Spontaneous middle fossa encephalocele and cerebrospinal fluid leakage: diagnosis and management.

OBJECTIVE: To evaluate the clinical presentation, operative findings, and surgical management of patients with spontaneous middle fossa encephalocele (SMFE) and cerebrospinal fluid (CSF) leakage repaired using a middle fossa craniotomy (MFC) approach.

STUDY DESIGN: Retrospective.

SETTING: Tertiary referral center.

PATIENTS: Fifteen consecutive patients with 16 SMFE repaired using an MFC approach between January 1999 and April 2006 were included.

INTERVENTIONS: Patients were evaluated clinically and radiologically with computed tomography or magnetic resonance imaging. Encephaloceles were approached via MFC, and the cranial base was repaired in multilayered fashion using a variety of materials, including hydroxyapatite cement. Patients were followed clinically after discharge.

MAIN OUTCOME MEASURES: Postoperative complications, including CSF leak and the need for surgical revision, are evaluated. Patient factors, diagnostic testing, and operative findings are reviewed.

RESULTS: Diagnosis was made using clinical and radiologic evaluation in most patients. Beta2-transferrin testing was occasionally used in the diagnostic workup. Intraoperatively, multiple defects of the floor of the middle fossa were found in more than half of patients. Fifteen SMFE in 14 patients were successfully repaired via MFC alone. One patient required revision with a combined transmastoid/MFC approach due to recurrent CSF leakage. Hydroxyapatite cement was used for repair of the cranial base in 9 patients without complication.

CONCLUSION: An MFC approach can be used to repair SMFE with CSF leakage with a high level of success. Hydroxyapatite cement is a safe and useful adjunct to aid in reconstruction of the cranial base defects in cases of SMFE.