Bridging the gap between neuroimaging and neurosurgery: a case of epidural arteriovenous fistula with an intradural presentation. Illustrative case.

BACKGROUND: Epidural arteriovenous fistulas (eAVFs) are rare vascular malformations often mistaken for their intradural counterparts due to similar angiographic features. Differentiation between epidural and intradural vascular lesions is crucial as it impacts surgical planning and prognosis. Despite advancements in diagnostic imaging, these entities can be misinterpreted and challenge management. OBSERVATIONS: The authors report the case of a 68-year-old male suspected to have a type I dural arteriovenous fistula based on magnetic resonance angiography and angiographic evaluation. He presented with progressive myelopathy and multiple neurological symptoms exacerbated by recent trauma. A superselective angiogram of the right T10 segmental artery suggested an intradural arteriovenous fistula; however, intraoperatively, the lesion was epidural. The arterialized venous structures were obliterated, and the patient reported significant postoperative symptomatic improvement. LESSONS: This case highlights the critical importance of comprehensive imaging and cautious interpretation in the diagnosis of spinal vascular malformations. It also underscores the need for a multidisciplinary approach to ensure accurate diagnosis and effective treatment. Surgeons must be prepared for intraoperative findings that diverge from preoperative imaging to adapt surgical strategies accordingly. Furthermore, this case contributes to the evolving understanding of eAVFs, suggesting that revised imaging protocols may be required to better distinguish epidural from intradural vascular abnormalities. https://thejns.org/doi/10.3171/CASE24331.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma Using N-Butyl Cyanoacrylate With a D5W Push Technique: A Multicentric North American Study of 269 Patients.

BACKGROUND AND OBJECTIVES: As the aging population increases, the incidence of chronic subdural hematomas (cSDHs) is expected to rise. Surgical evacuation, though effective, sees up to 30% recurrence. Middle meningeal artery (MMA) embolization, particularly with n-butyl cyanoacrylate (n-BCA) glue diluted in D5W for distal penetration, has shown promise in reducing recurrences. Limited reports have investigated the safety and technical feasibility of n-BCA as a primary liquid embolic agent using the D5W push technique in cSDH. This series is the largest in the literature investigating the outcomes of this technique in cSDH. METHODS: A multicenter retrospective database analysis was conducted on consecutive patients who underwent MMA embolization using n-BCA embolisate. Data collected included patient demographics, procedural information, angiographic data, and periprocedural complications. RESULTS: The study included 269 patients with a median age of 76 years. Nearly half of the patients had previous surgeries, and 93 underwent contralateral embolization for bilateral cSDH. Successful MMA embolization with effective distal penetration was achieved in all cases. The complication rate was 2.2%. Significant improvements were noted at a 60-day follow-up, with a median reduction in cSDH diameter of 40.6% (P < .001) and 53% of patients showing neurological improvement. No recurrent cSDH or need for retreatment was observed in patients who underwent follow-up. CONCLUSION: MMA embolization using n-BCA with the D5W push technique is safe and technically feasible. It can be used adjunctively or as an alternative to surgery in patients with cSDH, resulting in decreased recurrence, high technical success, improved distal penetration, and low complication rates.

Traumatic middle meningeal arteriovenous fistulas (MMAVFs): an exploratory systematic review.

This study aims to systematically review case reports and case series in order to compare the postoperative course of conservative, endovascular and surgical treatments for traumatic dural arteriovenous fistulas predominantly supplied by the middle meningeal artery (MMAVFs), which usually occur following head trauma or iatrogenic causes. We conducted a comprehensive search of PubMed, Embase, Scopus, Web of Science, and Google Scholar until June 23rd, 2024. Three cohorts were defined based on the treatment modality employed. The primary outcomes were the rates of overall obliteration and postoperative complications, with all-cause mortlality considered as secondary outcome. A total of 61 studies encompassing 78 pooled MMAVFs were included in the qualitative analysis. The predominant demographic consisted of males (53.9%) with a median age of 50.5 (IQR: 33.5-67.5) years. The main etiologies for fistula formation were head trauma (75.6%), cranial neurosurgical procedures (11.5%) and endovascular embolization (8.97%). Venous drainage patterns were categorized as follows based on anatomical confluence: Class I (16.7%), II (14.1%), III (12.8%), IV (14.1%), V (7.7%), and VI (3.9%). Regarding treatment efficacy, the overall obliteration rate was 89.74%, achieved through endovascular (95.83%), surgical (64.29%) or conservative (93.75%) approaches. In terms of safety, the overall postoperative complication rate was 6.49% with an all-cause mortality rate of 8.97%, predominantly observed in the surgical group (35.71%). Our systematic review highlights the challenging management of traumatic MMAVFs, frequently associated with head injuries. Endovascular therapy has emerged as the predominant treatment modality, demonstrating markedly higher rates of fistula obliteration, reduced all-cause mortality, and fewer postoperative complications.

