title: New endoscopic instruments for paranasal sinus surgery.
abstract: BACKGROUND
  Minimally invasive endoscopic and microscopic procedures represent state of the art paranasal sinus surgery techniques in both diagnostic and surgical fields. To combine favorable aspects of both techniques, we evaluated the clinical applicability and effectiveness of multifunctional microendoscopes, providing multiple features to ensure highest accuracy and surveillance when performing crucial steps in paranasal sinus surgery.
  
  
  METHODS
  The study included both anatomic experiments on cadaveric heads and clinical tests on patients undergoing routine paranasal surgery. The systems applicability was evaluated in procedures approaching the frontal and sphenoid sinus. Three different endoscopes, 2 straight and the other 1 with a 90 degrees angle, were tested. They integrate canals for flushing and suction and a working canal for either drilling or obtaining biopsies with a miniaturized forceps. For stereotactic feedback, the applicability in combination with a computer-navigation system was evaluated.
  
  
  RESULTS
  Anatomic tests were performed to optimize illumination and to test drilling features and forceps biopsies. In all cases, the frontal sinus ostium and the sphenoid sinus anterior wall was easily identified and enlarged by drilling under visual and stereotactic control. Continuous suction and irrigation ensured a constant visual surveillance by removing drilling debris and blood. Best suited for multifunctional endoscopic surgery were drill heads with a cylinder shape, for placing bore holes along the Z axis, and spherical drill heads, for furbishing and enlarging drill holes.
  
  
  CONCLUSIONS
  These new instruments have proven their applicability in paranasal sinus surgery. Multifunctional endoscopic procedures were deemed best suited for maneuvers requiring highest precision, such as the surgery of the frontal and sphenoid sinus.
authors.affiliation: Department of Otorhinolaryngology--Head and Neck Surgery, Friedrich-Alexander-University Erlangen-Nuremberg, Germany. klaus.bumm@hno.imed.uni-erlangen.de
authors.forename: Klaus
authors.initials: K
authors.lastname: Bumm
authors.forename: Jochen
authors.initials: J
authors.lastname: Wurm
authors.forename: Christopher
authors.initials: C
authors.lastname: Bohr
authors.forename: Johannes
authors.initials: J
authors.lastname: Zenk
authors.forename: Heinrich
authors.initials: H
authors.lastname: Iro
mesh_terms: D019723:Endoscopes; D004724:Endoscopy / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D010254:Paranasal Sinus Diseases / Q000601:surgery*; D011182:Postoperative Care; D016896:Treatment Outcome; D020535:Video-Assisted Surgery / Q000295:instrumentation