The Integration of 3D Virtual Reality and 3D Printing Technology as Innovative Approaches to Preoperative Planning in Neuro-Oncology.

Our study explores the integration of three-dimensional (3D) virtual reality (VR) and 3D printing in neurosurgical preoperative planning. Traditionally, surgeons relied on two-dimensional (2D) imaging for complex neuroanatomy analyses, requiring significant mental visualization. Fortunately, nowadays advanced technology enables the creation of detailed 3D models from patient scans, utilizing different software. Afterwards, these models can be experienced through VR systems, offering comprehensive preoperative rehearsal opportunities. Additionally, 3D models can be 3D printed for hands-on training, therefore enhancing surgical preparedness. This technological integration transforms the paradigm of neurosurgical planning, ensuring safer procedures.

Burnout in Neurosurgery.

BACKGROUND: Burnout is a pervasive psychosocial syndrome that manifests as a chronic response to interpersonal stressors encountered in the occupational setting. Neurosurgeons exhibit a high prevalence rate of burnout, ranging from 33% to 67%. The primary objective of this study is to examine the prevalence of Burnout syndrome within the neurosurgical community and identify the contributing factors. METHODS: A prospective observational study was conducted utilizing an anonymous survey format, incorporating the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) questionnaire. Additional inquiries were made regarding demographic characteristics, occupational factors, lifestyle choices, and the Hospital Anxiety and Depression Scale (HADS) questionnaire. The survey was disseminated between March 23rd, 2023, and April 4th, 2023, utilizing the email registries of the Spanish Society of Neurosurgery (SENEC) and the Latin American Federation of Neurosurgical Societies (FLANC). Descriptive analysis was performed, comparing responses between participants with and without burnout syndrome using cross-tabulation and the Chi-square test to assess the presence of dependency. RESULTS: A total of 282 neurosurgeons completed the survey. The sample comprised 30.1% females and 69.9% males, with a median age within the 30-40 range. Among the surveyed neurosurgeons, 66.7% exhibited a prevalence of burnout, while 23.4% met the criteria for defined burnout. Significantly higher rates of burnout syndrome were observed among residents, specifically those in their fifth year of residency, as well as those whose departments perform a moderate range of surgeries (500-1000), participating in on-call duties, lacking regular physical exercise (at least twice a week), engaging infrequently in social activities with friends, lacking extracurricular hobbies, and obtaining scores exceeding 10 points in any of the HADS subscales. CONCLUSIONS: Burnout syndrome affects nearly a quarter of the neurosurgical specialists included in this study. Moreover, a distinct profile associated with defined burnout among neurosurgeons emerges, encompassing characteristics such as being a fifth-year resident, belongs to departments with a moderate number of surgeries, with few extra-occupational distractions and exhibiting symptoms of depression or anxiety.

Entrenamiento microneuroquirúrgico en el espécimen anatómico. Propuesta de un plan estructurado de disección endoscópica y microquirúrgica basicraneal durante la residencia / Microneurosurgical training in the anatomical specimen: A structured plan for endoscopic and microsurgical skull base training during the residency

Antecedentes y objetivo: El desarrollo de una elevada capacidad crítica y competencia técnica constituye uno de los objetivos principales de todo programa de formación en Neurocirugía. Por múltiples factores, esta adquisición progresiva de habilidades técnicas puede resultar compleja durante la residencia. A pesar de su elevado coste y necesidad de infraestructura, existe un interés renovado respecto al papel de los laboratorios de anatomía. El estudio y disección del espécimen anatómico ha sido el contexto donde muchos neurocirujanos han desarrollado y perfeccionado la técnica microneuroquirúrgica. Proponemos un plan estructurado de disección y entrenamiento endoscópico y microquirúrgico que permita al residente obtener el máximo provecho durante su estancia en un laboratorio.Material y métodosDurante los meses de septiembre, octubre y noviembre de 2021 se realizó una estancia en el Laboratorio de Microneurocirugía y Base Craneal de la Universidad Miguel Hernández de Alicante. Se emplearon un total de 2 especímenes formolados e inyectados con silicona roja y azul. En el primer espécimen se realizó una primera fase de disección endoscópica endonasal. Tras completar la fase endonasal se plantearon un conjunto de incisiones para realizar los abordajes transcraneales. En el segundo espécimen se realizó primero la parte transcraneal dejando el trabajo endoscópico endonasal para la segunda fase.ResultadosSe muestran los resultados de la disección de los 2 especímenes. Durante la fase endoscópica endonasal se simuló el abordaje transesfenoidal a la silla incidiendo sobre los abordajes extendidos en el plano sagital. Durante la fase transcraneal se realizaron abordajes anterolaterales derecho e izquierdo, un abordaje interhemisférico transcalloso anterior izquierdo, un abordaje posterolateral transcondilar izquierdo y un abordaje lateral derecho combinado. (AU)

Background and objective: The development of a high level of competence and technical proficiency is one of the main objectives of any neurosurgical training program. Due to many factors, this progressive skill development can be complex during the residency. Despite its high cost and infrastructure requirements, there is renewed interest regarding the role of anatomy labs. The study and dissection of the human cadaver has been the environment where many surgeons have developed the necessary skills for microneurosurgery. We propose a structured endoscopic and microsurgical training dissection program to enable residents to maximize the benefits of their training in the lab.Material and methodsDuring the months of September, October and November 2021, a stay was done at the Microneurosurgery and Skull Base Laboratory of the Miguel Hernández University of Alicante. A total of 2 specimens were used. The first specimen underwent a first endoscopic endonasal dissection phase. After completing the endonasal part, a set of incisions were made to perform the transcranial part. In the second specimen, the transcranial part was performed first, leaving the endonasal endoscopic work for the last phase.ResultsThe results of the dissection program are presented. During the endonasal endoscopic phase, the transsphenoidal approach to the sella was simulated while focusing on the extended approaches in the sagittal plane. During the transcranial phase, right and left anterolateral approaches, a left anterior transcallosal interhemispheric approach, a left transcondylar posterolateral approach and a combined right lateral approach were performed. (AU)

Microneurosurgical training in the anatomical specimen: A structured plan for endoscopic and microsurgical skull base training during the residency.

BACKGROUND AND OBJECTIVE: The development of a high level of competence and technical proficiency is one of the main objectives of any neurosurgical training program. Due to many factors, this progressive skill development can be complex during the residency. Despite its high cost and infrastructure requirements, there is renewed interest regarding the role of anatomy labs. The study and dissection of the human cadaver has been the environment where many surgeons have developed the necessary skills for microneurosurgery. We propose a structured endoscopic and microsurgical training dissection program to enable residents to maximize the benefits of their training in the lab. MATERIAL AND METHODS: During the months of September, October and November 2021, a stay was done at the Microneurosurgery and Skull Base Laboratory of the Miguel Hernández University of Alicante. A total of 2 specimens were used. The first specimen underwent a first endoscopic endonasal dissection phase. After completing the endonasal part, a set of incisions were made to perform the transcranial part. In the second specimen, the transcranial part was performed first, leaving the endonasal endoscopic work for the last phase. RESULTS: The results of the dissection program are presented. During the endonasal endoscopic phase, the transsphenoidal approach to the sella was simulated while focusing on the extended approaches in the sagittal plane. During the transcranial phase, right and left anterolateral approaches, a left anterior transcallosal interhemispheric approach, a left transcondylar posterolateral approach and a combined right lateral approach were performed. CONCLUSIONS: The structured dissection of the specimen allowed both endonasal endoscopic and transcranial microsurgical training in the same specimen. This design facilitated the realization of the core skull base approaches in the same specimen. According to our initial experience, we believe that developing common dissection programs is a powerful tool to maximize the results of our residents' laboratory training.

Robot-assisted implantation of a microelectrode array in the occipital lobe as a visual prosthesis: technical note.

The prospect of direct interaction between the brain and computers has been investigated in recent decades, revealing several potential applications. One of these is sight restoration in profoundly blind people, which is based on the ability to elicit visual perceptions while directly stimulating the occipital cortex. Technological innovation has led to the development of microelectrodes implantable on the brain surface. The feasibility of implanting a microelectrode on the visual cortex has already been shown in animals, with promising results. Current research has focused on the implantation of microelectrodes into the occipital brain of blind volunteers. The technique raises several technical challenges. In this technical note, the authors suggest a safe and effective approach for robot-assisted implantation of microelectrodes in the occipital lobe for sight restoration.

Clinical and anatomical analysis of the epileptogenic spread patterns in focal cortical dysplasia patients.