Metabolic signatures derived from whole-brain MR-spectroscopy identify early tumor progression in high-grade gliomas using machine learning.

PURPOSE: Recurrence for high-grade gliomas is inevitable despite maximal safe resection and adjuvant chemoradiation, and current imaging techniques fall short in predicting future progression. However, we introduce a novel whole-brain magnetic resonance spectroscopy (WB-MRS) protocol that delves into the intricacies of tumor microenvironments, offering a comprehensive understanding of glioma progression to inform expectant surgical and adjuvant intervention. METHODS: We investigated five locoregional tumor metabolites in a post-treatment population and applied machine learning (ML) techniques to analyze key relationships within seven regions of interest: contralateral normal-appearing white matter (NAWM), fluid-attenuated inversion recovery (FLAIR), contrast-enhancing tumor at time of WB-MRS (Tumor), areas of future recurrence (AFR), whole-brain healthy (WBH), non-progressive FLAIR (NPF), and progressive FLAIR (PF). Five supervised ML classification models and a neural network were developed, optimized, trained, tested, and validated. Lastly, a web application was developed to host our novel calculator, the Miami Glioma Prediction Map (MGPM), for open-source interaction. RESULTS: Sixteen patients with histopathological confirmation of high-grade glioma prior to WB-MRS were included in this study, totaling 118,922 whole-brain voxels. ML models successfully differentiated normal-appearing white matter from tumor and future progression. Notably, the highest performing ML model predicted glioma progression within fluid-attenuated inversion recovery (FLAIR) signal in the post-treatment setting (mean AUC = 0.86), with Cho/Cr as the most important feature. CONCLUSIONS: This study marks a significant milestone as the first of its kind to unveil radiographic occult glioma progression in post-treatment gliomas within 8 months of discovery. These findings underscore the utility of ML-based WB-MRS growth predictions, presenting a promising avenue for the guidance of early treatment decision-making. This research represents a crucial advancement in predicting the timing and location of glioblastoma recurrence, which can inform treatment decisions to improve patient outcomes.

First multicenter study evaluating the utility of the BENCHMARKTM BMXTM 81 large-bore access catheter in neurovascular interventions.

INTRODUCTION: This study is the first multicentric report on the safety, efficacy, and technical performance of utilizing a large bore (0.081″ inner diameter) access catheter in neurovascular interventions. METHODS: Data were retrospectively collected from seven sites in the United States for neurovascular procedures via large bore 0.081″ inner diameter access catheter (Benchmark BMX81, Penumbra, Inc.). The primary outcome was technical success, defined as the access catheter reaching its target vessel. Safety outcomes included periprocedural device-related and access site complications. RESULTS: There were 90 consecutive patients included. The median age of the patients was 63 years (IQR: 53, 68); 53% were female. The most common interventions were aneurysm embolization (33.3%), carotid stenting (12.2%), and arteriovenous malformation embolization (11.1%). The transradial approach was most used (56.7%), followed by transfemoral (41.1%). Challenging anatomic variations included severe vessel tortuosity (8/90, 8.9%), type 2 aortic arch (7/90, 7.8%), type 3 aortic arch (2/90, 2.2%), bovine arch (2/90, 2.2%), and severe angle (<30°) between the subclavian artery and target vessel (1/90, 1.1%). Technical success was achieved in 98.9% of the cases (89/90), with six cases requiring a switch from radial to femoral (6.7%) and one case from femoral to radial (1.1%). There were no access site complications or complications related to the 0.081″ catheter. Two postprocedural complications occurred (2.2%), unrelated to the access catheter. CONCLUSION: The BMX™ 81 large-bore access catheters was safe and effective in both radial and femoral access across a wide range of neurovascular procedures, achieving high technical success without any access site or device-related complications.

