Endoscopic lateral transorbital approach for resection of a recurrent middle cranial fossa epidermoid cyst: Two-dimensional operative video

Background: Middle cranial fossa epidermoid cysts are uncommon. The endoscopic lateral transorbital approach (ELTOA) may provide a direct, less invasive alternative to transcranial surgery in selected cases. Case Description: A 55-year-old woman with a recurrent left middle cranial fossa epidermoid cyst, 21 years after subtotal resection through a pterional approach, developed medically refractory trigeminal neuralgia involving V1–V3. Magnetic resonance imaging (MRI) demonstrated a nonenhancing diffusion-restricting lesion extending into Meckel’s cave and the tentorial incisura. ELTOA was selected to provide a direct anterolateral trajectory, minimize temporal lobe manipulation, and avoid re-entering the previously operated corridor. Through a superior eyelid incision, the lateral orbital wall and roof were drilled. After division of the meningo-orbital band and dural opening, the lesion was internally decompressed endoscopically. The tentorial incisural component was addressed using ring curettes under endoscopic visualization. The capsule was sharply dissected where safely feasible, and a small portion densely adherent to neurovascular structures was intentionally preserved, resulting in near-total resection. Multilayer reconstruction used a dural substitute, autologous fat, and inlay/onlay fascia lata grafts. Trigeminal neuralgia resolved immediately, and medications were discontinued immediately postoperatively. A transient trochlear nerve palsy resolved by 3 months, while hemifacial hypoesthesia persisted without functional impairment. No cerebrospinal fluid leak or ophthalmological complications occurred. Six-month MRI showed no radiographically detectable residual epidermoid or diffusion restriction, consistent with a favorable short-term postoperative radiographic outcome. Conclusion: ELTOA offers a less invasive alternative for selected recurrent middle cranial fossa epidermoid cysts and expands the skull base armamentarium. Long-term surveillance remains necessary.