Background: Focal cortical dysplasia (FCD) is one of the main causes of intractable epilepsy, which is amendable by surgery. During the surgical management of FCD, the understanding of its epileptogenic foci, interconnections, and spreading pathways is crucial for attaining a good postoperative seizure free outcome. Methods: We retrospectively evaluated 54 FCD patients operated in Federal Center of Neurosurgery, Tyumen, Russia. The electroencephalogram findings were correlated to the involved brain anatomical areas. Subsequently, we analyzed the main white matter tracts implicated during the epileptogenic spreading in some representative cases. We prepared 10 human hemispheres using Klinger's method and dissected them through the fiber dissection technique. Results: The clinical results were displayed and the main white matter tracts implicated in the seizure spread were described in 10 patients. Respective FCD foci, interconnections, and ectopic epileptogenic areas in each patient were discussed. Conclusion: A strong understanding of the main implicated tracts in epileptogenic spread in FCD patient remains cardinal for neurosurgeons dealing with epilepsy. To achieve meaningful seizure freedom, despite the focal lesion resection, the interconnections and tracts should be understood and somehow disconnected to stop the spreading.

Erratum to "Development and evaluation of a 3d printed training model for endoscopic third ventriculostomy in low-income countries" [Brain and Spine 3 (2023) 101736].

[This corrects the article DOI: 10.1016/j.bas.2023.101736.].

Development and evaluation of a 3d printed training model for endoscopic third ventriculostomy in low-income countries.

Introduction: Pediatric hydrocephalus is highly prevalent and therefore a major neurosurgical problem in Africa. In addition to ventriculoperitoneal shunts, which have high cost and potential complications, endoscopic third ventriculostomy is becoming an increasingly popular technique especially in this part of the world. However, performing this procedure requires trained neurosurgeons with an optimal learning curve. For this reason, we have developed a 3D printed training model of hydrocephalus so that neurosurgeons without previous experience with endoscopic techniques can acquire these skills, especially in low-income countries, where specific techniques training as this, are relatively absent. Research Question: Our research question was about the possibility to develop and produce a low-cost endoscopic training model and to evaluate the usefulness and the skills acquired after training with it. Material and Methods: A neuroendoscopy simulation model was developed. A sample of last year medical students and junior neurosurgery residents without prior experience in neuroendoscopy were involved in the study. The model was evaluated by measuring several parameters, as procedure time, number of fenestration attempts, diameter of the fenestration, and number of contacts with critical structures. Results: An improvement of the average score on the ETV-Training-Scale was noticed between the first and last attempt (11.6, compared to 27.5 points; p<0.0001). A statistically significant improvement in all parameters, was observed. Discussion and Conclusion: This 3D printed simulator facilitates acquiring surgical skills with the neuroendoscope to treat hydrocephalus by performing an endoscopic third ventriculostomy. Furthermore, it has been shown to be useful to understand the intraventricular anatomical relationships.

Predictive model of resection in endoscopic endonasal approach for pituitary adenomas based on anatomical limits / Modelo predictivo de resección en abordaje endoscópico endonasal de adenomas hipofisarios basado en límites anatómicos

Introduction The aim of this project is to study several anatomical-radiological features of pituitary adenomas obtained from preoperative radiological images and to analyze their relationship with the extent of resection achieved through the endoscopic endonasal approach. The second objective was to create a prediction model of the extent of resection. Material and methods We retrospectively evaluated 105 patients. Tumor volume, Knosp grade, suprasellar-diaphragm coefficient and invasion of the posterior compartment have been analyzed. The extent of resection was assessed by analyzing the postoperative magnetic resonance. We created the predictive scale using statistically independent variables. Results When each of the variables has been studied individually, a statistically significant value of all of them is appreciated to obtain a complete resection. However, only the Knosp grade and the suprasellar-diaphragm coefficient had a statistically significant value as independent variables. The sum of the Odds Ratio obtained from the Knosp scale, and the suprasellar-diaphragm coefficient gives the probability of complete resection. A new set of cases was employed to validate the scale. Conclusions The cavernous sinus invasion and the newly designed suprasellar diaphragm coefficient are directly related to the extent of resection in pituitary adenoma surgery performed by a transellar endoscopic approach. Moreover, based on both radiologic factors, a predictive scale may predict the probability of complete resection in a series of patients (AU)

