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Background Breast cancer is the most common malignant tumor disease and the leading cause of female mortality. The evolution of nanomaterials science opens the opportunity to improve traditional cancer therapies, enhancing therapy efficiency and reducing side effects. Methods and major results Herein, protein cages conceived as enzymatic nanoreactors were designed and produced by using virus-like nanoparticles (VLPs) from Brome Mosaic Virus (BMV) and containing the catalytic activity of glucose oxidase enzyme (GOx). The GOx enzyme was encapsulated into the BMV capsid (VLP-GOx), and the resulting enzymatic nanoreactors were coated with human serum albumin (VLP-GOx@HSA) for breast tumor cell targeting. The effect of the synthesized GOx nanoreactors on breast tumor cell lines was studied in vitro. Both nanoreactor preparations VLP-GOx and VLP-GOx@HSA showed to be highly cytotoxic for breast tumor cell cultures. Cytotoxicity for human embryonic kidney cells was also found. The monitoring of nanoreactors treatement on triple negative breast cancer cells showed an evident production of oxygen by the catalase antioxidant enzyme induced by the high production of hydrogen peroxide from GOx activity. Conclusions and implications The nanoreactors containing GOx activity are fully suitable for cytotoxicity generation in tumor cells. The HSA functionalization of the VLP-GOx nanoreactors could result in a prevailing strategy to improve selective cancer targeting. The GOx containing enzymatic nanoreactors seems to be an interesting alternative to improve the current cancer therapy. In vivo studies are on going to reinforce the effectiveness of this treatment strategy.

OBJECTIVE: Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemor-rhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH. - METHODS: A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage. -RESULTS: On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored double dagger 1 peri-mesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH. CONCLUSIONS: In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse si-n us hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of double dagger 3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

Objective: Intraoperative magnetic resonance imaging (iMRI) can be useful for cerebral cavernous malformations (CCM) surgery. However, literature on this topic is scarce. We aim to investigate its clinical utility and propose criteria for the selection of patients who may benefit the most from iMRI. Methods: From 2017 to 2019, all patients with CCMs who required surgery assisted with iMRI were included in the study. Clinical and radiological features were analyzed. Outcome measures included the need for an immediate second-look resection and clinical course in early post-surgery-Timepoint 1(Tp1) and at the 6-to-12-month follow-up -Timepoint2-(Tp2). Results: Out of 19 patients with 20 CCMs, 89% had bleeding in the past, and in 75% the CCM affected an eloquent area. According to the iMRI results, an immediate second-look resection was needed in 16% of them. In one patient, a remnant was not seen on iMRI. The mRS worsened in the immediate postsurgical exam (median, 1; IQR, 1) with improvements on the 6-month visit (median, 1; IQR, 2), (p = 0.018). When comparing the outcome of patients with and without symptoms at baseline, the latter fared better at Tp2 (p = 0.005). Conclusions: iMRI is an intraoperative imaging tool that seems safe for CCM surgery and might reduce the risk of lesion remnants. In our series, it allowed additional revision for further resection in 16% of the patients. In our experience, iMRI may be especially useful for lesions in eloquent areas, those with a significant risk of brain shift and for large CCMs. (c) 2021 Elsevier Ltd. All rights reserved.

Currently available scores for predicting shunt dependency after aneurysmal spontaneous subarachnoid hemorrhage (aSAH) are limited and not widely accepted. The key purpose of this study was to validate a recently created score for shunt dependency in aSAH (SDASH) in an independent population of aSAH patients. We compared this new SDASH score based on a combination of the Hunt and Hess grade, Barrow Neurological Institute (BNI) score, and the presence or not of acute hydrocephalus with other published predictive scores. The SDASH score, Hijdra score, BNI grading system, chronic hydrocephalus ensuing from SAH score (CHESS), Graeb score, and modified Graeb score (mGS) were calculated for a cohort of aSAH patients. Logistic regression analysis was used to determine the reliability of the SDASH score, and the area under the curve (AUC) of the receiver operating characteristics (ROC) curve was used to assess the discriminative ability of the model. In 214 patients with aSAH, 40 (18.7%) developed shunt-dependent hydrocephalus (SDHC). The AUC for the SDASH score was 0.816. The SDASH score reliably predicted SDHC in aSAH (odds ratio: 2.93, 95% CI: 1.99–4.31; p < 0.001) with no statistically significant differences being found between the SDASH score and the CHESS score (AUC: 0.816), radiological-based Graeb score (AUC: 0.742), or modified Graeb score (AUC: 0.741). However, the Hijdra score (AUC: 0.673) and BNI grading system (AUC: 0.616) showed lower predictive values than the SDASH score. Our findings support the ability of the SDASH score to predict shunt dependency after SAH in a population independent to that used to develop the score. The SDASH score may aid in the early management of hydrocephalus in aSAH, and it does not differ greatly from other predictive scores.

BACKGROUND: Flow diverters (FDs) are an excellent option for the management of giant carotid artery aneurysms. However, in a nonnegligible percent of cases, the aneurysm may continue to grow despite multiple endovascular treatments and apparent occlusion on the angiogram. Due to the recent introduction of FDs, surgical experience after their failure is scarce and neurosurgeons have to face these challenging cases without much previous reference. Here we describe a giant ophthalmic-carotid aneurysm that presented with new severe mass effect 5 years after initially successful treatment with FDs and coils. We investigate the likely advantages of partial trapping versus complete trapping in this particular type of case. CASE DESCRIPTION: A 63-year-old patient with a subarachnoid hemorrhage from a 26-mm left carotid-ophthalmic aneurysm was initially embolized with coils. One year later a recanalization was observed and treated with an FD. Five years afterward, the patient's mild cognitive impairment prompted a magnetic resonance image that showed significant aneurysm growth despite apparent occlusion on angiogram. Rescue surgery consisted of partial trapping + extracranial-intracranial bypass and aneurysm debulking. The patient recovered from his deficits and remains asymptomatic 2 years later. CONCLUSIONS: In selected patients with previous long-term FDs, partial trapping may be a choice even if aneurysm debulking is needed. After years of stent placement, some endothelialization and neointimal membrane formation could have a summing effect to facilitate surgical exclusion and enable a safe thrombectomy. Classic revascularization techniques must be rethought and retested in this new FD era scenario.

Background Intracranial iatrogenic aneurysms (IIAs) developing after external ventricular drain (EVD) placement or removal have been only rarely reported. Most of these reports assumed a traumatic etiology; however, some have demonstrated an inflammatory origin. We have presented the case of an IIA that developed after an EVD had been inserted to treat acute hydrocephalus secondary to a ruptured arteriovenous malformation. We also performed a literature review and discussed how these IIAs might have an inflammatory rather than a traumatic etiology and how they might lie behind some of the cases of idiopathic hemorrhage observed after EVD manipulation. Case Description A 48-year-old woman had presented with acute hydrocephalus secondary to bleeding from a vermian arteriovenous malformation. The EVD inserted for hydrocephalus management required several revisions because of malfunction. Four weeks later, a diagnostic arteriogram had incidentally revealed the existence of a 5-mm aneurysm in an anterior branch of the right callosomarginal artery, coincidental to the EVD trajectory. The patient underwent emergent endovascular treatment of the aneurysm, with complete occlusion and no complications deriving from the procedure. Conclusions IIAs associated with EVD placement or removal have been described as a rare complication of the procedure. Despite the scarce number of cases reported and the lack of histological examinations, common features such as a distal location, an incidental diagnosis, and a benign clinical course might suggest a mycotic or inflammatory origin rather than a traumatic etiology. Considering the high volume of EVDs placed annually, this complication might be more frequent than reported. Further studies investigating the association of risk factors for inflammatory aneurysms and hemorrhage incidence after EVD could provide information on this intriguing topic.

BACKGROUND: Extracranial-to-intracranial bypass surgery is a well-established technique that has been practiced for over 50 years. Since then, numerous technical variants have developed nationally and internationally. OBJECTIVE: Based on a survey, to collect information on cerebrovascular bypass surgeons and their background, surgical volume, and technical steps of extracranial-to-intracranial bypasses with focus on superficial temporal artery to middle cerebral artery (STA-MCA) bypass. METHODS: An electronic survey was distributed among bypass neurosurgeons. Responses were analyzed for national-international variations of STA-MCA bypass surgery techniques. The survey focused on the technical aspects of the surgery itself rather than patient selection or perioperative management. RESULTS: Survey responses were collected from 51 neurosurgeons performing cerebrovascular bypass, from 11 different countries across North America, Europe, and Asia. The largest age block was early-to mid-career (66.7% aged 36-50 years). Most participating surgeons (80.40%) performed less than 20 bypasses annually, whereas a select few surgeons (3) performed more than 50 annually. The most common bypass was STA-M4MCA bypass with a linear incision (34%) over the parietal branch (44%) and choosing an MCA recipient based on diameter (61.2%). The interrupted anastomosis technique was most common (74%). CONCLUSIONS: The results of this electronic survey will help to identify common patterns in STA-MCA bypass surgery and will serve as a guide to other neurosurgeons to modify and improve their technique. Cerebrovascular bypass is still widely practiced, including by young neurosurgeons, who are actively learning from established masters who share their experience.

OBJECTIVEReliable tools are lacking to predict shunt-dependent hydrocephalus (SDHC) development after aneurysmal subarachnoid hemorrhage (aSAH). Quantitative volumetric measurement of hemorrhagic blood is a good predictor of SDHC but might be impractical in the clinical setting. Qualitative assessment performed using scales such as the modified Fisher scale (mFisher) and the original Graeb scale (oGraeb) is easier to conduct but provides limited predictive power. In between, the modified Graeb scale (mGraeb) keeps the simplicity of the qualitative scales yet adds assessment of acute hydrocephalus, which might improve SDHC-predicting capabilities. In this study the authors investigated the likely capabilities of the mGraeb and compared them with previously validated methods. This research also aimed to define a tailored mGraeb cutoff point for SDHC prediction.METHODSThe authors performed retrospective analysis of patients admitted to their institution with the diagnosis of aSAH between May 2013 and April 2016. Out of 168 patients, 78 were included for analysis after the application of predefined exclusion criteria. Univariate and multivariate analyses were conducted to evaluate the use of all 4 methods (quantitative volumetric assessment and the mFisher, oGraeb, and mGraeb scales) to predict the likelihood of SDHC development based on clinical data and blood amount assessment on initial CT scans.RESULTSThe mGraeb scale was demonstrated to be the most robust predictor of SDHC, with an area under the curve (AUC) of 0.848 (95% CI 0.763–0.933). According to the AUC results, the performance of the mGraeb scale was significantly better than that of the oGraeb scale (χ2 = 4.49; p = 0.034) and mFisher scale (χ2 = 7.21; p = 0.007). No statistical difference was found between the AUCs of the mGraeb and the quantitative volumetric measurement models (χ2 = 12.76; p = 0.23), but mGraeb proved to be the simplest model since it showed the lowest Akaike information criterion (66.4), the lowest Bayesian information criterion (71.2), and the highest R2Nagelkerke coefficient (39.7%). The initial mGraeb showed more than 85% specificity for predicting the development of SDHC in patients presenting with a score of 12 or more points.CONCLUSIONSAccording to the authors’ data, the mGraeb scale is the simplest model that correlates well with SDHC development. Due to limited scientific evidence of treatments aimed at SDHC prevention, we propose an mGraeb score higher than 12 to identify patients at risk with high specificity. This mGraeb cutoff point might also serve as a useful prognostic tool since patients with SDHC after aSAH have worse functional outcomes.

BACKGROUND: Chronic shunt-dependent hydrocephalus is a well-known complication of subarachnoid hemorrhage. Although the risk factors have been extensively investigated, most fail to predict permanent shunt dependency. It is unknown whether the volume of cerebrospinal fluid (CSF) from external ventricular drainage and the daily volume of drainage during the acute hydrocephalus phase (first 72 hours) can predict shunt dependency. We aimed to determine whether CSF output during the acute hydrocephalus phase is a risk factor for shunt dependency. -METHODS: Patients with aneurysmal subarachnoid hemorrhage and hydrocephalus treated with external ventricular drainage were prospectively registered in our database between January 2017 and March 2020. Factors evaluated for predicting shunt dependency included age; sex; Hunt and Hess grade; World Federation of Neurological Surgeons grade; acute hydrocephalus; modified Fisher grade; aneurysm treatment modality; hospital length of stay; modified Rankin score; average daily overall CSF production; average CSF output for the first 24, 48, and 72 hours; external ventricular drainage days; the number of wean/clamp failures; and ventriculoperitoneal shunting. -RESULTS: Univariate analysis identified Hunt and Hess grade; acute hydrocephalus at onset; external ventricular drainage; overall CSF output; average CSF output for the first 24, 48, and 72 hours; and CSF output until the first clamp as significant risk factors for shunt dependency (P < 0.001). In a multivariate logistic regression analysis, overall CSF output and average CSF output for the first 72 hours were significant risk factors for shunt dependency. -CONCLUSIONS: Overall CSF output, especially during the acute hydrocephalus phase (first 72 hours), predicts the development of chronic hydrocephalus.

