Antibiotic impregnated external ventricular drainage and third ventriculostomy in the management of hydrocephalus associated with posterior cranial fossa tumours.

BACKGROUND: The effectiveness of antibiotic pre-treated ventricular catheters in reducing the risk of CSF infections (determined on CSF cultures) resulting from the use of per-operative external ventricular drainages (EVD) and the success rate of post-operative endoscopic third ventriculostomy (ETV) in the management of persistent hydrocephalus after posterior cranial fossa tumour removal are assessed.

METHOD: Forty-seven children (group I) were prospectively managed by means of per-operative antibiotic impregnated EVD, post-operative ICP monitoring, and ETV. The results of this group were compared with those of a control group composed by 44 children treated with the same protocol as above except for the use of not-impregnated catheters (group II).

FINDINGS: The rate of positive CSF cultures due to EVD resulted significantly lower in group I (2.1% vs 31.8%); there was no clinical evidence of CSF infections. The success rate of ETV was the same in both groups (75%). Failures of ETV occurred in the patients with subarachnoid tumour seeding and/or tumour extension to the basal cisterns. All the children of group II with failed ETV also showed a bacterial growth in the CSF.

CONCLUSIONS: Antibiotic pre-treated catheters in our experience considerably limited EVD-related bacterial growth in the CSF. Preoperative hydrocephalus resolved in 60% of the cases after tumour removal, thus confirming recent data from the literature against the routine use of preoperative ETV. In our experience postoperative ETV had a high success rate; poor results were obtained in children with tumour seeding and/or the evidence of positive CSF cultures.