The Effect of the Coronavirus Disease 2019 Pandemic on Pituitary Surgery.

OBJECTIVE: As the coronavirus disease 2019 (COVID-19) pandemic spread to the United States in 2020, there was an impetus toward postponing or ceasing nonurgent transsphenoidal pituitary surgeries to prevent the spread of the virus. Some centers encouraged transcranial approaches for patients with declining neurologic function. However, no large-scale data exist evaluating the effects that this situation had on national pituitary practice patterns. METHODS: Pituitary surgeries in the National Inpatient Sample were identified from 2017 to 2020. Surgeries in 2020 were compared with the 3 years previously to determine any differences in demographics, surgical trends/approaches, and perioperative outcomes. RESULTS: In 2020, there was a decline in overall pituitary surgeries (34.2 vs. 36.3%; odds ratio (OR), 0.88; P < 0.001) yet transsphenoidal approaches represented a higher proportion of interventions (69.0 vs. 64.9%; P < 0.001). Neurosurgical complications were higher (51.9 vs. 47.4%; OR, 1.13; P < 0.001) and patients were less likely to be discharged home (86.4 vs. 88.5%; OR, 0.84; P < 0.001). This finding was especially true in April 2020 during the first peak in COVID-19 cases, when transcranial approaches and odds of mortality/complications were highest. CONCLUSIONS: In 2020, transsphenoidal surgery remained the preferred approach for pituitary tumor resection despite initial recommendations against the approach to prevent COVID-19 spread. Pituitary surgeries had a higher risk of periprocedural complications despite accounting for preoperative comorbidities, COVID-19 infection status, and surgical approach, suggesting that an overwhelmed hospital system can negatively influence surgical outcomes in noninfected patients.

Infrasellar Nasopharyngeal Craniopharyngiomas: An Individual Participant Data Meta-Analysis and Review of the Literature.

BACKGROUND: Craniopharyngiomas are benign tumors of the anterior skull base arising from epithelial remnants of Rathke pouch. They mainly occur in the suprasellar space, can be incredibly debilitating, and remain difficult to resect as they frequently involve critical neurovascular structures. Although it is embryologically possible for craniopharyngiomas to arise extracranially along the entire migrational path of Rathke pouch, these remain exceedingly rare, especially among adults, and can be mistaken for nasopharyngeal cancer. As such, minimal data exist evaluating the management and outcomes of such lesions. We evaluated our institutional experience with purely infrasellar nasopharyngeal craniopharyngiomas and obtained individual patient data reported in the contemporary literature to better characterize the demographics, presentation, surgical management, and long-term outcomes of these lesions. METHODS: A systematic review of the literature was performed to identify previously published cases of purely infrasellar nasopharyngeal craniopharyngioma in 3 electronic databases: MEDLINE (PubMed), Embase, and Scopus. Search terms were "infrasellar craniopharyngioma" and "nasopharyngeal craniopharyngioma." RESULTS: We identified 25 cases, in which 72% of patients presented with symptoms of nasal obstruction, epistaxis, or headache. An endoscopic approach was performed in 40% of cases; 83.3% of all patients had gross total resection, with 60% having no recurrence at a median follow-up of 13 months. No postoperative complications were reported. Tumor location involving the cavernous sinus was associated with incomplete resection (100%) compared with tumors not involving the cavernous sinus (87%) (P = 0.033). CONCLUSIONS: While uncommon, infrasellar nasopharyngeal craniopharyngiomas appear to have better perioperative and long-term surgical outcomes than their suprasellar counterparts.

Widening the Operative Corridor-Evaluating the Transcortical Approach to Giant Falcine Meningiomas.