Neurosurgery as a distinct speciality has been around for 100 years. Some of the earliest women neurosurgeons were European, emerging from the 19200s onwards. Here we detail the rise of women in neurosurgery across Europe with a decade by decade account of big events and firsts across the continent. The emerging themes are seen in stories of pioneers with enormous resilience, camaraderie, trailblazing and triumphing in a system with great obstacles and challenges. Our journey through this chronology brings us to the modern day, where most European countries have or have had a woman neurosurgeon and the future for women in neurosurgery in the continent is very bright. (C) 2021 Published by Elsevier Ltd.

A collaborative global working group of women neurosurgeons in multiple countries at different stages of their neurosurgical careers undertook the task of researching the history of European women in neurosurgery. While doing so, we happened upon many remarkable female neurosurgeons who overcame great adversity, made tremendous contributions to society and institutional neurosurgery, and displayed numerous talents beyond the operating room. In the first part of this paper, we recounted a chronology of female neurosurgeons in Europe, highlighting the most remarkable achievements of women in every decade, from the 1920 & rsquo;s to 2020. In this paper, we honor fascinating women in European neurosurgery, both historical characters and living legends. These women have overcome great adversity and have also excelled in a huge variety of pursuits. While some were themselves refugees, we also have uncovered noteworthy examples of women who immersed themselves in humanitarian missions and who tried to better the world through political action. There are stories of women beating the odds, taking on biased institutions and proving their worth, in spite of the prevailing system. Most inspirational, we have discovered through our comprehensive research on the history of women in European neurosurgery that the future is increasingly female. CO 2021 Elsevier Ltd. All rights reserved.

Microsurgical clipping is still regarded as the gold-standard treatment for broad-neck intracranial aneurysms. New endovascular techniques like balloon or stent assisted coiling are quickly rising to the challenge and showing promising outcomes. As a result, broad-neck aneurysms are increasingly addressed by these techniques despite they have not been tested against clipping in a randomized controlled trial and long-term complications might be unknown yet. Intraprocedural coil migration has been well documented in the literature, but the same complication in a delayed fashion is scarcely reported. We present a case of delayed coil migration occurring after a balloon-assisted embolization of a wide-necked intracranial aneurysm and we perform a literature review for similar cases. We discuss how, despite seeming an extremely rare complication, with new endovascular techniques increasingly perceived as the safer option in any aneurysm, potential adverse events may become more frequent. Strategies proposed to address this developing scenario are also reviewed.

Currently available scores for predicting shunt dependency after aneurysmal spontaneous subarachnoid hemorrhage (aSAH) are limited and not widely accepted. The key purpose of this study was to validate a recently created score for shunt dependency in aSAH (SDASH) in an independent population of aSAH patients. We compared this new SDASH score based on a combination of the Hunt and Hess grade, Barrow Neurological Institute (BNI) score, and the presence or not of acute hydrocephalus with other published predictive scores.The SDASH score, Hijdra score, BNI grading system, chronic hydrocephalus ensuing from SAH score (CHESS), Graeb score, and modified Graeb score (mGS) were calculated for a cohort of aSAH patients. Logistic regression analysis was used to determine the reliability of the SDASH score, and the area under the curve (AUC) of the receiver operating characteristics (ROC) curve was used to assess the discriminative ability of the model.In 214 patients with aSAH, 40 (18.7%) developed shunt-dependent hydrocephalus (SDHC). The AUC for the SDASH score was 0.816. The SDASH score reliably predicted SDHC in aSAH (odds ratio: 2.93, 95% CI: 1.99-4.31; p0.001) with no statistically significant differences being found between the SDASH score and the CHESS score (AUC: 0.816), radiological-based Graeb score (AUC: 0.742), or modified Graeb score (AUC: 0.741). However, the Hijdra score (AUC: 0.673) and BNI grading system (AUC: 0.616) showed lower predictive values than the SDASH score.Our findings support the ability of the SDASH score to predict shunt dependency after SAH in a population independent to that used to develop the score. The SDASH score may aid in the early management of hydrocephalus in aSAH, and it does not differ greatly from other predictive scores.

Resumen Introduccion Las tecnicas de revascularizacion cerebral constituyen una herramienta indispensable en el arsenal actual del neurocirujano vascular. Presentamos la experiencia adquirida y los resultados de la cirugia de revascularizacion tanto en la enfermedad de moyamoya como en la isquemia cerebral oclusiva. Pacientes y metodos Se analizan los pacientes con enfermedad isquemica oclusiva y enfermedad de moyamoya revascularizados microquirurgicamente en el periodo comprendido entre octubre de 2014 y septiembre de 2017. Resultados En el periodo de estudio, 23 pacientes con enfermedad isquemica oclusiva han sido revascularizados microquirurgicamente. Tres pacientes presentaron complicaciones postoperatorias graves (2 hemorragias intraparenquimatosas en el postoperatorio inmediato y una trombosis de la arteria femoral). En todos los pacientes, excepto en uno, el SPECT muestra una normalizacion de la reserva hemodinamica cerebral (RHC). Veinte pacientes presentaron un buen resultado neurologico, sin recurrencias isquemicas del territorio revascularizado. De la serie de pacientes con moyamoya, 20 presentaban una enfermedad de moyamoya y 5 un sindrome de moyamoya con afectacion unilateral. Cinco pacientes fueron tratados en edad pediatrica. Hubo un comienzo hemorragico en 2 pacientes. El estudio de la RHC mostro un compromiso hemodinamico en todos los pacientes. El SPECT cerebral al ano ha mostrado una resolucion del fracaso hemodinamico en todos los pacientes. Ha habido 4 complicaciones postoperatorias (hematoma subdural agudo, 2 colecciones subdurales y una dehiscencia de la herida quirurgica). Ningun paciente ha presentado un empeoramiento neurologico en los controles a los 6 y 12 meses. Conclusion La revascularizacion cerebral mediante la realizacion de una anastomosis termino-lateral entre la arteria temporal superficial y una rama cortical de la arteria cerebral media constituye una tecnica indiscutible en el tratamiento de la enfermedad de moyamoya y posiblemente pueda serlo en un subgrupo de pacientes con patologia oclusiva isquemica cerebral sintomatica.

