report, we review our institutional experience to understand the magnitude of association between IOH in spinal fusion operations and incidence of postoperative AKI.

METHODS

This retrospective cohort study included 910 patients who underwent posterior spinal fusion procedures performed in the prone position. Intraoperative variables collected and analyzed include minute-by-minute mean arterial pressure (MAP) from an arterial catheter, intermittent blood pressure cuff readings, volume of administered intravenous fluids, urine output, and all relevant vitals and administered medications. The electronic medical record was queried for additional patient data. IOH was defined as MAP <65 mm Hg for greater than 10 minutes. The primary endpoints of the study were presence and staging of AKI ( [Kidney Disease: Improving Global Outcomes] consensus classification), postoperative ileus, and postoperative troponin leak.

RESULTS

Using a partial correlation analysis, no association was found between IOH metrics (IOH occurrence, IOH duration >10 minutes, and total IOH time) and any outcome metrics, including AKI, except for vasopressor usage and estimated blood loss. Patient age at surgery was not associated with any outcome variables. The lack of association between IOH and AKI contrasts with existing literature; this could be due to underlying differences in our patient population or could highlight a more complex relationship between IOH and AKI than previously understood.

CONCLUSION

Occurrence and duration of IOH were not associated with AKI, postoperative ileus, troponin leak, length of stay, or any other major outcome variables in spinal fusion patients.

CLINICAL RELEVANCE

These findings depart from previous literature showing a correlation between IOH and AKI and provide level 3 evidence clinically relevant to spinal surgery. Further research is needed to better understand the exact nature of this relationship.

LEVEL OF EVIDENCE: 3

Refractory glossopharyngeal neuralgia successfully treated with onabotulinumtoxinA: A case report

BACKGROUND

Glossopharyngeal neuralgia is a rare but severe and disabling pain condition often caused by vascular compression of the glossopharyngeal nerve. Treatment is similar to that of trigeminal neuralgia, but some patients may be refractory to both medical and surgical approaches. Here we present a case of refractory glossopharyngeal neuralgia that responded well to onabotulinumtoxinA (BTX-A).

CASE

We report a case of a 65-year-old man with well-controlled human immunodeficiency virus disease with glossopharyngeal neuralgia symptoms since 2015. He had partial response to medications but was limited by side-effects. He underwent microvascular decompression twice with initial relief both times, but experienced recurrence of attacks 1-3 years after each surgery. He was treated with BTX-A using the chronic migraine PREEMPT protocol (i.e., 31-39 injection sites in head and neck muscles), which led to significant relief of his glossopharyngeal neuralgia pain.

CONCLUSIONS

This is the first case to our knowledge of glossopharyngeal neuralgia treated with BTX-A. BTX-A can be an effective treatment for glossopharyngeal neuralgia, even when injections are not administered directly over the sensory distribution of the glossopharyngeal nerve.

Socioeconomic Status Predicts Short-Term Emergency Department Utilization Following Supratentorial Meningioma Resection

Introduction By identifying drivers of healthcare disparities, providers can better support high-risk patients and develop risk-mitigation strategies. Household income is a social determinant of health known to contribute to healthcare disparities. The present study evaluates the impact of household income on short-term morbidity and mortality following supratentorial meningioma resection. Methods A total of 349 consecutive patients undergoing supratentorial meningioma resection over a six-year period (2013-2019) were analyzed retrospectively. Primary outcomes were unplanned hospital readmission, reoperations, emergency department (ED) visits, return to the operating room, and all-cause mortality within 30 days of the index operation. Standardized univariate regression was performed across the entire sample to assess the impact of household income on outcomes. Subsequently, outcomes were compared between the lowest (household income ≤ $51,780) and highest (household income ≥ $87,958) income quartiles. Finally, stepwise regression was executed to identify potential confounding variables. Results Across all supratentorial meningioma resection patients, lower household income was correlated with a significantly increased rate of 30-day ED visits (p = 0.002). Comparing the lowest and highest income quartiles, the lowest quartile was similarly observed to have a significantly higher rate of 30-day ED evaluation (p = 0.033). Stepwise regression revealed that the observed association between household income and 30-day ED visits was not affected by confounding variables. Conclusion This study suggests that household income plays a role in short-term ED evaluation following supratentorial meningioma resection.

