Impact of Race on Outcomes in the Endovascular and Microsurgical Treatment in Patients With Intracranial Aneurysms.

BACKGROUND AND OBJECTIVES: The impact of race on outcomes in the treatment of intracranial aneurysm (IA) remains unclear. We aimed to investigate the relationship between race classified into White, Black, Hispanic, and other and treatment outcomes in patients with ruptured and unruptured IAs. METHODS: The study population consisted of 2836 patients with IA with endovascular treatment or microsurgical treatment (MST) from 16 centers in the United States and Asia, all participating in the observational "STAR" registry. The primary outcome was a 90-day modified Rankin Scale of 0 to 2. Secondary outcomes included periprocedural cerebral infarction and intracranial hemorrhage, perioperative symptomatic cerebral vasospasm in ruptured IA and mortality, and all causes of mortality within 90 days. RESULTS: One thousand fifty-three patients were White (37.1%), 350 were Black (12.3%), 264 were Hispanic (9.3%), and 1169 were other (41.2%). Compared with White patients, Hispanic patients had a significantly lower proportion of primary outcome (adjusted odds ratio [aOR] 0.36, 95% CI, 0.23-0.56) and higher proportion of the periprocedural cerebral infarction, perioperative mortality, and all causes of mortality (aOR 2.53, 95% CI, 1.40-4.58, aOR 1.84, 95% CI, 1.00-3.38, aOR 1.83, 95% CI, 1.06-3.17, respectively). Outcomes were not significantly different in Black and other patients. The subgroup analysis showed that Hispanic patients with age ≥65 years (aOR 0.19, 95% CI, 0.10-0.38, interaction P = .048), Hunt-Hess grades 0 to 3 (aOR 0.29, 95% CI, 0.19-0.46, interaction P = .03), and MST (aOR 0.24, 95% CI, 0.13-0.44, interaction P = .04) had a significantly low proportion of primary outcome. CONCLUSION: This study demonstrates that Hispanic patients with IA are more likely to have a poor outcome at 90 days after endovascular treatment or MST than White patients. Physicians have to pay attention to the selection of treatment modalities, especially for Hispanic patients with specific factors to reduce racial discrepancies.

Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization.

OBJECTIVE: Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion. METHODS: The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs. RESULTS: Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment. CONCLUSIONS: Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

The VEBAS score: a practical scoring system for intracranial dural arteriovenous fistula obliteration.

BACKGROUND: Tools predicting intracranial dural arteriovenous fistulas (dAVFs) treatment outcomes remain scarce. This study aimed to use a multicenter database comprising more than 1000 dAVFs to develop a practical scoring system that predicts treatment outcomes. METHODS: Patients with angiographically confirmed dAVFs who underwent treatment within the Consortium for Dural Arteriovenous Fistula Outcomes Research-participating institutions were retrospectively reviewed. A subset comprising 80% of patients was randomly selected as training dataset, and the remaining 20% was used for validation. Univariable predictors of complete dAVF obliteration were entered into a stepwise multivariable regression model. The components of the proposed score (VEBAS) were weighted based on their ORs. Model performance was assessed using receiver operating curves (ROC) and areas under the ROC. RESULTS: A total of 880 dAVF patients were included. Venous stenosis (presence vs absence), elderly age (<75 vs ≥75 years), Borden classification (I vs II-III), arterial feeders (single vs multiple), and past cranial surgery (presence vs absence) were independent predictors of obliteration and used to derive the VEBAS score. A significant increase in the likelihood of complete obliteration (OR=1.37 (1.27-1.48)) with each additional point in the overall patient score (range 0-12) was demonstrated. Within the validation dataset, the predicted probability of complete dAVF obliteration increased from 0% with a 0-3 score to 72-89% for patients scoring ≥8. CONCLUSION: The VEBAS score is a practical grading system that can guide patient counseling when considering dAVF intervention by predicting the likelihood of treatment success, with higher scores portending a greater likelihood of complete obliteration.

Dural Arteriovenous Fistulas With Cognitive Impairment: Angiographic Characteristics and Treatment Outcomes.

