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OBJECTIVE Microsurgical training remains indispensable to master cerebrovascular bypass procedures, but simulation models for training that accurately replicate microanastomosis in narrow, deep-operating corridors are lacking. Seven simulation bypass scenarios were developed that included head models in various surgical positions with premade approaches, simulating the restrictions of the surgical corridors and hand positions for microvascular bypass training. This study describes these models and assesses their validity. METHODS Simulation models were created using 3D printing of the skull with a designed craniotomy. Brain and external soft tissues were cast using a silicone molding technique from the clay-sculptured prototypes. The 7 simulation scenarios included: 1) temporal craniotomy for a superficial temporal artery (STA)–middle cerebral artery (MCA) bypass using the M4 branch of the MCA; 2) pterional craniotomy and transsylvian approach for STA-M2 bypass; 3) bifrontal craniotomy and interhemispheric approach for side-to-side bypass using the A3 branches of the anterior cerebral artery; 4) far lateral craniotomy and transcerebellomedullary approach for a posterior inferior cerebellar artery (PICA)–PICA bypass or 5) PICA reanastomosis; 6) orbitozygomatic craniotomy and transsylvian-subtemporal approach for a posterior cerebral artery bypass; and 7) extended retrosigmoid craniotomy and transcerebellopontine approach for an occipital artery–anterior inferior cerebellar artery bypass. Experienced neurosurgeons evaluated each model by practicing the aforementioned bypasses on the models. Face and content validities were assessed using the bypass participant survey. RESULTS A workflow for model production was developed, and these models were used during microsurgical courses at 2 neurosurgical institutions. Each model is accompanied by a corresponding prototypical case and surgical video, creating a simulation scenario. Seven experienced cerebrovascular neurosurgeons practiced microvascular anastomoses on each of the models and completed surveys. They reported that actual anastomosis within a specific approach was well replicated by the models, and difficulty was comparable to that for real surgery, which confirms the face validity of the models. All experts stated that practice using these models may improve bypass technique, instrument handling, and surgical technique when applied to patients, confirming the content validity of the models. CONCLUSIONS The 7 bypasses simulation set includes novel models that effectively simulate surgical scenarios of a bypass within distinct deep anatomical corridors, as well as hand and operator positions. These models use artificial materials, are reusable, and can be implemented for personal training and during microsurgical courses.

Patient frailty is predictive of higher neurosurgical morbidity and mortality. However, existing frailty measures are hindered by lack of specificity to neurosurgery.To analyze the association between 3 risk stratification scores and outcomes for nationwide vestibular schwannoma (VS) resection admissions and develop a custom VS risk stratification score.We identified all VS resection admissions in the National Inpatient Sample (2002-2017). Three risk stratification scores were analyzed: modified Frailty Index-5, modified Frailty Index-11(mFI-11), and Charlson Comorbidity Index (CCI). Survey-weighted multivariate regression evaluated associations between frailty and inpatient outcomes, adjusting for patient demographics, hospital characteristics, and disease severity. Subsequently, we used k -fold cross validation and Akaike Information Criterion-based model selection to create a custom risk stratification score.We analyzed 32 465 VS resection admissions. High frailty, as identified by the mFI-11 (odds ratio [OR] = 1.27, P = .021) and CCI (OR = 1.72, P.001), predicted higher odds of perioperative complications. All 3 scores were also associated with lower routine discharge rates and elevated length of stay (LOS) and costs (all P.05). Our custom VS-5 score ( https://skullbaseresearch.shinyapps.io/vs-5_calculator/ ) featured 5 variables (age ≥60 years, hydrocephalus, preoperative cranial nerve palsies, diabetes mellitus, and hypertension) and was predictive of higher mortality (OR = 6.40, P = .001), decreased routine hospital discharge (OR = 0.28, P.001), and elevated complications (OR = 1.59, P.001), LOS (+48%, P.001), and costs (+23%, P = .001). The VS-5 outperformed the modified Frailty Index-5, mFI-11, and CCI in predicting routine discharge (all P.001), including in a pseudoprospective cohort (2018-2019) of 3885 admissions.Patient frailty predicted poorer inpatient outcomes after VS surgery. Our custom VS-5 score outperformed earlier risk stratification scores.

Giant pituitary adenomas (GPAs) comprise 5% to 15% of pituitary adenomas, but have higher rates of extrasellar invasion, subtotal resection, surgical morbidity, and recurrence. With the possible exception of giant prolactinomas, GPAs require surgical decompression. On review of 3 decades of case series encompassing 699 microsurgical transsphenoidal (MT), 1060 endoscopic endonasal trans-sphenoidal (EET), and 513 transcranial (TC) patients, gross total resection and recurrence rates were comparable across modalities, but the EET approach had lower perioperative mortality and superior restoration of visual function. Each approach has unique indications. Combined EET-TC approaches for minimizing residual tumor represent another area of study.

