Skull Base Anatomy Research Articles

Modified colored three-dimensional posterior and temporal cranial fossa model with mobility of the joint between C1 and occipital condyle

BackgroundSkull base surgery requires anatomical knowledge and appropriate surgical technique in bone drilling. We developed a newly modified three-dimensional (3D) model of the posterior cranial fossa as a learning tool that improves knowledge of skull base anatomy and surgical approaches, including skull base drilling techniques. MethodsThis bone model of the posterior cranial fossa was created based on computed tomography data using a 3D printer, and incorporates artificial cranial nerves, cerebral vessels, bony structures, dura mater, and cerebellar tentorial dura. These anatomical components are differentiated with various colors. In addition, the atlanto-occipital junction can be mobilized to fully expose the surface of the cartilage between the C1 condyle and occipital condyle to allow drilling to open the hypoglossal canal under a wide surgical field. The usefulness of the model for practicing skull base surgical approaches was evaluated. ResultsExperience of bone drilling, dural dissection, and 3D positioning of important structures, including cranial nerves and blood vessels, was identical to that in actual surgery. ConclusionsThis model is designed to facilitate teaching anatomical knowledge and essential epidural procedure-related skills, and is useful for teaching the essential elements of posterior skull base surgery.

Relationships of the vidian nerve and internal carotid artery: MRI and intraoperative surgical evaluation.

Skull base anatomy around the internal carotid artery (ICA) is extremely complex. Among anatomical landmarks studied, the vidian canal has been thoroughly evaluated, unlike the vidian nerve (VN). Our aim is to evaluate the VN-ICA relationships, and understand their role in terms of surgical planning. Fifty MRI examinations of 100 healthy petro-spheno-clival regions were reviewed in order to evaluate the relationship between the vidian nerve axis (VNA) and the petrous ICA. Twenty-seven cases of expanded endonasal approaches to petrous apex region were evaluated to check the VN-ICA relationship intraoperatively. MRI evaluations showed that, in 23% of cases, the VNA was below the edge of the ICA, in 45% it was at the edge of the ICA and in 32% it ended up above the edge of the ICA. Surgically speaking, in 9 of 28 petrous apex approaches, the VN ended above the inferior edge of the petrous carotid. MRI evaluation adds useful information in planning the surgical approach to petro-spheno-clival regions, even if the identification of VNA, in these cases, may not be radiologically possible. Surgical experience confirms the importance of VN identification in guiding the surgeon in complex cases, and also outline the possible risks of relying only on this landmark.

Anterior interhemispheric vs. pterional approach in the microsurgical management of anterior communicating artery aneurysms: a comparative analysis employing a novel multidimensional matching-tool

The surgical management of anterior communicating artery aneurysms (AcomA) is challenging due to their deep midline position and proximity to complex skull base anatomy. This study compares the pterional craniotomy with the interhemispheric approach based on the specific aneurysm angulation. A total of 129 AcomA cases were analyzed, with 50 undergoing microsurgical clipping via either the pterional or interhemispheric approach. All selected cases had computed tomography-angiography with sagittal imaging slices and 2D-angiography. Using an interactive tool, 14 cases treated via the interhemispheric approach were matched with 14 cases approached pterionally based on clinical and morphological parameters, emphasizing intracranial aneurysm (IA) dome angulation relative to the frontal skull base. Outcomes included IA occlusion, temporary clipping incidence, intraoperative rupture, postoperative strokes, hemorrhages, hydrocephalus, vasospasm, and patient functionality. Matched cohorts had consistent demographics. Both approaches resulted in similar IA occlusion rates, but the interhemispheric approach led to improved clinical outcomes, measured by the modified Rankin Scale. It also had a lower incidence of hydrocephalus and reduced need for permanent ventriculoperitoneal shunt placement. Vasospasms and postoperative infarction rates were comparable between the groups. Our findings suggest potential advantages of the interhemispheric approach in managing AcomA, depending on aneurysm angulation. Despite a small sample size, the results highlight the importance of customized surgical decision-making based on the unique traits of each aneurysm and the surgeon's expertise.

