Management of hydrocephalus in pediatric patients with posterior fossa tumors: the role of endoscopic third ventriculostomy

Analysis of CSF shunting procedure requirement in children with posterior fossa tumors

OBJECT

The authors analyze the factors that predispose to persistent hydrocephalus in children with posterior fossa tumors and compare their results and treatment policy with those described in the literature, particularly with regard to the higher postoperative shunt insertion rates, which have led some authors to the routine use of preoperative third ventriculostomy.

METHODS

The clinical records of 180 children treated for posterior fossa tumors in the Department of Pediatric Neurosurgery of the National Institute of Neurosurgery, Budapest, Hungary, between 1990 and 2000 were retrospectively reviewed.

CONCLUSIONS

The low postoperative shunt insertion rate in our series (15.5%) led us to believe that the routine use of preoperative third ventriculostomy is not entirely justified. Factors such as patient's age and tumor type, which showed a statistically significant association with the postoperative shunt requirement in our study, should be considered when the decision regarding treatment is made.

[Analysis of cerebrospinal fluid related complications (hydrocephalus, fistula, pseudomeningocele and infection) following surgery for posterior fossa tumors]

INTRODUCTION

Hydrocephalus, cerebrospinal fluid (CSF) leak, pseudomeningocele and CSF infection are potential complications related to surgical treatment of posterior fossa tumors. The objectives of this study were to review the incidence of such complications and to identify contributing factors related to them.

MATERIAL AND METHODS

This study is based on a retrospective review of the medical records of 71 consecutive patients who underwent posterior fossa surgery for a tumor between the period January 1997 and December 2001. Postoperative hydrocephalus was defined as enlargement of the ventricles and the subsequent clinical worsening requiring surgical treatment. Criteria for CSF leakage were:observed leak of CSF through the wound, rhinorrhea or otorrhea. Pseudomeningocele was determined when there was a large epidural CSF collection diagnosed in the postoperative period or by magnetic resonance imaging performed at least three months after posterior fossa surgery. Finally, CSF infection was defined on clinical ground and positive biochemical examination, but not necessarily positive cultures.

RESULTS

The series included 84 operations for resection of posterior fossa tumors on 71 patients. There were CSF related complications in 31% (26/84)with the following detailed incidence: 9.5% (8/84) postoperative hydrocephalus; 14.3% (12/84) CSF leak, 7.1% (6/84) pseudomeningocele; 8.3% (7/84) CSF infection. The mortality rate is 5.9% (5/84). The tumor size was the only statistically significant factor associated with the occurrence of CSF related complications (mean 39.43 mm, SD 18.51 mm vs.29.80 mm, SD 14.12 mm, p=0.015). In the subgroup of patients, in which hydrocephalus was managed preoperatively, the election of an external ventricular drain vs.other strategies (subcutaneous reservoir, definite shunt or endoscopic third ventriculostomy) was associated with a higher occurrence of CSF related complications (p=0.006). The mortality rate was associated with age (mean 63.60 years, SD 5.86 years vs.49.18 years, SD 16.39 years; p=0.002). The occurrence of CSF related complications also influenced mortality (p=0.030), particularly postoperative hydrocephalus (p< 0.001). Inpatient hospital stay was longer in the subgroup of patients who developed CSF related complications (p=0.002).

CONCLUSIONS

Tumor size was the only factor associated with the development of CSF related complications after surgery for posterior fossa tumors. In the subgroup of patients in which hydrocephalus was surgically treated preoperatively, the election of an external ventricular drain compared to other surgical modalities was associated with a higher rate of CSF related complications. The development of such complications, particularly hydrocephalus, was related with mortality.