Management of hydrocephalus complicating childhood posterior fossa tumors.

We examined the treatment of hydrocephalus in children with posterior fossa tumors to (1) compare the use of external ventricular drainage (EVD) with ventriculoperitoneal shunts (VPS), (2) determine the frequency of postoperative hydrocephalus requiring permanent shunts, and (3) determine which factors predict the need for a permanent shunt. The records of 58 children with posterior fossa tumors and associated hydrocephalus treated at our institution from 1979 to 1987 were retrospectively reviewed. Initial management of hydrocephalus included VPS in 25 patients, EVD in 17, and no treatment in 16. Patients in the 'VPS', 'EVD', and 'no treatment' groups differed only in the severity of hydrocephalus (less severe in the no treatment group than in the VPS and EVD groups) and in the method of dural closure following tumor resection (dura was left open more often in the EVD and no treatment groups). Of the 33 patients not initially shunted, only 9 (27%) subsequently required a shunt. These patients were compared with the remaining 24 patients who did not require a shunt. Two features predicted the need for a subsequent shunt: (1) resection of only a small volume of tumor and (2) the dura open following tumor resection. Complications of EVD were few; no patient deteriorated neurologically during or after ventricular catheter removal. We conclude that between two thirds and three quarters of patients with childhood posterior fossa tumors and associated hydrocephalus may be managed with perioperative EVD and will not require shunts. Patients in whom only a minimal tumor resection is performed and those in whom the dura is left open are more likely to need permanent VPS.