Meningiomas in the Central Skull Base:From the Perspective of Endoscopic Transnasal Surgery

Recent advancements in endoscopic transnasal surgery(ETS)have expanded the application of this technique to meningiomas in the central skull base area, offering a less invasive alternative with a potentially lower physical burden on patients than conventional microscopic skull base surgery. Notably, while ETS allows surgeons to reach tumors without traversing the brain and nerves, thus theoretically reducing the risk of cranial nerve damage, it requires a high level of proficiency to avoid inadequate resection and tumor recurrence. In this article, we discuss the various surgical considerations, including preoperative imaging, surgical setting, nasal cavity expansion, skull base opening, tumor removal, and skull base reconstruction, as general procedures for specific meningiomas. We further describe the concept and details of our multi-layer fascial closure technique for dural repair in ETS, underlining the importance of skilled dural reconstruction in preventing postoperative complications. In conclusion, while ETS for skull base meningiomas presents a promising and less invasive treatment option, its success relies heavily on the surgeon's experience and understanding of the skull base anatomy, stressing the need for careful approach selection.

Imaging of cerebrovascular complications from blunt skull base trauma.

Cerebrovascular complications from blunt trauma to the skull base, though rare, can lead to potentially devastating outcomes, emphasizing the importance of timely diagnosis and management. Due to the insidious clinical presentation, subtle nature of imaging findings, and complex anatomy of the skull base, diagnosing cerebrovascular injuries and their complications poses considerable challenges. This article offers a comprehensive review of skull base anatomy and pathophysiology pertinent to recognizing cerebrovascular injuries and their complications, up-to-date screening criteria and imaging techniques for assessing these injuries, and a case-based review of the spectrum of cerebrovascular complications arising from skull base trauma. This review will enhance understanding of cerebrovascular injuries and their complications from blunt skull base trauma to facilitate diagnosis and timely treatment.

The classical supraorbital minicraniotomy to approach the areas of origin of anterior skull base meningiomas: Anatomical nuances influencing accessibility, operability, and frontal lobe retraction.

The classical supraorbital minicraniotomy (cSOM) constitutes a minimally invasive alternative for the resection of anterior skull base meningiomas (ASBM). Surgical success depends strongly on optimal patient selection and surgery planning, for which a careful assessment of tumor characteristics, approach trajectory, and bony anterior skull base anatomy is required. Still, morphometrical studies searching for relevant anatomical factors with surgical relevance when intending a cSOM for ASBM resection are lacking. Bilateral cSOM was done in five formaldehyde-fixed heads toward the areas of origin of ASBM. Morphometrical data with potential relevant surgical implications were analyzed. The more tangential position of the cSOM with respect to the olfactory groove (OG) led to a reduction in surgical freedom (SF) in this area compared to others (P < 0.0001). Frontal lobe retraction (FLR) was also higher when approaching the OG (P < 0.05). Olfactory nerve mobilization was higher when accessing the planum sphenoidale (PS), tuberculum sellae (TS), and anterior clinoid process (ACP) (P < 0.0001). OG depth and the slope of the sphenoid bone between the PS and TS predicted lower SF and higher frontal retraction requirements along the OG and TS, respectively (P < 0.05). In contrast, longer distances to the ACP tip predicted lower SF over this structure (P < 0.01). Although clinical validation is still needed, the present anatomical data suggest that assessing minicraniotomy's position/extension, OG depth, the sphenoid's slope, and distance to ACP-tip might be of particular relevance to predict FLR, maneuverability, and accessibility when considering the cSOM for ASBM resection, thus helping surgeons optimize patient selection and surgical strategy.

Selective Vestibular Neurectomy through the Presigmoid Retrolabyrinthine Approach in the Treatment of Meniere's Disease.

