title: Evaluation of two- and three-dimensional visualization for endoscopic endonasal surgery using a novel stereoendoscopic system in a novice: a comparison on a dry laboratory model.
abstract: BACKGROUND
  Three-dimensional (3-D) stereoscopic vision is theoretically superior to two-dimensional (2-D) vision in endoscopic endonasal surgery. However, only few reports have quantitatively compared endoscopic performance under the two visual conditions. We introduced a newly designed stereoendoscopic system with a "dual-lens and single camera" for endoscopic endonasal surgery and objectively compared the performances under 3-D and high-definition 2-D visualizations on a dry laboratory model.
  
  
  METHODS
  Thirty subjects without experience performing endoscopic surgery, computer-simulated training or any 3-D video system were recruited and divided into two groups (Group A and Group B) for performing two different tasks. The novel 4.7-mm-diameter stereoendoscope provided high-definition (HD) images. In Task 1, Group A started the task under the 3-D condition followed by the 2-D condition, and Group B vice versa. In Task 2, Group A started the task under the 2-D condition followed by the 3-D condition, and Group B vice versa. The performance accuracy and speed under the two visual conditions were analyzed.
  
  
  RESULTS
  Significant improvement in performance accuracy and speed was seen under 3-D conditions in the both "3-D first" and "2-D first" subgroups during both tasks (P < .001). Regardless of order, the inaccuracy rate and performance time under 3-D conditions was significantly lower than that under 2-D conditions in each subject.
  
  
  CONCLUSIONS
  We demonstrated the advantage of 3-D visualization over 2-D visualization for inexperienced subjects. Further quantitative clinical studies are required to confirm whether stereoendoscopy actually provides benefits in clinical settings.
authors.affiliation: Department of Neurosurgery, Kochi Medical School, Kochi University, Kohasu, Okoh-cho, Nankoku, Kochi, 783-8505, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kawanishi
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Naoko
authors.initials: N
authors.lastname: Kumagai
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Takemura
authors.forename: Motonobu
authors.initials: M
authors.lastname: Nonaka
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakai
authors.forename: Noritaka
authors.initials: N
authors.lastname: Masahira
authors.forename: Takahito
authors.initials: T
authors.lastname: Nakajo
authors.forename: Keiji
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D002983:Clinical Competence / Q000592:standards; D004724:Endoscopy / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D009666:Nose / Q000601:surgery*; D055815:Young Adult