BACKGROUND AND OBJECTIVES: Anecdotal cases of rapidly progressing dementia in patients with dural arteriovenous fistulas (dAVFs) have been reported in small series. However, large series have not characterized these dAVFs. We conducted an analysis of the largest cohort of dAVFs presenting with cognitive impairment (dAVFs-CI), aiming to provide a detailed characterization of this subset of dAVFs. METHODS: Patients with dAVFs-CI were analyzed from the CONDOR Consortium, a multicenter repository comprising 1077 dAVFs. A propensity score matching analysis was conducted to compare dAVFs-CI with Borden type II and type III dAVFs without cognitive impairment (controls). Logistic regression was used to identify angiographic characteristics specific to dAVFs-CI. Furthermore, post-treatment outcomes were analyzed. RESULTS: A total of 60 patients with dAVFs-CI and 60 control dAVFs were included. Outflow obstruction leading to venous hypertension was observed in all dAVFs-CI. Sinus stenosis was significantly associated with dAVFs-CI (OR 2.85, 95% CI: 1.16-7.55, P = .027). dAVFs-CI were more likely to have a higher number of arterial feeders (OR 1.56, 95% CI 1.22-2.05, P < .001) and draining veins (OR 2.05, 95% CI 1.05-4.46, P = .004). Venous ectasia increased the risk of dAVFs-CI (OR 2.38, 95% CI 1.13-5.11, P = .024). A trend toward achieving asymptomatic status at follow-up was observed in patients with successful closure of dAVFs (OR 2.86, 95% CI 0.85-9.56, P = .09). CONCLUSION: Venous hypertension is a key angiographic feature of dAVFs-CI. Moreover, these fistulas present at a mean age of 58 years-old, and exhibit a complex angioarchitecture characterized by an increased number of arteriovenous connections and stenosed sinuses. The presence of venous ectasia further exacerbates the impaired drainage and contributes to the development of dAVFs-CI. Notably, in certain cases, closure of the dAVF has the potential to reverse symptoms.

Safety and Feasibility of a Fast-Track Pathway for Neurosurgical Craniotomy Patients: Bypassing the Intensive Care Unit.

Objective: To describe the safety and feasibility of a fast-track pathway for neurosurgical craniotomy patients receiving care in a neurosciences progressive care unit (NPCU). Patients and Methods: Traditionally, most craniotomy patients are admitted to the neurosciences intensive care unit (NSICU) for postoperative follow-up. Decreased availability of NSICU beds during the coronavirus disease-2019 delta surge led our team to establish a de-novo NPCU to preserve capacity for patients requiring high level of care and would bypass routine NSICU admissions. Patients were selected a priori by treating neurosurgeons on the basis of the potential need for high-level ICU services. After operation, selected patients were transferred to the postoperative care unit, where suitability for NPCU transfer was reassessed with checklist-criteria. This process was continued after the delta surge. Results: From July 1, 2021 to September 30, 2022, 57 patients followed the NPCU protocol. Thirty-four (59.6%) were women, and the mean age was 56 years. Fifty-seven craniotomies for 34 intra-axial and 23 extra-axial lesions were performed. After assessment and application of the checklist-criteria, 55 (96.5%) were transferred to NPCU, and only 2 (3.5%) were transferred to ICU. All 55 patients followed in NPCU had good safety outcomes without requiring NSICU transfer. This saved $143,000 and led to 55 additional ICU beds for emergent admissions. Conclusion: This fast-track craniotomy protocol provides early experience that a surgeon-selected group of patients may be suitably monitored outside the traditional NSICU. This system has the potential to reduce overall health care expenses, increase capacity for NSICU bed availability, and change the paradigm of NSICU admission.

Safety and efficacy of the pipeline embolization device for treatment of small vs. large aneurysms: a systematic review and meta-analysis.