Item does not contain fulltext Patients with germline SDHD pathogenic variants (encoding succinate dehydrogenase subunit D; ie, paraganglioma 1 syndrome) are predominantly affected by head and neck paragangliomas, which, in almost 20% of patients, might coexist with paragangliomas arising from other locations (eg, adrenal medulla, para-aortic, cardiac or thoracic, and pelvic). Given the higher risk of tumour multifocality and bilaterality for phaeochromocytomas and paragangliomas (PPGLs) because of SDHD pathogenic variants than for their sporadic and other genotypic counterparts, the management of patients with SDHD PPGLs is clinically complex in terms of imaging, treatment, and management options. Furthermore, locally aggressive disease can be discovered at a young age or late in the disease course, which presents challenges in balancing surgical intervention with various medical and radiotherapeutic approaches. The axiom-first, do no harm-should always be considered and an initial period of observation (ie, watchful waiting) is often appropriate to characterise tumour behaviour in patients with these pathogenic variants. These patients should be referred to specialised high-volume medical centres. This consensus guideline aims to help physicians with the clinical decision-making process when caring for patients with SDHD PPGLs.

High grade glioma has a poor overall survival with profoundly negative effects on the patient's quality of life and their caregivers. In this study, we investigate the factors associated with receiving palliative care in patients diagnosed with Glioblastoma (GBM) and the association of receiving or not receiving palliative care with overall survival.The National Cancer Database was analyzed for patterns of care in patients ≥18-years-old who were diagnosed with histologically confirmed grade IV GBM between 2004 and 2017. All statistical analyses were conducted based on univariate and multivariate regression models.A total of 85,380 patients with the diagnosis of GBM were identified. Of the study population, 2,803(3.28%) patients received palliative therapy. On multivariate logistic regression analysis, age ≥70 Years (odds ratio[OR]=1.28, 95% Confidence Interval[CI]=1.04-1.58; p0.001), Medicare (OR=1.348, CI=1.13-1.61; p=0.001), tumor size ≥5 cm (OR=1.15, CI=1.01-1.31; p=0.036), tumor multifocality (OR=1.69, CI=1.47-1.96; p0.001), lobe overlapping tumor (OR=2.09, CI=1.13-3.86; p=0.018), Charlson-Deyo score0, receiving treatment at a non-academic/research program, and medium volume of cancers managed at the treatment facility (OR=1.19, CI=1.02-1.38; p=0.026) were independent risk factors associated with an increased chance of receiving palliative care. In contrast, a household income of ≥$40,227 and high volume of cancer managed at the treatment facility (OR=0.75, CI=0.58-0.96; p=0.02) were independent risk factors associated with decreased palliative care. Patients who received no palliative care had a 2-year overall survival rate longer than those who received palliative care (22% vs. 8.8%; p0.001). In patients receiving palliative care, those who received recommended treatment had a 2-year overall survival rate longer than those who declined part or whole recommended treatment (9.1% vs. 3.8%; p=0.009).In patients with high grade glioma, receiving palliative care is associated with decreased survival. When receiving palliative care, recommended treatment increases the number of patients who survive more than two years approximately threefold when compared to those declining part or whole treatment.

Carcinomas metastatic to the brain are common, however, metastatic disease to the hypothalamic- pituitary region is uncommon and account for less than 3.6% of all resected malignant pituitary tumors. Most metastatic disease in that region derives from a lung or breast primary, with both ductal and lobular carcinoma reported. We report what we believe is the first case of pleomorphic lobular carcinoma metastatic to the hypothalamus. This case is also reaffirms that late metastasis from breast cancer should be considered in the differential diagnosis. It is important for the clinician to consider the clinical history of breast cancer, even when remote, in the differential diagnosis.

We sought to investigate the association between diabetes mellitus and incidence of adverse outcomes in patients who underwent meningioma surgery.The 2012-2014 National Inpatient Sample database was used. Prolonged length of stay was indicated by values greater than the 90th percentile of the sample. The Fisher exact test and analysis of variance were used to compare demographics, hospital characteristics, comorbidity, and complications among race cohorts. Logistic regression was used to analyze the independent effect of diabetes on adverse outcomes.After selecting for patients with primary diagnosis of meningioma who underwent a resection procedure, 7745 individuals were identified and divided into diabetic (n = 1518) and nondiabetic (n = 6227) cohorts. Demographics, hospital characteristics, and comorbidities were significantly different among the 2 cohorts. Average length of stay was longer in diabetic patients (8.15 vs. 6.04 days, P0.001), and total charges were higher in diabetic patients ($139,462.66 vs. $123,250.71, P0.001). Multivariate regression indicated diabetic patients have higher odds of experiencing a complication (odds ratio [OR] 1.442, 95% confidence interval [CI] 1.255-1.656, P0.001) and in-hospital mortality (OR 1.672, 95% CI 1.034-2.705, P = 0.036) after meningioma surgery. Analysis of individual postoperative complications revealed that diabetic patients experienced increased odds of pulmonary (OR 1.501, 95% CI 1.209-1.864, P0.001), neurologic (OR 1.690, 95% CI 1.383-2.065, P0.001), and urinary/renal complications (OR 2.618, 95% CI 1.933-3.545, P0.001). In addition, diabetic patients were more likely to have a prolonged length of stay (OR 1.694, 95% CI 1.389-2.065, P0.001).Diabetes is an important factor associated with complications after meningioma surgery. Preventative measures must be taken to optimize postoperative outcomes in these patients.