Introduction Cerebral revascularization techniques are an indispensable tool in the current armamentarium of vascular neurosurgeons. We present revascularization surgery experience and results in both moyamoya disease and occlusive cerebral ischaemia. Patients and methods Patients with ischaemic occlusive disease and moyamoya disease who underwent microsurgical revascularization between October 2014 and September 2017 were analysed. Results In the study period, 23 patients with occlusive ischaemic disease underwent microsurgical revascularization. Three patients presented with serious postoperative complications (2 intraparenchymal haemorrhages in the immediate postoperative period and one thrombosis of the femoral artery). All patients, except one, achieved normalisation of the cerebral haemodynamic reserve (CHR) in the SPECT study. Twenty patients had a good neurological result, with no ischaemic recurrence of the revascularized territory. Among patients with moyamoya, 20 had moyamoya disease and 5 had moyamoya syndrome with unilateral involvement. Five patients were treated at paediatric age. Haemorrhagic onset occurred in 2 patients. The CHR study showed haemodynamic compromise in all patients. Cerebral SPECT at one year showed resolution of the haemodynamic failure in all patients. There have been 4 postoperative complications (acute subdural haematoma, two subdural collections and one dehiscence of the surgical wound). No patient presented with neurological worsening at 6 and 12 months of follow-up. Conclusions Cerebral revascularization through end-to-side anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery is an indisputable technique in the treatment of moyamoya disease and possibly in a subgroup of patients with symptomatic occlusive ischaemic cerebrovascular disease.

Objective Acquired anomalies of the dural venous sinuses (DVS) have been correlated extensively with the development of dural arteriovenous fistulas (DAVFs). Despite the known similarities of DAVFs' pathogenesis with that of arteriovenous malformations (AVMs), the relationship of venous sinuses anomalies with AVMs scarcely has been studied. We aimed to investigate whether patients with AVM show a greater prevalence of congenital DVS anomalies. We hypothesized that these congenital anomalies trigger AVM development during early childhood just as acquired DVS anomalies trigger DAVFs formation during adulthood. Methods Angiographic anomalies of the brain venous sinuses were studied in a cohort of 45 consecutive patients with AVM and compared with the angiographic; venous sinus anomalies of a control group formed by a second consecutive; series of 45 patients with subarachnoid hemorrhage. Results Congenital anomalies of any DVS were more frequent in patients with AVM than in the control group (49.8% vs. 22.2%; P = 0.015). Congenital abnormalities of the superior sagittal sinus not only were more frequent in patients with AVM (27% vs. 6.7%; P = 0.021) but seemed also related to the AVM location: in 5 of the 6 AVM cases with unilateral superior sagittal sinus aplasia, the AVM was ipsilateral to the venous anomaly. Conclusions Patients with AVM have a greater likelihood of congenital anomalies of any DVS. These anomalies seem to be related also to the AVM location. These findings suggest that congenital anomalies of DVS may be related to the development of AVMs.

BACKGROUND: The present study aims to draw attention to the fact that endurance sport could be a risk factor for dural arteriovenous fistula (DAVF) development. DAVFs have been correlated with acquired dural venous sinus anomalies owing to trauma, infection, neoplasia, or other classic risk thrombogenic factors. Here we report 3 cases of intracranial DAVF in young healthy patients who had no known thrombogenic risk factors other than amateur intensive sports practice. CASE DESCRIPTION: Three young healthy individuals not fitting into the classical clinical picture of a DAVF patient presented to our institution. One was a 40-year-old man with an acute subdural hematoma secondary to an ethmoidal DAVF. Another 41-year-old man presented with a cerebellar hematoma due to a tentorial DAVF. A third 41-year-old man presented with numbness of his right arm in relationship to a superior sagittal sinus DAVF. None of them had a relevant medical history. All the usual thrombogenic risk factors for DAVF development were ruled out. Interestingly, the 3 patients had outstanding training and practice routines for endurance sports. CONCLUSIONS: Dehydration, microfractures, muscular contractures, low heart rate, long distance travel, and high altitudes are all well documented thrombogenic risk factors affecting endurance sports amateur athletes and might represent a plausible mechanism for the development of DAVF. Despite its limitations, to our knowledge, this is the first work suggesting a possible link between such sport practice and DAVF development. Further prospective research from larger dedicated vascular centers might shed further light on this hypothetic but intriguing link.

OBJECTIVEThe percentage of women publishing high-impact neurosurgical research might be perceived as a representation of our specialty and may influence the perpetuation of the existing gender gap. This study investigated whether the trend in women taking lead roles in neurosurgical research has mirrored the increase in female neurosurgeons during the past decade and whether our most prestigious publications portray enough female role models to stimulate gender diversity among the new generation of neurosurgeons.METHODSTwo of the most prominent neurosurgical journals—Journal of Neurosurgery and Neurosurgery—were selected for this study, and every original article that was published in 2009 and 2019 in each of those journals was investigated according to the gender of the first and senior authors, their academic titles, their affiliations, and their institutions’ region.RESULTSA total of 1328 articles were analyzed. The percentage of female authors was significantly higher in Europe and Russia compared with the US and Canada (first authors: 60/302 [19.9%] vs 109/829 [13.1%], p = 0.005; and senior authors: 32/302 [10.6%] vs 57/829 [6.9%], p = 0.040). Significantly increased female authorship was observed from 2009 to 2019, and overall numbers of both first and senior female authors almost doubled. However, when analyzing by regions, female authorship increased significantly only in the US and Canada. Female authors of neurosurgical research articles were significantly less likely to hold an MD degree compared with men. Female neurosurgeons serving as senior authors were represented in only 3.6% (48/1328) of articles. Women serving as senior authors were more likely to have a female colleague listed as the first author of their research (29/97 [29.9%] vs 155/1231 [12.6%]; χ2 = 22.561, p = 0.001).CONCLUSIONSAlthough this work showed an encouraging increase in the number of women publishing high-impact neurosurgical research, the stagnant trend in Europe may suggest that a glass ceiling has been reached and further advances in equity would require more aggressive measures. The differences in the researchers’ profiles (academic title and affiliation) suggest an even wider gender gap. Cultural unconscious bias may explain why female senior authors have more than double the number of women serving as their junior authors compared with men. While changes in the workforce happen, strategies such as publishing specific issues on women, encouraging female editorials, and working toward more gender-balanced editorial boards may help our journals to portray a more equitable specialty that would not discourage bright female candidates.

