The "Canopy Approach": Case Series Using Immersive Virtual Reality for Bottom-Up Target-Based Preoperative Planning in Pediatric Neurosurgery.

Background: Virtual reality (VR) is increasingly used for trajectory planning in neurosurgery.

Objective: To describe a case series showing the application of immersive VR involving both "top-down" from skull to lesion and "bottom-up" from lesion to skull approaches for trajectory planning in pediatric neurosurgical patients.

Methods: We detail the preoperative and intraoperative application of VR and clinical courses of 5 children (aged 7-14 years) with anatomically challenging intraparenchymal lesions that posed operative risks to nearby vascular anatomy and fiber tracts. Preoperative planning consisted of standard presurgical evaluation with computed tomography and magnetic resonance imaging used to render 3-dimensional models that could be viewed and manipulated using desktop software and immersive VR headsets and hand controllers by the surgeon and family. Patient satisfaction was evaluated by survey. Surgical outcomes were degree of seizure control or extent of resection.

Results: Three patients underwent lesion resection and 2 laser ablation. Modifications to 2-dimensional and "top-down" VR trajectory plans were made after "bottom-up" navigation in all cases. All families reported that the VR enhanced their understanding of the procedure. There were no complications, and no patients suffered permanent neurological deficits postoperatively. Gross total resection was achieved in all lesional cases, and patients with epilepsy achieved seizure freedom at 2 years postoperatively.

Conclusion: Immersive VR allows operative corridors to be virtually traveled and viewed from a "top-down" and "bottom-up" perspective, as if looking up from under a forest canopy of overlying anatomy, for optimal trajectory planning and improvement of family understanding in pediatric neurosurgery.