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Introduction The clival, paraclival, and craniocervical junction regions are challenging surgical targets. To approach these areas, endoscopic endonasal transclival approaches (EETCAs) and their extensions (far-medial approach and odontoidectomy) have gained popularity as they obviate manipulating and working between neurovascular structures. Although several cadaveric studies have further refined these contemporary approaches, few provide a detailed step-by-step description. Thus, we aim to didactically describe the steps of the EETCAs and their extensions for trainees. Methods Six formalin-fixed cadaveric head specimens were dissected. All specimens were latex-injected using a six-vessel technique. Endoscopic endonasal middle and inferior clivectomies, far-medial approaches, and odontoidectomy were performed. Results Using angled endoscopes and surgical instruments, an endoscopic endonasal midclivectomy and partial inferior clivectomy were performed without nasopharyngeal tissue disruption. To complete the inferior clivectomy, far-medial approach, and partially remove the anterior arch of C1 and odontoid process, anteroinferior transposition of the Eustachian–nasopharynx complex was required by transecting pterygosphenoidal fissure tissue, but incision in the nasopharynx was not necessary. Full exposure of the craniocervical junction necessitated bilateral sharp incision and additional inferior mobilization of the posterior nasopharynx. Unobstructed access to neurovascular anatomy of the ventral posterior fossa and craniocervical junction was provided. Conclusion EETCAs are a powerful tool for the skull-base surgeon as they offer a direct corridor to the ventral posterior fossa and craniocervical junction unobstructed by eloquent neurovasculature. To facilitate easier understanding of the EETCAs and their extensions for trainees, we described the anatomy and surgical nuances in a didactic and step-by-step fashion. [ABSTRACT FROM AUTHOR]

Introduction Although many neuroanatomic atlases have been published, few have detailed complex cranial approaches and pertinent anatomic considerations in a stepwise fashion intended for rapid comprehension by neurosurgery students, residents, and fellows. Methods Five sides of formalin-fixed latex-injected specimens were dissected under microscopic magnification. The frontotemporal and orbitozygomatic approaches were performed by neurosurgical residents and fellows at different training levels with limited previous experience in anatomical dissection mentored by the senior authors (M.P.C. and M.J.L.). Meticulous surgical anatomic dissections were performed until sufficient visual and technical completion was attained, with parameters of effectively demonstrating key surgical steps for educational training purposes. Following the completion of dissection and three-dimensional photography, illustrative case examples were reviewed to demonstrate the relative benefits and optimal applications of each approach. Results The frontotemporal and orbitozygomatic approaches afford excellent access to anterior and middle skull base pathologies, as well as the exposure of the infratemporal fossa. Key considerations include head positioning, skin incision, scalp retraction, fat pad dissection and facial nerve protection, true or false MacCarty keyhole fashioning, sphenoid wing drilling and anterior clinoidectomy, completion of the craniotomy and accessory orbital osteotomy cuts, dural opening, and intradural neurovascular access. Conclusion The frontotemporal and orbitozygomatic approaches are core craniotomies that offer distinct advantages for complex cranial operations. Learning and internalizing their key steps and nuanced applications in a clinical context is critical for trainees of many levels. The orbitozygomatic craniotomy in particular is a versatile but challenging approach; operative-style laboratory dissection is an essential component of its mastery and one that will be powerfully enhanced by the current work. [ABSTRACT FROM AUTHOR]

Introduction Safe, effective access to the fourth ventricle for oncologic resection remains challenging given the depth of location, restricted posterior fossa boundaries, and surrounding eloquent neuroanatomy. Despite description in the literature, a practical step-by step dissection guide of the suboccipital approaches to the fourth ventricle targeted to all training levels is lacking. Methods Two formalin-fixed, latex-injected specimens were dissected under microscopic magnification and endoscopic visualization. Dissections of the telovelar, transvermian, and supracerebellar infratentorial-superior transvelar approaches were performed by one neurosurgery resident (D.D.D.), under guidance of senior authors. The dissections were supplemented with representative clinical cases to highlight pertinent surgical principles. Results The telovelar and transvermian corridors afford excellent access to the caudal two-thirds of the fourth ventricle with the former approach offering expanded access to the lateral recess, foramen of Luschka, adjacent skull base, and cerebellopontine angle. The supracerebellar infratentorial-superior transvelar approach reaches the rostral third of the fourth ventricle, the cerebral aqueduct, and dorsal mesencephalon. Key steps described include positioning and skin incision, myofascial dissection, burr hole and craniotomy, durotomy, the aforementioned transventricular routes, and identification of relevant skull base landmarks. Conclusion The midline suboccipital craniotomy represents a foundational cranial approach, particularly for lesions involving the fourth ventricle. Operatively oriented resources that combine stepwise neuroanatomic dissections with representative cases provide a crucial foundation for neurosurgical training. We present a comprehensive guide for trainees in the surgical anatomy laboratory to optimize familiarity with fourth ventricle approaches, mastery of relevant microsurgical anatomy, and simultaneous preparation for learning in the operating room. [ABSTRACT FROM AUTHOR]

