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Background and Objectives: Moyamoya disease (MMD) is a chronic steno-occlusive disease of the intracranial circulation that depends on neoangiogenesis of collateral vessels to maintain cerebral perfusion and is primarily managed with cerebral revascularization surgery. A quantitative assessment of preoperative and postoperative collateral flow using quantitative magnetic resonance angiography with noninvasive optimal vessel analysis (NOVA) was used to illustrate the impact of revascularization on cerebral flow distribution., Methods: A retrospective review of patients with unilateral MMD who underwent direct, indirect, or combined direct/indirect cerebral revascularization surgery was conducted between 2011 and 2020. Using NOVA, flow was measured at the anterior cerebral artery (ACA), ACA distal to the anterior communicating artery (A2), middle cerebral artery (MCA), posterior cerebral artery (PCA), and PCA distal to the posterior communicating artery (P2). Pial flow (A2 + P2) and collateral flow (ipsilateral [A2 + P2])-(contralateral [A2 + P2]) were measured and compared before and after revascularization surgery. Total hemispheric flow (MCA + A2 + P2) with the addition of the bypass graft flow postoperatively was likewise measured., Results: Thirty-four patients with unilateral MMD underwent cerebral revascularization. Median collateral flow significantly decreased from 68 to 39.5 mL/min ( P = .007) after bypass. Hemispheres with maintained measurable bypass signal on postoperative NOVA demonstrated significant reduction in median collateral flow after bypass ( P = .002). Median total hemispheric flow significantly increased from 227 mL/min to 247 mL/min ( P = .007) after bypass. Only one patient suffered an ipsilateral ischemic stroke, and no patients suffered a hemorrhage during follow-up., Conclusion: NOVA measurements demonstrate a reduction in pial collateral flow and an increase in total hemispheric flow after bypass for MMD, likely representing a decrease in leptomeningeal collateral stress on the distal ACA and PCA territories. Further studies with these measures in larger cohorts may elucidate a role for NOVA in predicting the risk of ischemic and hemorrhagic events in MMD., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Purpose: Carotid endarterectomy (CEA) is effective in treating carotid artery stenosis to prevent stroke. Historically, this operation has been performed utilizing loupe magnification with or without the operating microscope (OM). However, there remains a need for continued improvement in operative visualization and surgical ergonomics. Recently, newly developed digital 'exoscope' has provided the surgeon with unique lighting and magnification as well as improvements in surgical ergonomics and working angle. We sought to review our cumulative experience using a novel 4K high-definition (4K-HD) 3-dimensional (3D) exoscope (EX) for CEA surgery., Methods: All CEA surgery cases at our institution between 2013 and 2019 using the 4K-HD 3D EX were reviewed. Operative parameters, patient outcome and operator's assessment of the EX compared to OM-assisted cases was conducted., Results: 28 patients were treated, 10 of which were operated using the EX. All procedures were performed without perioperative complications, or significant differences in operative parameters (blood loss <20 cm 3 and 164 ± 49.5 minutes) compared to OM-assisted cases. Operators reported improved level of comfort performing 'high' bifurcation surgery and improved visualization and posture during inspection of the distal ICA lumen as primary advantages of EX-assisted CEA over OM-assisted CEA., Conclusions: The ORBEYE EX, albeit a learning curve necessitating a short period of the OR team, provided safety and outcome comparable to OM-assisted surgery. Potential advantages noted were improved visualization and ergonomics specifically for when extreme working angles were required. Our experience suggests that the exoscope may become a valuable alternative to standard magnification tools in CEA surgery.

Background: Brachiocephalic steal is a rare phenomenon that may lead to hemodynamic abnormalities in the ipsilateral vertebral and carotid arteries. Current treatment includes management of vascular risk factors, endovascular stenting, and surgical management depending on the severity of symptoms. Case Information: We describe a patient with multiple vascular risk factors who presented with mild neurological symptoms and chronic right arm weakness associated with concurrent brachiocephalic steal and right MCA M1 stenosis on neuroimaging. Use of right superficial temporal artery to middle cerebral artery bypass and aorta-right subclavian bypass resulted in improved flow to the right hemisphere on quantitative magnetic resonance angiography and single-photon emission computed tomography, significantly lowering the risk of catastrophic ischemic stroke. Conclusion: Complex steal phenomena increase stroke risk. In cases of high-grade occlusion or advanced symptoms, endovascular or surgical management should be considered for optimal stroke prevention., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: The efficacy of systemic therapies for glioblastoma (GBM) remains limited due to the constraints of systemic toxicity and blood-brain barrier (BBB) permeability. Temporoparietal fascial flaps (TPFFs) and vascularized peri cranial flaps (PCF) are not restricted by the blood-brain barrier (BBB), as they derive their vascular supply from branches of the external carotid artery. Transposition of a vascularized TPFF or PCF along a GBM resection cavity may bring autologous tissue not restricted by the BBB in close vicinity to the tumor bed microenvironment, permit ingrowth of vascular channels fed by the external circulation, and offer a mechanism of bypassing the BBB. In addition, circulating immune cells in the vascularized flap may have better access to tumor-associated antigens (TAA) within the tumor microenvironment. We conducted a first-in-human Phase I trial assessing the safety of lining the resection cavity with autologous TPFF/PCF of newly diagnosed patients with GBM., Methods: 12 patients underwent safe, maximal surgical resection of newly diagnosed GBMs, followed by lining of the resection cavity with a pedicled, autologous TPFF or PCF. Safety was assessed by monitoring adverse events. Secondary analysis of efficacy was examined as the proportion of patients experiencing progression-free disease (PFS) as indicated by response assessment in neuro-oncology (RANO) criteria and overall survival (OS). The study was powered to determine whether a Phase II study was warranted based on these early results. For this analysis, subjects who were alive and had not progressed as of the date of the last follow-up were considered censored and all living patients who were alive as of the date of last follow-up were considered censored for overall survival. For simplicity, we assumed that a 70% PFS rate at 6 months would be considered an encouraging response and would make an argument for further investigation of the procedure., Results: Median age of included patients