BACKGROUND: Giant falcine meningiomas are surgically complex as they are deep in location, concealed by normal brain parenchyma, in close proximity to various neurovascular structures, and frequently involve the falx bilaterally. Although classically accessed using a bifrontal craniotomy and interhemispheric approach, little data exist on alternative operative corridors for these challenging tumors. We evaluated perioperative and long-term outcomes in patients undergoing transcortical resection of giant bilateral falcine meningiomas. METHODS: From 2013 to 2022, fourteen patients with giant bilateral falcine meningiomas treated via a transcortical approach at our institution were identified. Perioperative and long-term outcomes were evaluated to determine predictors of adverse events. Corticectomy depth was also analyzed to determine if it correlated with increased postoperative seizure rates. RESULTS: 57.1% of cases were WHO grade 2 meningiomas. Average tumor volume was 77.8 ± 46.5 cm3 and near/gross total resection was achieved in 78.6% of patients. No patient developed a venous infarct or had seizures in the 6 months after surgery. Average corticectomy depth was 0.83 ± 0.71 cm and increasing corticectomy depth did not correlate with higher risk of postoperative seizures (P = 0.44). Increasing extent of tumor resection correlated with lower tumor grade (P = 0.011) and only 1 patient required repeat resection during a median follow-period of 24.9 months. CONCLUSIONS: The transcortical approach is a safe alternative corridor for accessing giant, falcine meningiomas, and postoperative seizures were not found to correlate with increasing corticectomy depth. Further prospective studies are necessary to determine the best approach to these surgically complex lesions.

The Learning Curve and Clinical Outcomes With 250 Laser Ablations for Brain Tumors: A Pathway to Experience.

BACKGROUND AND OBJECTIVES: Laser interstitial thermal therapy (LITT) has gained popularity as a minimally invasive technique for treating brain tumors. Despite its proven safety profile, LITT is not yet widely available, and there is a lack of data on the learning curve required to achieve proficiency. This study analyzes a 250-patient cohort of laser-ablated tumors to describe changes in patient selection and clinical outcomes over time and experience, with the aim of providing insight into the learning curve for incorporating LITT into a neuro-oncology program and identifying a cutoff point that distinguishes novice from expert performance. METHODS: We retrospectively reviewed 250 patients with brain tumor who underwent LITT between 2013 and 2022. Demographic and clinical data were analyzed. Kaplan Meier curves were used for survival analysis. Operative time was evaluated using exponential curve-fit regression analysis to identify when consistent improvement began. RESULTS: The patients were divided into quartiles (Q) based on their date of surgery. Mean tumor volume increased over time (Q1 = 5.7 and Q4 = 11.9 cm 3 , P = .004), and newly diagnosed lesions were more frequently ablated ( P = .0001). Mean operative time (Q1 v Q4 = 322.3 v 204.6 min, P < .0001) and neurosurgical readmission rate (Q1 v Q4 = 7.8% v 0%, P = .03) were reduced over time. The exponential curve-fit analysis showed a sustained decay in operative time after case #74. The extent of ablation ( P = .69), the recurrence ( P = .11), and the postoperative complication rate ( P = .78) did not vary over time. CONCLUSION: After treating 74 patients, a downward trend in the operative time is observed. Patient selection is broadened as experience increases.

Laser interstitial thermal therapy for deep-seated perivascular brain tumors is not associated with distal ischemia.

PURPOSE: Laser interstitial thermal therapy (LITT) is a minimally invasive cytoreductive treatment option for brain tumors with a risk of vascular injury from catheter placement or thermal energy. This may be of concern with deep-seated tumors that have surrounding end-artery perforators and critical microvasculature. The purpose of this study was to assess the risk of distal ischemia following LITT for deep-seated perivascular brain tumors. METHODS: A retrospective review of a multi-institution database was used to identify patients who underwent LITT between 2013 and 2022 for tumors located within the insula, thalamus, basal ganglia, and anterior perforated substance. Demographic, clinical and volumetric tumor characteristics were collected. The primary outcome was radiographic evidence of distal ischemia on post-ablation magnetic resonance imaging (MRI). RESULTS: 61 LITT ablations for deep-seated perivascular brain tumors were performed. Of the tumors treated, 24 (39%) were low-grade gliomas, 32 (52%) were high-grade gliomas, and 5 (8%) were metastatic. The principal location included 31 (51%) insular, 14 (23%) thalamic, 13 (21%) basal ganglia, and 3 (5%) anterior perforated substance tumors. The average tumor size was 19.6 cm3 with a mean ablation volume of 11.1 cm3. The median extent of ablation was 92% (IQR 30%, 100%). Two patients developed symptomatic intracerebral hemorrhage after LITT. No patient had radiographic evidence of distal ischemia on post-operative diffusion weighted imaging. CONCLUSION: We demonstrate that LITT for deep-seated perivascular brain tumors has minimal ischemic risks and is a feasible cytoreductive treatment option for otherwise difficult to access intracranial tumors.