Meniere's disease (MD) is a disabling disease, especially in patients who are refractory to medical therapy. Moreover, selective vestibular neurectomy (VN), in these selected cases, can be considered a surgical alternative which preserves hearing function and facial nerve. We retrospectively studied 23 patients with MD diagnosis and history of failed extradural endolymphatic sac surgery (ELSS) who underwent combined micro-endoscopic selective VN, between January 2019 and August 2023, via a presigmoid retrolabyrinthine approach. All patients were stratified according to clinical features, assessing preoperative and postoperative hearing levels and quality of life. At the maximum present follow-up of 2 years, this procedure is characterized by a low rate of complications and about 90% vertigo control after surgery. No definitive facial palsy or hearing loss was described in this series. One patient required reintervention for a CSF fistula. Statistically significant (p = 0.001) difference was found between the preoperative and the postoperative performance in terms of physical, functional, and emotive scales assessed via the DHI questionnaire. Selective VN via a presigmoid retrolabyrinthine approach is a safe procedure for intractable vertigo associated with MD, when residual hearing function still exists. The use of the endoscope and intraoperative neuromonitoring guaranteed a precise result, saving the cochlear fibers and facial nerve. The approach for VN is a familiar procedure to the otolaryngologist, as is lateral skull base anatomy to the neurosurgeon; therefore, the best results are obtained with multidisciplinary teamwork.

The Displacement Patterns of Petrous Internal Carotid Artery and Its Morphometric Relations with Vidian Canal in Petroclival Chondrosarcomas Relevant to Extended Endoscopic Endonasal Approaches: A Radiological Study

PurposeExtended endoscopic endonasal approaches (EEAs) to petroclival chondrosarcomas (PCs) require a thorough understanding of skullbase anatomy, especially the anatomy of petrous ICA (pICA), as ICA injury is the most dreaded complication of extended EEAs. We conducted this study to determine the displacement patterns of pICA in patients with PCs. MethodsCECT & angiography images of patients with PCs were analyzed for following parameters -antero-posterior (AP), cranio-caudal (CC), medio-lateral (ML) & direct distances between anterior genu of pICA (AGpICA) and posterior end of vidian canal (pVC). pICA encasement/ narrowing by tumor was noted on MRI images. ResultsWe studied 11 patients with histopathologically proven PCs. pICA encasement/narrowing & pVC destruction were observed in one patient each. The mean AP & CC distances on tumor side/normal side were 7.7±1.9/6.4±1.0mm & 4.5±1.5/3.4±0.9mm, respectively. The overall displacement was posterior & superior. ML displacement was seen in 4 patients (lateral in 3 & medial in 1). In rest, AGpICA was centered on pVC. The mean direct distance was 9.4±2.5 mm. In 3 patients with displacement seen in all three axes, direct distance was measured by the “cuboid method”. Overall, posterior-superior-lateral, posterior-superior & anterior-inferior were the common displacement patterns of AGpICA relative to pVC. ConclusionsThe displacement patterns of AGpICA in PCs are variable. An individualized approach with meticulous analysis of preoperative imaging can help in determining the relation between AGpICA & pVC. This detailed morphometric information can facilitate better orientation to altered anatomy, which can be helpful in preventing pICA injury during extended EEAs.

Comparing the Clinical Orientation Benefits of Endoscopic demonstration on the Nose, Paranasal Sinuses, and Skull Base Versus Cadaveric Dissection for First-Year Medical Undergraduates.

The study aims to evaluate the advantages of using endoscopic demonstrations to teach nose, paranasal sinuses, and skull base anatomy compared to traditional cadaveric demonstrations. Traditional dissection methods do not provide an accurate representation of in vivo visualization of these anatomical areas. The goal is to align the teaching approach with the perspective students will have during clinical practice for better clinical orientation. In this study, 100 first-year medical students were split into two groups: Group A and Group B, each with 50 students. Group A received teaching through endoscopic demonstrations, while Group B had cadaveric demonstrations, both focused on nose, paranasal sinuses, and skull base anatomy. To assess comprehension and clinical orientation, both groups completed a questionnaire with clinically relevant questions, and their responses were collected and compared for analysis. Students who received endoscopic training showed better accuracy in addressing clinical queries than those only exposed to cadaveric dissection. Many participants favored incorporating endoscopic instruction, either as a replacement or addition to traditional cadaveric dissection, for the studied topics. The endoscopically trained group performed better in understanding anatomical landmarks, mentally reconstructing 3D images, and conceptualizing surgical approaches for the targeted anatomical areas. Incorporating endoscopic training for the nasal cavity, paranasal sinuses and skull base into the undergraduate medical curriculum would substantially augment students' clinical understanding and provide a more profound grasp of the dynamic anatomy in these areas.