was 57 years (range 46-69 years). All patients were Isocitrate dehydrogenase (IDH) wildtype. Average tumor volume was 56.6 cm 3 (range 14-145 cm 3 ). Resection was qualified as gross total resection (GTR) of all of the enhancing diseases in all patients. Grade III or above adverse events were encountered in 3 patients. No Grade IV or V serious adverse events occurred in the immediate post-operative period including seizure, infection, stroke, or tumor growing along the flap. Disease progression at the site of the original tumor was identified in only 4 (33%) patients (median 23 months, range 8-25 months), 3 of whom underwent re-operation. Histopathological analyses of those implanted flaps and tumor bed biopsy at repeat surgery demonstrated robust immune infiltrates within the transplanted flap. Importantly, no patient demonstrated evidence of tumor infiltration into the implanted flap. At the time of this manuscript preparation, only 4/12 (33%) of patients have died. Based on the statistical considerations above and including all 12 patients 10/12 (83.3%) had 6-month PFS. The median PFS was 9.10 months, and the OS was 17.6 months. 4/12 (33%) of patients have been alive for more than two years and our longest surviving patient currently is alive at 60 months., Conclusions: This pilot study suggests that insertion of pedicled autologous TPFF/PCF along a GBM resection cavity is safe and feasible. Based on the encouraging response rate in 6-month PFS and OS, larger phase II studies are warranted to assess and reproduce safety, feasibility, and efficacy. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION FOR PROSPECTIVELY REGISTERED TRIALS: ClinicalTrials.gov ID NCT03630289, dated: 08/02/2018., (© 2024. The Author(s).)

The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.

Introduction: Flow augmentation is the mainstay treatment for moyamoya disease as hemodynamic failure is believed to be the dominant mechanism. We aimed to investigate the mechanisms of stroke in moyamoya disease by assessing the relationship between infarction patterns and quantitative magnetic resonance angiography flow state., Methods: A retrospective study of adult patients with suspected MMD who presented with MRI confirmed acute ischemic stroke predating or following QMRA by a maximum of six months between 2009 and 2021 was conducted. Of the 177 consecutive patients with MMD who received QMRA, 35 patients, consisting of 41 hemispheres, met inclusion criteria. Flow-status was dichotomized into low-flow and normal-flow state based on previously established criteria., Results: Mixed infarction pattern was the most frequent finding (70.7 %), followed by embolic (17.1 %), perforator (7.3 %), and internal borderzone (IBZ) (4.9 %). Infarction patterns were further dichotomized into IBZ+ (internal borderzone alone or mixed) and IBZ- (no internal borderzone constituent). Low-flow states were not significantly more frequent in the IBZ+ compared to IBZ- population (48.4 % vs. 20.0 %, p = 0.14). Ipsilateral posterior cerebral artery fractional flow was significantly higher with IBZ+ compared to IBZ- (345.0 % vs. 214.7 %, p = 0.04)., Conclusion: Mixed infarction pattern was the most common pattern of infarction in patients with moyamoya disease, implying hypoperfusion and thromboembolism are codominant stroke mechanisms. An association between ICA flow status and infarction pattern was not found, although QMRA evidence of more robust posterior cerebral artery leptomeningeal collaterals was found in patients with a hypoperfusion contribution to their stroke mechanism., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest.., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Rarely, Pituitary adenomas (PA) can co-occur with intrasellar or intracavernous aneurysms. There is currently no clear guidance for the management of this dual pathology. We attempt to provide an algorithm to help guide clinical decision making for treatment of PAs co-occurring with adjacent cerebral aneurysms., Methods: A comprehensive literature search was conducted following PRISMA guidelines using various databases. Search terms included "(Pituitary Adenoma OR Prolactinoma OR Macroadenoma OR Adenoma) AND (ICA OR Internal Carotid Artery OR paracliniod OR clinoid) Aneurysm AND (Intra-cavernous OR intracavernous OR intrasellar OR Cavernous).", Results: A total of 24 studies with 24 patients were included. Twelve (50%) patients experienced visual symptoms. Ten patients (42%) had an aneurysm embedded within the adenoma. Fourteen patients (58%) had an aneurysm adjacent to the adenoma. Embedded aneurysms were significantly associated with rupture events., Conclusion: Vision loss is the most pressing determinant of treatment. In the absence of visual symptoms, the aneurysm should be treated first by coil embolization. If not amenable to coiling, place flow diverting stent followed by six months of anticoagulation and antiplatelet therapy. If visual loss is apparent, the adenoma-aneurysm spatial relationship becomes critical. In cases of an adjacent aneurysm, the adenoma should be removed transsphenoidally with extreme care and aneurysm rupture protocols in place. If the aneurysm is embedded within the adenoma, then a BTO is favored with permanent ICA occlusion followed by transsphenoidal resection if adequate collateral supply is demonstrated. If there is inadequate collateral supply, then an open-approach for amenable aneurysms with transcranial adenoma debulking should be performed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Intraoperative neurophysiological monitoring (IONM) is a technique used to assess the somatosensory and gross motor systems during surgery. While it is primarily used to detect and prevent surgically induced nervous system trauma, it can also detect and prevent injury to the nervous system that is the result of other causes such as trauma or ischemia that occur outside of the operative field as a result of malpositioning or other problematic physiologic states. We present a case study where a neuromonitoring alert altered the surgical procedure, though the alert was not correlated to the site of surgery. A 69-year-old male with a history of bilateral moyamoya disease and a left middle cerebral artery infarct underwent a right-sided STA-MCA bypass and encephaloduroarteriosynangiosis (EDAS) with multimodal IONM. During the procedure, the patient experienced a loss of motor evoked potential (MEP) recordings in the right lower extremity. Blood pressure was elevated, which temporarily restored the potentials, but they were lost again after the angiography team attempted to place an arterial line in the right femoral artery. The operation was truncated out of concern for left hemispheric ischemia, and it was later discovered that the patient had an acute right external iliac artery occlusion caused by a fresh thrombus in the common femoral artery causing complete paralysis of the limb. This case highlights the importance of heeding IONM alerts and evaluating for systemic causes if the alert is not thought to be of surgical etiology. IONM can detect adverse systemic neurological sequelae that is not necessarily surgically induced.

