Endoscopic Third Ventriculostomy in the Treatment of Childhood Hydrocephalus: Validation of a Success Score That Predicts Long-term Outcome

Object: The goal of this study was to externally validate the proposed Endoscopic Third Ventriculostomy Success Score (ETVSS), which predicts successful treatment for hydrocephalus on the basis of a child's individual characteristics.

Methods: The authors retrospectively identified 181 cases of consecutive endoscopic third ventriculostomy (ETV) performed in children at a single neurosurgery center in the United Kingdom. They compared actual success at both 6 and 36 months, with mean predicted probabilities for low, moderate, and high chance of success strata based on the ETVSS. Long-term success was calculated using Kaplan-Meier methods and comparisons were made by means of unpaired t-tests.

Results: Overall, 166 primary ETVs were performed; ETV success was 72.9% at 6 and 64.5% at 36 months. At long-term follow-up, the mean predicted probability of success was significantly higher in those with a successful ETV (99 patients) than in those with a failed ETV (67 patients) (p = 0.001). The ETVSS accurately predicted outcome at 36 months; the low, medium, and high chance of success strata had mean predicted probabilities of success of 82%, 63%, and 36%, and actual success of 76%, 66%, and 42%, respectively. The overall complication rate was 6%.

Conclusions: The ETVSS closely predicted the overall long-term success rates in high-, moderate-, and low-risk groups. The results of this study suggest that the ETVSS will aid clinical decision making in predicting outcome of ETV.