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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 Albert L. Rhoton Jr., MD, with particular attention to previously unpublished insights from the oral tradition of his fellows, recent technological advances including endoscopy, and high-dynamic range (HDR) photodocumentation, and, local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neuroanatomy, including specimen preparation, dissection, and 3D photodocumentation, supplemented by previously unpublished insights from the Rhoton fellowship experience and lessons learned in our laboratories in the past years such that Prof.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., Competing Interests: Conflict of Interest L.P.C. reports grants from Mayo Foundation, during the conduct of the study. M.P.C. reports grants from NREF, grants from Medtronic, grants from Storz, grants from CAPES, grants from Mayo Foundation, during the conduct of the study. L.C.P.C.L. reports grants from CAPES, during the conduct of the study.A.P. reports grants from Mayo Clinic, during the conduct of the study. M.J.L. reports grants from Mayo Foundation, during the conduct of the study., (Thieme. All rights reserved.)

Objective: To study the surgical anatomy of the labyrinthine artery (LA) and the subarcuate artery (SA), their anatomic relationships, and clinical implications, as injury of the LA can result in hearing loss., Methods: Ten formalin-fixed, latex-colored specimens were studied (20 sides). After retrosigmoid craniotomy and neurovascular dissection under microscopic magnification, 4-mm 0° and 30° endoscopic lenses were used to improve visualization. Results were statistically analyzed., Results: The LA was a constant artery that followed the vestibulocochlear nerve into the internal auditory canal. The SA was an inconstant artery that ended in the dura mater around the subarcuate fossa in 35% of cases. The LA originated from the anterior inferior cerebellar artery in 89.3% of specimens and from the basilar artery in 10.7% of specimens. The SA branched off from the anterior inferior cerebellar artery when present. The origin of the LA was inferomedial to the vestibulocochlear nerve in most cases (71.4%), whereas the SA was usually lateral (70%). The distal portion of the LA was inferomedial to the vestibulocochlear nerve in 71.4% of cases. The distal portion of the SA was superolateral to the nerve in all cases (P < 0.00001)., Conclusions: Knowledge of the different trajectory and anatomic relationship of the LA and the SA with the vestibulocochlear nerve is of paramount importance to differentiate them during surgery. The LA is usually inferomedial to the vestibulocochlear nerve at its distal and proximal aspects, whereas the SA usually originates lateral and ends superolateral to the nerve., (Copyright © 2020 Elsevier Inc. All rights reserved.)

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., Competing Interests: Conflict of Interest Grants from NREF, Medtronic, and Zeiss were received during the conduction of the study., (Thieme. All rights reserved.)