Objective: Direct cerebral revascularization is considered as one of the most technically challenging operations in neurosurgery. Technical errors are often not identified during the case, but only after the recirculation stage, making management crucial at that time of the procedure. In this study, the authors sought to describe troubleshooting of the technical errors encountered in initially failed bypass cases., Methods: A retrospective analysis describing a single-surgeon, single-institution experience between 2014 and 2021 was performed, based on operative reports and videos, including a 30-day follow-up period. Initially failed bypass was defined if the bypass was not patent or had a significant leak after recirculation, irrespective of the final result., Results: One hundred thirty-eight bypass cases were reviewed for complex aneurysms (n = 49), moyamoya disease (n = 59), and atherosclerosis (n = 30). Fifty-one initially failed anastomoses were identified; 43 of these were the result of a technical error. Etiologies of these failed anastomoses included a clot (n = 14), vessel kinking (n = 4), spasm (n = 5), suture-related cause (n = 5), inappropriate donor or recipient (n = 3), or lack of demand (n = 8). A major leak was attributed to an uncoagulated side branch (n = 4), vessel injury due to suture/clip placement (n = 1), or inadequate suture line coverage (n = 7). Thirty-seven (86%) of 43 cases were troubleshot successfully, as salvage maneuvers included papaverine vessel massage, donor repositioning, re-anastomosis for occlusion in select cases, local hemostatic agents, and suturing or coagulating side branches in a leak. Thirty-day follow-up revealed similar rates of patency between successfully troubleshot patients (35/37) and the rest of the cases (80/87, p = 0.6)., Conclusions: Three major patterns of a noncompatible bypass were found: a major leak, an acute occlusion, or a delayed occlusion. Based on the authors' experience, salvage strategies proved successful, showing an eventual high patency rate. The authors suggest a gradual, structured algorithm to address this stage in surgery that may contribute specifically to cerebrovascular neurosurgeons at the beginning of their careers.

Purpose: We systematically reviewed visual outcomes over the last three decades in patients undergoing treatment for base of skull (BOS) meningiomas and provide recommendations to preserve vision., Methods: In accordance with the PRISMA guidelines for systematic reviews, a search was conducted from 6/1/2022-9/1/2022 using PubMed and Web of Science. Inclusion criteria included (1) patients treated for BOS meningiomas (2) treatment modality specified (3) specifics of surgical techniques and/or dose/fractions of radiotherapy (4) individual patient outcomes of treatment. Each study was assessed for bias based on study design and heterogeneity of results., Results: A total of 50 studies were included (N = 2911). When comparing improved vision versus unchanged or worsened vision, studies investigating surgery alone published from 2006 and onward had significantly better visual outcomes compared to pre-2006 studies (p = 0.02). When comparing improved vision versus unchanged or worsened vision, studies investigating combined therapy with surgery and radiation published from 2008 and onward had significantly better visual outcomes compared to pre-2008 studies (p < 0.01). Combined modality therapy was less likely to worsen vision compared to either surgery or radiation monotherapy (p < 0.01). However, surgery and radiation monotherapy were more likely to actually improve outcomes compared to combination therapy (p < 0.01)., Conclusion: For over a decade we have observed improvement in visual outcomes in patients managed for meningioma of BOS, likely attributing the innovation in microsurgical and more targeted and conformal radiation techniques. Combination therapy may be the safest option for preventing worsening of vision, but the highest rates of improving visual function are achieved through monotherapy when indicated., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: The aim of this study was to describe the efficacy, clinical outcomes, and complications of open cerebrovascular surgery, endovascular surgery, and conservative management of dolichoectatic vertebrobasilar aneurysms (DVBAs)., Methods: Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane databases according to PRISMA guidelines. A meta-analysis was conducted for clinical presentation, treatment protocols, and clinical outcomes-good (improved or stable clinical status) or poor (deteriorated clinical status or death)-and mortality rates., Results: The 9 identified articles described 41 cases (27.5%) of open cerebrovascular surgery, 61 endovascular procedures (40.9%), and 47 cases (31.5%) of conservative management for DVBAs. The total cohort had a good outcome rate of 51.9% (95% CI 28.3%-74.6%), a poor outcome rate of 45.5% (95% CI 23.0%-70.1%), and a mortality rate of 22.3% (95% CI 11.8%-38.0%). The treatment groups had comparable good clinical outcome rates (open cerebrovascular surgery group: 24.7% [95% CI 2.9%-78.2%]; endovascular surgery group: 69.0% [95% CI 28.7%-92.5%]; conservative management group: 57.7% [95% CI 13.0%-92.5%]; p = 0.19) and poor outcome rates (open vascular surgery group: 75.3% [95% CI 21.8%-97.1%]; endovascular surgery group: 27.2% [95% CI 5.6%-0.70.2%]; conservative management group: 39.9% [95% CI 9.1%-81.6%]; p = 0.15). The treatment groups also had comparable mortality rates (open vascular surgery group: 39.5% [95% CI 11.4%-76.8%]; endovascular surgery group: 15.8% [95% CI 4.4%-43.0%]; conservative management group: 19.2% [95% CI 6.8%-43.5%]; p = 0.23)., Conclusions: The current study of DVBAs illustrated poor outcomes and high mortality rates regardless of the treatment modality. The subgroup analysis showed heterogeneity among the subgroups and advice for personalized management.

Purpose: Iatrogenic neurologic deficits adversely affect patient outcomes following brain tumor resection. Motor evoked potential (MEP) monitoring allows surgeons to assess the integrity of motor-eloquent areas in real-time during tumor resection to lessen the risk of iatrogenic insult. We retrospectively associate intraoperative transcranial and direct cortical MEPs (TC-MEPs, DC-MEPs) to early and late post-operative motor function to prognosticate short- and long-term motor recovery in brain tumor patients undergoing surgical resection in peri-eloquent regions., Methods: We reviewed 121 brain tumor patients undergoing craniotomies with DC-MEP and/or TC-MEP monitoring. Motor function scores were recorded at multiple time-points up to 1 year postoperatively. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated at each time point., Results: The sensitivity, specificity, PPV, and NPV of TC-MEP in the immediate postoperative period was 17.5%, 100%, 100%, and 69.4%, respectively. For DC-MEP monitoring, the respective values were 25.0%, 100%, 100%, and 68.8%. By discharge, sensitivity had increased for both TC-MEP and DC MEPs to 43.8%, and 50.0% respectively. Subset analysis on patients without tumor recurrence/progression at long term follow-up (n = 62 pts, 51.2%) found that all patients with stable monitoring maintained or improved from preoperative status. One patient with transient intraoperative TC-MEP loss and permanent DC-MEP loss suffered a permanent deficit., Conclusion: Brain tumor patients who undergo surgery with intact MEP monitoring and experience new postoperative deficits likely suffer transient deficits that will improve over the postoperative course in the absence of disease progression., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Webinars offer novel educational opportunities beyond those of traditional, in-person experiences. BRAINterns is an open-access webinar-based education platform created to replace opportunities lost during the coronavirus disease 2019 pandemic. This program previously showed the efficacy of webinars to expand access to careers in medicine, and in particular, neurosurgery. BRAINterns 2.0 was established to assess the durability of Web-based learning., Methods: A modified 4-week webinar series was held during July 2021. A retrospective exit survey was distributed to participants and responses analyzed., Results: A total of 16,045 people registered for BRAINterns 2.0, representing 103 countries. Survey responses were received from 3765 participants (23% response rate). New, first-time registrants comprised 66% of participants, with the rest being returning participants. A total of 342 students participated in a dedicated module delivered entirely in Spanish. Females represented 81% of respondents. Participants identified that desirable elements of the program were opportunities to hear from women (53%) and people of color (44%) in health care. Participants heard about the series through TikTok (n = 1251; 33%), Instagram (n = 1109; 29%), Facebook (n = 637; 17%), and word of mouth (n = 708; 19%) with assistance from an ambassador program., Conclusions: Webinar-based education programs continue to be of interest to students in an increasingly digital world. Social media, and specifically the use of educational ambassadors, are effective to improve visibility of educational programs across a diverse population of students. Understanding the desires of participants is critical to building a successful online education platform., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background Moyamoya disease is characterized by progressive nonatherosclerotic stenosis and eventual occlusion of the supraclinoid cerebral arteries with the associated development of abnormal collateral vessels. Treatment of moyamoya disease revolves around restoring cerebral blood flow (CBF) distal to the steno-occlusive disease. Numerous modalities can be used to assess hemodynamic parameters. We sought to determine the impact of preoperative imaging on surgical decision-making. Methods A retrospective review was performed of all patients seen with the diagnosis of moyamoya. Patients were grouped on presentation based on CT/MRI findings of infarction, hemorrhage, or normal. Patients who did not have all of the preoperative tests were excluded. Preoperative radiological results were dichotomized as either normal or abnormal. Results During a five-year period, 34 patients with moyamoya met the inclusion criteria. All patients had an abnormal magnetic resonance angiography (MRA) Non-invasive Optimal Vessel Analysis (NOVA; VasSol, Inc, River Forest, IL). Three patients had normal initial MRI. All symptomatic patients had abnormal preoperative workup and underwent revascularization, as all were found to have abnormal single photon emission computed tomography (SPECT). The only occasion where the decision for surgery or type of surgery was influenced by imaging findings was in patients with nonclassical or minimal symptoms. Conclusion Although hemodynamic imaging studies can aid in establishing a preoperative baseline of CBF and cerebral vascular reserve (CVR) for follow-up studies, the true implication of these tests in the preoperative evaluation of clearly symptomatic moyamoya patients is debatable. In asymptomatic/mildly symptomatic patients, hemodynamic studies are necessary to determine the need for treatment. For symptomatic patients, surgery can be performed without an exhaustive and costly preoperative hemodynamic evaluation., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, White et al.)