Introducción El objetivo principal de este proyecto es estudiar diversas variables anatomo-radiológicas de los adenomas hipofisarios obtenidas a partir de imágenes radiológicas preoperatorias y analizar su relación con el grado de resección logrado mediante el abordaje endoscopio endonasal. El segundo objetivo ha sido crear un modelo de predicción del grado de resección tumoral. Material y métodos Se ha evaluado retrospectivamente a 105 pacientes, analizando el volumen tumoral, el grado de Knosp, el coeficiente supraselar-diafragma y la invasión del compartimento posterior. El grado de resección se ha evaluado mediante el análisis de la resonancia magnética postoperatoria. Se ha creado la escala predictiva empleando variables estadísticamente independientes. Resultados Al estudiar cada una de las variables de forma individual, se aprecia un valor estadísticamente significativo en cada una de ellas para obtener una resección completa. Sin embargo, tan solo el grado de Knosp y el coeficiente supraselar-diafragma tuvieron un valor estadísticamente significativo como variables independientes. Empleando la suma de la odds ratio obtenida de la escala Knosp y el coeficiente supraselar-diafragma, se ha obtenido la probabilidad de resección completa. Se ha empleado un nuevo conjunto de casos para validar la escala. Conclusiones La invasión del seno cavernoso y el coeficiente supraselar-diafragma son variables que están directamente relacionadas con el grado de resección en la cirugía de adenoma hipofisario realizada mediante un abordaje endoscópico transellar. Además, basándose en ambos factores radiológicos, se ha creado una escala predictiva que permite predecir la probabilidad de resección completa en una serie de pacientes (AU)

Dynamic Lateral Semisitting Position for Supracerebellar Approaches: Technical Note and Case Series.

BACKGROUND: It has always been a matter of debate which position is ideal for the supracerebellar approach. The risk of venous air embolism (VAE) is the major deterrent for surgeons and anesthesiologists, despite the fact that sitting and semisitting positions are commonly used in these operations. OBJECTIVE: To demonstrate a reduction on the risk of VAE and tension pneumocephalus throughout the operation period while taking advantages of the semisitting position. METHODS: In this study, 11 patients with various diagnoses were operated in our department using the supracerebellar approach in the dynamic lateral semisitting position. We used end-tidal carbon dioxide and arterial blood pressure monitoring to detect venous air embolism. RESULTS: None of the patients had clinically significant VAE in this study. No tension pneumocephalus or major complications were observed. All the patients were extubated safely after surgery. CONCLUSION: The ideal position, with which to apply the supracerebellar approach, is still a challenge. In our study, we presented an alternative position that has advantages of the sitting and semisitting positions with a lower risk of venous air embolism.

Predictive model of resection in endoscopic endonasal approach for pituitary adenomas based on anatomical limits.

INTRODUCTION: The aim of this project is to study several anatomical-radiological features of pituitary adenomas obtained from preoperative radiological images and to analyze their relationship with the extent of resection achieved through the endoscopic endonasal approach. The second objective was to create a prediction model of the extent of resection. MATERIAL AND METHODS: We retrospectively evaluated 105 patients. Tumor volume, Knosp grade, suprasellar-diaphragm coefficient and invasion of the posterior compartment have been analyzed. The extent of resection was assessed by analyzing the postoperative magnetic resonance. We created the predictive scale using statistically independent variables. RESULTS: When each of the variables has been studied individually, a statistically significant value of all of them is appreciated to obtain a complete resection. However, only the Knosp grade and the suprasellar-diaphragm coefficient had a statistically significant value as independent variables. The sum of the Odds Ratio obtained from the Knosp scale, and the suprasellar-diaphragm coefficient gives the probability of complete resection. A new set of cases was employed to validate the scale. CONCLUSIONS: The cavernous sinus invasion and the newly designed suprasellar diaphragm coefficient are directly related to the extent of resection in pituitary adenoma surgery performed by a transellar endoscopic approach. Moreover, based on both radiologic factors, a predictive scale may predict the probability of complete resection in a series of patients.

Micromirrors in Neurosurgery: Technical Overview and Benefits Assessment.

