The optic canal (OC) is a bony channel that transmits the optic nerve (ON) and ophthalmic artery (OphA) as they course through the lesser wing of the sphenoid bone to the orbital apex. The OC is involved in a variety of intracranial and extracranial pathologies,1 and opening of the canal may be necessary in order to achieve adequate exposure, better disease control, and vision preservation.2 Depending on the location of the pathology and its relationship with the optic nerve, the OC may be decompressed through an open transcranial approach or an endoscopic endonasal approach.1,3 OC drilling can be tailored based on the location of the pathology and its extension. Anterior clinoid process and optic strut drilling can be added based on these factors as well.4,5 In this video, we demonstrate the steps of OC drilling in both transcranial microscopic and endoscopic endonasal approaches through a combination of animated illustrations and operative videos. We present 4 cases, including 2 transcranial microscopic and 2 endoscopic endonasal approaches,6 demonstrating OC decompression and its technical nuances. Each case was selected to represent the range of pathologies relevant to OC drilling to allow for a complete understanding of the techniques and concepts required for optimal treatment. An informed written consent has been obtained from each of the patients in this publication. Video © Mayo Foundation for Medical Education and Research. All rights reserved. Images at 1:03-1:10 © The Rhoton Collection. Images at 3:56-4:07 Reprinted from World Neurosurgery, vol 124, Caporlingua et al,3 Copyright 2019, with permission from Elsevier. Images at 9:02-9:48 reprinted from Bendok et al,6 by permission of the Congress of Neurological Surgeons.
Keywords: Endoscopic endonasal; Microsurgery; Ophthalmic artery; Optic canal; Optic canal decompression; Optic canal drilling; Optic nerve.
© Congress of Neurological Surgeons 2021.