Flow diversion with the pipeline embolization device (PED) is increasingly used to treat intracranial aneurysms with high obliteration rates and low morbidity. However, long-term (≥ 1 year) angiographic and clinical outcomes still require further investigation. The aim of this study was to compare the occlusion and complication rates for small (< 10 mm) versus large (10-25 mm) aneurysms at long-term following treatment with PED. A systematic review and meta-analysis were performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We conducted a comprehensive search of English language databases including Ovid MEDLINE and Epub Ahead of Print, In-Process, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. Our studies included a minimum of 10 patients treated with PED for small vs. large aneurysms and with at least 12 months of follow-up. The primary safety endpoint was the rate of clinical complications measured by the occurrence of symptomatic stroke (confirmed clinically and radiographically), intracranial hemorrhage, or aneurysmal rupture. The primary efficacy endpoint was the complete aneurysm occlusion rate. Our analysis included 19 studies with 1277 patients and 1493 aneurysms. Of those, 1378 aneurysms met our inclusion criteria. The mean age was 53.9 years, and most aneurysms were small (89.75%; N = 1340) in women (79.1%; N = 1010). The long-term occlusion rate was 73% (95%, CI 65 to 80%) in small compared to 84% (95%, CI 76 to 90%) in large aneurysms (p < 0.01). The symptomatic thromboembolic complication rate was 5% (95%, CI 3 to 9%) in small compared to 7% (95%, CI 4 to 13%) in large aneurysms (p = 0.01). The rupture rate was 2% vs. 4% (p = 0.92), and the rate of intracranial hemorrhage was 2% vs. 4% (p = 0.96) for small vs. large aneurysms, respectively; however, these differences were not statistically significant. The long-term occlusion rate after PED treatment is higher in large vs. small aneurysms. Symptomatic thromboembolic rates with stroke are also higher in large vs. small aneurysms. The difference in the rates of aneurysm rupture and intracranial hemorrhage was insignificant. Although the PED seems a safe and effective treatment for small and large aneurysms, further studies are required to clarify how occlusion rate and morbidity are affected by aneurysm size.

The effect of myelopathic symptoms on hospital costs, length of stay, and discharge location in anterior cervical discectomy and fusion.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is a common clinical degenerative disease treated with anterior cervical discectomy and fusion (ACDF), which seriously impacts quality of life and causes severe disability. The objective of the study was to determine the effect of different characteristics of the neurological deficit found in myelopathic patients undergoing ACDFs on hospital cost, length of stay (LOS), and discharge location. METHODS: This is a retrospective review of ACDF cases performed at a single institution by multiple surgeons from 2011 to 2017. Patient symptomatology, complications, comorbidities, demographics, surgical time, LOS, and discharge location were collected. Patients with readmissions or reoperations were excluded. Symptoms evaluated were based on clinical diagnosis, Japanese Orthopaedic Association classification, Ranawat grade, and Cooper scales. Symptoms were further grouped using principal component analysis. Cost was defined as surgical episode hospital stay costs plus outpatient clinic costs plus discharge disposition cost. Multivariate linear regression models were created to evaluate correlations with outcomes. The primary outcome was total 90-day hospital costs. Secondary outcomes were discharge location and LOS. RESULTS: A total of 250 patients were included in the analyses. Discharge location, neuromonitoring use, number of surgical vertebral levels, cage use, LOS, surgical time, having a complication, and sex were all found to be predictive of total 90-day costs. Myelopathic symptomatology was not found to be associated with increased 90-day costs (p ≥ 0.131) when correcting for these other factors. Lower-extremity functionality was found to be associated with increased LOS (p < 0.0001). Upper-extremity myelopathy was found to be associated with increased discharge location needs (p < 0.0001). CONCLUSIONS: Cervical myelopathy was not found to be predictive of total 90-day costs using symptomatology based on multiple myelopathy grading systems. Lower-extremity functionality was, however, found to predict LOS, while upper-extremity myelopathy was found to predict increased discharge location needs. This implies that preoperative deficits from myelopathy should not be considered in a bundled payment system; however, certain myelopathic symptoms should be considered when determining the cost of care.

A Scoping Review of Simulation-Based Training Paradigms for Carotid Artery Endarterectomy and Carotid Artery Stenting.