The Utility of Transcranial Electrical Stimulation Motor Evoked Potential Monitoring in Predicting Postoperative Supplementary Motor Area Syndrome and Motor Function Recovery.

BACKGROUND: Postoperative hemiparesis following frontal lobe lesion resection is alarming, and predicting motor function recovery is challenging. Supplementary motor area (SMA) syndrome following resection of frontal lobe lesions is often indistinguishable from postoperative motor deficit due to surgical injury of motor tracts. We aimed to describe the use of intraoperative transcranial electrical stimulation (TES) with motor evoked potential monitoring data as a diagnostic tool to distinguish between SMA syndrome and permanent motor deficit (PMD). METHODS: A retrospective analysis of 235 patients undergoing craniotomy and resection with TES-MEP monitoring for a frontal lobe lesion was performed. Patients who developed immediate postoperative motor deficit were included. Motor deficit and TES-MEP findings were categorized by muscle group as left upper extremity, left lower extremity, right upper extremity, or right lower extremity. Statistical analysis was performed to determine the predictive value of stable TES-MEP for SMA syndrome versus PMD. RESULTS: This study included 20 patients comprising 29 cases of immediate postoperative motor deficit by muscle group. Of these, 27 cases resolved and were diagnosed as SMA syndrome, and 2 cases progressed to PMD. TES-MEP stability was significantly associated with diagnosis of SMA syndrome (P = 0.015). TES-MEP showed excellent diagnostic utility with a sensitivity and positive predictive value of 100% and 92.6%, respectively. Negative predictive value was 100%. CONCLUSIONS: Temporary SMA syndrome is difficult to distinguish from PMD immediately postoperatively. TES-MEP may be a useful intraoperative adjunct that may aid in distinguishing SMA syndrome from PMD secondary to surgical injury.

Balloon-mounted covered stent as endovascular management of a traumatic cervical internal carotid artery pseudoaneurysm in a 23-year-old: a case report.

Background: Distal cervical internal carotid artery (cICA) pseudoaneurysms are uncommon. They may lead to thromboembolic or hemorrhagic complications, especially in young adults. We report one of the first cases in the literature regarding the management via PK Papyrus (Biotronik, Lake Oswego, Oregon, USA) balloon-mounted covered stent of a 23-year-old male with an enlarging cervical carotid artery pseudoaneurysm and progressive internal carotid artery stenosis. Case Description: We report the management of a 23-year-old male with an enlarging cervical carotid artery pseudoaneurysm and progressive internal carotid artery stenosis. Based on clinical judgment and imaging analysis, the best option to seal the aneurysm was a PK Papyrus 5×26 balloon-mounted covered stent. A follow-up angiogram showed no residual filling of the pseudoaneurysm, but there was some contrast stagnation just proximal to the stent, which is consistent with a residual dissection flap. We then deployed another PK Papyrus 5×26 balloon-mounted covered stent, providing some overlap at the proximal end of the stent. An angiogram following this subsequent deployment demonstrated complete reconstruction of the cICA with no residual evidence of pseudoaneurysm or dissection flap. There were no residual in-stent stenosis or vessel stenosis. The patient was discharged the day after the procedure with no complications. Conclusions: These positive outcomes support the use of a balloon-mounted covered stent as a safe and feasible modality with high technical success for endovascular management of pseudoaneurysm.

Transradial or Transulnar Long Sheath Access to the Brachial Artery Allows for Neuroendovascular Procedures in Patients with Radial or Ulnar Artery Occlusion.

