title: The Medial Extra-Sellar Corridor to the Cavernous Sinus: Anatomic Description and Clinical Correlation.
abstract: OBJECTIVE
  The zenith of surgical interest in the cavernous sinus peaked in the 1980s, as evidenced by reports of 10 surgical triangles that could access the contents of the lateral sellar compartment (LSC). However, these transcranial approaches later became marginalized, first by radiosurgery's popularity and lower morbidity, and then by clinical potential of endoscopic corridors noted in several qualitative studies. Our anatomic study, taking a contemporary look at the medial extra-sellar corridor, gives a detailed qualitative-quantitative analysis for its use with increasingly popular endoscopic endonasal approaches to the cavernous sinus.
  
  
  METHODS
  In 20 cadaveric specimens, we re-examined the anatomic landmarks of the medial corridor into the LSC with qualitative descriptions and measurements. An illustrative case highlights a recurrent symptomatic pituitary adenoma that invaded the cavernous sinus approached through the medial corridor.
  
  
  RESULTS
  The corridor's shape varied from tetrahedron to hexahedron. Comparing right and left sides, width averaged 3.6 ± 4.5 mm and 4.0 ± 4.4 mm, and height averaged 2.3 mm and 2.1 mm, respectively. About 35% of sides showed ample space for access into the cavernous sinus. Our case report of successful outcome lends support for the safety and efficacy of this endoscopic approach.
  
  
  CONCLUSIONS
  Our re-examination of this particular surgical access into the LSC refines the understanding of the medial extra-sellar corridor as a main endoscopic access route to this compartment. Achieving safe access to the contents of the LSC, this 11th triangle is clinically relevant and potentially superior for select lesions in this region.
authors.affiliation: Department of Neurological Surgery, University of California San Francisco, San Francisco, California, USA.
authors.forename: Philip V
authors.initials: PV
authors.lastname: Theodosopoulos
authors.affiliation: Department of Neurosurgery, Lariboisiere University Hospital, Paris, France.
authors.forename: Helene
authors.initials: H
authors.lastname: Cebula
authors.affiliation: Department of Neurosurgery, University of Cincinnati (UC) College of Medicine, Cincinnati, Ohio, USA.
authors.forename: Almaz
authors.initials: A
authors.lastname: Kurbanov
authors.affiliation: Department of Neurological Surgery, University of California San Francisco, San Francisco, California, USA.
authors.forename: Arnau Benet
authors.initials: AB
authors.lastname: Cabero
authors.affiliation: Department of Neurological Surgery, University of California San Francisco, San Francisco, California, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Osorio
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, University of Cincinnati (UC) College of Medicine, Cincinnati, Ohio, USA; Brain Tumor Center at UC Neuroscience Institute, Cincinnati, Ohio, USA.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Zimmer
authors.affiliation: Department of Neurosurgery, Lariboisiere University Hospital, Paris, France.
authors.forename: Sebastien C
authors.initials: SC
authors.lastname: Froelich
authors.affiliation: Department of Neurosurgery, University of Cincinnati (UC) College of Medicine, Cincinnati, Ohio, USA; Brain Tumor Center at UC Neuroscience Institute, Cincinnati, Ohio, USA; Mayfield Clinic, Cincinnati, Ohio, USA. Electronic address: mary.kemper@uc.edu.
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Keller
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D002102:Cadaver; D002426:Cavernous Sinus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D004724:Endoscopy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009296:Nasal Cavity / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods; D009666:Nose / Q000601:surgery; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D019291:Skull Base / Q000000981:diagnostic imaging / Q000601:surgery
keywords: Anatomic study; Cavernous sinus; Endoscopic endonasal approaches; Lateral sellar compartment; Medial corridor; Surgical triangles