The exoscope is the technological successor to the operating microscope in cerebrovascular neurosurgery. It offers advantages including improved operative field magnification, resolution, lighting, ergonomics, team cohesiveness, and microsurgical training However, these advantages of using the exoscope must be weighed against the learning curve during its adoption, especially for senior microneurosurgeons. As exoscope technology is refined, seamless integration of robotics, automation, augmented reality, and hands-free real-time neuronavigation is anticipated., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: TikTok is a social media platform that has gained popularity and become a powerful engine to disseminate public health and medical information. To date, no study has characterized the qualities of popular TikTok videos related to neurosurgery, or assessed biases in the content of these videos., Methods: The TikTok web browser application was queried using "#neurosurgery" to identify neurosurgery-related videos. The top 100 videos meeting inclusion criteria were analyzed and video characteristics determined. Bias was assessed by the DISCERN scoring system using 3 independent reviewers. A Kruskal-Wallis H test was used to correlate video popularity with video characteristics and to correlate bias with creator and video type., Results: The 100 videos evaluated totaled 8.8 million likes, 104,718 comments, and 100,856 shares. The oldest video was posted February 2020 and the most recent March 2022. Videos were most commonly entertaining ( n  = 64, 64%), and educational ( n  = 46, 46%). Video popularity was associated with videos that aimed to entertain, and least associated with videos depicting neurosurgery lifestyle. Low DISCERN scores, indicating more biased content, were seen across the neurosurgical content with the entertaining video category demonstrating the highest bias., Conclusions: Neurosurgical content on TikTok contains a high degree of bias across all creator and video types. Entertaining videos are associated with the highest numbers of likes but also the greatest bias. These data may be used to guide institutions and neurosurgeons to grow interest in the field of neurosurgery and disseminate unbiased information while expanding their social media presence., (© 2022 The Author(s).)

Objective: Stimulated Raman histology (SRH) offers efficient and accurate intraoperative neuropathological tissue analysis without procedural alteration to the diagnostic specimen. However, there are limited data demonstrating one-to-one tissue comparisons between SRH and traditional frozen sectioning. This study explores the non-inferiority of SRH as compared to frozen section on the same piece of tissue in neurosurgical patients., Methods: Tissue was collected over a 1-month period from 18 patients who underwent resection of central nervous system lesions. SRH and frozen section analyses were compared for diagnostic capabilities as well as assessed for quality and condition of tissue via a survey completed by pathologists., Results: SRH was sufficient for diagnosis in 78% of specimens as compared to 94% of specimens by frozen section of the same specimen. A Fisher's exact test determined there was no significant difference in diagnostic capability between the two groups. Additionally, both quality of SRH and condition of tissue after SRH were deemed to be non-inferior to frozen section., Conclusions: This study provides further evidence for the non-inferiority of SRH techniques. It is also the first study to demonstrate SRH accuracy using one-to-one tissue analysis in neuropathological specimens., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Enhanced Recovery After Surgery (ERAS) protocols describe a standardized method of preoperative, perioperative, and postoperative care to enhance outcomes and minimize complication risks surrounding elective surgical intervention. A growing body of evidence is being generated as we learn to apply principles of ERAS standardization to neurosurgical patients. First applied in spinal surgery, ERAS protocols have been extended to cranial neuro-oncologic procedures. This review synthesizes recent findings to generate evidence-based guidelines to manage neurosurgical oncology patients with standardized systems and assess ability of these systems to coordinate multidisciplinary, patient-centric care efforts. Furthermore, we highlight the potential usefulness of multimedia, app-based communication platforms to facilitate patient education, autonomy, and team communication within each of the 3 settings., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Glioblastoma multiforme (GBM) patients continue to suffer a poor prognosis. The blood brain barrier (BBB) comprises one of the obstacles for therapy, creating a barrier that decreases the bioavailability of chemotherapeutic agents in the central nervous system. Previously, a vascularized temporoparietal fascial scalp flap (TPFF) lining the resection cavity was introduced in a trial conducted in our institution, in newly-diagnosed GBM patients in an attempt to bypass the BBB after initial resection. In this paper, we report on a new technique to bypass the BBB after re-resection and potentially to allow tumor antigens to be surveilled by the immune system. The study aims to assess the feasibility of performing a cranial transposition and revascularization of autologous omentum after re-resection of GBM. Laparoscopically harvested omental free flap was transposed to the resection cavity by a team consisting of neurosurgeons, otolaryngologists, and general surgeons. This was done as part of a single center, single arm, open-label, phase I study. Autologous abdominal omental tissue was harvested laparoscopically on its vascularized pedicle in 2 patients, transposed as a free flap, revascularized using external carotid artery, and carefully laid into the tumor resection cavity. Patients did well postoperatively returning to baseline activities. Graft viability was confirmed by cerebral angiogram. Omental cranial transposition of a laparoscopically harvested, vascularized flap, into the cavity of re-resected GBM patients is feasible and safe in the short term. Further studies are needed to ascertain whether such technique can improve progression free survival and overall survival in these patients., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: There has been a paradigm shift in the management of hypothalamic hamartoma (HH) from traditional microsurgical techniques to less invasive alternatives. However, large and extensive HH may fail to respond to these therapies, necessitating craniotomies., Methods: All patients who underwent microsurgical resection of a complex HH by the 2 senior authors from 2011 to 2021 were included. Charts were retrospectively reviewed and demographic, clinical, imaging, and outcome data were recorded., Results: Eight patients (mean age, 7 years) were included. Two had failed previous treatments. All 7 presented with gelastic seizures and cognitive dysfunction, 6 showed central precocious puberty, and 3 had behavioral problems. The mean lesion size was 21.6 mm and all had interpeduncular extension, 5 had intraventricular extension (Delalande type I, 3; type III, 4; type IV, 1). A frontotemporal orbitozygomatic approach with optic nerve decompression was used in all patients, supplemented by another approach in 3 (endoscopic transventricular, 3; transcallosal, 1). Gross total resection was achieved in 6 patients and subtotal resection in 2. Transient complications occurred in 3 patients (37.5%): self-limited sodium imbalance (n = 3), subdural hygroma (n = 2). Permanent complications occurred in 2 patients (25%): perforator infarct (n = 1) and short-term memory loss (n = 1). All patients experienced seizure resolution with preserved hypothalamic-pituitary axis function. After a mean follow-up of 41 months (range, 2-66 months), 7 patients remained seizure free, and 1 had rare seizures. Cognitive and behavioral symptoms improved in all patients., Conclusions: For large HH with interpeduncular extension, microsurgery via the frontotemporal orbitozygomatic approach is a safe and highly effective