AIM: To weight the benefits and limitations of intraoperative use of micromirrors in neurosurgery. MATERIAL AND METHODS: Surgical cases where micromirrors were employed were retrospectively selected from the surgical database of five different surgeons in different hospitals. Complications directly attributable to the micromirrors were assessed intraoperatively and confirmed with postoperative neuroimaging studies. RESULTS: Fourteen patients were selected. The site of the lesion was as follows: posterior fossa (43%), frontal lobe (22%), temporal lobe (14%), parietal lobe (7%), insula (7%), and basal ganglia (7%). Five tumors (35%) were gliomas, 3 (21%) epidermoid, and 3 (21 %) supratentorial metastases. Two patients underwent microvascular decompression for neurovascular conflict, and 1 harbored a brain arteriovenous malformation. A gross total resection was achieved in all the tumors and the AVM, while an effective decompression was successfully performed in both patients with conflict. No complications directly attributable to the use of the micromirror occurred. A relatively easy learning curve was noted. CONCLUSION: Micromirrors proved to be useful in enhancing the visualization of neurovascular structures and pathology residuals within deep-seated surgical fields without the need for fixed brain retraction. Their cost-effectiveness and easy learning curve constitute solid reasons for advocating a revitalization of this ?old but gold? tool in neurosurgery.

Central quadrantotomy for intractable childhood epilepsy: operative technique and functional neuroanatomy.

Refractory subhemispheric epilepsy has been traditionally treated by resection. The last few decades have seen the emergence of disconnective techniques, for both hemispheric and subhemispheric disease. The aim of this study was to describe the technique for a disconnective surgery for large epileptogenic lesions involving the central (perirolandic cortices), parietal, and occipital lobes. This junctional cortex within the hemisphere (in contrast to anterior and posterior quadrantotomies) presents unique challenges when contemplating a complete disconnection of the region. The surgical technique is achieved through six distinct steps: fronto-central, inferior frontoparietal, lateral temporo-occipital, medial frontal, basal temporo-occipital, and posterior parasagittal callosal disconnections. The functional neuroanatomy of each step is described, along with cadaveric dissections. The authors describe this technique and include a case description of a young girl who presented with childhood-onset intractable epilepsy associated with cognitive stagnation. The postoperative seizure outcome in this patient remains excellent at 2 years' follow-up, with gains in cognition and behavior. Excellent seizure outcomes can be achieved if the network encompassing the entire epileptogenic cortex is disconnected while ensuring preservation of fiber systems that link functionally eloquent uninvolved cortices adjacent to the central quadrant.

Working in low- and middle-income countries: Learning from each other.

•Barriers may limit LMICs-HICs collaborations: infrastructure, equipment's lack/inadequacy, political issues, brain drain.•Local training is crucial for universal health coverage; several activities are headed by Global Neurosurgery organisations.•The â€‹EANS Global and Humanitarian Neurosurgery Committee aims to become a gateway for partnerships between HICs and LMICs.

Global neurosurgery amongst the EANS community: Where are we at?

•Awareness of Global Neurosurgery opportunities is limited in the EANS and a minority have had previous experiences with such activities.•Most training programs and job environments don't encourage participation in Global Neurosurgery and mentors are lacking.•However, most European neurosurgeons and trainees remain interested in Global Neurosurgery and are willing to participate.•Junior trainees is the group with the highest rate of interest for Global Neurosurgery.•Barriers exist that may limit participation in Global Neurosurgery, and funding is the most relevant.

A Frontal Route to Middle and Posterior Cranial Fossa: Quantitative Study for the Lateral Transorbital Endoscopic Approach and Comparison with the Subtemporal Approach.

BACKGROUND: Skull base lesions within the middle cranial fossa (MCF) remain challenging. Recent reports suggest that transorbital endoscopic approaches (TOEAs) might be particularly suitable to access the MCF and expose the lateral wall of the cavernous sinus and the Meckel's cave. METHODS: The present study was developed to compare the nuances of the subtemporal approach (STA) with those of the lateral TOEA (LTOEA) to the MCF and posterior cranial fossa (PCF) in cadaveric specimens. After orbital craniectomy, interdural opening of the cavernous sinus lateral wall (CSlw), exposure of the Gasserian ganglion, and extradural elevation of the temporal lobe was performed. Next, anterior endoscopic petrosectomy was performed and the PCF was accessed. We quantitatively analyzed and compared the angles of attack and distances between LTOEA and STA to different structures at the CSlw, petrous apex (PA), and PCF. RESULTS: Cadaveric dissection through the LTOEA completely exposed the CSlw and PA. LTOA exhibited larger distances than the STA to all targets. Importantly, these differences were greater at the PA and its surrounding key anatomic landmarks. The horizontal and vertical angles of attack allowed by the LTOA were smaller both for the CSlw and PA. However, these differences were not significant for the vertical angle of attack at the CSlw. CONCLUSIONS: LTOEA provides a direct ventral route to the medial aspect of MCF, PA, and PCF. Although TOEAs are versatile approaches, the unfamiliar surgical anatomy and limited instrument maneuverability demand extensive cadaveric dissection before moving to the clinical setting.