Background Management of asymptomatic meningiomas represents a challenge due to the absence of a solid consensus on which is the best management strategy. There are various known factors predicting meningiomas growth risk. However, the Asian Intracranial Meningioma Scoring System (AIMSS) is the only described score to quantify such risk thus emerging as a potential tool for management decisions. This study aims to validate this score on our series of asymptomatic meningiomas. Method We performed a retrospective review of asymptomatic meningiomas diagnosed at our institution between January 2008 and October 2016 and followed by an annual cerebral Magnetic Resonance Imaging (MRI). For each lesion, the AIMSS score was calculated thus classifying them in low (0-2), intermediate (3-6) or high risk (7-11) of rapid growth (>2 cm(3)/year). We investigated the correlation between the expectedAverage Growth Rate (AGR) according to the score and the one obtained in our study. The mean growth velocity over the different risk groups was also compared. Results Overall, 69 asymptomatic meningiomas found incidentally in 46 patients were included in the study; 31 were assigned to the low-risk group, 34 to the intermediate-risk group and 4 to the high-risk group. Attending to the AGR, 0% showed rapid growth in the low-risk group, 12% in the intermediate-risk group, and 25% in the high-risk group. The mean growth velocity showed a significant difference over the different risk groups (p < 0,001). Conclusions According to our finding, the AIMSS score is a valid tool to estimate the risk of rapid growth of asymptomatic meningiomas. It is especially useful distinguishing between low-and intermediate-risk meningiomas. This feature would allow physicians to adjust the periodicity of radiological and clinical controls. Adding more known risk factors of rapid growth to the score might improve its predictive capabilities with the high-risk group.

OBJECTIVE: To describe the technique and initial experience of using a rotational 3-dimensional (3D) fluoroscopy system (O-arm; Medtronic) as intraoperative angiography (IA) in the surgery of cerebral aneurysms. METHODS: The 3D IA with O-arm (IAWOA) was performed in a consecutive cohort of patients with unruptured intracranial aneurysms. Conventional microsurgical clipping was performed with the assistance of indocyanine green videoangiography. Then the O-arm chassis was brought in, the ipsilateral internal carotid artery was catheterized, and contrasted images were acquired. Resulting datasets were exported in Digital Imaging and Communications in Medicine and processed using the Osirix software in an accessory computer. The 3D image reconstruction was evaluated intraoperatively to confirm aneurysm occlusion and parent vessel patency. Afterward, agreement among IAWOA, indocyanine green videoangiography, and standard postoperative angiography was analyzed. RESULTS: The initial pilot study was performed in 6 patients with 7 unruptured aneurysms. The aneurysm occlusion rate was 100%. The concordance of the IAWOA and the standard postoperative angiography was complete, both in terms of occlusion and parent vessel patency. No complications derived from the IAWOA were observed except in 1 patient, who presented a retroperitoneal hematoma without clinical consequences. CONCLUSIONS: The 3D rotational fluoroscopy (O-arm) device could be safely and effectively used as an IA system in selected patients. To the best of our knowledge, this is the first study reporting its use as an IA device. This technique seems to offer excellent image quality that could be compared with that of the gold standard 3D digital subtraction angiography but with a lower cost and versatility of use for other subspecialties.

OBJECTIVEAnterior communicating artery (ACoA) aneurysms are common intracranial aneurysms. Despite advances in endovascular therapy, microsurgical clipping remains an important treatment for aneurysms with broad necks, large size, intraluminal thrombus, complex branches, or previous coiling. Anatomical triangles identify safe corridors for aneurysm access. The authors introduce the A1-A2 junctional triangle and the A1-A1 precommunicating triangle and examine relationships between dome projection, triangular corridors of access, and surgical outcomes.METHODSPreoperative catheter and CT angiograms were evaluated to characterize aneurysm dome projection. Aneurysm projection was categorized into quadrants and octants. Preoperative, intraoperative, and postoperative factors were correlated to aneurysm dome projection and patient outcomes using univariate and multivariate analyses.RESULTSA total of 513 patients with microsurgically treated ACoA aneurysms were identified over a 13-year period, and 400 had adequate imaging and follow-up data for inclusion. Surgical clipping was performed on 271 ruptured and 129 unruptured aneurysms. Good outcomes were observed in 91% of patients with unruptured aneurysms and 86% of those with ruptured aneurysms, with a mortality rate < 1% among patients with unruptured aneurysms. Increasing age (p < 0.01), larger aneurysm size (p = 0.03), and worse preoperative modified Rankin Scale score (p < 0.01) affected outcomes adversely. Aneurysms projecting superiorly and posteriorly required dissection in the junctional triangle, and multivariate analysis demonstrated worse clinical outcomes in these patients (p < 0.01).CONCLUSIONSAnteriorly and inferiorly projecting aneurysms involve only the precommunicating triangle, are simpler to treat microsurgically, and have more favorable outcomes. Superior and posterior dome projections make ACoA aneurysms more difficult to visualize and require opening the junctional triangle. Added visualization through the junctional triangle is recommended for these aneurysms in order to facilitate dissection of efferent branch arteries, careful clip application, and perforator preservation. Dome projection can be determined preoperatively from images and can help anticipate dissection routes through the junctional triangle.

Criterios para la formacion y capacitacion en Neurorradiologia IntervencionistaNeurointervencionismo, acordados por el Grupo Espanol de Neurorradiologia Intervencionista (GENI), la Sociedad Espanola de Neurorradiologia (SENR) y los grupos expertos en patologia vascular de las sociedades espanolas de Neurocirugia (SENEC) y Neurologia (SEN). Bases para la obtencion de una acreditacion de centros y especialistas en Neurorradiologia Intervencionista-Neurointervencionismo

Hydrocephalus associated with different types of intracranial arteriovenous malformations (AVMs) has been scarcely studied. In the present report we investigate this association with posterior fossa AVMs (pfAVMs). We hypothesized that there is an increased risk of hydrocephalus and required permanent cerebrospinal fluid (CSF) shunt in patients with pfAVMs that may be linked to the increased risk of bleeding of these lesions. We also review the factors associated with this increased risk of hemorrhagic presentation and we assess how it affects management strategies and functional outcomes in these patients.Out of a prospective registry of 374 patients with brain AVMs diagnosed in our center from 1993 to 2013, 60 (16%) had a pfAVM. We described these patients' demographics, their AVM characteristics, clinical presentation, and hydrocephalus incidence and compared the results with those of the supratentorial AVM (spAVM) patients recorded during the same period.Out of the 60 patients with pfAVMs, 10 (16.7%) presented AVMs located in the brainstem. Hemorrhagic presentation (49/60; 82%) was significantly higher in pfAVMs than in spAVMs (122/314; 38.8%; p0.05). Hydrocephalus was a common complication in pfAVM patients who had a statistically significant higher need for both temporary external ventricular drain (EVD) (6.7 vs. 20%; p0.05) and permanent CSF shunts (3.5 vs. 20%; p0.05). The initial mortality was high (12/60; 20.3%) and half of these patients died before any treatment option could be offered. However, out of those who survived, 70% (42/60) had already shown good clinical outcome at the 6-month follow-up.Hemorrhagic presentation and hydrocephalus have a higher incidence in pfAVM patients, which initially results in more neurological deficits and an elevated mortality even before receiving any treatment. However, a large number of survivors present good functional outcomes at early follow-up, justifying an aggressive management strategy with microsurgery as the first treatment option in most cases, and radiosurgery as an alternative, especially in brainstem AVMs.