A computed tomography (CT)-based morphometric study of various skull base parameters and their anatomical relationships relevant to endoscopic endonasal skull base surgery.

Endoscopic skull base surgery requires a thorough understanding of skull base anatomy. Orientation to regional anatomy to avoid complications like internal carotid artery injury can be assisted by knowledge of certain bony landmarks. These landmarks are themselves highly variable structures. This study focuses on the radiological morphometric characterization of these landmarks, which can be of great assistance to surgeons for better planning of endoscopic skull base approaches. Computed tomography scans of patients without skull base pathologies were analyzed retrospectively for the following parameters - Vidian canal (VC) length, VC and foramen rotundum (FR) distance from midline, the angle between the axis of VC and petrous internal carotid artery (pICA) and between VC and palatovaginal canal, the horizontal, vertical and direct distances between VC and FR and the patterns of sphenoid sinus (SS) pneumatization. The VC-pICA angle was more obtuse and VC and FR were placed farther off the midline on the left as compared to the right side. Similarly, the distances between VC and FR were more on the left side. The VC length and distance of VC and FR from the midline were longer in males than in females. The VC-pICA angle was more obtuse in females. The post-sellar variant was the predominant pneumatization pattern seen (57.9%), and the incidence of lateral recess pneumatization was 15%. The results of our study can be utilized for a better understanding of the anatomy of the skull base. In skull base pathologies with distorted anatomical landmarks, a basic understanding of their interrelations can be used to have a better anatomical orientation. All these measures can help in avoiding complications and make extended endoscopic approaches safe.

Canalis Basilaris Medianus as an Anatomical Variation in the Basilar Part of the Occipital Bone: A Descriptive Cone Beam Computed Tomographic Study

Abstract Objectives: Canalis basilaris medianus (CBM) is a unique anatomical variation located in the basal occipital region of the skull, rarely encountered in head and neck radiographic imaging. The aim of the present study was to evaluate the prevalence and types of CBM using Cone Beam Computed Tomography (CBCT) scans. Materials and Methods: CBCT (Full FOV) images of 200 patients aged between 10 to 70 years were selected for the current retrospective study following the inclusion and exclusion criteria. The image sections from the scan data were scrutinized for the presence of CBM, in addition to its classification based on the type of morphology. The presence and types of CBM were recorded based on the age and gender. The chi-square test was used to analyze the presence and types of CBM with regard to gender and age group. Results: The overall prevalence of CBM was estimated as 9.5%. CBM was present in 13% of males and 3% of females (p = 0.021). Considering the types of CBM, the superior recess type was predominantly observed followed by the inferior recess, superior and inferior type. However, there was no significant gender-based differences noted among the types of CBM (p &gt; 0.05). Also, there was no statistically significant difference noted in the prevalence of CBM in different age groups (p &gt; 0.05). Conclusion: It is necessary for maxillofacial radiologists to have a solid understanding of both normal and variant skull-base anatomy to facilitate recognition of variants such as CBM in order to recognize the associated anomalies. To our knowledge, this was the first study done which assesses the gender-based differences among the various types of CBM.

Outcomes following proton therapy for pediatric esthesioneuroblastoma.

