Failure of third ventriculostomy in the treatment of aqueductal stenosis in children

Object. The goal of this study was to analyze the types of failure and long -term efficacy of third ventriculostomy in children. Methods. The authors retrospectively analyzed clinical data obtained in 213 children affected by obstructive triventricular hydrocephalus who were tre ated by third ventriculostomy between 1973 and 1997. There were 120 boys an d 93 girls. The causes of the hydrocephalus included: aqueductal stenosis i n 126 cases; toxoplasmosis in 23 cases, pineal, mesencephalic, or rectal tu mor in 42 cases; and other causes in 22 cases. In 94 cases, the procedure w as performed using ventriculographic guidance (Group I) and in 119 cases by using endoscopic guidance (Group II). In 19 cases (12 in Group I and seven in Group II) failure was related to the surgical technique. Three deaths r elated to the technique were observed in Group I. For the remaining patient s, Kaplan-Meier survival analysis showed a functioning third ventriculostom y rate of 72% at 6 years with a mean follow-up period of 45.5 months (range 4 days-17 years). No significant differences were found during long-term f ollow up between the two groups. In Group I, a significantly higher failure rate was seen in children younger than 6 months of age, but this differenc e was not observed in Group II. Thirty-eight patients required reoperation (21 in Group I and 17 in Group II) because of persistent or recurrent intra cranial hypertension. In 29 patients shunt placement was necessary. In nine patients in whom there was radiologically confirmed obstruction of the sto ma, the third ventriculostomy was repeated; this was successful in seven ca ses. Cine phase-contrast (PC) magnetic resonance (MR) imaging studies were performed in 15 patients in Group I at least 10 years after they had underg one third ventriculostomy (range 10-17 years, median 14.3 years); this conf irmed long-term patency of the stoma in all cases. Conclusions. Third ventriculostomy effectively controls obstructive trivent ricular hydrocephalus in more than 70% of children and should be preferred to placement of extracranial cerebrospinal shunts in this group of patients . When performed using ventriculographic guidance, the technique has a high er mortality rate and a higher failure rate in children younger than 6 mont hs of age and is, therefore, no longer preferred. When third ventriculostom y is performed using endoscopic guidance, the same long-term results are ac hieved in children younger than 6 months of age as in older children and, t hus, patient age should no longer be considered as a contraindication to us ing the technique. Delayed failures are usually secondary to obstruction of the stoma and often can be managed by repeating the procedure. Midline sag ittal T-2-weighted MR imaging sequences combined with cine PC MR imaging fl ow measurements provide a reliable tool for diagnosis of aqueductal stenosi s and for ascertaining the patency of the stoma during follow-up evaluation .