External validation of the ETVSS scale for predicting the outcomes after third ventriculostomy in children less than one year of age with obstructive hydrocephalus

Background. Successful endoscopic third ventriculostomy (ETV) depends on patient characteristics, including age, etiology of hydrocephalus and previous shunting. Kulkarni et al. [1] developed the Endoscopic Third Ventriculostomy Success Score (ETVSS) to predict the success of ETV using these factors. We analyzed own experience of ETV in children under one year of age and validity of the ETVSS scale. Objective. To assess prognostic significance of the ETVSS scale in children under one year of age after ETV. Material and methods. There were 1105 surgeries in children with hydrocephalus between 2012 and 2021 including 273 ETV procedures. Primary ETV was performed in 129 patients (47.3% of all procedures), they met the inclusion criteria. ETVSS score was calculated retrospectively for each patient and compared with actual success of ETV. ROC analysis was used to determine the quality of the validated version of the ETVSS scale. Results. The study included 129 primary ETVs in children under one year of age. Success rate was 52.7% (n=68), the minimum follow-up — 6 months. When analyzing the results, we found mild prognostic underestimation in short-term and long-term outcomes of ETV according to the ETVSS scale. ROC analysis revealed AUC 0.67 that corresponds to satisfactory level of this classification. Sensitivity was 66%, specificity — 63%. Conclusion. ETVSS scale demonstrated good ability to predict success according to actual success rate of ETV in neonates and infants. This tool may be useful in decision-making for endoscopic surgery. The ETVSS scale should be used by neurosurgeons to assess possible outcomes after ETV in infants.