Vestibular schwannomas (VS) are usually hypovascularized benign tumors. Large VS (Koos grade IV) with unusual vascular architecture are defined as hypervascular (HVVS); the excessive bleeding during microsurgery has a negative impact on results.Forty consecutive patients were operated on for HVVS (group A). A tendency to bleed and adherence of capsule to nervous structures were evaluated by reviewing intraoperative video records. The cisternal facial nerve (FN) position was reported. Microsurgical removal was classified as total, near-total, subtotal, or partial and the MIB-1 index was evaluated in all. FN results were classified according to the House-Brackmann scale.Results of Group A were compared with those of 45 patients operated on for large low-bleeding VS (group B). Mean tumor diameter was 3.81 cm in group A and 3.58 cm in group B; the mean age was 42.4 and 56.3 years, respectively. The mean American Society of Anesthesiologists Physical Status Scale class of group A was 1.67 versus 2.31 of group B (P0.01). Total or near-total resection was accomplished in 76.5% of group A versus 73.3% of group B. Tight capsule adhesion was observed in 67.5% of group A versus 57.8% of group B. Mean MIB-1 was 1.25% and 1.08%, respectively.FN anatomic preservation was possible in 84.6% of group A versus 95.5% of group B; 67.5% of group A had HB grade I or II FN outcome versus 93.3% of group B (Intraoperative video for classification of HVVS was used. Microsurgery of large HVVS was associated with higher (usually transient) complications and recurrence/regrowth rates and poorer FN outcome, especially in patients with tight capsule adhesion.

BackgroundLittle is known about the safety and efficacy of concurrent capecitabine and stereotactic radiotherapy in the setting of breast cancer brain metastases (BCBM).MethodsTwenty-three patients with BCBM underwent 31 stereotactic sessions to 90 lesions from 2005 to 2019 with receipt of capecitabine. The Kaplan-Meier method was used to calculate overall survival (OS), local control (LC), and distant intracranial control (DIC) from the date of stereotactic radiation. Imaging was independently reviewed by a neuro-radiologist.ResultsMedian follow-up from stereotactic radiation was 9.2 months. Receptor types of patients treated included triple negative (n = 7), hormone receptor (HR)+/HER2- (n = 7), HR+/HER2+ (n = 6), and HR−/HER2+ (n = 3). Fourteen patients had stage IV disease prior to BCBM diagnosis. The median number of brain metastases treated per patient was 3 (1 to 12). The median dose of stereotactic radiosurgery (SRS) was 21 Gy (range: 15–24 Gy) treated in a single fraction and for lesions treated with fractionated stereotactic radiation therapy (FSRT) 25 Gy (24–30 Gy) in a median of 5 fractions (range: 3–5). Of the 31 stereotactic sessions, 71% occurred within 1 month of capecitabine. No increased toxicity was noted in our series with no cases of radionecrosis. The 1-year OS, LC, and DIC were 46, 88, and 30%, respectively.ConclusionsIn our single institution experience, we demonstrate stereotactic radiation and capecitabine to be a safe treatment for patients with BCBM with adequate LC. Further study is needed to determine the potential synergy between stereotactic radiation and capecitabine in the management of BCBM.

Microvascular decompression is the surgery of choice for typical trigeminal neuralgia (TN) that fails conservative medical management. Visual loss after MVD is a rare complication that has not been reported. In this article, we present a patient who developed delayed visual loss and papilledema from transverse sinus stenosis resulting from bone wax compression after MVD for TN. While waxing the edges of a retrosigmoid craniotomy may seem mundane, meticulous care should be taken to ensure that there is no compression of the venous sinuses, as this could lead to intracranial hypertension.

