title: Sinus anatomy associated with inadvertent cerebrospinal fluid leak during functional endoscopic sinus surgery.
abstract: OBJECTIVE
  Anatomic variations in skull base anatomy may predispose the surgeon to inadvertent skull base injury with resultant cerebrospinal fluid (CSF) leak during functional endoscopic sinus surgery (ESS). Our objective was to compare preoperative sinus imaging of patients who underwent FESS with and without CSF leak to elucidate these variations.
  
  
  METHODS
  In this retrospective case-control study, 18 patients with CSF leak following FESS for chronic rhinosinusitis (CRS) from 2000 to 2011 were compared to 18 randomly selected patients who underwent preoperative imaging for FESS for CRS.
  
  
  METHODS
  Measurements were obtained from preoperative computed tomography images with specific attention to anatomic differences in cribriform plate and ethmoid roof heights in the coronal plane, and the skull base angle in the sagittal plane. Mean values of measured variables were compared using a nonparametric Mann-Whitney test.
  
  
  RESULTS
  When compared to controls, patients with CSF leak demonstrated a greater angle of the skull base in the sagittal plane (P < .001) and a greater slope of the skull base in the coronal plane (P < .006). A lower cribriform height relative to ethmoid roof height was also noted in cases of CSF leak as compared to controls (P < .04).
  
  
  CONCLUSIONS
  A steep skull base angle in the sagittal plane, a greater slope of the skull base in the coronal plane, and a low cribriform height relative to the ethmoid roof predispose the patient to CSF leak during FESS. Preoperative review of imaging with specific attention paid to these anatomic variations may help to prevent iatrogenic CSF leak.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of California-San Francisco, San Francisco, California, USA.
authors.forename: Chase M
authors.initials: CM
authors.lastname: Heaton
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Goldberg
authors.forename: Steven D
authors.initials: SD
authors.lastname: Pletcher
authors.forename: Christine M
authors.initials: CM
authors.lastname: Glastonbury
mesh_terms: D016022:Case-Control Studies; D065634:Cerebrospinal Fluid Leak; D002559:Cerebrospinal Fluid Rhinorrhea / Q000209:etiology*; D002908:Chronic Disease; D004724:Endoscopy; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010256:Paranasal Sinuses / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012220:Rhinitis / Q000150:complications / Q000601:surgery*; D012852:Sinusitis / Q000150:complications / Q000601:surgery*; D019291:Skull Base / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed