title: Anatomic Variations of the Floor of the Third Ventricle: An Endoscopic Study.
abstract: OBJECTIVE
  Anatomical variations of the floor of the third ventricle are common in hydrocephalic patients and can significantly affect outcomes of endoscopic third ventriculostomy (ETV). We sought to categorize variations in third ventricle anatomy and to discuss the implications of these variations for ETV.
  
  
  METHODS
  Intraoperative videos and pictures of 50 patients who underwent ETV between April 2001 and August 2010 were reviewed. Twenty-seven patients with clearly demonstrable third ventricular floors that satisfied our criteria were selected for the study.
  
  
  RESULTS
  Images of variations were organized into the following categories: 1) thinned floor, 2) thickened floor, 3) partially effaced floor, 4) ballooning/herniating floor, 5) small prepontine interval, 6) narrowed third ventricle, and 7) other significant anomalies.
  
  
  CONCLUSIONS
  The third ventricle is a common site for anatomical variations in hydrocephalic patients. A good knowledge of these variations is essential before performing ETV, because they have the potential to increase operative risk.
authors.affiliation: Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. Electronic address: michael-sughrue@ouhsc.edu.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Sughrue
authors.affiliation: The Centre for Minimally Invasive Neurosurgery, Prince of Wales Private Hospital, Sydney, Australia.
authors.forename: Judy
authors.initials: J
authors.lastname: Chiou
authors.affiliation: Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Burks
authors.affiliation: Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Bonney
authors.affiliation: The Centre for Minimally Invasive Neurosurgery, Prince of Wales Private Hospital, Sydney, Australia.
authors.forename: Charles
authors.initials: C
authors.lastname: Teo
mesh_terms: D059925:Anatomic Landmarks / Q000002:abnormalities* / Q000473:pathology*; D006801:Humans; D006849:Hydrocephalus / Q000473:pathology*; D010781:Photography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020542:Third Ventricle / Q000002:abnormalities* / Q000473:pathology*; D014741:Video Recording / Q000379:methods
keywords: Anatomy; Endoscopic; Endoscopy; Floor; Intraventricular; Neuroendoscopy; Third ventricle