This article, titled "Surgical Anatomy of the Retrosigmoid Approach with Transtentorial Extension: Protecting the 4th Cranial Nerve," explores the challenges and techniques involved in safely incising the tentorium cerebelli during the Retrosigmoid Approach with Transtentorial Extension (RTA). The study was conducted on cadaver head specimens, and the researchers identified a working area for the incision, outlined by the tentorium's free edge and the trigeminal nerve. They described six different incisions for the tentorial opening, which allows access to the middle incisural space, the ventrolateral brainstem, and the base of the temporal lobe. The study provides a systematic description and illustration of the tentorial incision in the RSA, with a focus on protecting the 4th cranial nerve. [Extracted from the article]

This article compares the minipterional (MPT) and supraorbital eyebrow (SE) approaches to the parasellar region in neurosurgery. The study used cadaveric specimens to evaluate the exposures and anatomical indications of both approaches. The results showed that both approaches provided sufficient exposure along the ipsilateral parasellar region, but the viewing angle was significantly different. The MPT approach allowed for early access to the ipsilateral neurovascular structures, while the SE approach provided direct access to the anterior skull base and parasellar region bilaterally. The article concludes that both approaches minimize manipulation of the temporal muscle and may decrease retraction of brain parenchyma, but the SE approach is recommended for lesions requiring early proximal vascular control and access to the contralateral parasellar region. [Extracted from the article]

This article discusses the endoscopic endonasal transpterygoid approach (EETPA), a surgical technique used to access different regions of the brain. However, the presence of neurovascular structures in the pterygopalatine fossa (PPF) limits the optimal trajectory of this approach. The article presents anatomical foundations and surgical techniques for the neurovascular-sparing transposition of PPF content through the release of the orbito-pterygo-sphenoidal (OPS) ligament and the decompression of the descending palatine canal (DPC). The study was conducted on cadaveric head specimens, and the results showed successful transposition of the PPF while preserving important structures. The authors conclude that this technique is a viable option for surgery. [Extracted from the article]

This article discusses the management of an anatomical variant called the intraosseous subarcuate loop of the Anterior Inferior Cerebellar Artery (AICA) during the resection of a trigeminal schwannoma. The intraosseous subarcuate loop occurs when the AICA is entrapped in the temporal bone, posing a surgical challenge. The article presents a case study of a 42-year-old male who underwent a retrosigmoid approach with anterior reverse petrosectomy to safely mobilize the intraosseous loop and achieve gross total resection of the schwannoma. The article emphasizes the importance of identifying and safely mobilizing the intraosseous AICA loop to avoid complications during surgery. [Extracted from the article]

This article, titled "Anatomical Step-By-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Endoscopic Endonasal Superior Ethmoidectomy," describes a surgical technique for endoscopic anterior cranial base resection that aims to preserve nasal structures while providing access to the anterior skull base. The traditional technique involves removing ethmoidal cells, which can lead to postoperative complications such as nasal crusting. The authors performed the endoscopic endonasal superior ethmoidectomy on cadaveric head specimens and documented each step with endoscopic techniques. They concluded that this approach is a safe and effective method for accessing the anterior skull base while preserving nasal structures. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, provides a comprehensive anatomical overview and comparison of different surgical approaches to the petrous apex. The authors performed transcranial and endoscopic endonasal approaches on specimens and took 3D images at each step. The transcranial approaches included anterior petrosectomy, transcochlear approach, and retrosigmoid approach, while the endoscopic approaches included transclival-transcavernous approach, transmaxillary-transpterygoid approach, and contralateral transmaxillary approach. The article concludes by describing the different exposures of the petrous apex and related structures through these approaches. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, discusses a novel surgical technique for accessing tumors in the infratemporal fossa (ITF) that extend into the buccal space. Traditionally, a sublabial incision is made to expose the anterior wall of the maxilla, and the ITF is accessed by opening the maxillary sinus walls. However, this approach limits visibility and makes dissection behind the lateral buttress of the maxilla challenging. The authors describe a new technique involving osteotomies in the lateral buttress of the maxilla, allowing for a wider exposure of the ITF and buccal space. This approach improves visualization, safety, and the feasibility of removing large tumors. [Extracted from the article]

This article, titled "Expanded Endoscopic Approach to the Interpeduncular and Prepontine Cisterns: Pituitary Transposition Techniques," explores different surgical approaches for accessing the prepontine and interpeduncular cisterns using an expanded endonasal approach (EEA). The study compares three pituitary transposition techniques: extradural, interdural, and intradural. The results show that the interdural route provides the largest exposure and easier manipulation of structures in the interpeduncular cistern. The article emphasizes the importance of preoperative assessment to determine the safest and most effective technique for accessing these regions. [Extracted from the article]

This article discusses the use of a novel nasoseptal mucosal flap for the reconstruction of skull base and oropharyngeal defects. The traditional nasoseptal flap design may not be sufficient for large defects, so modified designs have been proposed. The study measured the dimensions of the standard and novel flap designs using computed tomography scans and found that the novel flap had a significantly larger usable area and increased length compared to the standard flap. The authors conclude that the novel nasoseptal flap is a viable option for reconstructing skull base and oropharyngeal defects. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, explores the microsurgical anatomy of the peritrigeminal zone (PTZ) and compares different transcranial skull base approaches for accessing this area. The study used cadaveric head specimens and MRIs to examine the surgical exposure and intrinsic architecture of the PTZ. The results showed that the retrosigmoid (RS), retrolabyrinthine (RL), and anterior petrosectomy (AP) approaches all provided access to the PTZ, but each approach had different trajectories and depths of access. The choice of approach depends on the location and axis of development of the pontine lesion being treated. [Extracted from the article]

This article, titled "The Extensions of the Far Lateral Approach: An Anatomical Guide," provides a detailed anatomical description and comparison of various extensions of the far lateral approach (FLA) used in surgical procedures for the craniocervical junction (CCJ) and foramen magnum (FM). The study used cadaveric head specimens to perform step-by-step extensions of the FLA and assessed the visualized structures and accessed areas before and after each extension. The results show that different extensions of the FLA provide access to specific regions and structures, and the choice of approach should be based on the dimensions of each osseous structure and the width of the surgical corridor created. The article concludes by providing recommendations for the appropriate use of each extension based on the location and characteristics of the lesions. [Extracted from the article]

This article provides a detailed description of both microsurgical and endoscopic approaches to the orbit, aimed at trainees in skull base surgery. The study utilized six cadaveric head specimens to perform various approaches, including endoscopic transorbital approaches, endoscopic endonasal approaches, the Caldwell-Luc approach, and orbitotomies and cranio-orbitotomies. The results highlight the distinct anatomical landmarks and advantages of each approach, such as improved aesthetics, reduced scarring, and enhanced visibility. The article aims to enhance the understanding and learning experience for trainees in skull base surgery. [Extracted from the article]

The article discusses the Retrosigmoid Approach with Endoscopic-Assisted Reverse Anterior Petrosectomy (RAP), a surgical technique used to treat lesions in the brain. The study examines the extent of access to Meckel's cave (MC) and the middle cranial fossa (MCF) during the procedure and provides guidance for protecting the internal carotid artery (ICA). The researchers performed dissections on anatomical specimens and measured various distances to MC and ICA. The results suggest that extended inferolateral drilling of the petrous apex provides greater access to MC, but carries a higher risk of injury to the ICA. The article recommends drilling in an anterior and superior direction to achieve better MCF access and avoid ICA injury. [Extracted from the article]

This article, titled "Origin and Course of the Branches of the Cavernous Internal Carotid Artery from the Endoscopic Endonasal Perspective: A Cadaveric Study," explores the anatomical variations and course of the branches of the cavernous internal carotid artery (cICA) from an endoscopic endonasal perspective. The study was conducted using thirty formalin-fixed latex-injected specimens, and the researchers identified the origin, course, and localization of cICA branches such as the inferolateral trunk (ILT), meningohypophyseal trunk (MHT), anterior and inferior McConnel's capsular arteries (MCAs), and superolateral trunk (SLT). The results showed that the ILT and MHT were present in all cases, while the anterior and inferior MCAs were present in 28% and 25% of cases, respectively. The study provides valuable information for surgeons performing endoscopic endonasal approaches to treat cavernous sinus lesions. [Extracted from the article]