Endoscopic Microvascular Decompression for Hemifacial Spasm: A Technical Case Report Demonstrating the Benefits of the Angled Endoscope and Intraoperative Neuromonitoring

A 57-year-old female with eight years of hemifacial spasm (HFS) underwent endoscopic microvascular decompression (MVD) of the facial nerve. Baseline stimulation of the zygomatic branch of the facial nerve activated at 1.2 mA. Lateral spread response (LSR) to the buccal and mandibular branches was observed at 2.2 mA. A straight endoscope was used to enter the cerebellopontine angle, allowing for visualization of the vestibulocochlear and facial nerve. Neurovascular compression was not clearly identified. A 30-degree endoscope was directed medially/inferiorly and compression at the root entry zone was identified and decompressed. Subsequent LSR to the buccal/mandibular branches was seen at 3.2 mA/3.6 mA, respectively. Additional vascular compression was suspected given persistent LSR. The 30-degree endoscope was directed laterally. Compression was seen at the porus acustics and decompressed. Subsequent LSR to the buccal/mandibular branches was not observed until 9.8 mA, indicating good decompression. The patient tolerated the procedure well with complete resolution of her symptoms and remains spasm-free as of three months post-procedure without a hearing deficit. The 30-degree endoscope enabled visualization of pathology that was not easily seen at 0-degree. Additionally, LSR indicated persistent nerve compression following root entry zone decompression. Subsequent distal decompression resulted in greater LSR reduction. This case report suggests that MVD for HFS may yield better results with both proximal and distal decompression of the seventh nerve, and this type of decompression can benefit from endoscopic visualization.

Do-It-Yourself Augmented Reality Heads-Up Display (DIY AR-HUD): A Technical Note

BACKGROUND

We present a "Do-It-Yourself" method to build an affordable augmented reality heads-up display system (AR-HUD) capable of displaying intraoperative images. All components are commercially available products, which the surgeons may use in their own practice for educational and research purposes.

METHODS

Moverio BT 35-E smart glasses were connected to operating room imaging modalities (ie, fluoroscopy and 3D navigation platforms) via a high-definition multimedia interface (HDMI) converter, allowing for continuous high-definition video transmission. The addition of an HDMI transmitter-receiver makes the AR-HUD system wireless.

RESULTS

We used our AR-HUD system in 3 patients undergoing instrumented spinal fusion. AR-HUD projected fluoroscopy images onto the surgical field, eliminating shift of surgeon focus and procedure interruption, with only a 40- to 100-ms delay in transmission, which was not clinically impactful.

CONCLUSIONS

An affordable AR-HUD capable of displaying real-time information into the surgeon's view can be easily designed, built, and tested in surgical practice. As wearable heads-up display technology continues to evolve rapidly, individual components presented here may be substituted to improve its functionality and usability. Surgeons are in a unique position to conduct clinical testing in the operating room environment to optimize the augmented reality system for surgical use.

Second-Window Indocyanine Green for Visualization of Hemangioblastoma: A Case Report With Two-Dimensional Operative Video

BACKGROUND AND IMPORTANCE

The proper differentiation of neoplastic tissue from adjacent brain parenchyma can pose a great challenge, especially in eloquent areas of the brain. With the novel technique, "Second-Window Indocyanine Green," injection of a near-infrared fluorophore (ICG) allows for intraoperative visualization of tumors by taking advantage of the compromised vasculature surrounding the tumor. Thus, such a technique may demonstrate utility for hemangioblastomas, which are hypervascular tumors of the central nervous system.

CLINICAL PRESENTATION

Here we present the case of a 39-yr-old male with a demonstrated cystic mass in the left cerebellum, with additional edema spreading towards the vermis. A total of 5 mg/kg of ICG was delivered intravenously 24 h prior to the operation. The tumor was approached via the infratentorial suboccipital approach. We observed strong near-infrared fluorescence through the intact dura, consistent with the tumor location. Surgical pathology confirmed a final diagnosis of cerebellar hemangioblastoma. There was complete resection of the tumor, with the patient discharged uneventfully.

CONCLUSION

We report the first successful case of fluorescence-guided surgery of a cerebellar hemangioblastoma using near-infrared fluorescence imaging with the Second-Window ICG technique. This joins a growing series of publications that demonstrate the efficacy of a novel application of ICG, a near-infrared fluorophore, in accurate intraoperative visualization of neoplastic tissue. While the use of a dedicated near-infrared platform (ie, the VisionSense Iridium [Visionsense, Philadelphia, Pennsylvania]) yields a higher signal-to-background ratio, a neurosurgical microscope (ie, the Leica OH6 [Leica Microsystems, Wetzlar, Germany]) may also provide a suitable option in cases where fluorescence is very strong.

A Primer on Human Brain Organoids for the Neurosurgeon

Human brain organoids emerged in 2013 as a technology that, unlike prior in Vitro neural models, recapitulates brain development with a high degree of spatial and temporal fidelity. As the platform matured with more accurate reproduction of cerebral architecture, brain organoids became increasingly valuable for studying both normal cortical neurogenesis and a variety of congenital human brain disorders. While the majority of research utilizing human brain organoids has been in the realm of basic science, clinical applications are forthcoming. These present and future translational efforts have the potential to make a considerable impact on the field of neurosurgery. For example, glioma organoids are already being used to study tumor biology and drug responses, and adaptation for the investigation of other neurosurgery-relevant diseases is underway. Moreover, organoids are being explored as a structured neural substrate for repairing brain circuitry. Thus, we believe it is important for our field to be aware and have an accurate understanding of this emerging technology. In this review, we describe the key characteristics of human brain organoids, review their relevant translational applications, and discuss the ethical implications of their use through a neurosurgical lens.

Endoscopic Microvascular Decompression for Vagoglossopharyngeal Neuralgia

Glossopharyngeal neuralgia (GN) is a nerve compression syndrome that presents with episodes of unilateral sharp, stabbing pain in the distribution of the ninth cranial nerve. This syndrome may present with cardiac and autonomic manifestations - a condition termed vagoglossopharyngeal neuralgia (VGPN). Most cases of VGPN arise from neurovascular insult at the cerebellopontine angle. Conservative treatment for VGPN includes antiepileptic medications. Surgical treatments include trigeminal tractotomy-nucleotomy, Gamma Knife® stereotactic radiosurgery, radiofrequency thermocoagulation, rhizotomy, and, as shown in this paper, endoscopic microvascular decompression (E-MVD). In this article, we present two cases. Case 1 demonstrates a 53-year-old male with right-sided GN symptoms that began to experience syncopal episodes 10-years after the initial presentation. Case 2 presents a 61-year-old female with a history of Ehlers-Danlos syndrome, and the malignant vasovagal syndrome that became associated with painful, shooting left anterior neck spasms consistent with GN. Both patients underwent E-MVD, leading to complete relief of neuralgia and cardiac symptoms. Our outcomes support previously published reports of successful treatment of VGPN using microvascular decompression (MVD) and describe a purely endoscopic surgical technique. MVD is the preferred treatment option for VGPN with evident neurovascular insult.

The Impact of Household Economics on Short-Term Outcomes in a Posterior Fossa Tumor Population

Background

Disparities exist in medical care and may result in avoidable negative clinical care outcomes for those affected. There remains a paucity in the literature regarding the impact of economic disparities on neurosurgical outcomes.

Methods

A total of 283 consecutive posterior fossa brain tumor resections, excluding cerebellopontine angle tumors, over a six-year period (June 07, 2013, to April 29, 2019) at a single, multihospital academic medical center were analyzed retrospectively. Outcomes evaluated included 30-day readmission and mortality, emergency department (ED) evaluation, unplanned return to surgery within 30 days, and return to surgery after index admission within 30 days. The population was divided into quartiles based on median household income, and univariate analysis was conducted between the lowest (Q1) and highest (Q4) socioeconomic quartiles, with significance set at a p < 0.05. Stepwise regression was conducted to determine the correlations among study variables and identify confounding factors.

Results

Whole population univariate analysis demonstrated lower socioeconomic status (SES) to be correlated with increased mortality within 30 post-operative days and increased return to surgery after index admission. No significant difference was found with regard to 30-day readmission, ED evaluation, unplanned reoperation, or return to surgery after index admission. Decreasing, but not significant, mortality was demonstrated between Q1 and Q4 socioeconomic quartiles.

Conclusions

This study suggests that low SES, when defined by household income, correlates with increased mortality within 30 days and an increased need for return to surgery within 30 days. There may be an opportunity for hospitals and care providers to use SES to proactively identify high-risk patients and test the impact of supports in the post-operative setting.

Complication Rates During Endoscopic Microvascular Decompression Surgery Are Low With or Without Petrosal Vein Sacrifice

OBJECTIVE

Endoscopic-microvascular decompression (E-MVD) is a well-described treatment for trigeminal neuralgia (TGN), but there has been debate on the safety of intraoperative sacrifice of the petrosal vein (PV) due to concern for subsequent venous insufficiency. Our objective was to investigate the risk of PV sacrifice during E-MVD in TGN and subsequent postoperative complications and pain outcomes.

METHODS

5 five-year review yielded 201 patients who underwent MVD for TGN. PV sacrifice, vascular compressive anatomy, and postoperative complications attributable to venous insufficiency were analyzed. Preoperative and postoperative pain outcomes were analyzed.

RESULTS

PV was sacrificed in 118 of 201 (59%) of patients, with 43 of 201 (21%) patients undergoing partial sacrifice versus 75 of 201 (37%) with complete sacrifice. No cases of venous infarction, cerebellar swelling, or fatal complications were noted in either cohort. Non-neurologic complications occurred in 1.69% (2 of 118) of patients with PV sacrifice and 0% (0 of 83) of patients with PV preservation. Neurologic deficits (facial palsy, conductive hearing loss, gait instability, memory deficit) occurred in equal proportions in PV preservation and sacrifice groups (2.41% vs. 1.69%) Overall, 87.3% (145 of 166) patients reported their pain as "very much improved" or "much improved" at 1 month, and no difference between groups was identified.

CONCLUSIONS

This study did not find higher complication rates in patients undergoing petrosal vein sacrifice during E-MVD for trigeminal neuralgia. In this series where petrosal vein was sacrificed only 59% of the time, it appears to be a safe technique, but larger studies will be needed to determine true incidence of complications after PV sacrifice.

Osteoradionecrosis of the Occipitocervical Junction After Radiation for Head and Neck Cancer: A Report of 8 Cases

BACKGROUND

Osteoradionecrosis (ORN) refers to the degenerative changes seen in bone after local radiation, particularly in head and neck cancer. ORN can present as neck or facial pain and may be confused with tumor recurrence. Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans are often inconclusive, requiring percutaneous biopsy to differentiate ORN from infection and recurrent disease. We reviewed the utility of preprocedural imaging in guiding the decision to biopsy in cases of ORN.

CASE DESCRIPTION

Eight patients with a history of prior head and neck cancer, radiation therapy, and suspected ORN at the skull base, occipitocervical junction, and atlantoaxial spine were identified retrospectively from a single academic medical center. In 4 cases, MRI findings and PET imaging were negative for recurrence. One patient in this group underwent an aborted biopsy. Four patients had MRI concerning for infection or recurrent tumor with PET-positive lesions. Three patients in this group underwent biopsy that was negative for recurrent tumor. One patient developed an arteriovenous fistula after biopsy. The fourth patient was observed and did not demonstrate progression at 5 months. At last follow-up for all patients, there was no evidence of tumor recurrence or metastasis at the index site to indicate a misdiagnosis for recurrent tumor.

CONCLUSIONS

This case series highlights that PET scanning may not be useful in predicting which patients will benefit from biopsy for ORN because no patients with PET-positive lesions had histopathologic evidence of tumor recurrence or metastasis on biopsy.

Fully endoscopic microvascular decompression for hemifacial spasm

OBJECTIVE

Hemifacial spasm (HFS) is characterized by involuntary tonic and/or clonic contractions of facial nerve muscles. Fully endoscopic microvascular decompression (E-MVD) for HFS has not been widely adopted. This paper aims to illustrate the safety and efficacy of the fully endoscopic technique for HFS treatment.

METHODS

The authors conducted a single-center retrospective study of 27 patients (28 separate E-MVD cases; 1 patient had bilateral E-MVD) diagnosed with HFS who underwent fully E-MVD from January 2013 to October 2016. Intraoperative brainstem auditory evoked potentials and lateral spread resolution were reviewed. Outcome was based on the clinical status of the patient at the last contact point with the senior author. Complications were categorized as facial weakness, hearing loss, ataxia, dysphagia, or any adverse event able to be attributed to the surgical procedure.

