Three-dimensional 4K resolution video microscope in an orbitozygomatic approach for skull base tumor

•The newly developed 3D-4K video microscope, Orbeye™, was approved in Japan.•The skull base drilling procedure is easily visualized, which have been difficult in conventional methods.•The wider depth of field decrease the effort to reposition the focus of the microscope.•The 3D-4K image is easily shared by all members of the operative team.•The ergonomics of Orbeye™ decreases surgeons’ intraoperative fatigue and stress. The authors propose that the newly developed three-dimensional 4K resolution (3D-4K) video microscope, Orbeye™, can be a user-friendly alternative tool for performing orbitozygomatic craniotomy and tumor removal. It was officially approved in Japan in October 2017. A 38-year-old, otherwise healthy, woman presented with left impaired visual acuity, motor aphasia, headache, and vomiting. Magnetic resonance imaging (MRI) revealed the presence of a large left sphenoid ridge meningioma with marked perifocal edema and mass effect. Using Orbeye™, en bloc orbitozygomatic craniotomy and skull base tumor removal were safely performed. It enabled us to perform the procedure, and to share the operative image owing to the realistic 3D perception of the operative field, its excellent illumination, and viewing angle. Especially, the lower viewing angle appeared to be extremely difficult to obtain using conventional methods. The patient resumed her daily life, and a postoperative MRI showed total removal of the tumor. Orbeye™ has overcome shortcomings of the operative microscope. It has a user-friendly design, and surgeons’ intraoperative fatigue and stress appear to be decreased. It is useful for observers to understand the skull base technical nuances using the 3D-4K image.