BACKGROUND: Surgical simulation has come to the forefront to enhance the training of residents. The aim of our scoping review is to analyze the available simulation-based carotid revascularization techniques, including carotid endarterectomy (CEA) and carotid artery stenting (CAS) and suggest critical steps for evaluating competency in a standardized fashion. METHODS: A scoping review of all reports on simulation-based carotid revascularization techniques including CEA and CAS was performed in PubMed/MEDLINE, Scopus, Embase, Cochrane, Science Citation Index Expanded, Emerging Sources Citation Index, and Epistemonikos databases. Data were collected according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The English language literature was searched from January 1, 2000 to January 9, 2022. The outcomes evaluated included measures of assessment of operator performance. RESULTS: Five CEA and 11 CAS manuscripts were included in this review. The methods of assessments employed by these studies to judge performance were comparable. The 5 CEA studies sought to validate and demonstrate improved performance with training or distinguish surgeons by their experience level, either through assessing operative performance or end-product results. The 11 CAS studies used 1 of 2 types of commercial simulators and focused on determining the efficacy of simulators as teaching tools. By examining the steps of the procedure associated with preventable perioperative complications, it provides a reasonable framework for determining which elements of the procedure should be emphasized most. Furthermore, using potential errors as a basis for assessment of competency could reliably distinguish operators based on level of experience. CONCLUSIONS: Competency-based simulation training is becoming more relevant as our surgical training paradigm shifts with the increased scrutiny within training programs of work-hour regulations and the need to develop a curriculum to assess our trainees' ability to perform specific operations competently during their stipulated training period. Our review has given us an insight into the current efforts in this space regarding 2 specific procedures that are key for all vascular surgeons to master. Although many competency-based modules are available, there is a lack of standardization in the grading/rating system of what surgeons consider vital steps of each procedure to assess these simulation-based modules. Therefore, the next steps of curriculum development should be based on standardization efforts for the different protocols available.

Absence of the torcular, review of venous sinus anatomy, and the simplified dural sinus classification.

BACKGROUND: Classically, the torcular Herophili is described as the symmetric junction between the superior sagittal sinus (SSS), transverse sinuses (TSs), and straight sinus (SS). However, finding this pattern in practice is not standard. Anatomical variations are common, and different drainage patterns should be expected. Existing literature proposes highly detailed descriptions and classifications of this region. Still, a simplified and practical categorization is not available. METHODS: We present an anatomical finding of the torcular Herophili discovered on a cadaveric dissection. Then, we conducted a retrospective study examining the 100 most recent cranial magnetic resonance venographies (MRVs) from the Mayo Clinic, labeling them with a new proposed dural sinus classification system. Images were initially classified by two authors and further validated by a board-certified neurosurgeon and a board-certified neuroradiologist from our institution. To measure consistency in image identification, two additional international neurosurgeons were asked to classify a subset of the same MRV images, and their answers were compared. RESULTS: Of the MRV cohort, 33 patients were male and 67 were female. Their ages ranged from 18 to 86 years, with a mean of 47.35 years and a median of 49 years. Upon examination, 53 patients presented as confluent (53%), 9 as SSS divergent (9%), 25 as SS divergent (25%), 11 as circular (11%), and 2 as trifurcated (2%). The inter-rater reliability ranked very good; agreement between the two neurosurgeons was 83% (κ = 0.830, p < 0.0005). CONCLUSION: The confluence of the venous sinuses is a highly variable anatomical area that is rarely evaluated with neuroimaging before surgery. The classic textbook configuration is not the rule. Using a simplified classification system may increase awareness and hopefully patient safety by preparing the physician for anatomical variations that they will encounter in a surgical or clinical scenario.

Focused selection of open cerebrovascular cases for residents interested in cerebrovascular neurosurgery / Selección enfocada de casos cerebrovasculares abiertos para residentes interesados en neurocirugía cerebrovascular

Introduction National and international trends continue to show greater emphasis on endovascular techniques for the treatment of cerebrovascular disease. The cerebrovascular neurosurgeon however must be adequately equipped to treat these patients via both open and endovascular techniques. Methods The decline in open cerebrovascular cases for aneurysm clipping has forced many trainees to pursue open cerebrovascular fellowships to increase case volume. An alternative strategy has been employed at our institution, which is early identification of subspecialty focus with resident driven self-selection of open cerebrovascular cases. Result This has allowed recent graduates to obtain enfolded endovascular training and a significant number of open cerebrovascular cases in order to obtain competence and exposure. Discussion We advocate for further self-selection paradigms supplemented with simulation training in order to obviate the need for extended post-residency fellowships (AU)