treatment modality., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Pre-clinical evidence suggests bevacizumab (BV) depletes the GBM peri-vascular cancer-stem cell niche. This phase I/II study assesses the safety and efficacy of repeated doses of superselective intra-arterial cerebral infusion (SIACI) of BV after blood-brain barrier disruption (BBBD)., Methods: Date of surgery was day 0. Evaluated patients received repeated SIACI bevacizumab (15 mg/kg) with BBBD at days 30 ± 7, 120 ± 7, and 210 ± 7 along with 6 weeks of standard chemoradiation. Response assessment in neuro-oncology criteria and the Kaplan-Meier product-limit method was used to evaluate progression free and overall survival (PFS and OS, respectively)., Results: Twenty-three patients with a median age of 60.5 years (SD = 12.6; 24.7-78.3) were included. Isocitrate dehydrogenase mutation was found in 1/23 (4%) patients. MGMT status was available for 11/23 patients (7 unmethylated; 3 methylated; 1 inconclusive). Median tumor volume was 24.0 cm3 (SD = 31.1, 1.7-48.3 cm 3 ). Median PFS was 11.5 months (95% CI 7.7-25.9) with 6, 12, 24 and 60 month PFS estimated to be 91.3% (95% CI 69.5-97.8), 47.4% (26.3-65.9), 32.5% (14.4-52.2) and 5.4% (0.4-21.8), respectively. Median OS was 23.1 months (95% CI 12.2-36.9) with 12, 24, and 36 month OS as 77.3% (95% CI 53.6-89.9), 45.0% (22.3-65.3) and 32.1% (12.5-53.8), respectively., Conclusions: Repeated dosing of IA BV after BBBD offers an encouraging outcome in terms of PFS and OS. Phase III trials are warranted to determine whether repeated IA BV combined with Stupp protocol is superior to Stupp protocol alone for newly diagnosed GBM., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Chronic subdural hematoma (cSDH) is a common pathology that typically affects the elderly. It is believed to occur due to injury to the dural border cells, which creates an inflammation/proliferation reaction. Ineffective repair leads to the formation of a new external layer of cells and fragile capillaries, which damage easily and can worsen the condition. Conventionally, asymptomatic cSDH is managed by observation, and symptomatic cases are treated by surgical evacuation. Unfortunately, recurrence rates of the SDH following surgical evacuation can be high. One treatment option for SDH involves embolization of the middle meningeal artery (MMA). The MMA provides blood supply to the dura mater and feeds the membrane capillaries covering the SDH. MMA embolization blocks the blood flow to this system and can promote hematoma resolution. In this paper, we review the existing literature on MMA embolization and discuss the underlying pathophysiology of cSDH., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Désir et al.)

Background: Attainment of micro-neurosurgical skills is a challenge in teaching hospitals throughout training. Models that mimic the workflow as well as haptics are time-consuming, expensive, and unsuitable to serve as a routine platform. Our objective was to present a model and a set of tasks, based on a hard-boiled egg, microscope, and a Cavitron ultrasonic aspirator (CUSA; Integra Lifesciences Corp., Tullamore, Ireland), which is cheap, easy to setup and can be used for training microsurgery and CUSA skills, required for removal of deep-seated tumors., Methods: The goal was to remove the egg yolk from within a hard-boiled egg, representing an intrinsic brain tumor, surrounded by the egg's white, representing adjacent brain tissue, while preserving it. Assessment was based on the yolk's exposure, completeness of removal, and collateral damage and task completion duration, with repeated trials (n = 4), for validation purposes, for 6 operators with different experience levels., Results: Improvement in overall score (mean of 47.5 ± 19 in the first trial vs. 80.0 ± 12 in the fourth trial, P < 0.01), and task duration completion (mean initial duration of 21:25 ± 4:52 minutes to 15:30 ± 5:17 minutes, P < 0.01) was observed. Parameters gradually improved on repeated attempts, and experience level of the operators correlated with scores., Conclusions: The egg model is an easy-to-handle, cheap model that enables the acquisition of basic micro-neurosurgical skills and basic workflow required for removing of intrinsic brain tumors. This study has validated and defined reproducible tasks that can be scored, correlated with performance. This model can be incorporated into a resident's routine and potentially provide an accessible training platform for neurosurgical trainees., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To replace educational opportunities lost during the coronavirus disease 2019 (COVID-19) pandemic, the Department of Neurosurgery at Lenox Hill Hospital produced an open-access webinar series ("BRAINterns") that covered a broad range of health care topics with a focus on neurosurgery., Methods: This 8-week webinar series ran from July 1 to August 28, 2020. An optional exit survey was distributed to participants. Data were analyzed to characterize and better understand trends among a global cohort of participants., Results: A total of 16,484 people registered for BRAINterns, and 6675 took the survey (40.5% response rate). Responders represented 87 countries, of which the majority were from the United States and Canada (90.48%, n = 6039). Responders were primarily female (82.9%, n = 5521). Racial and ethnic representation was majority Asian (42%, n = 2798), followed by White (22.7%, n = 1514), Hispanic/Latino (16.2%, n = 1080), and Black and African American (7.7%, n = 516). Participants reported hearing about BRAINterns through various social media platforms (72.18%, n = 4818)-the most popular was TikTok (33.4%, n = 2232). Overall, 93.4% of participants reported that the course was a good use of their time during the pandemic, and 86.7% reported that the course helped replace lost opportunities., Conclusions: These data demonstrate that webinar-based education is an effective method of expanding access to careers in medicine and in particular, neurosurgery, to traditionally underrepresented populations. Social media can be a powerful tool to combat barriers to early exposure and vastly improve diversity within the field., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: In the post-Carotid Occlusion Surgery Study (COSS) era, multiple reviews suggested subset groups of patients as potential candidates for superficial temporal artery to middle cerebral artery (STA-MCA) bypass. Among them are patients with recurrent strokes despite optimal medical therapy. There is a paucity of data on the outcome of bypass in these specific patients., Objective: To examine the safety and efficacy of direct STA-MCA bypass in patients with nonmoyamoya, symptomatic steno-occlusive disease with impaired distal perfusion, who failed optimal medical management or endovascular treatment., Methods: A retrospective review was performed to identify patients with cerebrovascular steno-occlusive disease who underwent bypass after symptomatic recurrent or rapidly progressive strokes, despite optimal conservative or endovascular treatment., Results: A total of 8 patients (mean age 60 ± 6 yr) underwent direct or combined direct/indirect STA-MCA bypass between 2016 and 2019. All anastomoses were patent. One bypass carried slow flow. There were no procedure-related permanent deficits. One patient developed seizures which were controlled by medications. A total of 7 out of 8 patients were stable or improved clinically at last follow-up (mean 27.3 ± 13.8 mo) without recurrent strokes. One patient did not recover from their presenting stroke, experienced severe bilateral strokes 4 mo postoperatively, and subsequently expired. Modified Rankin Scale (mRS) improved in 6 patients (75%), remained stable in 1 patient (12.5%), and deteriorated in 1 (12.5%). Good long-term functional outcome was achieved in 5 patients (63%, mRS ≤ 2)., Conclusion: Patients with symptomatic, hypoperfused steno-occlusive disease who fail optimal medical or endovascular treatment may benefit from cerebral revascularization. Direct or combined STA-MCA bypass was safe and provided favorable outcomes in this small series., (© Congress of Neurological Surgeons 2021.)