We investigated the prognostic ability of tumor subtype for patients with breast cancer brain metastases (BCBM) treated with stereotactic radiation (SRT). This is a retrospective review of 181 patients who underwent SRT to 664 BCBM from 2004 to 2019. Patients were stratified by subtype: hormone receptor (HR)-positive, HER2-negative (HR+/HER2−), HR-positive, HER2-positive (HR+/HER2+), HR-negative, HER2-positive (HR−/HER2+), and triple negative (TN). The Kaplan–Meier method was used to calculate overall survival (OS), local control (LC), and distant intracranial control (DIC) from the date of SRT. Multivariate analysis (MVA) was conducted using the Cox proportional hazards model. Median follow up from SRT was 11.4 months. Of the 181 patients, 47 (26%) were HR+/HER2+, 30 (17%) were HR−/HER2+, 60 (33%) were HR+/HER2−, and 44 (24%) were TN. Of the 664 BCBMs, 534 (80%) received single fraction stereotactic radiosurgery (SRS) with a median dose of 21 Gy (range 12–24 Gy), and 130 (20%) received fractionated stereotactic radiation therapy (FSRT), with a median dose of 25 Gy (range 12.5–35 Gy) delivered in 3 to 5 fractions. One-year LC was 90%. Two-year DIC was 35%, 23%, 27%, and 16% (log rank, p = 0.0003) and 2-year OS was 54%, 47%, 24%, and 12% (log rank, p

Purpose: Breast cancer brain metastases (BCBM) diagnosis is increasing in frequency due to improved systemic control and imaging techniques. Differences have been noted in rates of central nervous system (CNS) relapse and biologic subtype. The modified breast graded prognostic assessment (breast-GPA) was initially validated in patients treated between 1996-2013 and considers biologic subtype. In this study, we characterize patients diagnosed with BCBM by subtype and validate the breast-GPA in a modern cohort of patients. Methods: All patients with BCBM treated at our institution with radiotherapy between 2016 and 2019 were identified. Characteristics of patients’ initial brain metastasis diagnosis were retrieved from the clinical chart and radiologic examinations. To test differences between cohorts, the Kruskal-Wallis and Pearson’s chi-square tests were used when appropriate. Overall survival (OS) was calculated from the date of brain metastasis diagnosis to the date of death using the Kaplan-Meier (KM) method, with the log-rank test used to examine differences between groups. Results: A total of 122 BCBM patients were identified. Breast cancer subtypes included hormone receptor (HR)+/HER2- (45%), triple negative (TN) (25%), HR-/HER2+ (16%), and HR+/HER2+ (14%). The first treatment for BCBM patients following diagnosis was whole brain radiation (51%), surgery followed by stereotactic radiation (28%), and stereotactic radiation (21%). The interval between breast cancer diagnosis and diagnosis of BCBM was longest for HR+/HER2- 4.5 years, followed by TN 2.8 years, HR+/HER2+ 2.3 years, HR-/HER2+ 1.9 years, p=0.003. The interval from systemic metastases to BCBM diagnosis trended towards the shortest for TN patients 6.6 months, p=0.15. A total of 34 patients (28%) were diagnosed with leptomeningeal disease (LMD) at initial brain metastases presentation. LMD was diagnosed most commonly at presentation in HR+/HER2- (36%) followed by , TN (26%), HR-/HER2+ (26%), and HR+/HER2+ (6%), p=0.06. No differences were noted based on receptor typessubtype and age, symptomatic intracranial disease, number of brain metastases, type of first intracranial treatment or concurrent systemic metastases at initial BCBM presentation, all p > 0.05. Twenty-four month KM OS rates following diagnosis of brain metastasis for breast-GPA 0-1, 1.5-2, 2.5-3, and 3.5-4 groups were 14%, 27%, 33%, and 86% (p=0.0005), respectively. Conclusions: In our institutional analysis, similarities were noted in the initial presentation of BCBM based on receptor typesubtype. Significant differences were noted in OS based on the modified breast-GPA. Further investigation is needed to determine which subtypes of asymptomatic breast cancer patients are at sufficient risk to warrant brain MRI screening. Citation Format: Yuki Kawahara, Matthew Fahey, Thrisha K Potluri, Matthew N Mills, Nicholas B Figura, Iman R Washington, Roberto Diaz, Timothy J Robinson, Hsiang-Hsuan M Yu, Arnold B Etame, James Liu, Michael A Vogelbaum, Brian J Czerniecki, Peter A Forsyth, Hatem H Soliman, Hyo S Han, Kamran A Ahmed. Characteristics of breast cancer brain metastases presentation by subtype and validation of the modified breast graded prognostic assessment [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-19.

Management of patients with pituitary lesions is complex given the delicate nature of the surrounding anatomy and complexity of underlying disease. The care of these patients ideally involves a multidisciplinary team composed of endocrinologists, neuroradiologists, otolaryngologists, neurosurgeons, critical care physicians, and anesthesiologists. The endoscopic endonasal approach to the skull base has revolutionized pituitary and anterior skull base surgery and has gained popularity worldwide. This article presents an overview of the diagnosis, work-up, and management of patients with pituitary lesions, with an emphasis on surgical, perioperative, and postoperative considerations.

