title: Third ventricular shape: a predictor of endoscopic third ventriculostomy success in pediatric patients.
abstract: OBJECTIVE
  The criteria for identifying patients in whom endoscopic third ventriculostomy (ETV) provides control of hydrocephalus remain in evolution. In particular, it is not clear when ETV would be effective if intraventricular obstruction is not found preoperatively. The authors postulated that 1) displacement of the third ventricle floor inferiorly into the interpeduncular cistern and displacement of the lamina terminalis anteriorly into the lamina terminalis cistern could predict clinical success of ETV, and 2) improvement in these displacements would correlate with the success of ETV.
  
  
  METHODS
  Magnetic resonance imaging in 38 consecutive patients treated between 2004 and 2010 was reviewed to assess displacement of the lamina terminalis and third ventricular floor prior to and following ETV. Displacements of the floor and lamina terminalis were judged qualitatively and quantitatively, using a newly created index, the Third Ventricular Morphology Index (TVMI). The association between the aforementioned morphological features and clinical success of ETV was analyzed.
  
  
  RESULTS
  Ninety-six percent of patients in whom the authors preoperatively observed displacement of the lamina terminalis and the third ventricular floor were successfully treated with ETV. Displacements of the third ventricular floor and lamina terminalis, as judged qualitatively, correlated with the clinical success of ETV. The TVMI correlated with the qualitative assessments of displacement. Postoperative decrease in the TVMI occurred in the majority of successfully treated patients. Changes in third ventricular morphology preceded changes in other measures of third and lateral ventricular volume following ETV.
  
  
  CONCLUSIONS
  Assessment of third ventricular floor and lamina terminalis morphology is useful in predicting clinical success of ETV and in the follow-up in treated patients. The TVMI provided a quantitative assessment of the third ventricular morphology, which may be useful in equivocal cases and in research studies.
authors: Division of Neurosurgery, Department of Surgery, University of British Columbia and BC Children's Hospital, Vancouver, British Columbia, Canada.
authors: Mansoor
authors: M
authors: Foroughi
authors: Andrew
authors: A
authors: Wong
authors: Paul
authors: P
authors: Steinbok
authors: Ash
authors: A
authors: Singhal
authors: Michael A
authors: MA
authors: Sargent
authors: D Douglas
authors: DD
authors: Cochrane
mesh_terms: D002557:Cerebrospinal Fluid Shunts; D002648:Child; D002675:Child, Preschool; D004724:Endoscopy / Q000379:methods*; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D011182:Postoperative Care; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011379:Prognosis; D020542:Third Ventricle / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome; D014696:Ventriculostomy