Background: Tranexamic acid (TA) administration in aneurysmal subarachnoid hemorrhage (SAH) within the first 24 hours may reduce the incidence of early aneurysmal rebleeding. However, this is also the potential for an increased risk of delayed cerebral ischemia if TA is administered for more than 72 hours following the initial aneurysmal rupture., Methods: In the ultra-early tranexamic acid after subarachnoid hemorrhage randomized controlled trial by Post et al ., patients were randomized to receive TA within the first 24 hours, or until start of aneurysm treatment. These results were compared to a matched control group., Results: Ultra-early administration (≤24 h) of TA reduced the incidence of rebleeding, and did not alter the incidence of delayed cerebral ischemia and/or extracranial thrombosis. Further, no significant differences were noted between the TA group and control arm in the incidence of good (modified Rankin scores 0-3) clinical outcomes at 6 months., Conclusion: Ultra-early administration of TA (≤24 h) resulted in a lower rate of recurrent hemorrhage, without increasing the incidence of delayed cerebral ischemia in SAH patients., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Surgical Neurology International.)

Background:  Well-designed studies assessing the treatment outcome of brain arteriovenous malformations (AVMs) are infrequent and have not consistently included all of the available treatment modalities, making their results not completely generalizable. Moreover, the predictors of poor outcome are not well defined., Methods:  We performed an observational retrospective study of AVM patients. We included patients with clinical, radiologic, and outcome data, with a minimum follow-up of 1 year. Neurologic outcome was documented using the modified Rankin Scale (mRS) at the AVM diagnosis and 30 days after the treatment., Results:  There were 117 patients, with equal male/female proportion. The mean follow-up time was 51 months. Treatment distribution in the Spetzler-Martin grades I-III was as follows: 52 (54.6%) surgery, 31 (32.35%) radiosurgery, 2 (0.02%) embolization, and 11 (12%) conservative follow-up. Treatment distribution in Spetzler-Martin grades IV and V was as follows: 4 (20%) surgery, 7 (35%) radiosurgery, and 10 (45%) conservative follow-up. Poor neurologic outcome (mRS ≥ 3) was significantly associated with poor clinical status at diagnosis (Glasgow Coma Scale [GCS] score< 14; odds ratio [OR]: 0.20; 95% confidence interval [CI]: 0.001-0.396; p  = 0.010). The rupture of the AVM was associated with poor neurologic outcome. The Lawton-Young Supplementary scale (LYSS) proved to be the most effective in predicting poor outcome. The existence of seizures, treatment-related complications, and conservative treatment was associated with the worsening of the mRS score, whereas the existence of hemorrhage was associated with the likelihood of disability., Conclusion:  Our results suggest that poor neurologic status at diagnosis, AVM rupture, and conservative treatment were associated with worse outcome. Hemorrhage as initial presentation is related to disability, not with mRS worsening. The LYSS appeared to be the best method to predict outcome., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Attainment of basic microsurgical skills in neurosurgery presents a departmental challenge worldwide. Models for teaching are either not readily available or expensive and are incompatible with a resident's busy schedule, requiring lengthy and proper setup. We present a model and a set of measurable tasks, based on a fruit (orange) that is cheap, easy to set up instantly when desired, and useful for training of basic microsurgical skills., Methods: Basic microsurgical skills were identified, necessitating hand-eye coordination working with the microscope. The goal was to dissect an orange segment while preserving adjacent segments. Assessment was based on the number of side tears and task completion duration. The task was repeated in a sequential manner (n = 10), for validation purposes, for 3 operators at different seniority levels., Results: An improvement in the number of side tears (mean of 12.66 ± 9.01 in the first trial vs. 4 ± 4.35 in the 10th trial, P < 0.01), as well as duration of time required for task completion (mean initial duration of 28:16 ± 19:00 minutes to a duration of 16:33 ± 10:50 minutes in the last attempt, P < 0.01), was observed. Daily practice scores and time gradually improved, and the seniority level of operators was correlated with scoring between individuals., Conclusions: The orange model is an easily accessible, cheap model that enables the acquisition of basic microneurosurgical skills. In this work, we validated and defined reproducible tasks that can be scored and tracked, correlated with operator's proficiency and experience. This model can be incorporated into a resident's workflow environment and provides a platform for attainment of elementary microsurgical skills for neurosurgical residents., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The internal carotid artery (ICA) may inhibit visualization of a basilar tip aneurysm during an orbitozygomatic craniotomy. Retraction of the ICA may be warranted for better visualization; however, it may lead to impending neurological sequelae. Impending neurological injury due to ICA retraction may be mitigated if multi-modal neuromonitoring techniques are employed. The authors present a case report showing the contemporaneous loss of transcranial motor evoked potentials and direct cortical motor evoked potentials during an exoscopic clipping of a basilar tip aneurysm due to ICA retraction and subsequent loss of perfusion to the vascular territory supplied by ICA. The motor evoked potentials immediately returned after retraction was removed and the patient awoke neurologically intact.

