gms | German Medical Science

Objective: ETV has the advantage of leaving the patient free of shunt hardware and thus avoiding long-term implant complications. Except for the ETV Success Score (ETVSS), which has been validated in pediatric hydrocephalus, no reliable predictors for successful ETV have been defined. Aim of the present study was to systematically analyze preoperative symptoms as a potential indicator of future ETV success in children and adults.

Methods: Patients aged two years and older who were treated with ETV in the last 10 years were retrospectively identified, representing a "closed-skull" population, and relevant demographic, medical and radiological variables retrieved. Patients were stratified according to preoperative presentation: symptoms of acutely raised intracranial pressure (group A), normal pressure hydrocephalus-like symptoms (group B) and diffuse unspecific symptoms (group C). Ventricular size was measured with frontal to occipital horn ratio (FOHR). Clinical improvement was defined as partial or complete remission of hydrocephalic symptoms with patient satisfaction. Surrogate marker of failed ETV was cerebrospinal fluid diversion within 6 months.

Results: Forty-three patients with a mean age of 25 years (range 15 days to 72 years) were enrolled. In group A (N = 17) the mean preoperative ETVSS was 82%. Despite early clinical improvement in 82% (N = 14) and reduction of FOHR in 79% (N = 11), only 65% (N = 11) were shunt-free at 6 months. In group B (N = 11) the mean ETVSS was 89%. All patients had an early clinical improvement, although reduction of FOHR was detected in only 29% (N = 2). Ten patients (91%) remained shunt-free at 6 months. In group C (N = 15) the mean ETVSS was 89% and clinical improvement was noted in 82% (N = 11). FOHR remained stable in almost all patients and 93% (N = 14) were shunt-free at 6 months.

Conclusion: ETVSS did not predict ETV success in this mixed cohort of adult and pediatric patients, due to inadequate discrimination in patients aged older than ten years. Ventricular size did not correlate with ETV success, probably owing to the overall mild and delayed dynamics of ventricular size after ETV compared to shunts. Main predictor of ETV success in this cohort was acute symptoms (group A) versus chronic symptoms (group B and C), with 65% versus 91% and 93% of patients being shunt-free at 6 months. The development of an unbiased indicator of future ETV success independent of patient age requires further research.