Introducción Las tendencias nacionales e internacionales continúan mostrando un mayor énfasis en las técnicas endovasculares para el tratamiento de la enfermedad cerebrovascular. Sin embargo, el neurocirujano cerebrovascular debe estar adecuadamente equipado para tratar a estos pacientes mediante técnicas tanto abiertas como endovasculares. Métodos La disminución de los casos cerebrovasculares abiertos por clipaje de aneurismas ha obligado a muchos alumnos a buscar becas cerebrovasculares abiertas para aumentar el volumen de casos. Se ha empleado una estrategia alternativa en nuestra institución, que es la identificación temprana del enfoque de subespecialidad con la autoselección impulsada por el residente de casos cerebrovasculares abiertos. Resultados Esto ha permitido a los recién graduados obtener una formación endovascular completa y un número significativo de casos cerebrovasculares abiertos para obtener competencia y exposición Discusión Abogamos por nuevos paradigmas de autoselección complementados con capacitación en simulación para evitar la necesidad de becas extendidas posteriores a la residencia (AU)

No Sex Differences in the Prevalence of Intracranial Aneurysms in Patients with Ascending Thoracic Aortic Aneurysms: A Multi-Center Experience.

BACKGROUND: Previous studies suggest a coprevalence of intracranial aneurysms (IA) in patients with infrarenal abdominal aortic aneurysms (AAA). We reviewed our multicenter experience in the detection/treatment of IAs in patients with ascending thoracic aortic aneurysms (ATAA) relative to patients without ATAA. METHODS: Surgical cases of ATAA repaired at 3 sites from January 1998 to December 2018 were retrospectively reviewed. Out of these patients, those with intracranial vascular imaging were selected for our study, and these individuals were concurrently randomly matched with a control group of patients who underwent intracranial vascular imaging without an ATAA in a 1:1 ratio by age, sex, smoking history, and year of intracranial vascular imaging. Conditional logistic regression was used to calculate odds ratios (OR). RESULTS: We reviewed 2176 ATAA repairs. 74% (n = 1,615) were men. Intracranial vascular imaging was available in 298 (13.7%) patients. Ninteen patients were found to have 22 IAs for a prevalence of 6.4%. Mean size of IA was 4.6 ± 3.3 mm; mean age at IA detection, 63.4 ± 12.1 years. IA was present on head imaging in 4.7% of male and 12.5% of female patients. Eleven (58%) patients were men. The OR of having IA in female versus male patients is 2.90, 95% confidence interval [CI] [1.08-7.50], P = 0.029. Time from IA diagnosis to ATAA repair was 1.7 ± 116.2 months. Two patients underwent treatment for IA, one ruptured and one unruptured. All were diagnosed before ATAA repair. Treatment included 1 clipping and 1 coiling with subsequent reintervention of the coiling using a flow diversion device. In the matched group of patients who had intracranial vascular imaging without ATAA, the rate of IA is 5.0%. IA was detected in 3.8% of males and 9.4% of female patients for an OR of 2.59, 95% CI [0.84-7.47], P = 0.083. Association within our study and matched groups, the OR of developing an IA with and without ATAA was not statistically significant 1.29, 95% CI [0.642.59], P = 0.48. There was also no evidence of sex differences in the association of ATAA with IA (interaction P = 0.88). The OR for the association of ATAA with IA was 1.33, 95% CI [0.46-3.84], P = 0.59 in females and 1.25, 95% CI [0.49-3.17], P = 0.64 in males. CONCLUSIONS: Our study found that IA was present in 6.4% of patients with ATAA who had intracranial vascular imaging available. The odds of IA were 1.29 times higher than a matched cohort of patients who had intracranial vascular imaging without ATAA but this failed to achieve statistical significance. We found that the odds of IA were more than 2 times higher in females than males for both those with ATAA (OR = 2.90) and those without ATAA (OR = 2.59); however, it only reached statistical significance in those with ATAA.

Focused selection of open cerebrovascular cases for residents interested in cerebrovascular neurosurgery.