Background: The coronavirus disease 2019 (COVID-19) pandemic has infected more than 13 million people on a global scale and claimed more than half million deaths across 213 countries and territories. While the focus is currently on recovery from the pandemic, the disease has significantly changed the way we practice medicine and neurosurgery in New York City and the United States. Apart from the emergency cases, several health systems across the country have similarly started to perform elective surgeries. Although COVID-19 screening and testing guidelines have been proposed and adopted by many hospitals, these may not adequately protect the operating room personnel who are in proximity to the patient for prolonged periods. There are concerning reports of especially high transmission rates of COVID-19 in transmucosal head and neck procedures conducted by otolaryngologists and neurosurgeons, despite attempts at wearing what constitutes appropriate personal protective equipment., Methods: Here, we describe a simple technique of additional draping that can be used for all cranial, endonasal, spinal, and neurointerventional cases to limit the transmission of coronavirus., Results: The proposed technique offers a simple, commonly available, cost-effective alternative that avoids the use of additional retractor systems. Moreover, this technique can be used in all neurosurgical procedures., Conclusions: With the rising concerns regarding airborne spread of the virus, we expect that these precautions will prove highly useful as we enter the recovery phase of this pandemic and hospitals attempt to prevent a return to widespread infection. In addition, its availability and cost effectiveness make this technique especially attractive to practical use in centers with limited resources., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Both conventional bypass utilizing temporary recipient vessel occlusion and the excimer laser-assisted nonocclusive anastomosis (ELANA) bypass technique are possible strategies in the treatment of giant aneurysms. These treatments have only been studied in single institutional retrospective studies. The potential advantage of the ELANA technique is the absence of temporary occlusion of major arteries, decreasing the risk of intraoperative ischemia., Objective: To investigate the risks and potential benefits of high-flow bypass surgery for giant and complex aneurysms of the anterior cerebral circulation. In addition, the effectiveness of the ELANA bypass procedure in the treatment of these aneurysms is determined., Methods: A total of 37 patients were included in 8 vascular neurosurgical centers in the United States, Canada, and Europe. A 30-d postoperative bypass follow-up was studied by using digital subtraction angiography and/or magnetic resonance angiography and computed tomography angiography to assess patency as well as by clinical monitoring in all patients., Results: In 35 patients, an ELANA high-flow bypass was performed and the aneurysm treated. Four patients had remaining neurological deficits after 30 d caused by stroke (11.4%). These strokes were not related to the ELANA anastomosis device., Conclusion: This study does not prove that the ELANA technique has an advantage over conventional bypass techniques, but it appears to be an acceptable alternative to conventional transplanted high-flow bypass in this very-difficult-to-treat patient group, especially in select patients whom cannot be bypassed using conventional means in which temporary occlusion is considered to be not recommended., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Fusiform aneurysms remain challenging entities to treat, as maintenance of flow and prevention of branch occlusion are concerns. Use of endovascular stents may risk nearby branch occlusion. We present a 31-yr-old male with a prior subarachnoid hemorrhage from a left middle cerebral artery (MCA) M1 aneurysm. Informed consent for use of the operative video and information was obtained from the patient. Initially, open clipping was performed with noted residual because of risk of nearby branches. On angiography, a growing fusiform segment distal to the initial aneurysm was noted. The patient was referred to our institution for this finding, and a multidisciplinary team reviewed the case. Endovascular treatment was felt to be risky, as stenting could jail nearby MCA branches. Clipping would also risk occlusion because of scaring from previous hemorrhage. Sufficient flow would be needed, and because the ipsilateral superficial temporal artery was sacrificed in the initial craniotomy, the internal maxillary artery (IMAX) was chosen as the bypass source. A cerebrovascular neurosurgeon, skull base otolaryngologist, and vascular surgeon worked together to perform a left-side IMAX to MCA bypass using an anterior tibial artery graft under 3-dimensional exoscopic visualization. Specifically, a 9-0 nylon suture on a BV-130 needle along with straight and tying forceps were used along with heparinized saline. The bypass was noted to be of robust flow, and the patient did very well on postoperative follow-up. The utilization of an anterior tibial artery graft, IMAX exposure, and corresponding bypass provides educational value, as there are only a limited number of videos on this topic., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: The Coronavirus disease 2019 (COVID-19) outbreak has left a lasting mark on medicine globally., Methods: Here we outline the steps that the Lenox Hill Hospital/Northwell Health Neurosurgery Department-located within the epicenter of the pandemic in New York City-is currently taking to recover our neurosurgical efforts in the age of COVID-19., Results: We outline measurable milestones to identify the transition to the recovery period and hope these recommendations may serve as a framework for an effective path forward., Conclusions: We believe that recovery following the COVID-19 pandemic offers unique opportunities to disrupt and rebuild the historical patient and office experience as we evolve with modern medicine in a post-COVID-19 world., (Copyright © 2020 Elsevier Inc. All rights reserved.)