Abstract: Objective To explore the management of obstructive hydrocephalus caused by posterior fossa tumors before tumor
resection in children. Methods The clinical data were reviewed of 162 pediatric patients of posterior fossa tumors with
obstructive hydrocephalus undergoing surgical tumor removal between January 2008 and June 2012. Ninety children received
preoperative Ommaya external drainage (group A) and 72 underwent preoperative ventriculo-peritoneal shunting (V-Ps)
(group B). The therapeutic effects were evaluated and compared between the two groups. Results Postoperative complications
found in a total of 67 cases including infection (27), shunt blockage (19), subdural hematoma or effusion (16), ventricle fissure
syndrome (5), and tumor hernia (4). Significant differences were found in the incidences of shunt blockage (P=0.047) and
subdural hematoma or effusion (P=0.039) but not in the incidences of intracranial infection (P=0.478) or tumor hernia (P=0.462)
between the two groups. Conclusion Ommaya reservoir can produce good results through simple surgical procedures for
treatment of acute hydrocephalus in children with posterior fossa tumors and is associated less trauma and complications．