Combined use of 3D printing and mixed reality technology for neurosurgical training: Getting ready for brain surgery

Abstract-Text

Objective
Learning surgical skills is an essential part of neurosurgical training. Ideally, these skills are acquired to a sufficient extent in an ex vivo setting. We previously described an in vitro brain tumor model, consisting of a cadaveric animal brain injected with fluorescent agar-agar, for acquiring a wide range of basic neuro-oncological skills. This model focuses on haptic skills such as safe tissue ablation technique and the training of fluorescence-based resection. As important didactical technologies such as mixed reality and 3D printing become more readily available, we developed a readily available training model that integrates the haptic aspects into a mixed reality setup.
Methods
The anatomical structures of a brain tumor patient were segmented from medical imaging data to create a digital twin of the case. Bony structures were 3D printed and combined with the in vitro brain tumor model. The segmented structures were visualized in mixed reality headsets and the congruence of the printed and the virtual objects allowed them to be spatially superimposed. In this way, users of the system were able to train the entire treatment process from surgery planning to instrument preparation and execution of the surgery.
Results
Mixed reality visualization in the joint model facilitated model (patient) positioning as well as the craniotomy and the extent of resection planning respecting case-dependent specifications. The advanced physical model allowed brain tumor surgery training including skin incision, craniotomy, dura opening, fluorescence-guided tumor resection and dura, bone, and skin closure.
Conclusions
Combining mixed reality visualization with the corresponding 3D printed physical hands-on model allowed advanced training of sequential brain tumor resection skills. 3D printing technology facilitates the production of a precise, reproducible, and world-wide accessible brain tumor surgery model. The described model for brain tumor resection advanced regarding important aspects of skills training for neurosurgical residents, e.g., locating the lesion, head position planning, skull trepanation, dura opening, tissue ablation techniques, fluorescence-guided resection and closure. Mixed reality enriches the model with important structures that are difficult to model (e.g., vessels, fibre tracts etc.) and advanced interaction concepts (e.g., craniotomy simulations). Finally, this concept demonstrates a bridging technology towards intraoperative application of mixed reality.