This article, titled "Relevance of the Cochlear Aqueduct in Presigmoid Approaches: A Radio-Anatomical Study," explores the role of the cochlear aqueduct (CA) in presigmoid surgery. The CA is a bony canal that drains perilymph from the cochlea. The study examines whether the CA can serve as a reference for determining the height of the jugular bulb (JB) in presigmoid approaches. The researchers performed surgical approaches on cadaveric heads and analyzed CT scans of patients. They found that the presence of a supra-jugular CA predicted a larger presigmoid window and better access to prepontine structures. The CA's relationship to the JB can be discerned on preoperative CT scans, which may help surgeons decide whether to use a presigmoid approach. [Extracted from the article]

This article, titled "Approaches to Basilar Artery and Prepontine Cistern: An Anatomical Study," explores different surgical approaches to access the basilar artery and prepontine cistern. The study compares and illustrates six approaches: orbitozygomatic, pterional, subtemporal, anterior petrosectomy, retrosigmoid, and endoscopic endonasal. The authors utilized anatomical specimens and performed dissections under a microscope and endoscope for better visualization. The results show that each approach provides different degrees of access to the basilar artery and its branches, and the choice of approach should be based on the location of the lesion. [Extracted from the article]

Introduction The endoscopic endonasal transpterygoid approach (EETPA) with or without the addition of the endoscopic-assisted sublabial anterior transmaxillary approach (ESTA) has become increasingly utilized for lesions posterior to the pterygopalatine fossa (PPF), including infratemporal fossa (ITF), lateral recess of the sphenoid sinus, Meckel's cave, petrous apex, and parapharyngeal space. The main goal of this study is to develop an educational resource to learn the steps of the EETPA for trainees. Methods EETPA and ESTA were performed in 12 specimens by neurosurgery trainees, under supervision from the senior authors. One EETPA and one ESTA were performed on each specimen on opposite sides. Dissections were supplemented with representative cases. Results After a wide unilateral sphenoidotomy, ethmoidectomy, and partial medial maxillectomy, the anteromedial bone limits of the PPF were identified and drilled out. The pterygoid progress was modularly removed. By enlarging the opening of the posterior and lateral walls of the maxillary sinus through EETPA and ESTA, respectively, the neurovascular and muscular compartments of the PPF and ITF were better identified. The EETPA opens direct corridors to the PPF, medial ITF, middle cranial fossa, cavernous sinus, Meckel's cave, petrous apex, and internal carotid artery. If a more lateral exposure of the ITF is needed, the ESTA is an appropriate addition. Conclusion Despite the steep learning curve of the EETPA, granular knowledge of its surgical anatomy and basic surgical steps are vital for those advancing their learning in complex endoscopic approaches to the ventral skull base when expanding the approach laterally in the coronal plane. [ABSTRACT FROM AUTHOR]

Introduction Surgery of the sellar and parasellar regions can be challenging due to the complexity of neurovascular relationships. The main goal of this study is to develop an educational resource to help trainees understand the pertinent anatomy and procedural steps of the endoscopic endonasal approaches (EEAs) to the sellar and parasellar regions. Methods Ten formalin-fixed latex-injected specimens were dissected. Endoscopic endonasal transsphenoidal transsellar, transtuberculum-transplanum, and transcavernous approaches were performed by a neurosurgery trainee, under supervision from the senior authors and a PhD in anatomy with advanced neuroanatomy experience. Dissections were supplemented with representative case applications. Results Endoscopic endonasal transsphenoidal approaches afford excellent direct access to sellar and parasellar regions. After a wide sphenoidotomy, a limited sellar osteotomy opens the space to sellar region and medial portion of the cavernous sinus. To reach the suprasellar space (infrachiasmatic and suprachiasmatic corridors), a transplanum-prechiasmatic sulcus-transtuberculum adjunct is needed. The transcavernous approach gains access to the contents of the cavernous sinus and both medial (posterior clinoid and interpeduncular cistern) and lateral structures of the retrosellar region. Conclusion The anatomical understanding and technical skills required to confidently remove skull base lesions with EEAs are traditionally gained after years of specialized training. We comprehensively describe EEAs to sellar and parasellar regions for trainees to build knowledge and improve familiarity with these approaches and facilitate comprehension and learning in both the surgical anatomy laboratory and the operating room. [ABSTRACT FROM AUTHOR]

