Lateral Transorbital Neuroendoscopic Approach for Intraconal Meningioma of the Orbital Apex: Technical Nuances and Literature Review

Surgical approaches to orbital apex lesions involve the medial and lateral corridors. The transorbital neuroendoscopic (TONE) approach has been recently proposed as an elegant, bone-sparing, and minimally invasive alternative for tumors of the lateral orbital compartment. However, its effectiveness compared with the standard lateral orbitotomy approach still requires confirmation. The aim of the present report was to describe the key technical aspects of the lateral trans-eyebrow TONE approach and to review the relevant reported data on the surgical management of ectopic orbital intraconal meningiomas.The TONE approach was used in a 63-year-old man with a diagnosis of a left ectopic intraconal meningioma of the orbital apex involving the lateral compartment. The TONE approach involves performing a lateral 3-cm eyebrow skin incision. A subperiosteal dissection of the periorbita permits intermittent medialization of the eyeball and extracapsular access to the orbital apex region. A lateral periorbital incision under full endoscopic view allows for early access to 2 different intermuscular corridors that do not require mechanical retraction of the oculomotor muscles. The reported data included studies of 23 cases of intraconal meningioma, which were usually benign, although the meningothelial variant has been associated with a greater recurrence rate.In our limited experience, the lateral TONE approach proved to be an effective, feasible, versatile, and minimally invasive promising alternative to resect orbital apex meningiomas involving the lateral compartment. Its technical strengths include increased illumination and magnification of the surgical field and an unparalleled lateral view of the orbital apex.