Endoscopic Endonasal Approach for Clival Chordoma with Subarachnoid Invasion: A Two-Dimensional Step-by-Step Operative Video.

Chordomas are slow-growing, low-grade, locally invasive, and locally aggressive tumors. They peak at 40-60 years of age, with a male preponderance (2:1). Belonging to the sarcoma family and thought to develop from the notochord remnant, they are most commonly found in the midline, with half located at the sacrum and about one third at the skull base. Their treatment mainly consists of surgical excision, followed by radiation therapy. The endoscopic endonasal approach provides direct access to the clival chordomas with no need for brain retraction or manipulation of neurovascular structures. Herein we present a step-by-step resection technique of a clival chordoma invading the subarachnoid space and touching the brainstem and vertebrobasilar vessels in a 46-year-old man with headaches, with a prior failed attempt of resection at an outside institution, resulting in a biopsy only in the palate. An endoscopic endonasal transclival approach was performed and gross total removal was achieved (Video 1). The patient had an uneventful recovery with no deficits, and he was then sent to proton beam therapy.