Research productivity is a vital component to an academic neurosurgeon's career. We sought to evaluate gender differences in NIH funding among faculty in neurological surgery departments. NIH funding awarded to PIs of neurological surgery departments from 2014 to 2019 were obtained and analyzed for gender differences in funding trends, with attention to terminal degree and academic rank, as well as publication range in length of years and h-index. 79.4% of all NIH grants were awarded to male PIs, with the remaining 20.5% given to their female counterparts. Mean of the total NIH grants awarded to men was significantly higher at $1,796,684 (± Standard Error of Mean (SEM) $155,849, IQR: $1,759,250) compared to women at $1,151,968 (± SEM $137,914, IQR: $1,388,538) (P = 0.022). Mean NIH funding per grant for men was $365,760 (± SEM: $39,592, IQR: $189,692) and for women was $292,912 (± SEM: 28,239, IQR: $283,177). Differences in mean NIH funding per grant approached but did not reach statistical significance between men and women (P = 0.122). When stratified for academic rank, there was a significant difference in mean NIH funding per grant between men and women on the associate professor level (p 0.005), with women exceeding men in funding at this academic level, with other academic ranks remaining non-significant. Overall, male neurosurgeons receive significantly more total NIH grant funding than their female counterparts, except at the level of associate professor where women were found to surpass men.

Background: The type of sellar barrier observed between a pituitary tumor and cerebrospinal fluid (CSF) on preoperative magnetic resonance imaging (MRI) may predict intraoperative CSF leak during endonasal pituitary surgery. This is the first multicentric prospective cohort trial to study the sellar barrier concept and CSF leak rate during endoscopic pituitary surgery. Methods: This multi-center, international study enrolled patients operated for pituitary adenomas via fully endoscopic endonasal surgery over a period of 4 months. The independent variable was the subtype of sellar barrier observed on preoperative MRI (strong, mixed or weak); the dependent variable was the presence of an intraoperative CSF leak. The primary goal was to determine the association between a particular type of sellar barrier and the risk of intraoperative CSF leak. Appropriate statistical methods were then applied for data analysis. Results: Over the study period, 310 patients underwent endoscopic endonasal surgery for pituitary tumor. Preoperative imaging revealed a weak sellar barrier in 73 (23.55%), a mixed sellar barrier in 75 (24.19%), and a strong sellar barrier in 162 (52.26%) patients. The overall rate of intraoperative CSF leak among all patients was 69 (22.26%). A strong sellar-type barrier was associated with significantly reduced rate of intraoperative CSF leak (RR = 0.08; 95% CI 0.03–0.19; p < 0.0001), while a weak sellar barrier associated with higher rates of CSF leak (RR = 8.54; 95% CI 5.4–13.5; p < 0.0001). Conclusions: The preoperative MRI of pituitary patients can suggest intraoperative CSF leak rates, utilizing the concept of the sellar barrier. Patients with a weak sellar barrier carry a higher risk for an intraoperative CSF leak, whereas a strong sellar barrier on MRI seems to mitigate intraoperative CSF leak. We propose that preoperatively assessment of the sellar barrier can prepare surgeons for intraoperative CSF leak repair.

Background Spinal subdural hematomas (SDHs) have been reported secondary to direct trauma or iatrogenic causes associated with coagulopathies. Spinal SDHs found after the development of acute intracranial SDHs, without any evidence of trauma to the spine, are extremely rare. In addition to this rare presentation, there is a lack of consensus regarding whether surgical decompression is the ideal treatment strategy. Depending on the extent of SDH within the spinal canal, surgical decompression may be difficult where diffuse hematoma within the intradural space requires multilevel decompression for treatment. Case Description A 46-year-old man initially presented with an acute cranial SDH following isolated head trauma. After a period of full recovery, he developed delayed lower extremity paraparesis secondary to the formation of a thoracolumbar SDH. This hematoma coincided with resolution of the cranial SDH and likely was due to redistribution of blood from the cranial subdural space into the spinal canal. Given the diffuse multilevel nature of the spread of hematoma and lack of a focal area of compression, he was managed conservatively. He demonstrated small signs of neurologic improvement over several days and regained considerable strength over the following several weeks. Conclusions This report demonstrates a very rare occurrence of a traumatic intracranial SDH migrating into the thoracic and lumbar spine. This case also highlights that despite acute neurologic deficits, conservative management may be a feasible strategy that can result in recovery of neurologic function.

