title: Endoscopic transnasal approach to the clivus: a radiographic anatomical study.
abstract: OBJECTIVE
  Operative intervention of anterior skull base lesions is challenging. Various endoscopic surgical approaches have been described. The goal of the present study is to perform a radiographic analysis of the endoscopic transnasal approach to the clivus.
  
  
  METHODS
  Anatomic study utilizing computed tomography (CT).
  
  
  METHODS
  High-resolution surgical-guidance CT images of the sinuses from 97 patients at a tertiary care medical center between 2002 and 2007 were evaluated. Axial and sagittal images were used to evaluate surgical access to the clivus. Multiple anatomical measurements were obtained and analyzed with imaging and statistical software.
  
  
  RESULTS
  Of the 97 imaging studies, there were 39 males and 58 females. The width of exposure of the clivus without removal of the septum was 2.7 cm (1.9-3.4 cm) and with removal of the bony septum was 3.6 cm (2.6-4.8 cm) (P < .001). No patients had complete exposure of the width of the clivus without the septum removed compared to 56 (58%) patients with the septum removed. Endoscopic exposure of the inferior and superior limits of the clivus was not limited in any images studied.
  
  
  CONCLUSIONS
  The endoscopic transnasal approach to the clivus is a viable option in the treatment of anterior skull base lesions with the preservation of functional anatomy in select patients. A large portion of the population has limited lateral exposure secondary to the eustachian tube and the medial pterygoid plate with an endoscopic transnasal approach. Vertically, this approach allows complete access to the clivus in all patients studied.
authors: Department of Otolaryngology, Head and Neck Surgery, University of Cincinnati Medical Center, Cincinnati, OH 45267-0528, USA.
authors: Collin M
authors: CM
authors: Burkart
authors: Philip V
authors: PV
authors: Theodosopoulos
authors: Jeffrey T
authors: JT
authors: Keller
authors: Lee A
authors: LA
authors: Zimmer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D035262:Cranial Fossa, Anterior / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D004724:Endoscopy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009666:Nose / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009777:Occipital Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D010254:Paranasal Sinus Diseases / Q000601:surgery; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult