Endoscopic Third Ventriculostomy in Infants of Less Than 1 Year of Age: Which Factors Influence the Outcome?

Objectives: Endoscopic third ventriculostomy (ETV) is a successful method of treatment for obstructive hydrocephalus. In infants, however, it is reported to have a higher failure rate. On the basis of our own data and a meta-analysis of the literature, we try to define factors prognosticating potential failure in infants aged less than 1 year.

Methods: Data were collected retrospectively. Between October 1994 and October 2002, 20 ETVs were performed in 16 patients younger than 1 year. Ages ranged from 8 to 311 days (median 103). Etiology was aqueductal stenosis in all 16 patients (idiopathic in 7, posthemorrhagic in 3, postmeningitic in 3, and related to CNS or vascular malformation in 3). ETV failure was defined as subsequent need for shunt implantation. For non-shunted patients, follow up was 16-52 months (median 25).

Results: ETV was successful in 5 patients and eventually failed in 11. There was no mortality or permanent morbidity following ETV. In the successful cases, etiology was idiopathic aqueductal stenosis in 4 and postmeningitic aqueductal stenosis in 1; the median age was 206 days (range 82-311). In the 11 unsuccessful patients, it was idiopathic aqueductal stenosis in 3, posthemorrhagic in 3, postmeningitic in 2 and CNS/vascular malformation in 3 cases; median age was 94 days (range 8-299). Median time interval between (last) ETV and shunt was 38 days (range 2-70). The difference in median age between the success group and the failure group roughly corresponded to data gained from a meta-analysis of the literature. Four patients underwent a second ETV. In intraoperative ventriculoscopy, the stoma was closed or there were new membranes below the floor of the third ventricle and a second ETV was performed. But finally, all re-ETVs failed and the patients needed a shunt.

Conclusion: Factors indicating potential failure of ETV were very young age and etiology other than idiopathic aqueductal stenosis. Probability of success seems to increase during the first 2 or 3 months of life. Ventriculoscopy with the option of a second ETV should be regularly performed after failure of ETV.