Background A novel viral strain known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has created a worldwide pandemic known as coronavirus 2019 (COVID-19). Early reports from China have highlighted the risks associated with performing endoscopic endonasal skull base surgery in patients with SARS-CoV-2. We present a rare complication of nasoseptal flap (NSF) necrosis associated with COVID-19, further emphasizing the challenges of performing these procedures in this era. Case Description A 78-year-old man underwent an extended endoscopic endonasal transplanum resection of a pituitary macroadenoma for decompression of the optic chiasm. The resulting skull base defect was repaired using a pedicled NSF. The patient developed meningitis and cerebrospinal fluid (CSF) leak on postoperative day 13, requiring revision repair of the defect. Twelve days later, he developed persistent fever and rhinorrhea. The patient was reexplored endoscopically, and the NSF was noted to be necrotic and devitalized with evident CSF leakage. At that time, the patient tested positive for SARS-CoV-2. Postoperatively, he developed acute respiratory distress syndrome complicated by hypoxic respiratory failure and death. Conclusions To our knowledge, this is the first reported case of NSF necrosis in a patient with COVID-19. We postulate that the thrombotic complications of COVID-19 may have contributed to vascular pedicle thrombosis and NSF necrosis. Although the pathophysiology of SARS-CoV-2 and its effect on the nasal tissues is still being elucidated, this case highlights some challenges of performing endoscopic skull base surgery in the era of COVID-19.

Background The mainstay treatment for petrous apicitis (Gradenigo’s syndrome) is medical management with antibiotics, steroids, and placement of pressure equalization tubes. The role for surgery is limited as second-line treatment if conservative methods have failed. Case Description We report 2 cases of medically refractory petrous apicitis presenting with progressive cranial neuropathies who underwent petrous apex resection and debridement via an anterior petrosal (Kawase) approach. Both patients had improvement of their preoperative cranial nerve deficits within 24–48 hours of surgery, that previously did not improve after 2 weeks of medical management. Conclusions To our knowledge, the use of the Kawase approach for petrous apicitis has not been previously reported. In addition, we postulate that surgical intervention can potentially result in quicker recovery of preexisting cranial nerve deficits in medically refractory petrous apicitis. This raises the potential role of earlier surgical intervention.

OBJECTIVEThe transradial approach (TRA) has been widely adopted by interventional cardiologists but is only now being accepted by neurointerventionalists. The benefits of the TRA over the traditional transfemoral approach (TFA) include reduced risk of adverse clinical events and faster recovery. The authors assessed the safety and feasibility of the TRA for neurointerventional cases in the pediatric population.METHODSPediatric patients undergoing cerebrovascular interventions since implementation of the TRA at the authors’ institution were retrospectively reviewed. Pertinent patient information, procedure indications, vessels catheterized, fluoroscopy time, and complications were reviewed.RESULTSThere were 4 patients in this case series, and their ages ranged from 13 to 15 years. Each patient tolerated the procedure performed using the TRA without any postprocedural issues, and only 1 patient experienced radial artery spasm, which resolved with the administration of intraarterial verapamil. None of the patients required conversion to the TFA.CONCLUSIONSThe TRA can be considered a safe alternative to the TFA for neurointerventional procedures in the pediatric population and provides potential advantages. However, as pediatric patients require special consideration due to their smaller-caliber arteries, routine use of ultrasound guidance is advised when attempting the TRA.

OBJECTIVE Patient frailty is associated with poorer perioperative outcomes for several neurosurgical procedures. However, comparative accuracy between different frailty metrics for cerebral arteriovenous malformation (AVM) outcomes is poorly understood and existing frailty metrics studied in the literature are constrained by poor specificity to neurosurgery. This aim of this paper was to compare the predictive ability of 3 frailty scores for AVM microsurgical admissions and generate a custom risk stratification score. METHODS All adult AVM microsurgical admissions in the National (Nationwide) Inpatient Sample (2002–2017) were identified. Three frailty measures were analyzed: 5-factor modified frailty index (mFI-5; range 0–5), 11-factor modified frailty index (mFI-11; range 0–11), and Charlson Comorbidity Index (CCI) (range 0–29). Receiver operating characteristic curves were used to compare accuracy between metrics. The analyzed endpoints included in-hospital mortality, routine discharge, complications, length of stay (LOS), and hospitalization costs. Survey-weighted multivariate regression assessed frailty-outcome associations, adjusting for 13 confounders, including patient demographics, hospital characteristics, rupture status, hydrocephalus, epilepsy, and treatment modality. Subsequently, k-fold cross-validation and Akaike information criterion–based model selection were used to generate a custom 5-variable risk stratification score called the AVM-5. This score was validated in the main study population and a pseudoprospective cohort (2018–2019). RESULTS The authors analyzed 16,271 total AVM microsurgical admissions nationwide, with 21.0% being ruptured. The mFI-5, mFI-11, and CCI were all predictive of lower rates of routine discharge disposition, increased perioperative complications, and longer LOS (all p < 0.001). Their AVM-5 risk stratification score was calculated from 5 variables: age, hydrocephalus, paralysis, diabetes, and hypertension. The AVM-5 was predictive of decreased rates of routine hospital discharge (OR 0.26, p < 0.001) and increased perioperative complications (OR 2.42, p < 0.001), postoperative LOS (+49%, p < 0.001), total LOS (+47%, p < 0.001), and hospitalization costs (+22%, p < 0.001). This score outperformed age, mFI-5, mFI-11, and CCI for both ruptured and unruptured AVMs (area under the curve [AUC] 0.78, all p < 0.001). In a pseudoprospective cohort of 2005 admissions from 2018 to 2019, the AVM-5 remained significantly associated with all outcomes except for mortality and exhibited higher accuracy than all 3 earlier scores (AUC 0.79, all p < 0.001). CONCLUSIONS Patient frailty is predictive of poorer disposition and elevated complications, LOS, and costs for AVM microsurgical admissions. The authors’ custom AVM-5 risk score outperformed age, mFI-5, mFI-11, and CCI while using threefold less variables than the CCI. This score may complement existing AVM grading scales for optimization of surgical candidates and identification of patients at risk of postoperative medical and surgical morbidity.