Background Surgical trapping or endovascular deconstruction commonly is used for the treatment of giant or complex intracranial aneurysms. Preoperative balloon test occlusion and cerebral blood flow studies and intraoperative neurophysiologic monitoring can indicate whether sufficient collateralization exists or whether revascularization is needed. Hemodynamic insufficiency can occur, however, despite passing these tests, necessitating posttreatment revascularization. Methods We conducted a retrospective review of patients who underwent surgical or endovascular parent vessel occlusion for the management of giant or complex intracranial aneurysms and subsequently required rescue bypass for symptoms of hemodynamic insufficiency. Pre- and postrevascularization functional status was measured with the modified Rankin Scale. Results During a 15-year period from 1997 to 2012, a rescue bypass was performed in 5 patients each harboring a giant or complex intracranial internal carotid artery (ICA) aneurysm that was treated with surgical trapping or endovascular deconstruction in a previous procedure. All bypasses were extracranial-to-intracranial and included cervical ICA to middle cerebral artery, subclavian to middle cerebral artery, and cervical ICA to supraclinoid ICA anastomoses via either a saphenous vein or radial artery graft. Functional outcome at time of last follow-up was improved in each patient (improvement in modified Rankin Scale of 1–3 points). Conclusions Ischemic complications must always be anticipated in the treatment of giant or complex intracranial aneurysms, even if pre- and intraoperative blood flow studies indicate sufficient collateralization. Here we show that extracranial-to-intracranial bypass is an effective option to rescue unanticipated hemodynamic insufficiency after parent vessel occlusion. This study emphasizes the need for cerebrovascular surgeons to maintain proficiency in complex bypass techniques.

Objective Systemic lupus erythematosus (SLE) is an autoimmune disorder of multifactorial etiology with a broad range of clinical manifestations. Cerebral disorders such as psychosis, seizures and cerebrovascular accidents are commonly described in SLE patients. Subarachnoid hemorrhage (SAH) presents a higher incidence than in the general population. Saccular aneurysms are the most frequent cause, but uncommon forms of SAH had been repeatedly reported in SLE patients. Through three case examples we outline these uncommon patterns, which we hypothesized, might be responsible for the higher incidence of SAH in SLE patients. Methods We present three patients previously diagnosed with SLE, who suffered a SAH and we perform a systematic literature review. Results All three cases presented with a Fisher grade IV bleeding. One harbored a distal middle cerebral artery aneurysm, another had multiple aneurysms, and the youngest patient had no findings on the cerebral angiography. A focal vasculitic process seemed most likely responsible for the two aneurismal cases. The angiography negative case was attributed to severe SLE systemic complications and had an unexpected bad outcome. Literature review yielded 39 previously reported cases. Conclusions The uncommon SAH patterns make etiological diagnosis challenging. Management can also be daunting due to both local and systemic consequences of SLE. Awareness of these uncommon patterns, management challenges, and higher likelihood of bad outcomes may help physicians dealing with this disease. Further research to unveil the mechanisms behind it is granted to fully understand SAH in SLE patients.

Object Descriptions of temporal lobe arteriovenous malformations (AVMs) are inconsistent. To standardize reporting, the authors blended existing descriptions in the literature into an intuitive classification with 5 anatomical subtypes: lateral, medial, basal, sylvian, and ventricular. The authors' surgical experience with temporal lobe AVMs was reviewed according to these subtypes. Methods Eighty-eight patients with temporal lobe AVMs were treated surgically. Results Lateral temporal lobe AVMs were the most common (58 AVMs, 66%). Thirteen AVMs (15%) were medial, 9 (10%) were basal, and 5 (6%) were sylvian. Ventricular AVMs were least common (3 AVMs, 3%). A temporal craniotomy based over the ear was used in 64%. Complete AVM resection was achieved in 82 patients (93%). Four patients (5%) died in the perioperative period (6 in all were lost to follow-up); 71 (87%) of the remaining 82 patients had good outcomes (modified Rankin Scale scores 0–2); and 68 (83%) were unchanged or improved after surgery. Conclusions Categorization of temporal AVMs into subtypes can assist with surgical planning and also standardize reporting. Lateral AVMs are the easiest to expose surgically, with circumferential access to feeding arteries and draining veins at the AVM margins. Basal AVMs require a subtemporal approach, often with some transcortical dissection through the inferior temporal gyrus. Medial AVMs are exposed tangentially with an orbitozygomatic craniotomy and transsylvian dissection of anterior choroidal artery and posterior cerebral artery feeders in the medial cisterns. Medial AVMs posterior to the cerebral peduncle require transcortical approaches through the temporo-occipital gyrus. Sylvian AVMs require a wide sylvian fissure split and differentiation of normal arteries, terminal feeding arteries, and transit arteries. Ventricular AVMs require a transcortical approach through the inferior temporal gyrus that avoids the Meyer loop. Surgical results with temporal lobe AVMs are generally good, and classifying them does not offer any prediction of surgical risk.

Distal intracranial aneurysms are rare, have unclear origins, and are frequently nonsaccular. Published clinical experience with these aneurysms is limited.To examine differences between distal aneurysms of cerebral and cerebellar arteries and to examine results associated with surgical therapy in 140 patients.Distal aneurysms in the cerebral arteries were defined as outside the circle of Willis, on or beyond the A2 anterior cerebral artery, M2 middle cerebral artery, or P2 posterior cerebral segments. Distal aneurysms in the cerebellar arteries were on or beyond the s2 superior cerebellar artery, a2 anterior inferior cerebellar artery, or p2 posterior inferior cerebellar artery segments. Clinical data, microsurgical technique, and patient outcomes were reviewed.The incidence of distal cerebellar artery aneurysms was 4.3 times greater than distal cerebral artery aneurysms (6.5% vs. 28.6%; P0.01). The A3 anterior cerebral artery segment and the p2 and p3 posterior inferior cerebellar artery segments were the most common sites. Presentation with aneurysm rupture was more frequent with cerebellar aneurysms (65% vs. 40%; P0.05). Distal cerebellar artery aneurysms were less likely than distal cerebral artery aneurysms to be clipable (40% vs. 72%; P0.01), with 42% treated with trapping alone. Overall, 14% required a bypass.Distal intracranial aneurysms have a predilection for cerebellar arteries and are not as rare as the literature suggests. Application of standardized nomenclature for segmental anatomy to these lesions will increase the precision of anatomic description and clarity of clinical discourse. Although technically difficult, good clinical results can be expected with surgical management.

