Surgical Simulation of Endoscopic Endonasal Anterior Skull Base Surgery using 3D Head Model and Cone Beam CT

Endoscopic endonasal anterior skull base surgery is currently applied for the treatment of olfactory neuroblastoma, and other skull base lesions. In the surgical approach to the anterior skull base, one of the important step is extended frontal sinus surgery, including modified endoscopic Lothrop procedure (MELP). Surgical simulation using artificial three dimensional (3D) models is known to a useful training method to learn the surgical steps and to gain the surgical skills. In this study, we investigated the usefulness of a 3D head model with the detailed CT information in the surgical simulation for extended frontal sinus surgeries and anterior skull base resections. 3D head models (KEZLEX, Ohno, Japan) were used as a surgical simulator. This model is exactly reconstructed and made as a human head including sinonasal structure and anterior/posterior skull base by 3D printer. In this model, we made the first olfactory nerve with a steel wire at the skull base as the posterior limit of the frontal sinus flour to the skull base. In addition, the head model was examined for surgical anatomy by using the cone-beam CT (Accuitomo, Morita, Japan). Then, endoscopic endonasal surgery was performed using a high speed bur (M5, Medtronic, Japan) for the bone resection guided with a navigation system (Fusion, Medtronic, Japan). MELP was performed according to the surgical steps of the outside-in frontal drill-out technique. In results, MELP and the anterior skull base resection including crista galli were successfully performed for 3D model with CT and the navigation. These findings suggest that surgical simulation using artificial 3D head model and cone beam CT combined with a navigation system is useful in the surgical training for endoscopic endonasal anterior skull base surgery.