Introduction Skull base neuroanatomy is classically taught using surgical atlases. Although these texts are critical and rich resources for learning three-dimensional (3D) relationships between key structures, we believe they could be optimized and complemented with step-by-step anatomical dissections to fully meet the learning needs of trainees. Methods Six sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A far lateral craniotomy was performed by each of three neurosurgery resident/fellow at varying stages of training. The study objective was the completion and photodocumentation of the craniotomy to accompany a stepwise description of the exposure to provide a comprehensive, intelligible, and anatomically oriented resource for trainees at any level. Illustrative case examples were prepared to supplement approach dissections. Results The far lateral approach provides a wide and versatile corridor for posterior fossa operation, with access spanning the entire cerebellopontine angle (CPA), foramen magnum, and upper cervical region. Key Steps Include The study includes the following steps: positioning and skin incision, myocutaneous flap, placement of burr holes and sigmoid trough, fashioning of the craniotomy bone flap, bilateral C1 laminectomy, occipital condyle/jugular tubercle drilling, and dural opening. Conclusion Although more cumbersome than the retrosigmoid approach, a far lateral craniotomy offers unparalleled access to lesions centered lower or more medially in the CPA, as well as those with significant extension into the clival or foramen magnum regions. Dissection-based neuroanatomic guides to operative approaches provide a unique and rich resource for trainees to comprehend, prepare for, practice, and perform complex cranial operations, such as the far lateral craniotomy. [ABSTRACT FROM AUTHOR]

Introduction Although endonasal endoscopic approaches (EEA) to the orbit have been previously reported, a didactic resource for educating neurosurgery and otolaryngology trainees regarding the pertinent anatomy, techniques, and decision-making pearls is lacking. Methods Six sides of three formalin-fixed, color latex–injected cadaveric specimens were dissected using 4-mm 0- and 30-degree rigid endoscopes, as well as standard endoscopic equipment, and a high-speed surgical drill. The anatomical dissection was documented in stepwise three-dimensional (3D) endoscopic images. Following dissection, representative case applications were reviewed. Results EEA to the orbit provides excellent access to the medial and inferior orbital regions. Key steps include positioning and preoperative considerations, middle turbinate medialization, uncinate process and ethmoid bulla removal, complete ethmoidectomy, sphenoidotomy, maxillary antrostomy, lamina papyracea resection, orbital apex and optic canal decompression, orbital floor resection, periorbita opening, dissection of the extraconal fat, and final exposure of the orbit contents via the medial-inferior recti corridor. Conclusion EEA to the orbit is challenging, in particular for trainees unfamiliar with nasal and paranasal sinus anatomy. Operatively oriented neuroanatomy dissections are crucial didactic resources in preparation for practical endonasal applications in the operating room (OR). This approach provides optimal exposure to the inferior and medial orbit to treat a wide variety of pathologies. We describe a comprehensive step-by-step curriculum directed to any audience willing to master this endoscopic skull base approach. [ABSTRACT FROM AUTHOR]

Background  Despite the use of vascularized intranasal flaps, endoscopic endonasal posterior fossa defects remain surgically challenging with high rates of postoperative cerebrospinal fluid leak. Objective  The aim of the study is to describe a novel surgical technique that allows complete drilling of the clivus and exposure of the craniovertebral junction with preservation of the nasopharynx. Methods  Two formalin-fixed latex-injected anatomical specimens were used to confirm feasibility of the technique. Two surgical approaches were used: sole endoscopic endonasal approach and transnasion approach. The sole endonasal approach was used in a patient with a petroclival meningioma. Results  In both anatomical dissections, the inferior clivectomy with exposure of the foramen magnum was achieved with a sole endoscopic endonasal approach. The addition of the transnasion approach helped to complete drilling of the inferior border of the foramen magnum and exposure of the arch of C1. Conclusion  This study shows the anatomical feasibility of total clivectomy and exposure of the craniovertebral junction with preservation of the nasopharynx. A more favorable anatomical posterior fossa defect for the reconstruction is achieved with this technique. Further clinical studies are needed to assess if this change would impact the postoperative CSF leak rate. [ABSTRACT FROM AUTHOR]

