title: Image guided navigation system-a new technology for complex endoscopic endonasal surgery.
abstract: OBJECTIVE
  Endoscopic endonasal surgery (EES) has become the standard practice in sinonasal and anterior skull base surgery. The purpose of this manuscript is to describe experience using a new technology-the image guided navigation system (IGNS)-in complex cases undergoing EES. The advantages and disadvantages of computer aided surgery are discussed.
  
  
  METHODS
  A total of 165 endoscopic endonasal procedures were performed between April 2001 and January 2003. IGNS was used in 34 patients in whom it was assumed that the ability to identify surgical sites accurately could be compromised by previous surgery, massive recurrent polyposis, or abnormal anatomy, or when biopsies had to be taken from specific anatomic locations (for example, clivus, wall of sphenoid sinus, orbital apex). The precision of the navigation system, total operating room time, surgeon's satisfaction and confidence, and intraoperative and postoperative complications were recorded.
  
  
  RESULTS
  In 33 out of 34 patients the surgical procedure was uneventful. One patient with an atelectatic maxillary sinus developed a minor complication of preseptal orbital haematoma. In 94% the IGNS provided accurate anatomical localisation with less than 2 mm localisation error (1.1-2.0 mm, mean 1.6 mm). In all cases the surgical team felt that the system increased the intraoperative safety factor for the patient. The overall operating room time at the end of the study was 15 minutes longer than when regular EES was used.
  
  
  CONCLUSIONS
  IGNS enables a new level of efficiency and safety in EES. Nevertheless, it is not advised for surgeons who are not familiar with regular EES. For the experienced endoscopist, however, IGNS is a valuable new tool in complex procedures.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, Hadassah University Hospital, Jerusalem, Israel. ron@eliashar.com
authors.forename: R
authors.initials: R
authors.lastname: Eliashar
authors.forename: J-Y
authors.initials: JY
authors.lastname: Sichel
authors.forename: M
authors.initials: M
authors.lastname: Gross
authors.forename: E
authors.initials: E
authors.lastname: Hocwald
authors.forename: I
authors.initials: I
authors.lastname: Dano
authors.forename: A
authors.initials: A
authors.lastname: Biron
authors.forename: A
authors.initials: A
authors.lastname: Ben-Yaacov
authors.forename: A
authors.initials: A
authors.lastname: Goldfarb
authors.forename: J
authors.initials: J
authors.lastname: Elidan
mesh_terms: D000328:Adult; D000368:Aged; D004724:Endoscopy / Q000379:methods* / Q000592:standards; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D010254:Paranasal Sinus Diseases / Q000601:surgery*; D019291:Skull Base / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods* / Q000592:standards