title: Malleable endoscope increases surgical freedom compared with a rigid endoscope in endoscopic endonasal approaches to the parasellar region.
abstract: BACKGROUND
  One challenge when performing endoscopic endonasal approaches is the surgical conflict that occurs between the surgical instruments and endoscope in the crowded nasal corridor. This conflict decreases surgical freedom, increases surgeon frustration, and lengthens the learning curve for trainees.
  
  
  OBJECTIVE
  To evaluate the impact a malleable endoscope has on surgical freedom for endoscopic approaches to the parasellar region.
  
  
  METHODS
  Uninostril and binostril endoscopic transsphenoidal approaches to the pituitary gland and cavernous carotid arteries were performed on 8 silicon-injected, formalin-fixed cadaveric heads using both rigid and flexible 3-dimensional endoscopes. Surgical freedom to targets in the parasellar region was assessed using an established technique based on image guidance. Results are presented as 3 measurements: area of surgical freedom for a point target, area for the surgical field (cavernous carotids and sella), and angular surgical freedom (angle of attack).
  
  
  RESULTS
  Point target surgical freedom, exposed area surgical freedom, and angle of attack were all significantly greater in approaches using the malleable endoscope compared with the rigid endoscope (P values .06 to <.001), with values varying between 17% and 28%. The improved surgical freedom noted with the malleable endoscope was due to the minimization of instrument-endoscope conflict at the back end (camera) and front end (tip) of the endoscope.
  
  
  CONCLUSIONS
  This study demonstrates that application of a malleable endoscope to transsphenoidal approaches to the parasellar region decreases instrument-endoscope conflict and improves surgical freedom.
authors.affiliation: Division of Neurological Surgery, St. Joseph's Hospital and Medical Center, Barrow Neurological Institute, Phoenix, Arizona.
authors.forename: Ali M
authors.initials: AM
authors.lastname: Elhadi
authors.forename: Hasan A
authors.initials: HA
authors.lastname: Zaidi
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Hardesty
authors.forename: Richard
authors.initials: R
authors.lastname: Williamson
authors.forename: Claudio
authors.initials: C
authors.lastname: Cavallo
authors.forename: Mark C
authors.initials: MC
authors.lastname: Preul
authors.forename: Peter
authors.initials: P
authors.lastname: Nakaji
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Little
mesh_terms: D002102:Cadaver; D006801:Humans; D044583:Neuroendoscopy / Q000295:instrumentation*; D009666:Nose; D010902:Pituitary Gland / Q000601:surgery*