Three-Dimensional Reconstruction of the Sphenoid Sinus Anatomy for Presurgical Planning with Free OSIRIX Software.

Background A preoperative three-dimensional (3D) surgical field understanding remains a key factor to achieve safer endonasal transsphenoidal endoscopic approaches (ETSE). The aim of this article is to describe how we can get a reliable 3D sphenoidal anatomical reconstruction for surgical planning by using a user-friendly, accurate, and free image software. Methods Free computer software (OSIRIX Medical Imaging Software) was used to create in a personal computer a three-dimensional (3D) reconstruction of the sphenoid sinus (SS) based on head computed tomography angiographies (CTAs) from a series of 67 patients who were operated for sellar tumors during a 4-year period (March 2016 to March 2020). The aim of the 3D reconstruction with OSIRIX was to reveal preoperatively the most important intrasphenoidal structures seen from the endonasal point of view. Results The intraoperative visible sphenoidal structures were previously recognized in the virtual 3D reconstructed image with 100% of specificity (SP) and positive predictive value. The OSIRIX view by using region of interest points allowed us to see preoperatively the internal carotid artery parasellar course even in those cases in which it was hidden by bone or tumor. Moreover, the 3D reconstruction was able to provide a clear differentiation between the tumor and the pituitary gland when both structures were in contact with the sellar floor. Conclusion Our experience with the OSIRIX software from CTA as preoperative planning for endonasal pituitary surgery was valuable, because it gave us access in simple way to a free and reliable 3D image of the SS.

Interhemispheric Approach.

The interhemispheric approach is the natural route to reach the parafalcine and paraventricular structures through the interhemispheric fissure. In this chapter, we report the main anterior and posterior corridors of the interhemispheric approach.

3D Stereoscopic View in Neurosurgical Anatomy: Compilation of Basic Methods.

BACKGROUND: Stereoscopy has been demonstrated to be a useful method of education in the field of anatomy because it allows users to see, in a simulation, the anatomical structures in their actual volume and depth. METHODS: Cadaveric specimens preserved under formaldehyde using the Thiel and Klinger techniques have been dissected and photographed in the medical school anatomy laboratory (University Miguel Hernández) for the past 10 years. The photographic material and technique required to capture and project stereoscopic photographs have been described in different fields of surgical neuroanatomy. We used the results from a survey completed by the participants of different training courses to evaluate the utility of the 3-dimensional (3D) method. RESULTS: A large database of photographs taken of different anatomical regions and approaches of neurosurgical interest was obtained. We have presented some examples in the form of pairs of photographs in 2-dimensional (2D) format, with explanatory labels, paired with the corresponding 3D photograph in anaglyph format. The survey showed that the lectures that had included 3D photographs were significantly better accepted than the lectures with conventional 2D photographs. CONCLUSIONS: The teaching of basic, academic, and clinical neuroanatomy through the projection of stereoscopic photographs can be useful. The methods of image capture and stereoscopic projection in neuroanatomy, once combined with the necessary theoretical and practical knowledge, can be reproduced at other centers of neuroanatomy teaching.

Middle fossa approach for a facial nerve schwannoma: how I do it.

BACKGROUND: Facial nerve schwannomas can extend to the middle fossa or the cerebellopontine angle through the labyrinthine and cisternal segments of the facial nerve. The middle fossa approach (MFA) and its extensions provide a wide approach to deal with a large variety of lesions located in the middle and posterior cranial fossa junction. METHODS: We describe the MFA along with its advantages and limitations to treat a facial nerve schwannoma involving the middle and posterior cranial fossa. CONCLUSIONS: The MFA is a well-established route to surgically deal with tumors located in and around the proximal four segments of the facial nerve.