International Infant Hydrocephalus Study (IIHS): 5-year health outcome results of a prospective, multicenter comparison of endoscopic third ventriculostomy (ETV) and shunt for infant hydrocephalus

Introduction: One of the most important unanswered questions in pediatric hydrocephalus is determining whether treatment with endoscopic third ventriculostomy (ETV) versus shunt results in improved health status and quality of life (QOL). To answer this, the International Infant Hydrocephalus Study (IIHS) was started in 2005 as a prospective, multicenter study to compare ETV and shunt in infants (< 24 months old) with symptomatic triventricular hydrocephalus from aqueductal stenosis. Herein, we present the 5-year primary outcome results.

Methods: IIHS utilized a prospective comprehensive cohort design, in which patients received ETV or shunt, based on either randomization or parental preference. For this analysis, we pooled the randomized arm and the parental preference arm, analyzing them together. At 5 years of age, children were assessed with the Health Utilities Index Mark 2 (HUI-2) (primary outcome) and the Hydrocephalus Outcome Questionnaire (HOQ), a measure of QOL. Results were compared in an analysis of covariance, adjusting for baseline variables including age at surgery and baseline development status.

Results: From a total of 158 patients who met eligibility criteria, complete 5-year outcomes were available on 78 (19 treated initially with shunt, 61 treated initially with ETV), assessed at a mean age of 62.1 months (SD 6.3). The mean 5-year HUI-2 utility score was 0.90 (SD 0.19) for ETV and 0.94 (SD 0.10) for shunt (p = 0.21). The mean 5-year HOQ overall score was 0.81 (SD 0.15) for ETV and 0.85 (SD 0.12) for shunt (p = 0.42). Similarly, there were no significant differences noted between 5-year HOQ subscores (cognitive, social-emotional, physical) or developmental measures at 1, 2, and 3 years.

Conclusions: This is the first prospective direct comparison of long-term outcomes of ETV and shunt for infant hydrocephalus. These results suggest that overall health status and quality of life in this cohort of infants treated for aqueductal stenosis are high, with no significant difference between those treated initially with ETV or shunt.

Trial registration: NCT00652470.