BACKGROUND: Transradial access is an important tool for many neuroendovascular procedures. Occlusion of the radial or ulnar artery is not uncommon after transradial or transulnar access and can present a challenge for patients requiring repeat angiography. METHODS: Between March 2022 and June 2023, patients undergoing transradial or transulnar angiography who were found to have a radial artery occlusion or ulnar artery occlusion were identified. Repeat catheterization of the occluded artery was attempted using a 21-gauge single wall puncture needle and a 0.021-inch wire to traverse the occlusion and insert a 23-cm sheath into the brachial artery. RESULTS: A total of 25 patients undergoing 26 angiograms during the study period were found to have a radial artery occlusion or ulnar artery occlusion. Successful repeat catheterization of the occluded artery was achieved in 21 of 26 cases (80.7%). Outer diameter sheath size ranged from 5 Fr (0.0655 inch) to 8 Fr (0.1048 inch). No access complications were encountered. Number of prior angiograms, time since prior angiogram, and prior angiogram procedure time were associated with lower likelihood of successful access. CONCLUSIONS: Transradial or transulnar neuroangiography through an occluded radial or ulnar artery is safe and feasible by traversing the occlusion into the brachial artery with a 23-cm sheath. Repeat catheterization is most successful in patients with an arterial occlusion <6 months old. This technique is important in patients who have limited options for arterial access, avoiding access site complications inherent in transfemoral access, and in patients who specifically require radial or ulnar artery access.

Step-by-Step Dissection of the Extreme Lateral Transodontoid Approach to the Anterior Craniovertebral Junction: Surgical Anatomy and Technical Nuances.

BACKGROUND: Multicompartmental lesions of the anterior craniovertebral junction require aggressive management. However, the lesions can be difficult to reach, and the surgical procedure is difficult to understand. The aim of this study was to create a procedural, stepwise microsurgical educational resource for junior trainees to learn the surgical anatomy of the extreme lateral transodontoid approach (ELTOA). METHODS: Ten formalin-fixed, latex-injected cadaveric heads were dissected under an operative microscope. Dissections were performed under the supervision of a skull base fellowship-trained neurosurgeon who has advanced skull base experience. Key steps of the procedure were documented with a professional camera and a high-definition video system. A relevant clinical case example was reviewed to highlight the principles of the selected approach and its application. The clinical case example also describes a rare complication: a pseudoaneurysm of the vertebral artery. RESULTS: Key steps of the ELTOA include patient positioning, skin incision, superficial and deep muscle dissection, vertebral artery dissection and transposition, craniotomy, clivus drilling, odontoidectomy, and final extradural and intradural exposure. CONCLUSIONS: The ELTOA is a challenging approach, but it allows for significant access to the anterior craniovertebral junction, which increases the likelihood of gross total lesion resection. Given the complexity of the approach, substantial training in the dissection laboratory is required to develop the necessary anatomic knowledge and to minimize approach-related morbidity.

Impact of COVID-19 pandemic on treatment and outcomes of cerebral arteriovenous malformations.

BACKGROUND: There has been a recent decrease in interventional management of cerebral arteriovenous malformations (AVMs). The objective of our study was to evaluate the changing patterns in management of AVMs in the first year of the COVID-19 pandemic. METHODS: The National Inpatient Sample (NIS) database was used. From 2016 to 2020, patients with an International Classification of Diseases, 10th revision (ICD-10) diagnosis code for a cerebral AVM were included. An intervention was defined as ICD-10 code for surgical, endovascular, or stereotactic radiosurgery treatment. Odds ratios (ORs) were calculated using a logistic regression model with covariates deemed to be clinically relevant. RESULTS: 63 610 patients with AVMs were identified between 2016 and 2020, 14 340 of which were ruptured. In 2020, patients had an OR of 0.69 for intervention of an unruptured AVM (P<0.0001) compared with 2016-19. The rate of intervention for unruptured AVMs decreased to 13.5% in 2020 from 17.6% in 2016-19 (P<0.0001). The rate of AVM rupture in 2020 increased to 23.9% from 22.2% in 2016-19 (P<0.0001). In 2020, patients with ruptured AVMs had an OR for inpatient mortality of 1.72 compared with 2016-19. Linear regression analysis from 2016 to 2020 showed an inverse relationship between intervention rate and rupture rate (slope -0.499, R2=0.88, P=0.019). CONCLUSION: In 2020, the rate of intervention for unruptured cerebral AVMs decreased compared with past years, with an associated increase in the rate of rupture. Patients with ruptured AVMs also had a higher odds of mortality.

