title: Which Routes for Petroclival Tumors? A Comparison Between the Anterior Expanded Endoscopic Endonasal Approach and Lateral or Posterior Routes.
abstract: OBJECTIVE
  Petroclival tumors remain a surgical challenge. Classically, the retrosigmoid approach (RSA) has long been used to reach such tumors, whereas the anterior petrosectomy (AP) has been proposed to avoid crossing cranial nerves. More recently, the endoscopic endonasal approach has been "expanded" (i.e., EEEA) to the petroclival region. We aimed to compare these 3 approaches to help in the surgical management of petroclival tumors.
  
  
  METHODS
  Petroclival approaches were performed on 5 specimens after they were prepared with formaldehyde colored via latex injection.
  
  
  RESULTS
  The EEEA provides a simple straightforward route to the clivus, but reaching the petrous apex requires the surgeon to circumvent the internal carotid artery either via a medial transclival, an inferior transpterygoid, or a lateral variant through the Meckel's cave. In contrast, the AP offers a narrow direct superolateral access to the petroclival region crossed by the trigeminal nerve. Finally, the RSA provides a wide simple and quick exposure of the cerebellopontine angle, but access to the petroclival region needs the surgeon to deal with the V(th) to XI(th) cranial nerves.
  
  
  CONCLUSIONS
  The EEEA should be preferred for extradural midline tumors (chordomas, chondrosarcomas) or for cystic lesions when drainage is essential. The AP could be optimal for the radical removal of intradural vascularized tumors (meningiomas) with intrapetrous or supratentorial extensions. The RSA retains an advantage for small or cystic tumors near the internal acoustic meatus. The skull base surgeon has to master all of these routes to choose the more appropriate one according to the surgical objective, the tumor characteristics, and the patient's medical status.
authors.affiliation: Skull Base Multidisciplinary Unit, Department of Neurosurgery, Neurological Hospital Pierre Wertheimer, Lyon Cedex, France; Department of Anatomy, University of Lyon, Lyon, France. Electronic address: timothee.jacquesson@neurochirurgie.fr.
authors.forename: Timothée
authors.initials: T
authors.lastname: Jacquesson
authors.affiliation: Skull Base Multidisciplinary Unit, Department of Neurosurgery, Neurological Hospital Pierre Wertheimer, Lyon Cedex, France.
authors.forename: Moncef
authors.initials: M
authors.lastname: Berhouma
authors.affiliation: Skull Base Multidisciplinary Unit, Department of Neurosurgery, Neurological Hospital Pierre Wertheimer, Lyon Cedex, France; Department of Otorhinolaryngology, Pierre Benite, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Tringali
authors.affiliation: Department of Anatomy, University of Lyon, Lyon, France.
authors.forename: Emile
authors.initials: E
authors.lastname: Simon
authors.affiliation: Skull Base Multidisciplinary Unit, Department of Neurosurgery, Neurological Hospital Pierre Wertheimer, Lyon Cedex, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jouanneau
mesh_terms: D002102:Cadaver; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology* / Q000601:surgery*; D006801:Humans; D008866:Microsurgery / Q000379:methods; D009296:Nasal Cavity / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods*; D010579:Petrous Bone / Q000033:anatomy & histology* / Q000601:surgery*; D019291:Skull Base / Q000601:surgery; D019292:Skull Base Neoplasms / Q000473:pathology / Q000601:surgery*
keywords: Endonasal; Endoscopy; Petroclival; Petrosectomy; Petrous apex; Skull base