RESULTS

HFS was relieved either completely or partially in the majority of cases (24 of 28, 85.7%). Of the 28 separate procedures, 17 (60.7%) resulted in complete resolution of symptoms, 4 (14.3%) resulted in near-complete resolution, 2 (7.1%) resulted in 50% reduction of symptoms, 1 (3.6%) resulted in minimal reduction, and 4 (14.3%) resulted in no relief. Of the 27 patients, 26 (96%) had no permanent postoperative complications. In multivariate logistic regression, the best predictor of greater than 50% resolution of spasm was resolution of intraoperative lateral spread response.

CONCLUSIONS

A fully E-MVD for HFS provides a safe and comprehensive view of the neurovascular conflict. Exclusive use of the endoscope in MVD is both safe and feasible in the treatment of HFS. Attention to lateral spread response monitoring remains an integral part of comprehensive neurosurgical management.

Transplantation of Human Brain Organoids: Revisiting the Science and Ethics of Brain Chimeras

Recent demonstrations of human brain organoid transplantation in rodents have accentuated ethical concerns associated with these entities, especially as they relate to potential "humanization" of host animals. Consideration of established scientific principles can help define the realistic range of expected outcomes in such transplantation studies. This practical approach suggests that augmentation of discrete brain functions in transplant hosts is a more relevant ethical question in the near term than the possibility of "conscious" chimeric animals. We hope that this framework contributes to a balanced approach for proceeding with studies involving brain organoid transplantation and other forms of human-animal brain chimeras.

Risk of Vertebral Artery Injury and Stroke Following Blunt and Penetrating Cervical Spine Trauma: A Retrospective Review of 729 Patients

BACKGROUND

Cervical spine trauma (CST) may result in vertebral artery injury (VAI), increasing the risk of developing stroke. Stroke risk following CST is poorly reported.

METHODS

In total, 729 patients with CST were retrospectively analyzed, including rates of VAI, age at injury, cause of injury, cardiovascular history, smoking history, substance abuse history, embolization therapy, and antiplatelet or anticoagulant therapy prior or after injury. VAIs were identified and graded following the Modified Denver Criteria for Blunt Cerebrovascular Injury using magnetic resonance angiography and computed tomography angiography. Brain scans were reviewed for stroke rates and statistically significant variations.

RESULTS

Thirty-three patients suffered penetrating trauma, whereas 696 patients experienced blunt trauma. In total, 81 patients met the criteria for analysis with confirmed VAI. VAI was more common in penetrating injury group compared with blunt injury group (64% vs. 9%, P < 0.0005). However, low-grade VAI (less than grade III) was more common in blunt injury group versus penetrating group (37% vs. 14%, P < 0.05). The frequency of posterior circulation strokes did not vary significantly between groups (26.3% vs. 13.8%, P = 0.21). Cardiovascular comorbidities were significantly more common in the blunt group (50%, P = 0.0001) compared with the penetrating group (0%).

CONCLUSIONS

VAI occurs with a high incidence in penetrating CST. Although stroke risk following penetrating and blunt CST did not vary significantly, they resulted in serious complications in a group of patients. Further study of this patient population is required to provide high-level, evidence-based preventions for VAI complications.

The Medication Reduction Project: combating polypharmacy in South Dakota elders through community-based interventions

The Medication Reduction Project (MED RED) is a community-based program addressing polypharmacy issues in elders. Using educational presentations and one-on-one medication reviews conducted by a pharmacist specializing in geriatrics, MED RED reached over 1,100 older adults in rural and urban southeastern South Dakota communities during 1993. Analysis of the longitudinal data indicate that older adults participating in one-on-one reviews were on fewer medications, had dosage reductions, were more likely to take their medications as directed, and increased their use of non-pharmacological alternatives. These elders also reported feeling better, spent less money per month on medications, and offered indications of improved functioning and increased levels of independence. These findings suggest that education about medication use is a dynamic tool in empowering community-based older adults to be assertive participants in their own health care.