Outcomes in patients with large vessel occlusion strokes undergoing mechanical thrombectomy with concurrent COVID-19: a nationwide retrospective analysis.

BACKGROUND: Preliminary studies show that patients with large vessel occlusion (LVO) acute ischemic strokes have worse outcomes with concurrent COVID-19 infection. We investigated the outcomes for patients with LVO strokes undergoing mechanical thrombectomy (MT) with concurrent COVID-19 infection. METHODS: The National Inpatient Database (NIS) was used for our analysis. Patients in the year 2020 with an ICD-10 diagnosis code for acute ischemic stroke and procedural code for MT were included with and without COVID-19. Odds ratios (OR) were calculated using a logistic regression model with age, sex, stroke location, Elixhauser comorbidity score, and other patient variables deemed clinically relevant as covariates. RESULTS: Patients in the COVID-19 group were younger (64.3±14.4 vs 69.4±14.5 years, P<0.001), had a higher rate of inpatient mortality (22.4% vs 10.1%, P<0.001), and a longer length of stay (10 vs 6 days, P<0.001). Patients with COVID-19 had higher odds of death (OR 2.78, 95% CI 2.11 to 3.65) and lower odds of a routine discharge (OR 0.65, 95% CI 0.48 to 0.89). There was no difference in the odds of subsequent stroke and cerebral hemorrhage, but patients with COVID-19 had statistically significantly higher odds of respiratory failure, pulmonary embolism, deep vein thrombosis, myocardial infarction, acute kidney injury, and sepsis. CONCLUSIONS: Patients with LVOs undergoing MT within the 2020 NIS database had worse outcomes when co-diagnosed with COVID-19, likely due to non-neurological manifestations of COVID-19.

Rathke's cleft cysts causing Cushing's disease: Two unique cases and review of the literature.

Background: The presentation of isolated Rathke's cleft cysts (RCC) without any associated pituitary adenoma in patients with symptoms consistent with Cushing's disease (CD) remains exceedingly rare. As such, we aim to present two cases of RCC presenting with CD with a resultant resolution of their CD following surgical resection. Case Description: Here, we present two cases of RCCs presenting with symptoms suggestive of CD. A functional pituitary microadenoma was the presumed diagnosis based on initial clinical presentation and diagnostic imaging suggesting a pituitary lesion. However, pathology results demonstrated no evidence of adenoma but cysts lined with columnar epithelia consistent with RCC. Complete surgical resection was achieved in both patients through endoscopic endonasal pituitary resection with postoperative symptomatic resolution and normalization of cortisol levels. In addition, we discuss the literature on this rare presentation and suggest a pathological mechanism for this unique presentation of RCC-causing CD. Conclusion: Surgical resection of RCC may provide a "biochemical cure" for patients presenting with CD, as demonstrated by these two unique cases. The clinical features, histological findings, and possible pathological mechanisms for this unique presentation of RCC causing CD discussed lay the groundwork for future studies into the pathophysiology of RCC and CD.

Perioperative Outcomes in Transcarotid Artery Revascularization Versus Carotid Endarterectomy or Stenting Nationwide.

BACKGROUND AND OBJECTIVES: Transcarotid artery revascularization (TCAR) is a newer treatment for carotid stenosis where the carotid artery is accessed directly in the neck for stenting. It is less invasive than carotid endarterectomy (CEA) and has less embolic potential than carotid artery stenting (CAS), but population-level utilization of TCAR and outcomes are currently unknown. Our study compares outcomes of TCAR with those of CEA and CAS. METHODS: The National Inpatient Database was used for years 2015 to 2019. A multivariate logistic regression model was used to compare CEA, CAS, and TCAR outcomes with age, sex, race, hospital teaching status, symptomatic carotid disease status, side of procedure, intraoperative monitoring, and the weighted Elixhauser comorbidity score as covariates. RESULTS: TCAR comprised 0.69% of these procedures in 2016, rising to 1.35% in 2019. The inpatient rates of death, stroke, and myocardial infarction for TCAR were 0.63% (95% confidence interval: 0.36%, 1.06%), 0.42% (0.21%, 0.80%), and 1.46% (1.04%, 2.05%), respectively. Compared with CEA, TCAR had statistically insignificant difference odds of death, odds ratio (95% CI) for stroke was 0.47 (0.25, 0.87), and for myocardial infarction, it was 0.66 (0.37, 0.94). Compared with CAS, for TCAR, the odds ratio for death was 0.41 (0.24, 0.71), and for stroke, it was 0.48 (0.26, 0.91). CONCLUSION: TCAR is underutilized relative to other revascularization techniques yet has favorable outcomes compared with CEA and CAS. TCAR may be preferred to CAS in patients not surgical candidates for CEA and has a less invasive possibility for those eligible for CEA.

