Changes in third ventricular size in pediatric patients undergoing endoscopic third ventriculostomy

Abstract

Optimal methods of evaluating radiographic data following endoscopic third ventriculostomy (ETV) are not yet known. This study analyzes imaging parameters, including third ventricular width and cross-sectional area (CSA), in pediatric ETV patients. Hydrocephalic pediatric patients treated by ETV at the senior authors' institution from 2004 to 2011 were stratified clinically (successful versus unsuccessful outcome) and retrospectively reviewed. Measured from pre- and post-operative imaging studies, third ventricular parameters included maximal width and mid-sagittal CSA, while lateral ventricular parameters included the ratio of greatest frontal horn width to co-linear skull internal diameter and the frontal-occipital horn ratio. Ten successful ETV patients (mean age 10.6years; range 11months to 19.8years) obtained imaging at least 2.75months following surgery, while four unsuccessful ETV patients (mean age 9.8years; range 4months to 17.3years) underwent imaging before repeat intervention. Third ventricular width showed an average decline of 0.32cm and 17.4% in the successful ETV cohort, but average increases of 0.35cm and 21.0% in the ETV failure group. Successful ETV patients exhibited mean decreases of 1.85cm(2) and 19.7% in third ventricular mid-sagittal CSA, while unsuccessful ETV patients showed mean increases of 1.17cm(2) and 17.3% per patient. These differences were statistically significant. Measures of lateral ventricular size showed similar trends, but with lower magnitude. Third ventricular imaging parameters (width and mid-sagittal CSA) exhibited more pronounced responses to ETV than lateral ventricular measurements in pediatric hydrocephalic patients.