Total removal of a trigeminal schwannoma via the expanded endoscopic endonasal approach. Technical note.

BACKGROUND: Because of their deep location surrounded by closed numerous neurovascular structures, skull base tumors of the cavernous sinus are still difficult to manage. Recently, the endoscopic endonasal approach commonly used for pituitary tumor resection has been "expanded" to the parasellar, infratemporal and orbital compartments with some advantages compared to the intracranial route. METHODS: The authors reported the case of a 49-year-old male presenting a large extradural tumor of the left cavernous sinus with extensions toward the orbit, sphenoid sinus and infratemporal fossa. His ophthalmological examination was normal, and the body CT scan revealed no primary neoplasm. RESULTS: In this operative video, the approach is described step by step with surgical nuances. The endoscopy provided a close-up panoramic view and various angles of vision. Also, it avoided an invasive craniotomy, cerebral retraction and cranial nerves damages. Thus, it allowed the total removal of this tumor originating from the maxillary branch of the trigeminal nerve. The pathologic examination confirmed a schwannoma. CONCLUSION: The expanded endoscopic endonasal approach provides an interesting corridor to cavernous sinus tumors with satisfactory control of extensions inferiorly toward the infratemporal fossa, anteriorly via the superior orbital fissure and medially within the sphenoid. Finally, the skull base surgeon has to master this anterior endoscopic route as well as all the other "open" transcranial skull base approaches to propose the best surgical route fitting the tumor characteristics.