INTRODUCTION: National and international trends continue to show greater emphasis on endovascular techniques for the treatment of cerebrovascular disease. The cerebrovascular neurosurgeon however must be adequately equipped to treat these patients via both open and endovascular techniques. METHODS: The decline in open cerebrovascular cases for aneurysm clipping has forced many trainees to pursue open cerebrovascular fellowships to increase case volume. An alternative strategy has been employed at our institution, which is early identification of subspecialty focus with resident driven self-selection of open cerebrovascular cases. RESULTS: This has allowed recent graduates to obtain enfolded endovascular training and a significant number of open cerebrovascular cases in order to obtain competence and exposure. DISCUSSION: We advocate for further self-selection paradigms supplemented with simulation training in order to obviate the need for extended post-residency fellowships.

Procedural, workforce, and reimbursement trends in neuroendovascular procedures.

BACKGROUND: This study aims to define the proportion of Medicare neuroendovascular procedures performed by different specialists from 2013 to 2019, map the geographic distribution of these specialists, and trend reimbursement for these procedures. METHODS: The Medicare Provider Utilization Database was queried for recognized neuroendovascular procedures. Data on specialists and their geographic distribution were tabulated. Reimbursement data were gathered using the Physician Fee Schedule Look-Up Tool and adjusted for inflation using the United States Bureau of Labor Statistics' Consumer Price Index Inflation calculator. RESULTS: The neuroendovascular workforce in 2013 and 2019, respectively, was as follows: radiologists (46% vs 44%), neurosurgeons (45% vs 35%), and neurologists (9% vs 21%). Neurologists increased proportionally (p=0.03). Overall procedure numbers increased across each specialty: radiology (360%; p=0.02), neurosurgery (270%; p<0.01), and neurology (1070%; p=0.03). Neuroendovascular revascularization (CPT 61645) increased in all fields: radiology (170%; p<0.01), neurosurgery (280%; p<0.01), neurology (240%; p<0.01); central nervous system (CNS) permanent occlusion/embolization (CPT61624) in neurosurgery (67%; p=0.03); endovascular temporary balloon artery occlusion (CPT61623) in neurology (29%; p=0.04). In 2019, radiologists were the most common neuroendovascular specialists everywhere except in the Northeast where neurosurgeons predominated. Inflation adjusted reimbursement decreased for endovascular temporary balloon occlusion (CPT61623, -13%; p=0.01), CNS transcatheter permanent occlusion or embolization (CPT61624, -13%; p=0.02), non-CNS transcatheter permanent occlusion or embolization (CPT61626, -12%; p<0.01), and intracranial stent placement (CPT61635, -12%; p=0.05). CONCLUSIONS: The number of neuroendovascular procedures and specialists increased, with neurologists becoming more predominant. Reimbursement decreased. Coordination among neuroendovascular specialists in terms of training and practice location may maximize access to acute care.

Natural history, angiographic presentation and outcomes of anterior cranial fossa dural arteriovenous fistulas.

BACKGROUND: Anterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs. METHODS: The CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990-2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed. RESULTS: 60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs. CONCLUSION: Most ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation.

Resolution of atlanto-occipital cyst with conservative management: A case report and review of the literature.

Background: Spinal synovial cysts are cystic dilatations of synovial sheaths that extrude into the spinal canal. Despite their generally benign behavior, they can cause severe symptoms due to compression of neural structures. They are most commonly found in the lumbar spine and are rare in the cervical region, especially at the atlanto-occipital junction. Case Description: A 65-year-old presented with neck pain and headaches. The magnetic resonance imaging (MRI) revealed a degenerative cyst within the anterior foramen magnum causing anterior spinal cord and brainstem compression. Multiple surgical treatment options were discussed, and he was prescribed methylprednisolone and immobilization of his cervical spine with a rigid collar. One month later, the patient reported dramatic improvement of his symptoms, and no surgery was performed. One year later, his pain had remained much improved with the continued use of the collar and pain management (i.e., using anti-inflammatories and muscle relaxants). The 1-year follow-up MRI showed the atlanto-occipital cyst compressing the cervicomedullary junction had completely resolved along with the brainstem compression. Conclusion: A 65-year-old presented with myelopathy attributed to a large anterior foramen magnum atlanto-occipital cyst compressing the cord. Conservative management for 1 month with a rigid cervical collar and steroids resulted in marked neurological improvement; at 1 year follow-up, the patient was markedly improved with an MR that demonstrated spontaneous cyst regression.

