Endoscopic lateral transorbital approach for resection of a recurrent trigeminal schwannoma: Two-dimensional operative video.

Background: Trigeminal schwannomas with middle and posterior fossa extension are difficult to treat, particularly after prior surgery or stereotactic radiosurgery (SRS). A minimally invasive interdural approach such as the endoscopic lateral transorbital approach (ELTOA) may offer safer access in these settings. Case description: We present the case of a 33-year-old woman with a history of partial resection of a left trigeminal schwannoma through a pterional approach and adjuvant SRS, who developed progressive left V1 paresthesia and trigeminal neuralgia. Neurological examination revealed hypoesthesia in V1-V2. Magnetic resonance imaging (MRI) demonstrated a dumbbell-shaped mass occupying the left middle cranial fossa, with a cystic component extending into the posterior fossa through Meckel's cave, displacing the brainstem. Given symptom progression and mass effect, reoperation was indicated. An ELTOA, performed through a superior eyelid-crease incision, was selected to exploit a surgically naive interdural corridor parallel to the tumor axis, thereby minimizing brain retraction while providing direct access to Meckel's cave and the posterior fossa. Postoperatively, the patient developed a transient cranial nerve IV palsy, her trigeminal neuralgia resolved, and she was discharged on postoperative day 5. Postoperative MRI demonstrated complete resection and decompression of the middle and posterior cranial fossae. Conclusion: This report demonstrates that the ELTOA is a feasible and safe reoperative strategy for trigeminal schwannomas in previously operated or irradiated corridors, reducing morbidity while achieving effective decompression.