title: Evaluation of the ethmoid skull-base height prior to endoscopic sinus surgery: a preoperative computed tomography evaluation technique.
abstract: BACKGROUND
  Iatrogenic ethmoid skull base (ESB) injury during endoscopic sinus surgery (ESS) is a potentially devastating complication. The height of the ESB can vary substantially and should be assessed during preoperative evaluation of the sinus computed tomography (CT) scan.
  
  
  METHODS
  The objective of this study is to describe an objective preoperative CT evaluation technique to assist the surgeon in defining the height of the ESB prior to performing ESS.
  
  
  RESULTS
  We propose a technique which measures the height of the ESB from a single horizontal mid-orbital line located on a standardized coronal sinus CT image at the level of the anterior ethmoid artery canal.
  
  
  CONCLUSIONS
  Utilization of an objective preoperative CT measurement technique may quantify identification of a low ESB and optimize surgical awareness of this potentially dangerous anatomic skull base variation.
authors.affiliation: Rhinology and Sinus Surgery, Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Luke
authors.initials: L
authors.lastname: Rudmik
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Smith
mesh_terms: D004724:Endoscopy; D005004:Ethmoid Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D009915:Orbit / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D010256:Paranasal Sinuses / Q000601:surgery; D057234:Preoperative Period; D019291:Skull Base / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*