Introduction: No consensus exists regarding the management of hydrocephalus in children with posterior fossa tumors. The prophylactic use of endoscopic third ventriculostomy (ETV) is not justified as it potentially exposes ~ 70% of patients to an unnecessary procedure that can have significant risks. In the present study we analyse the factors that predispose to persistent hydrocephalus and predict the need for a postoperative CSF diversion procedure.

Methods: Pediatric patients who underwent surgery for posterior fossa tumors with hydrocephalus at our hospital were reviewed. Patients having undergone CSF diversion preoperatively were excluded from the study group. The factors evaluated included age at diagnosis, duration of symptoms, severity of preoperative hydrocephalus, tumor size, tumor location, tumor histology, extent of tumor resection and postoperative complications.

Results: 84 consecutive patients were included in the study. 25/84 (29.8%) patients required a CSF diversion procedure in the postoperative period. Symptom duration of less than 3 months (p=0.016); degree of hydrocephalus based on Evan’s index (p=0.001) and frontal and occipital horn ratio (p<0.001); midline tumors (p=0.04); tumor histology suggestive of medulloblastoma (p<0.001) and ependymoma (p=0.016) and need for perioperative external ventricular drain (p<0.001) were found closely to correlate with the need for postoperative shunt. Patients with postoperative meningitis and pseudomeningocele had a greater risk of CSF diversion (P=0.008 and P=0.016 respectively).

Conclusions: The fact that less than one-third of patients require a CSF diversion after posterior fossa tumor resection refutes the role of prophylactic ETV in all patients with hydrocephalus. Awareness regarding the factors that can predict persistent postoperative hydrocephalus is essential for the surgeon during patient counselling, surgical planning and to decide regarding the intensity of postoperative clinical and radiological monitoring. These patients might selectively be exposed to the risks of preresection ETV to improve outcome. This study also highlights the need for a predictive model to guide management issues.

Patient Care: Awareness regarding the factors that can predict persistent postoperative hydrocephalus is essential for the surgeon during patient counselling, surgical planning and to decide regarding the intensity of postoperative clinical and radiological monitoring. These patients might selectively be exposed to the risks of preresection endoscopic third ventriculostomy to improve outcome. This will avoid routine shunting in the preoperative period that has been proven to be an unnecessary procedure in approximately two-thirds of the patients.

Learning Objectives: By the conclusion of this session, participants should be able to describe the role of various factors that can predict persistence of hydrocephalus after posterior fossa tumor surgery in children. They should be able to appreciate the low requirement of CSF diversion after definitive surgery and understand the rationale in the use of endoscopic third ventriculostomy in the preoperative management of children with posterior fossa tumors and concomitant hydrocephalus. The participants should be able to discuss the treatment of such children in their hospitals and appreciate the varied forms of management practiced across the globe. The need to have a multicentre trial to propose a prediction model for postoperative hydrocephalus should be appreciated by the participants. Thus the goal should be to identify the best possible treatment in such children with minimal morbidity and mortality.

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