Pediatric esthesioneuroblastoma (EN) can infiltrate skull base anatomy, presenting challenges due to high radiation doses and pediatric tissue sensitivity. This study reports outcomes of pediatric EN treated with proton radiotherapy (PT). Using an IRB-approved prospective outcomes registry, we evaluated patient, tumor, and treatment-related variables impacting disease control and toxicity in pediatric nonmetastatic EN treated with modern multimodality therapy, including PT. Fifteen consecutive patients (median age 16) comprising Kadish stage B (n=2), C (n=9), and D (n=4) tumors were assessed, including six with intracranial involvement, four with cranial nerve deficits, and four with cervical lymphadenopathy. Before radiation, two had subtotal and 13 had gross total resections (endoscopic or craniofacial). Two underwent neck dissection. Eleven received chemotherapy before radiation (n=5), concurrent with radiation (n=4), or both (n=2). Median total radiation dose (primary site) was 66Gy/CGE for gross disease and 54Gy/CGE (cobalt Gray equivalent) for microscopic disease. Median follow-up was 4.8years. No patients were lost to follow-up. Five-year disease-free and overall survival rates were 86% (no local or regional recurrences). Two patients developed vertebral metastases and died. Two required a temporary feeding tube for oral mucositis/dysphagia. Late toxicities included symptomatic retinopathy, major reconstructive surgery, cataracts, chronic otitis media, chronic keratoconjunctivitis, hypothyroidism, and in-field basal cell skin cancer. A multimodality approach for pediatric EN results in excellent local control. Despite the moderate-dose PT, serious radiation toxicity was observed; further dose and target volume reductions may benefit select patients. Longer follow-up and comparative data from modern photon series are necessary to fully characterize any relative PT advantage.

Transvenous embolization for an intraosseous clival arteriovenous fistula via a proper access route guiding a three-dimensional fusion image: illustrative case.

Intraosseous clival arteriovenous fistulas (AVFs), in which the shunt drains extracranially from the posterior and anterior condylar veins rather than from the cavernous sinus (CS), are rare. Targeting embolization of an intraosseous clival AVF is challenging because of its complex venous and skull base anatomy; therefore, a therapeutic strategy based on detailed preoperative radiological findings is required to achieve a favorable outcome. Here, the authors report the successful targeted embolization of an intraosseous clival AVF using an ingenious access route. A 74-year-old woman presented with left-sided visual impairment, oculomotor nerve palsy, and right facial pain. A fusion image of three-dimensional rotational angiography and cone-beam computed tomography revealed a left CS dural AVF and a right intraosseous clival AVF. The shunt flow of the clival AVF drained extracranially from the posterior and anterior condylar veins via the intraosseous venous route. Transvenous embolization was performed by devising suboccipital, posterior condylar, and intraosseous access routes. The symptoms resolved after the bilateral AVFs were treated. Accurate diagnosis and proper transvenous access based on detailed intraosseous and craniocervical venous information obtained from advanced imaging modalities are key to resolving intraosseous clival AVF.

Pediatric Esthesioneuroblastoma Treated with Proton Radiotherapy

Given its tendency to abut and infiltrate critical skull base anatomy, pediatric esthesioneuroblastoma (EN) presents a local control challenge, particularly given the high dose of radiation historically utilized in adult patients and the sensitivity of developing pediatric normal tissue. The purpose of this study was to report the outcomes of pediatric EN treated with proton radiotherapy. Using an IRB-approved, single institutional prospective outcomes registry, we analyzed disease control and toxicity in pediatric patients with non-metastatic EN treated with a multimodality approach, including proton radiotherapy, between March 2008 and March 2022. Of the 15 patients, 8 were female, and 7 were male. The median age was 16 years (range, 3-21 years). Patients were Kadish stage B (n = 2), C (n = 8), and D (n = 5) and Hyams low-grade (n = 9), high-grade (n = 5), and not specified (n = 1). Six patients had intracranial involvement, 4 had cranial nerve deficits, and 4 had positive cervical lymph nodes. Prior to radiation, 2 patients had a subtotal resection and 13 had a gross total resection via either endoscopic (n = 8) or craniofacial (n = 7) approaches. Two patients underwent neck dissection (one unilateral and one bilateral). A total of 11 patients received chemotherapy before (n = 5), concurrent (n = 4) with radiation, or both (n = 2). The median total radiation dose delivered to the primary site was 66 Gy/CGE (range, 59.4-72.8 Gy/CGE) for patients with gross disease and 54 Gy/CGE (range, 54-74.4 Gy/CGE) for patients with microscopic disease. With a median follow-up of 4.8 years (range, 0.1-12.2 years), both the 5-year disease free and overall survival rates were 86%. There were no local or regional recurrences. Two patients with Kadish D, high grade tumors developed vertebral metastases and died with disease. Serious acute toxicity included 2 patients requiring a temporary feeding tube for oral mucositis/dysphagia. Serious late toxicity included symptomatic retinopathy (n = 3), major reconstructive surgery (n = 2), cataracts requiring intervention (n = 2), chronic otitis media (n = 2), chronic keratoconjunctivitis (n = 2), hypothyroidism (n = 2), and in-field basal cell skin cancer (n = 1). A multimodality approach to pediatric EN results in excellent local control. Despite the use of moderate dose proton therapy, serious radiation toxicity was observed and thus select patients may benefit from further dose and target volume reduction. Longer follow-up and comparative data from modern photon series are necessary to fully characterize any relative advantage of proton therapy.

