Background: Endoscopic third ventriculocisternostomy has gained widespread use in the treatment of hydrocephalus.
Materials and methods: In 1999 and 2000 endoscopic third ventriculostomy was performed in 120 patients (60 males) at Rikshospitalet, Oslo, Norway. Median age was 3.3 years (range 0.0 to 71.7). 69 procedures were done as primary treatment of hydrocephalus and 51 procedures for shunt failure.
Results: After one year, 62% of the patients older than 6 months at time of treatment and 8% of the patients younger than 6 months were successfully treated for their hydrocephalus with ventriculostomy only. The success rate for patients with hydrocephalus secondary to aqueductal stenosis or a space-occupying lesion in the posterior fossa was 72% and 31% for patients with other causes of hydrocephalus. The success rate of endoscopic third ventriculostomy as primary treatment of hydrocephalus was 55%; for the procedure at time of shunt failure 45%. The overall likelihood of success was significantly correlated to age, cause of hydrocephalus, and whether the procedure was done as primary treatment of hydrocephalus or at time of shunt failure.
Interpretation: Endoscopic third ventriculostomy seems to be effective in treating hydrocephalus caused by aqueductal stenosis or a space-occupying lesion in the posterior fossa in patients older than 6 months. The procedure should not be routinely attempted on patients younger than 6 months.