title: How I do it: the endoscopic endonasal optic nerve and orbital apex decompression.
abstract: BACKGROUND
  With the refinement of the technique, endoscopic endonasal surgery increases its field of indications. The orbital compartment is among the locations easily reached through the nostril. This anteromedial approach has been described primarily for inflammatory or traumatic diseases, with few data for tumoral diseases.
  
  
  METHODS
  Since 2010, this route has been used at our institution either for decompression or for biopsy of orbital tumoral diseases.
  
  
  CONCLUSIONS
  Even if further studies are warranted, this strategy proved to be beneficial for patients, with improvements in visual outcome. In this article, the authors summarize their technique and their experience with endonasal endoscopic orbital decompression.
  
  
  CONCLUSIONS
  Nasal and sphenoidal anatomies determine the feasibility and risks for doing an efficient medial optic or orbit decompression. • Techniques and tools used are those developed for pituitary surgery. • A middle turbinectomy and posterior ethmoidectomy are mandatory to expose the medial wall of the orbit. • The Onodi cell is a key marker for the optic canal and must be opened up with caution. • The lamina papyracea is opened first with a spatula and the optic canal opened up by a gentle drilling under continuous irrigation from distal to proximal. • Drilling might always be used under continuous irrigation to avoid overheating of the optic nerve. An ultrasonic device can be used as well. • The nasal corridor is narrow and instruments may hide the infrared neuronavigation probe. To overcome this issue, a magnetic device could be useful. • Doppler control could be useful to locate the ICA. • The optic canal must be opened up from the tuberculum of the sella to the orbital apex and from the planum (anterior cranial fossa) to the lateral OCR or ICA canal • At the end of the procedure, the optic nerve becomes frequently pulsatile, which is a good marker of decompression.
authors.affiliation: Skull Base Surgery Unit - Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital - Hospices Civils de Lyon, Lyon, France, timothee.jacquesson@neurochirurgie.fr.
authors.forename: Timothée
authors.initials: T
authors.lastname: Jacquesson
authors.forename: Lucie
authors.initials: L
authors.lastname: Abouaf
authors.forename: Moncef
authors.initials: M
authors.lastname: Berhouma
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jouanneau
mesh_terms: D019299:Decompression, Surgical / Q000379:methods* / Q000592:standards; D004724:Endoscopy / Q000379:methods* / Q000592:standards; D006801:Humans; D019635:Neurosurgical Procedures / Q000379:methods* / Q000592:standards; D009666:Nose / Q000601:surgery; D019574:Optic Nerve Neoplasms / Q000601:surgery*; D009918:Orbital Neoplasms / Q000601:surgery*