Cytokine Profiling of Cyst Fluid and Tumor-Associated Macrophages in Cystic Vestibular Schwannoma.

BACKGROUND: The vestibular schwannoma (VS) secretome can initiate monocyte recruitment and macrophage polarization to M1 (proinflammatory) and/or M2 (protumorigenic) phenotypes, which in turn secrete additional cytokines that contribute to the tumor microenvironment. Profiling cyst fluid and cerebrospinal fluid (CSF) in cystic VS provides a unique opportunity to understand mechanisms that may contribute to tumor progression and cyst formation. HYPOTHESIS: Cystic VSs secrete high levels of cytokines into cyst fluid and express abundant M1 and M2 macrophages. METHODS: Tumor, CSF, and cyst fluid were prospectively collected from 10 cystic VS patients. Eighty cytokines were measured in fluid samples using cytokine arrays and compared with normal CSF from normal donors. Immunofluorescence was performed for CD80 + M1 and CD163 + M2 macrophage markers. Demographic, audiometric, and radiographic information was obtained through retrospective chart review. RESULTS: Cyst fluid expressed more osteopontin and monocyte chemotactic protein-1 (MCP-1; p < 0.0001), when compared with normal CSF. Cyst fluid also expressed more protein ( p = 0.0020), particularly MCP-1 ( p < 0.0001), than paired CSF from the same subjects. MCP-1 expression in cyst fluid correlated with CD80 + staining in VS tissue ( r = 0.8852; p = 0.0015) but not CD163 + staining. CONCLUSION: Cyst fluid from cystic VS harbored high levels of osteopontin and MCP-1, which are cytokines important in monocyte recruitment and macrophage polarization. MCP-1 may have a significant role in molding the tumor microenvironment, by polarizing monocytes to CD80 + M1 macrophages in cystic VS. Further investigations into the role of cytokines and macrophages in VS may lead to new avenues for therapeutic intervention.

Laser Interstitial Thermal Therapy Induces Robust Local Immune Response for Newly Diagnosed Glioblastoma With Long-term Survival and Disease Control.

Laser interstitial thermal therapy (LITT) is a minimally invasive neurosurgical technique used to ablate intra-axial brain tumors. The impact of LITT on the tumor microenvironment is scarcely reported. Nonablative LITT-induced hyperthermia (33-43˚C) increases intra-tumoral mutational burden and neoantigen production, promoting immunogenic cell death. To understand the local immune response post-LITT, we performed longitudinal molecular profiling in a newly diagnosed glioblastoma and conducted a systematic review of anti-tumoral immune responses after LITT. A 51-year-old male presented after a fall with progressive dizziness, ataxia, and worsening headaches with a small, frontal ring-enhancing lesion. After clinical and radiographic progression, the patient underwent stereotactic needle biopsy, confirming an IDH-WT World Health Organization Grade IV Glioblastoma, followed by LITT. The patient was subsequently started on adjuvant temozolomide, and 60 Gy fractionated radiotherapy to the post-LITT tumor volume. After 3 months, surgical debulking was conducted due to perilesional vasogenic edema and cognitive decline, with H&E staining demonstrating perivascular lymphocytic infiltration. Postoperative serial imaging over 3 years showed no evidence of tumor recurrence. The patient is currently alive 9 years after diagnosis. Multiplex immunofluorescence imaging of pre-LITT and post-LITT biopsies showed increased CD8 and activated macrophage infiltration and programmed death ligand 1 expression. This is the first depiction of the in-situ immune response to LITT and the first human clinical presentation of increased CD8 infiltration and programmed death ligand 1 expression in post-LITT tissue. Our findings point to LITT as a treatment approach with the potential for long-term delay of recurrence and improving response to immunotherapy.