Success and failure of endoscopic third ventriculostomy in young infants: are there different age distributions?

Objective Patient's age and etiology of hydrocephalus are the most important factors influencing the success rate of endoscopic third ventriculostomy (ETV). Failure rates are reported to be particularly high in the first year of age. On the basis of our own data and a metaanalysis of the literature, we try to further define the impact of age on ETV success in infants younger than 1 year. Materials and methods Only patients with a minimum follow-up of 12 months were considered. Between October 1994 and July 2004, 28 patients younger than 1 year underwent ETV in our institution. Age ranged from 8 to 311 days (median 96). The etiology of hydrocephalus was aqueductal stenosis (AS) in all patients (idiopathic in 13, posthemorrhagic in three, postmeningitic in four, and related to CNS or vascular malformation or to tumor in eight). ETV failure was defined as subsequent need for shunt implantation. The metaanalysis of the literature took into account reported series on ETV in infants with detailed data on age and etiology in every single patient. Results In our own patients, ETV was successful in 13 patients and eventually failed in 15. In the ETV success group, the median age was 200 days and the mean age was 176 days (range 13-311 days). In the ETV failure group, the ages were 105 days (median), 117 days (mean), and 8-299 days (range). The differences were not statistically significant. Age distributions in both outcome groups showed a tendency of failures to occur more frequently in the first 2-4 months of life. The separate analysis of patients with idiopathic AS yielded similar figures and distributions. The data from the metaanalysis of the literature corresponded to our own results. Conclusion There is a clear impact of age on ETV failure rate even when excluding etiological factors. The probability of ETV success gradually increases during the first months of life. The consequence of these findings for decision-making as well as parental counseling is to try to weigh the age of the infant and its estimated impact on ETV success with other factors guiding the decision to perform ETV or shunt in the treatment of obstructive hydrocephalus.