MealMate: improving the nutritional status of elders using a milk-based nutritional supplement

MealMate was a longitudinal research project conducted by the staff at the Geriatric Health Institute, a joint venture between Sioux Valley Hospital and the University of South Dakota School of Medicine. During Fall 1994, 64 older adults enrolled in this nutrition study at a Sioux Falls congregate dining site and drank a half-pint of whole milk combined with Carnation Instant Breakfast daily for one month. Pre-test and post-test data collected included anthropometric measures, specific blood tests from a venipuncture blood draw and use of standardized instruments to assess nutritional risk, depression, mental status and general demographic information. Results suggest that a longitudinal study with elders can be done effectively (attrition rate of less than 11%). While elders were very healthy at the onset, they nevertheless showed improved nutritional status over time. Laboratory tests showed significant increases in Vitamin D levels in adults over age 79. Using a more malnourished, home-bound sample of elders over age 79 and adding only whole milk to their diets are discussed as possible considerations for future research.

CNS-directed case management. Cost and quality in harmony

Preserving the integrity of high quality care in a financially restricted environment is the primary challenge facing healthcare providers. The critical question is which delivery system will use limited resources most efficiently without jeopardizing quality of care? Case management has been identified as a solution that offers the most promise. The case management model at Sioux Valley Hospital was developed to deal proactively with resource-intensive patients with chronic illnesses who have frequent admissions and who create financial risk for the hospital. The authors describe the fiscal and clinical outcomes of these select patients.

Simultaneously collected monopolar and discrete bipolar electrograms: comparison of activation time detection algorithms

Designation of the time of local activation is fundamental to electrophysiological mapping. In normal myocardium, the minimum slope in extracellular monopolar (MP) electrograms has been linked through simultaneous intracellular and extracellular recordings to phase 0 of the action potential. However, no similar correlation has been demonstrated for a parameter from bipolar (BP) electrograms, now commonly used during electrophysiological studies and intraoperative mapping. The purpose of this work is to compare the activation time, determined according to several common algorithms applied to BP electrograms, with the time of the minimum slope in MP electrograms. Simultaneous normal epicardial MP and BP electrograms were acquired from subjects undergoing surgery for Wolf-Parkinson-White Syndrome and from dogs. The activation time in BP electrograms was defined by four algorithms: (1) peak (P); (2) greatest absolute slope (S); (3) zero crossing of the segment containing the greatest slope (FZC); and (4) morphological (M). Each was compared to the time of the minimum slope in the simultaneously recorded MP response. The incidence of outliers was tabulated. The distribution of activation times computed using each BP algorithm was statistically different from the distribution of activation times derived from MP electrograms. M performed best (absolute difference: 2.6 +/- 2.9 msec; cor coef: 0.9925 in man). The M, P, FZC, and S algorithms produced 3.2%, 3.5%, 4.7% and 4.7% outliers, respectively. The overall performance of a morphologically based algorithm is superior to simplistic BP algorithms based only on slope or peak.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of time of sampling onset on parameters used for activation time determination in computerized intraoperative mapping

The purpose of this work is to determine the sensitivity of the estimated time of peaks and maximum slopes, commonly used in activation time computations, to the instant at which sampling is initiated. Based on complex and quickly changing waveforms, 471 monopolar (MP) and bipolar (BP) epicardial responses in man were selected. These were decimated from 10 kHz to simulate sampling at frequencies ranging from 200 Hz to 2,000 Hz. The peak and maximum absolute slope for BP and the minimum slope for MP were computed repeatedly starting at successive 100 microseconds intervals extending throughout the sampling period and compared with these parameters computed from the waveform sampled at 10 kHz. Slopes were estimated using each of four different algorithms. The average greatest shift (AGS) due to variations in sampling onset ranged from 11.2 +/- 3.5 (200 Hz) to 0.3 +/- 0.2 msec (2,000 Hz). For bipolar algorithms, the peak performed better than the slope algorithms (AGS: 5.9 +/- 3.3 to 0.3 +/- 1.0 msec). For MP algorithms, 2 point linear, and 3 and 5 point Lagrange slope estimates performed similarly (AGS: 5.6 +/- 3.3 to 0.3 +/- 0.2 msec); a 5 point least square fit algorithm performed poorly. Sampling MP and BP electrograms below 500 and 400, respectively, often caused maximum shifts greater than 4 msec. Thus, the resolution of the peak and estimated slope is not limited to the sampling period, variations in initiation of sampling can cause significant outliers especially at low sampling rates, and MP electrograms should be sampled faster than BP electrograms for comparable accuracy.