Surgical outcome of pediatric hydrocephalus treated by endoscopic III ventriculostomy: prognostic factors and interpretation of postoperative neuroimaging

In order to analyze the surgical outcome according to clinical characterist ics and to evaluate the correlation between clinical improvement and neuroi maging chang es, we retrospectively reviewed 32 children who had undergone endoscopic III ventriculostomy (ETV) from February 1994 to May 1998. There were 15 boys and 17 girls, with a mean age of 5.2 years (range: 1 month to 13 years). The etiology of the hydrocephalus was primary aqueductal stenosi s in 18 patients, secondary aqueductal stenosis caused by tumors in 5, IV v entricle outlet obstruction in 5, and hydrocephalus associated with meningo myelocele in 4. The mean duration of follow-up was 19.4 months (range 1-50 months). Overall, surgical outcome was regarded as good in 21 of 29 patient s. Surgical outcome was poor in patients younger than 1 year (P<0.05). Neur oimaging 1 month after ETV showed a decrease in ventricular size in 11 of t he 16 patients with good surgical outcomes. Five showed minimal changes onl y. In patients with good outcomes, ventricular size tended to decrease as t ime passed. Resolution of periventricular edema, flow void in the III ventr icle on T2-weighted axial images, and cine-MR imaging were sensitive indica tors of good outcome. We suggest that ETV be considered as a primary treatm ent option in patients older than 1 year of age with noncommunicating hydro cephalus. In addition, time factors should be taken into consideration when surgical outcome is judged. Changes in ventricular size could not predict surgical outcome completely in themselves. Therefore, a comprehensive posto perative assessment should be made with the help of T2-weighted MRI and cin e-MRI.