Figure 3.

Stepwise dissection of the endoscopic transorbital surgery procedures using the simulation model. The superior eyelid incision was made on the simulation model (A). Subperiosteal elevation of the periorbital was performed (B). After identifying the superior (SOF) and inferior orbital fissure, the ocular surface of the greater sphenoidal wing was drilled to expose the middle cranial fossa (C, D). The temporal dura was exposed, and the bone composing the lateral border of the SOF and maxillary strut was completely removed (E, F). The lateral wall of the cavernous sinus (CS) (blue shaded area) was peeled off from the dura propria of the temporal lobe, and the tumor (Tm) lesion reconstructed from the patient with a trigeminal schwannoma was identified (G, H). The ophthalmic branch (V1), maxillary branch (V2), and mandibular branch (V3) of the trigeminal nerve were identified after resection of the Tm (I). Anterior petrosectomy was performed, and the seventh and eighth cranial nerves were identified (J, K). The lateral wall of the CS was opened, and the neurovascular structures were identified (L). TM, temporalis muscle; ACP, anterior clinoid process; OC, optic canal; PA, petrous apex; SPS, superior petrosal sinus; pICA, petrous segment of the internal carotid artery; GG, Gasserian ganglion.