Iatrogenic pseudoaneurysms are rare but serious complications of transsphenoidal surgery, and an iatrogenic pseudoaneurysm of the posterior cerebral artery (PCA) has been reported just once in the literature. The authors encountered such a case with a new P1 segment PCA pseudoaneurysm after endoscopic transsphenoidal resection of a pituitary adenoma. The aneurysm proved ideal for a novel intracranial–intracranial bypass in which the superior cerebellar artery (SCA) was used as an in situ donor artery to revascularize the recipient P2 segment. The bypass allowed aneurysm trapping without causing ischemic stroke or neurological morbidity. This case represents the first reported surgical treatment of an iatrogenic PCA pseudoaneurysm. Endovascular occlusion with coils was an option, but dolichoectatic morphology requires sacrifice of the P1 segment, with associated risks to the thalamoperforators and circumflex perforators. The SCA-PCA bypass was ideal because of low-flow demands. Like other in situ bypasses, it requires no dissection of extracranial arteries, no second incision for harvesting interposition grafts, and has a high likelihood of long-term patency. The SCA-PCA bypass is also applicable to fusiform SCA aneurysms requiring revascularization with trapping. This case demonstrates a dangerous complication that results from the limited view of the posterolateral surgical field through the endoscope and the imprecision of endoscopic instruments.

This report portrays our pitfall in the initial diagnosis of an intracranial arterial dissection that we misinterpreted as a saccular aneurysm. Intracranial arterial dissections presenting with convexity subarachnoid hemorrhage are rare, thus being easily mistaken with mild traumatic head injuries and therefore preventing transfer to a tertiary hospital. Even in those cases where the dissection is suspected and the patient is transferred to the appropriate facility for a diagnostic angiogram, misdiagnosis is not infrequent. The typical radiographic signs such as the double lumen or "pearl and string" are scarcely present in the diagnostic angiogram. Thrombus within the dissected segment can be mistaken by vasospasm and may even reveal fake images of saccular aneurysms, thus prompting inadequate endovascular or surgical treatment. The case reported here illustrates all these likely pitfalls in the diagnosis and management of intracranial arterial dissections.

Multiple cerebral arteriovenous malformations (AVMs) are a rare occurrence usually associated with defined genetic disorders or a family history of cerebrovascular disease. The remaining cases cannot be associated to a genetic pathogenesis and are considered idiopathic. We report an extremely unusual case nor genetic neither idiopathic, but linked to an anatomical intracranial venous variation. The patient presented two independent frontal AVMs associated with rostral hypoplasia of the superior sagittal sinus. This anatomical variation may have induced frontal venous hypertension (VHT) triggering the development of the two AVMs. Throughout this intriguing case, we discuss the role of VHT in AVM development.

Background Distal middle cerebral artery (MCA) aneurysms frequently have nonsaccular morphology that necessitates trapping and bypass. Bypasses can be difficult because efferent arteries lie deep in the opercular cleft and may not be easily identifiable. Objective We introduce the "flash fluorescence" technique, which uses videoangiography with indocyanine green (ICG) dye to identify an appropriate recipient artery on the cortical surface for the bypass, enabling a more superficial and easier anastomosis. Methods Flash fluorescence requires 3 steps: (1) temporary clip occlusion of the involved afferent artery; (2) videoangiography demonstrating fluorescence in uninvolved arteries on the cortical surface; and (3) removal of the temporary clip with flash fluorescence in the involved efferent arteries on the cortical surface, thereby identifying a recipient. Alternatively, temporary clips can occlude uninvolved arteries, and videoangiography will demonstrate initial fluorescence in efferent arteries during temporary occlusion and flash fluorescence in uninvolved arteries during reperfusion. Results From a consecutive series of 604 MCA aneurysms treated microsurgically, 22 (3.6%) were distal aneurysms and 11 required a bypass. The flash fluorescence technique was used in 3 patients to select the recipient artery for 2 superficial temporal artery-to-MCA bypasses and 1 MCA-MCA bypass. The correct recipient was selected in all cases. Conclusion The flash fluorescence technique provides quick, reliable localization of an appropriate recipient artery for bypass when revascularization is needed for a distal MCA aneurysm. This technique eliminates the need for extensive dissection of the efferent artery and enables a superficial recipient site that makes the anastomosis safer, faster, and less demanding.

Objective Although most ischemic strokes are thromboembolic in origin and their management is endovascular or medical, some are hemodynamic in origin and their management may be surgical. Extracranial-intracranial bypass with superficial temporal artery-to-middle cerebral artery (MCA) bypass, high-flow interposition grafts, and reconstructive techniques have been developed. Clinical indications and efficacy are controversial, and this review examines current practices. Methods Bypass surgery is indicated for patients with athero-occlusive disease that results in chronic, low cerebral blood flow accompanied by episodes of ischemic symptoms. Specific diagnoses include: (1) internal carotid artery occlusion; (2) MCA occlusion and, rarely, high-grade MCA stenosis; (3) vertebrobasilar atherosclerotic steno-occlusive disease; (4) vasculitis resulting in severe occlusive disease; and (5) moyamoya disease. Results Discouraging results from the Extracranial-Intracranial Bypass Trial demonstrated the importance of selecting surgical patients based on objective measures of hemodynamic insufficiency. Two such tests are xenon-enhanced computed tomography with acetazolamide challenge and positron emission tomography with measurement of oxygen extraction fraction. Perfusion computed tomography may be another, more practical test. Surgical series, systematic reviews of the literature, and two new randomized clinical trials that use these diagnostic techniques reveal contradictory results. Although they demonstrate that bypass surgery has a morbidity rate of less than 5% and a patency rate of more than 95%, they have not proven a clear benefit. Conclusions Patients with athero-occlusive disease and symptoms of hemodynamic insufficiency have significant risk of stroke if left untreated or managed medically. On the other hand, surgical intervention lacks supporting evidence. Clinicians must individualize their management recommendations until additional data are published or further consensus develops.