An Applied Anatomic Guide to Anterior Temporal Lobectomy and Amygdalohippocampectomy: Laboratory Cranial and White Matter Dissections to Inform Surgical Practice.

Anterior temporal lobectomy and amygdalohippocampectomy is a challenging procedure because of the deep surgical trajectory and complex regional neurovascular anatomy. A thorough knowledge of the involved anatomic structures is crucial for a safe and effective procedure. Our objective is to explore the white matter pathways in or around the operative corridor and to illuminate the 3-dimensional relationships of the pertinent operative parenchymal and skull base anatomy, aiming to inform and simplify surgical practice. Four normal, adult, cadaveric, formalin-fixed cerebral hemispheres (2 left and 2 right) treated with the Klinger's technique and 2 formalin-fixed and colored-latex-injected cadaveric heads (4 sides) were used. Focused white matter and cadaveric dissections were used to study the relevant anatomy implicated during an anterior temporal lobectomy. Four illustrative cases were also included. Digital photographs from every dissection step were obtained. Major white matter pathways that are inevitably traversed during the approach are the inferior longitudinal fasciculus, uncinate fasciculus, and inferior arm of the cingulum. Tracts that can be potentially injured, should the dissection plane tilt inadvertently superiorly or posteriorly, are the inferior fronto-occipital fasciculus, Meyer's loop, superior longitudinal fasciculus/arcuate fasciculus complex, and basal ganglia. Consistent cranial and parenchymal landmarks that can act as a roadmap during the procedure are recorded and paired with their intraoperative equivalent to provide a thorough, yet simple, stepwise guide for the surgeon. White matter dissections, cadaveric cranial dissections, and intraoperative images are put together to provide a simplified stepwise surgical manual for anterior temporal lobectomy. Laboratory investigations that focus on the intricate 3-dimensional relationships of the pertinent operative anatomy from the surgeon's eye may enrich anatomic knowledge and push surgical boundaries, to minimize complication rates and ultimately improve patient outcomes.

News from the European Journal of Therapeutics: A new issue and a new editorial board

News from the European Journal of Therapeutics: A new issue and a new editorial board

Imaging of Skull Base Tumors.

The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.

Frontotemporal Orbitozygomatic Transcavernous Approach: Stepwise Cadaveric Dissection for a Safe Corridor.

