Mixed reality application of virtual surgical planning for cranial vault remodeling

Mixed reality (MR) overlays interactive three-dimensional virtual content onto the real world and is increasingly being explored for surgical planning and intraoperative guidance. Virtual surgical planning can improve precision and reduce operative time through patient-specific cutting guides and templates; however, evidence supporting their integration in craniofacial surgery remains limited.

Imaging was processed using an "in-house approach" through Mimics-Materialise. Using virtual surgical planning, we planned the osteotomies and created a patient-specific cutting template, which was then uploaded to Microsoft HoloLens. The MR guide and an industry-made guide were traced independently on an anatomically accurate 3D-printed skull model, and the distance between tracings was measured using calipers to quantify accuracy.

We successfully performed preoperative surgical planning and developed a MR patient-specific cutting guide for augmented visualization. The use of MR and 3D-printed guides was compared. MR template markings demonstrated a mean difference of 1.89 mm (SD 1.52 mm) compared to commercial cutting guides, with a total MR template production time of approximately 1.75 h.

Integrating virtual surgical planning with intraoperative MR appears feasible and potentially cost-effective for cranial vault reconstruction. Further refinement will require more accurate, reliable real-time registration of projected guides in the operative field.