IntroductionMoyamoya disease is characterized by the gradualocclusion of distal internal carotid artery and thedevelopment of a collateral network of arteries torevascularize middle and anterior cerebral artery territo-ries. Similar collateral networks have also been describedin response to other occlusive vasculopathies differentfrom moyamoya disease. Rarely, aneurysms can formwithin these non-moyamoya collateral networks andpresent with hemorrhage. Overall, 12 cases of non-moyamoya occlusions revascularized by collateral arterialnetworks with an associated aneurysm have beenreported [1, 3–6, 9–14]. We report a case of a middlecerebral artery (MCA) occlusion with a collateral networkaneurysm. We also report two cases of aneurysm within acollateral arterial network arising from distal posteriorinferior cerebellar artery (PICA), which have not previ-ously been described. We present our management strategyand results in these three cases.Case reportsCase 1History and examinationA previously healthy 52-year-old man awoke with a severeright-sided headache, left-sided weakness, and difficultyambulating. His past medical history was not relevant. Onneurological exam, he was alert and oriented. He had a leftfacial droop and left hemiparesis with 4/5 strength in hisarm and leg.Diagnostic studiesHead CT scan revealed a right-sided 2.5-cm basal gangliahemorrhage. Cerebral angiography revealed a proximalocclusion of the right M1 MCA segment. A tangle of smallcaliber, tortuous arteries originating from the right A1anterior cerebral artery (ACA) segment reconstituted theM1 segment distally. The distal MCA and its branches hadnormalcaliberandcourse.A2-mmaneurysmwasseenwithinthat collateral network (Fig. 1a). Left internal carotid artery(ICA) angiography demonstrated normal left-sided vascula-ture with filling of the right-sided collateral network via apatent anterior communicating artery. Bilateral P1 segmentswere patent, and no arteriovenous shunting was observed.ManagementThe surgical plan was to perform a superficial temporalartery (STA) to MCA bypass to augment flow to the right

Object Surgical routes to posterior inferior cerebellar artery (PICA) aneurysms are opened between the vagus (cranial nerve [CN] X), accessory (CN XI), and hypoglossal (CN XII) nerves for safe clipping, but these routes have not been systematically defined. The authors describe 3 anatomical triangles and their relationships with PICA aneurysms, routes for surgical clipping, outcomes, and angiographically demonstrated anatomy. Methods The vagoaccesory triangle is defined by CN X superiorly, CN XI laterally, and the medulla medially. It is divided by CN XII into the suprahypoglossal triangle (above CN XII) and the infrahypoglossal triangle (below CN XII). From a consecutive surgical series of 71 PICA aneurysms in 70 patients, 51 aneurysms were analyzed using intraoperative photographs. Results Forty-three PICA aneurysms were located inside the vagoaccessory triangle and 8 were outside. Of the aneurysms inside the vagoaccessory triangle, 22 (51%) were exposed through the suprahypoglossal triangle and 19 (44%) through the infrahypoglossal triangle; 2 were between triangles. The lesions were evenly distributed between the anterior medullary (16 aneurysms), lateral medullary (19 aneurysms), and tonsillomedullary zones (16 aneurysms). Neurological and CN morbidity linked to aneurysms in the suprahypoglossal triangle was similar to that associated with aneurysms in the infrahypoglossal triangle, but no morbidity was associated with PICA aneurysms outside the vagoaccessory triangle. A distal PICA origin on angiography localized the aneurysm to the suprahypoglossal triangle in 71% of patients, and distal PICA aneurysms were localized to the infrahypoglossal triangle or outside the vagoaccessory triangle in 78% of patients. Conclusions The anatomical triangles and zones clarify the borders of operative corridors to PICA aneurysms and define the depth of dissection through the CNs. Deep dissection to aneurysms in the anterior medullary zone traverses CNs X, XI, and XII, whereas shallow dissection to aneurysms in the lateral medullary zone traverses CNs X and XI. Posterior inferior cerebellar artery aneurysms outside the vagoaccessory triangle are frequently distal and superficial to the lower CNs, and associated surgical morbidity is minimal. Angiography may preoperatively localize a PICA aneurysm's triangular anatomy based on the distal PICA origin or distal aneurysm location.

Background Superior cerebellar artery (SCA) aneurysms are usually grouped with aneurysms that arise from the upper basilar artery or more broadly, the posterior circulation. However, the SCA aneurysm has distinctive anatomy that facilitates safe surgical management, notably few associated perforating arteries, and excellent exposure in the carotid-oculomotor triangle. Objective To demonstrate the outcomes of patients treated with microsurgery in a continuous surgical series. Methods Sixty-two patients harboring 63 SCA aneurysms were retrospectively reviewed from a prospectively maintained database, focusing on clinical characteristics, surgical techniques, and clinical outcomes. Results Of 31 patients (49%) presenting with subarachnoid hemorrhage, the SCA aneurysm was the source in 16 (25%). Thirty-three aneurysms were complex (52%) and 43 patients (59%) had multiple aneurysms. Fifty-seven SCA aneurysms (90.5%) were clipped and 5 were bypassed/trapped or wrapped. Complete angiographic occlusion was achieved in 91.7%. Permanent neurological morbidity occurred in 3 patients and 3 patients that presented in coma after subarachnoid hemorrhage died. All patients with "simple" aneurysms and without subarachnoid hemorrhage had improved or unchanged modified Rankin scale scores. Overall, outcomes were stable or improved in 82.5% of patients. Conclusion SCA aneurysms are favorable for microsurgical clipping with low rates of permanent morbidity and mortality. Microsurgery should be considered alongside endovascular techniques as a treatment option in many patients.

Acute subdural hematomas (aSDH) secondary to intracranial aneurysm rupture are rare. Most patients present with coma and their functional prognosis has been classically considered to be very poor. Previous studies mixed good-grade and poor-grade patients and reported variable outcomes. We reviewed our experience by focusing on patients in coma only and hypothesized that aSDH might worsen initial mortality but not long-term functional outcome. Between 2005 and 2013, 440 subarachnoid hemorrhage (SAH) patients were admitted to our center. Nineteen (4.3%) were found to have an associated aSDH and 13 (2.9%) of these presented with coma. Their prospectively collected clinical and outcome data were reviewed and compared with that of 104 SAH patients without aSDH who presented with coma during the same period. Median aSDH thickness was 10mm. Four patients presented with an associated aneurysmal cortical laceration and only one had good recovery. Overall, we observed good long-term outcomes in both SAH patients in coma with aSDH and those without aSDH (38.5% versus 26.4%). Associated aSDH does not appear to indicate a poorer long-term functional prognosis in SAH patients presenting with coma. Anisocoria and brain herniation are observed in patients with aSDH thicknesses that are smaller than those observed in trauma patients. Despite a high initial mortality, early surgery to remove the aSDH results in a good outcome in over 60% of survivors. Aneurysmal cortical laceration appears to be an independent entity which shows a poorer prognosis than other types of aneurysmal aSDH.