Endoscopic third ventriculostomy in the treatment of hydrocephalus in posterior fossa tumors in children

The purpose of the present study is to assess the effectiveness of endoscopic third ventriculostomy (ETV) in children with hydrocephalus related to posterior fossa tumors.

Between September 1999 and December 2002, 63 children with posterior fossa tumors were treated at Santobono Hospital in Naples, Italy. Twenty-six patients had severe hydrocephalus. In order to relieve intracranial hypertension before tumor removal, 20 were treated with ETV, and 6 with ventriculo-peritoneal (VP) shunts. Twenty patients with mild hydrocephalus were treated with diuretics, corticosteroid agents, and early posterior fossa surgery, and 17 patients who did not have hydrocephalus were treated by elective posterior fossa surgery. Another 4 ETV were performed in the management of postoperative hydrocephalus.

Preoperative ETV procedures were technically successful. One was complicated by intraventricular bleeding. The successful 19 preoperative ETV resolved intracranial hypertension before posterior fossa surgery in all cases. Three of these 19 patients developed postoperative hydrocephalus and were treated by VP shunt insertion after posterior fossa surgery. Out of the 4 ETV performed after posterior fossa surgery, only 2 were successful, both when the shunt malfunctioned.

Endoscopic third ventriculostomy should be considered as an alternative procedure to ventriculo-peritoneal shunting and external ventricular draining for the emergency control of severe hydrocephalus caused by posterior fossa tumors, since it can quickly eliminate symptoms, and hence, can delay surgery scheduling if required. Even though ETV does not prevent postoperative hydrocephalus in all cases, it does protect against acute postoperative hydrocephalus due to cerebellar swelling. In addition, it eliminates the risks of cerebrospinal fluid (CSF) infection related to external drainage and minimizes the risk of overdrainage because it provides more physiological CSF drainage than the other procedures. Since postoperative hydrocephalus is very often physically obstructive, ETV should always be considered a possible treatment procedure.