Background Advances in skull base surgery have increased the need for a detailed understanding of skull base anatomy and its intrinsic relationship to surrounding structures. This has resulted in an improvement in patient outcomes. The frontotemporal orbitozygomatic (FTOZ) transcavernous approach (TCA) is an excellent option for treating complex lesions involving multiple compartments of the skull base, including the sellar and parasellar, third ventricle, orbit, and petroclival region. Objective This article aimed to provide a detailed cadaveric dissection accompanying a thorough procedure description, including some tips and pitfalls of this technique. Methods Microsurgical dissection was performed in four freshly injected cadaver heads at the Cranial Base Neuroanatomy Laboratory, Cleveland Clinic Florida. The FTOZ TCA was performed on both sides of the four specimens. The advantages and disadvantages were discussed based on the anatomic nuances of this approach. Results The FTOZ TCA represented a wide access to the anterior, middle, and posterior fossa. When combined with an anterior clinoidectomy, it allowed for significant and safe internal carotid artery mobilization. This approach created numerous windows, including opticocarotid, carotid-oculomotor, supratrochlear, infratrochlear, anteromedial, anterolateral, and posteromedial triangles. The only drawback was the length of the dissection and the level of surgical acumen required to perform it. Conclusion Despite its technical difficulty, the FTOZ TCA should be considered for the surgical management of basilar apex aneurysms and tumors surrounding the cavernous sinus, sellar/parasellar, retrochiasmatic, and petroclival region. Continuous training and dedicated time in the skull base laboratory can help achieve the necessary skills required to perform this approach.

Skull base dural reflection models: tool for teaching neuroanatomy at resource-scarce centers.

Skull base dural reflections are complex, and along with various ligaments joining sutures of the skull base, are related to most important vessels like internal carotid arteries (ICA), vertebral arteries, jugular veins, cavernous sinus, and cranial nerves which make surgical approaches difficult and need thorough knowledge and anatomy for a safe dissection and satisfactory patient outcomes. Cadaver dissection is much more important for the training of skull base anatomy in comparison to any other subspecialty of neurosurgery; however, such facilities are not available at most of the training institutes, more so in low- and middle-income countries (LMICs). A glue gun (100-Watt glue gun, ApTech Deals, Delhi, India) was used to spread glue over the superior surface of the bone of the skull base over desired area (anterior, middle, or lateral skull base). Once glue was spread over the desired surface uniformly, it was cooled under running tap water and the glue layer was separated from the skull base. Various neurovascular impressions were colored for ease of depiction and teaching. Visual neuroanatomy of the inferior surface of dural reflections of the skull base is important for understanding neurovascular orientations of various structures entering or exiting the skull base. It was readily available, reproducible, and simple for teaching neuroanatomy to the trainees of neurosurgery. Skull base dural reflections made up of glue are an inexpensive, reproducible item that may be used for teaching neuroanatomy. It may be useful for trainees and young neurosurgeons, especially at resource-scarce healthcare facilities.

Endoscopy-Assisted Microneurosurgery for Sella and Optic Foramen Invading Anterior Cranial Fossa Base Meningiomas

Anterior skull base meningioma produces symptoms as a result of mass effect and neurovascular compression. The bony anatomy of the anterior skull base is complex and houses the critical cranial nerves and vessels. Traditional microscopic approaches remove these tumors effectively but require extensive brain retraction and bone drilling. Endoscope assistance offers the advantages of a smaller incision, less brain retraction, and bone drilling. The most significant advantage of endoscope-assisted microneurosurgery for lesions invading the sella and optic foramen is the complete resection of the sellar and foraminal components frequently responsible for recurrence. In this report, we describe the technique of endoscope-assisted microneurosurgical resection of anterior skull base meningiomas invading the sella and foramen. We present 10 cases and 3 case examples of endoscope-assisted microneurosurgery for meningiomas invading the sella and optic foramen. This report presents the operating room setup and surgical details to resect sellar and foraminal tumors. The surgical procedure is presented as a video. Endoscope-assisted microneurosurgery yielded excellent clinical and radiologic results and no recurrence at the last follow-up of meningiomas invading the sella and optic foramen. The present article discusses the challenges faced with endoscope-assisted microneurosurgery, techniques, and challenges in the procedure. Endoscope assistance enables complete tumor excision under vision with less retraction and bone drilling in anterior cranial fossa meningioma, invading the chiasmatic sulcus, optic foramen, and sella. The mixed use of microscope and endoscope makes it safer and saves time and is like bringing out the best of both worlds.