The Sellar Region as Seen from Transcranial and Endonasal Perspectives: Exploring Bony Landmarks Through New Surface Photorealistic Three-Dimensional Model Reconstruction for Neurosurgical Anatomy Training

Background: Virtual reality-based learning of neuroanatomy is a new feasible method to explore, visualize, and "dissect" interactively complex anatomical regions. We provide a new interactive photorealistic 3D-model of sellar region microsurgical anatomy which allows to explore side-by-side views of exocranial and endocranial surfaces with the aim of assisting young neurosurgery residents in learning microsurgical anatomy of this complex region. Methods: Four head specimens underwent endoscopic endonasal approach extended to anterior and posterior skull base to expose main bony anatomical landmarks of sellar region. The same bony structures were exposed from transcranial perspective. By using photogrammetry method, multiple photos from both endocranial and exocranial perspectives, different for angulations and depth, were captured, fused and processed through dedicated software. Results: All relevant bony structures were clearly distinguishable in the 3D-model reconstruction, which provides several benefits in neuroanatomy learning: first, it replicates bony structures with high degrees of realism, accuracy and fidelity; in addition, it provides realistic spatial perception of depth of the visualized structures and their anatomical relationships; again, the 3D model is interactive and allows a 360 degrees self-guided tour of the reconstructed object, so that the learner can "read the bones" and their anatomical relationship from all desired points of view. Conclusion: Detailed knowledge of key surgical landmarks representing keyholes and/or anatomical structures to not violate is mandatory for a safer surgery, especially for complex region like skull base. Highly accurate virtual and functional neurosurgical models, like photogrammetry, can generate realistic look to further improve surgical simulators and learning neuroanatomy.