Introduction  The middle fossa (MF) approaches encompass a group of versatile surgical accesses to pathologies in the MF, internal auditory canal (IAC), and superomedial aspect of the posterior fossa. Although many descriptions of the MF approaches have been published, a practical surgical guide that allows an easy understanding for Skull Base trainees is needed. Methods  Three formalin-fixed, colored-injected specimens were dissected under microscopic magnification (six sides). A MF craniotomy followed by IAC drilling was performed on three sides, and anterior petrosectomy (AP) was performed in the remaining three sides. The anatomical dissection was documented in stepwise three-dimensional photographic images. Following dissection, representative case applications were reviewed. Results  The MF approach provides direct access to the MF structures and IAC. The AP provides excellent access to the superomedial aspect of the posterior fossa. Key common steps include: positioning and skin incision; scalp and muscle flaps; burr holes; craniotomy flap elevation; dural dissection along the petrous ridge; division of the middle meningeal artery; and exposure of the greater superficial petrosal nerve, tegmen tympani, and V3. Then, to approach the IAC: superior IAC drilling, and longitudinal dura opening. The area drilled in the AP approach forms a pentagon limited by the petrous internal carotid artery, cochlea, IAC, petrous ridge, and lateral border of V3. Conclusion  The MF approaches are challenging. Operatively oriented skull base dissections provide a crucial foundation for learning these techniques. We describe comprehensive step-by-step approaches intended to develop familiarity in the cadaver laboratory and facilitate understanding of their potential for skull base disorders. Basic surgical principles are described to help in the operating room as well as illustrative cases. [ABSTRACT FROM AUTHOR]

Objective  This study was aimed to provide a key update to the seminal works of Prof. Albert L. Rhoton Jr., MD, with particular attention to previously unpublished insights from the oral tradition of his fellows, recent technological advances including endoscopy, and high-dynamic range (HDR) photodocumentation, and, local improvements in technique, we have developed to optimize efficient neuroanatomic study. Methods  Two formaldehyde-fixed cadaveric heads were injected with colored latex to demonstrate step-by-step specimen preparation for microscopic or endoscopic dissection. One formaldehyde-fixed brain was utilized to demonstrate optimal three-dimensional (3D) photodocumentation techniques. Results  Key steps of specimen preparation include vessel cannulation and securing, serial tap water flushing, specimen drainage, vessel injection with optimized and color-augmented latex material, and storage in 70% ethanol. Optimizations for photodocumentation included the incorporation of dry black drop cloth and covering materials, an imaging-oriented approach to specimen positioning and illumination, and single-camera stereoscopic capture techniques, emphasizing the three-exposure-times-per-eye approach to generating images for HDR postprocessing. Recommended tools, materials, and technical nuances were emphasized throughout. Relative advantages and limitations of major 3D projection systems were comparatively assessed, with sensitivity to audience size and purpose specific recommendations. Conclusion  We describe the first consolidated step-by-step approach to advanced neuroanatomy, including specimen preparation, dissection, and 3D photodocumentation, supplemented by previously unpublished insights from the Rhoton fellowship experience and lessons learned in our laboratories in the past years such that Prof. Rhoton's model can be realized, reproduced, and expanded upon in surgical neuroanatomy laboratories worldwide. [ABSTRACT FROM AUTHOR]

Advances in skull base and orbital surgery have led to an increased need to understand the anatomy of the orbit and surrounding structures to safely perform surgeries in this area. The purpose of this article is to review the surrounding anatomy of the orbit from a practical and operative point of view. We describe the orbit from an inferomedial endoscopic endonasal perspective (focusing on its inferior relationship with the maxillary sinus and related structures and its medial relationship with the ethmoid bone), from a posterior and superolateral intracranial perspective (describing the anatomy of the superior orbital fissure, optic canal, inferior orbital fissure, cavernous sinus, orbitofrontal cortex, and surrounding dura) and from an anterior perspective (focusing on the muscles, connective tissue, lateral and medial canthus, and relevant neurovascular anatomy). A deep knowledge of the critical neurovascular and osseous structures surrounding the orbit is necessary for adequately choosing and performing the most favorable orbital approach in every case. [ABSTRACT FROM AUTHOR]