MIS lateral retroperitoneal transpsoas approach allows gross total resection of a giant L4 schwannoma.

In this surgical video, the authors present a successful minimally invasive (MIS) lateral retroperitoneal transpsoas approach for resection of an L4 nerve root schwannoma. They describe the surgical approach in detail, with special emphasis on patient positioning for an orthogonal view, as well as technical nuances throughout the procedure. Using a sequential tubular retractor, they performed a microscopic dissection of the lesion. The tumor was debulked and the tumor capsule was disconnected from the surrounding tissue. During dissection, direct stimulation identified a functional nerve root that was carefully dissected from the tumor capsule. The tumor was then removed en bloc. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2220.

Utility of evoked potentials during anterior cerebral artery and anterior communicating artery aneurysm clipping.

Objective: To investigate the optimal combination of somatosensory- and transcranial motor-evoked potential (SSEP/tcMEP) modalities and monitored extremities during clip reconstruction of aneurysms of the anterior cerebral artery (ACA) and its branches. Methods: A retrospective review of 104 cases of surgical clipping of ruptured and unruptured aneurysms was performed. SSEP/tcMEP changes and postoperative motor deficits (PMDs) were assessed from upper and lower extremities (UE/LE) to determine the diagnostic accuracy of each modality separately and in combination. Results: PMDs were reported in 9 of 104 patients; 7 LE and 8 UE (3.6% of 415 extremities). Evoked potential (EP) monitoring failed to predict a PMD in 8 extremities (1.9%). Seven of 8 false negatives had subarachnoid hemorrhage. Sensitivity and specificity in LE were 50% and 97% for tcMEP, 71% and 98% for SSEP, and 83% and 98% for dual-monitoring of both tcMEP/SSEP. Sensitivity and specificity in UE were 38% and 99% for tcMEP, and 50% and 97% for tcMEP/SSEP, respectively. Conclusions: Combined tcMEP/SSEP is more accurate than single-modality monitoring for LE but is relatively insensitive for UE PMDs. Significance: During ACA aneurysm clipping, multiple factors may confound the ability of EP monitoring to predict PMDs, especially brachiofacial hemiparesis caused by perforator insufficiency.

Interactive Neurosurgery Lecture Series: A Global Education Platform of Tele-Teaching During the Coronavirus Disease 2019 Pandemic and Beyond.

OBJECTIVE: To explore the worldwide impact of a virtual neurosurgery-neuroscience lecture series on optimizing neurosurgical education with tele-teaching. METHODS: A retrospective analysis was performed from our Zoom database to collect data from October 15, 2020, to December 14, 2020, and from September 27, 2021, to December 13, 2021. A comparative analysis of participants in the 2 different time frames was performed to investigate the impact of tele-teaching on neurosurgical education worldwide. To evaluate participant satisfaction, the yearly continuing medical education reports of 2020-2021 were analyzed. Data related to the distribution of lectures by subspecialties were also described. RESULTS: Among the 11 lectures of the first period, 257 participants from 17 countries in 4 different continents were recorded, with a mean of 64 (standard deviation = 9.30) participants for each meeting; 342 attendees participated from 19 countries in 5 continents over the 11 lectures of the second part, with an average of 82.8 (standard deviation = 14.04) attendees; a statistically significant increase in participation between the 2 periods was identified (P < 0.001) A total of 19 (2020) and 21 (2021) participants submitted the continuing medical education yearly survey. More than 86.4% of overall responses considered the lectures "excellent." The main topics reported during lectures in 2020-2021 were related to brain tumors (33.7%) and education (22.1%). CONCLUSIONS: The COVID-19 pandemic has increased the need to introduce new educational approaches for teaching novel ways to optimize patient care. Our multidisciplinary Web-based virtual lecture series could represent an innovative tele-teaching platform in neurosurgical training.