A Model Is Worth 1,000 Pictures: Applications of 3D-Modeling in Skull Base Surgery Neuroanatomy Education

Introduction: Complex skull base surgery is a technically challenging niche that requires not only sound operative skills, but also nuanced consideration of various operative approaches, and an intimate appreciation for neuroanatomy and its pathologic variations. Successful training models have been consistent over many years, and include the mainstay of traditional apprenticeships (e.g., residency, fellowship), supplemented by cadaver-based laboratories and dissection courses, as well as surgical atlases, textbooks, and other 2D resources. However, mentored experiences and cadaver dissection are resource-intensive, and while it can provide insight regarding normal anatomy, the considerations of complex skull base pathology are not always made clear by the combination of normal cadaveric specimens combined with 2D images. Our goal was to use new 3D modeling technologies including 3D printing, and virtual/augmented/mixed realities, spaces to develop neurosurgical education resources that are approach-based, resident-oriented, and derived from advanced neuroanatomic dissections.

Methods: We manufactured anatomically accurate 3D models obtained through high-resolution head CTs that included actual patient skull base pathology neoplastic and cerebrovascular lesions. Neurologic surgery and ENT residents and fellows at all training levels, were asked to describe the surgical approach and intraoperative considerations after reviewing one of the following: (1) Patient imaging along; (2) Patient imaging, supplemented by pertinent neuroanatomy print resources; (3) Patient imaging supplemented by 3D-printed models; or (4) Immersive AR/MR models derived from the patient imaging and pathology. Subjects were then tested on their neuroanatomical knowledge, and asked to complete a self-reported survey based on a validated Likert’s agreement scale (e.g., strongly agree, agree, neutral, disagree, strongly disagree), which assessed their perception of the utility of the resources provided with respect to parameters such as understanding of anatomical relationships, knowledge of approach indications and relative risks/benefits, and appropriately anticipated operative complications.

Results: Survey and neuroanatomy test results indicated a significant improvement in understanding of 3D neuroanatomic relationships and principles of approach selection after having seen the printed models, as compared with 2D imaging alone. Residents across all training levels survey reported significantly enhanced appreciation for surgical approach considerations, better understanding of nuanced pathology involvement with surrounding neuroanatomy, and increased rates of confidence in their ability to perform various aspects of the surgical case. Subjects participating in the dissection and/or 3D modeling phases of development performed at a higher level than those provided access to study resources, who in turn outperformed residents using traditional resources.

Conclusion 3D printing and related modeling techniques have a very high potential to positively impact neuroanatomy education for skull base trainees, with particular attention to the nuances of individualizing approach selection across a wide range of pathologies. Applied appropriately, 3D modeling is anticipated to improve the educational yield of almost all aspects of skull base education, ranging from understanding of basic neuroanatomic relationships, to augmented laboratory dissections, preparation for cases, intraoperative augmentation for positioning or approach planning, and studying operative results and complications.