How I do it: a purely endoscopic endonasal approach for anterior clinoidal meningioma.

BACKGROUND: Surgery for anterior clinoid meningiomas (ACMs) remains challenging due to their tight adhesion to vital neurovascular and has been traditionally performed through a transcranial approach. METHOD: We present the key steps of the endoscopic endonasal approach (EEA) for ACMs with a video illustration and figures. The relevant surgical anatomy is described along with the indications and limitations of this approach. CONCLUSION: The EEA offers a good treatment option for selected ACMs. It allows for the removal of involved hyperostotic bone and dural attachments, early identification and control of the neurovascular structure, and avoidance of brain retraction.