OBJECTIVE Metastatic brain tumors (MBTs) are the most common type of malignant brain tumors. Due to the deviation of MBTs from the parental tumors, the effective therapies for primary tumors often are not useful in brain metastases. Even more new intracranial lesions were developed though the primary lesion was under control. The model of brain metastatic stem-like cells (BMSCs) could partially explain the progression of intracranial lesions. Here we aimed to explore the biological behavior in cell motility of BMSCs and understand the potential mechanisms. METHODS In vitro and in vivo phage display biopanning strategies were used to isolate dodecapeptides that specifically target BMICs by selecting against primary lung cancer cells and normal brain cells. In silico analysis was used to derive specific protein targets in BMICs. Potential targets were narrowed down through analysis in patient databases and verified for their presence in BMIC through RT-PCR. Cell migration and adhesion in BMICs were analyzed using Transwell, scratch, and adhesion assays. Protein expression and cell morphology were detected by immunofluorescence. Immune blot was performed to detect the epithelial-mesenchymal related molecules and explore protein-protein interactions. RESULTS In silico analysis of BMSCs specific peptides revealed Angiomotin (Amot) as a potential target in BMSCs. Amot was found to be overexpressed in BMSCs compared to primary lung cancer cells. Kaplan-Meier analysis demonstrated Amot was negatively correlated with overall survival among lung adenocarcinoma patients. Functionally, knockdown of AMOT in BMSCs decreased the capability of cell migration and adhesion by reduced active Cdc42/Rac1 signals caused by downregulation of E-Cadherin. Amot was found to maintain the E-Cadherin in BMSCs through reducing ubiquitination of E-Cadherin. CONCLUSIONS Amot plays a role in promoting migration and adhesion in BMSCs through preservation of E-cadherin.

BACKGROUND OS2966 is a first-in-class, humanized and deimmunized monoclonal antibody which antagonizes CD29/β1integrin, a mechanosignaling receptor prominently upregulated in glioblastoma. Preclinical studies in mice and non-human primates have demonstrated safety and encouraging efficacy. A two-part, ascending concentration, phase I clinical trial was therefore initiated to evaluate the safety and feasibility of delivering OS2966 directly to the site of disease via convection-enhanced delivery (CED) in recurrent high-grade glioma patients. METHODS This study has a 2-part design: In part 1, patients undergo stereotactic tumor biopsy followed by placement of a multiport CED catheter for delivery of OS2966 to the bulk contrast enhancing tumor. Subsequently, patients undergo a clinically-indicated tumor resection followed by placement of two CED catheters and delivery of OS2966 to the surrounding tumor-infiltrated brain. A unique concentration-based accelerated titration design is utilized for dose escalation. Given availability of pre and post infusion samples, pharmacodynamic data will be analyzed to explore mechanism of action of OS2966. RESULTS Two subjects have been treated at two corresponding dose levels (0.2mg/mL and 0.4 mg/mL). No dose-limiting toxicity or unexpected safety issues have been identified. To date, reported adverse events were mild (i.e., grade 1) and consistent with underlying disease and surgical procedures. No adverse events were attributed to OS2966 or CED catheter placement. Further, no clinically significant changes from baseline neurological exam have been noted for either patient through initial follow-up. Maximal tumor coverage and concomitant gross total resection were achieved for both patients. Tumor volume measured 1.63 cm3 and 16 cm3 for Patient 1 and 2 respectively with an intratumoral Vd/Vi ratio of 1.3. and 0.94. Pharmacodynamic analysis via tissue-level biomarkers is ongoing and will be presented. CONCLUSION Initial data demonstrates the safety and feasibility of direct intracranial delivery of OS2966.

Basilar invagination is a congenital or acquired craniovertebral junction abnormality where the tip of the odontoid process projects through the foramen magnum which can cause severe symptomatic compression of the brainstem and spinal cord. If left untreated, patients can develop progressive quadriparesis. Traditionally, basilar invagination can be treated with cervical traction and posterior stabilization. However, in irreducible cases, anterior decompression via a transoral or endonasal approach may be necessary. In this operative video, we demonstrate an endoscopic endonasal transclival approach for odontoidectomy to successfully treat a 37-year-old female with severe basilar invagination causing symptomatic compression on the cervicomedullary junction resulting in unsteady gait and motor weakness. The patient had Klippel–Feil syndrome where the C1 arch was assimilated to the foramen magnum and transclival drilling was needed to adequately access the odontoid process for removal. A second-stage posterior occipitocervical stabilization and fusion was performed the following day. Immediate postoperative imaging showed excellent decompression of the cervicomedullary junction. Postoperatively, the patient had significant improvement in gait and motor strength in all extremities, and was ambulating independently without assistance at 1 year after surgery. The endoscopic endonasal transclival odontoidectomy is a useful strategy to treat severe irreducible basilar invagination causing symptomatic neural compression. The surgical technique and nuances are described in a step-by-step fashion in this illustrative operative video.The link to the video can be found at: https://youtu.be/HL4K7KqJEJM.

Background Falcotentorial meningiomas are surgically challenging. Currently accepted approaches include occipital interhemispheric and supracerebellar infratentorial approaches, which have documented drawbacks. Objective To propose an alternative approach to the posterior tentorial incisural space, the interhemispheric precuneus retrosplenial transfalcine approach (IPRTA). Methods A total of 6 colored-silicone-injected adult cadaveric heads were dissected. We measured the interval between bridging veins and studied computed tomography venography scans of 20 subjects to confirm the feasibility of the IPRTA. Bony landmarks, the region's bridging veins, and the anterior and posterior borders of the approach were identified. The surgical corridor widths (veins' interval) and lengths were compared between alternative midline approaches. We also reviewed 4 consecutive clinical cases using this approach. Results The IPRTA provides the shortest distance to the anterior and posterior limits of the posterior tentorial incisura. Moreover, it is the only approach that provides direct visualization of the anterior and posterior limits of falcotentorial junction meningiomas. In all specimens and patients, a minimum 30-mm interval between the anterior and posterior parietal veins was found in at least one of the hemispheres. Tumor removal was successful in all 4 patients but resulted in mild paresthesia in the lower extremities of 2 patients and temporary foot drop in 1 patient. Conclusion The IPRTA offers the shortest and most direct corridor for falcotentorial meningiomas and provides excellent visualization of most of the critical structures in the region. Detailed preoperative evaluation of the deep and superficial venous structures is recommended.

Background Minimally invasive endoscopic techniques in spine surgery continue to gain in popularity. Unfortunately, there is a long learning period for novice endoscope users to acquire basic skills, and complex training simulators are frequently cost-prohibitive. This paper describes the development and validation of a low-cost endoscopic spine training simulator. Methodology A low-cost endoscopic spine training model was created utilizing a budget of less than 65 USD. Afterward, a training curriculum consisting of five tasks was designed to mimic standard techniques frequently utilized in endoscopic spine surgery. This curriculum was tested on a cohort of surgical trainees. The initial time to completion as well as errors made during the tasks and repeat trials were recorded. A composite score was generated to quantify the overall scores which included both time and errors in each task. Results In total, 11 students and surgical residents completed the curriculum. The first attempt required an average of 622 seconds for the completion of the curriculum compared to 283 seconds in the second trial (p < 0.001; SD = 36.75). In regards to trials in which errors were counted, fewer errors occurred during the second attempt (2.55 vs. 1.53); however, this difference was not statistically significant (p > 0.05). In regards to the composite score, the composite score of the intern group demonstrated an average improvement of 0.345 compared to an average improvement of 0.47 in the resident group. Conclusions Our study demonstrates the feasibility of a low-cost endoscopic spine trainer as well as its efficacy in improving basic endoscopic skills in trainees.

BackgroundVestibular schwannomas (VS) are usually hypovascularized. Large VS with unusual vascular architecture are defined hyper-vascular (HVVS); excessive bleeding during microsurgery has negative impact on results. Methods Thirty-two consecutive patients were operated on for HVVS (Group-A). Results were compared with those of 25 patients (Group-B) operated on for large low-bleeding VS. Tendency to bleed and adherence of capsule to nervous structures were evaluated by reviewing video records. Cisternal facial nerve (FN) position was reported. Microsurgical removal was classified as total, near-total, subtotal or partial and MIB-1 index evaluated in all. FN results were classified according the House-Brackmann scale.Results Mean tumor diameter was 3,99cm in Group-A and 3,67 in Group-B; mean age was 42,3 and 58,1 years, respectively. Mean ASA class of Group-A was 1,72 versus 2,48 of Group-B (pConclusions Microsurgery of large HVVS was associated with higher complication and recurrence/re-growth rate and poorer FN outcome, especially in cases with tight capsule adhesion.