Surgical Management of Skull Base Encephaloceles

Background: Surgical treatment of encephaloceles is recommended to prevent the occurrence of meningitis, epilepsy, and other complications. Among otolaryngologists, the endoscopic endonasal approach (EEA) has become the preferred technique to repair the anterior fossa (AF) encephaloceles. However, neurosurgeons generally prefer a craniotomy to approach these lesions. Middle fossa (MF) encephaloceles can be more difficult to treat and pose even more controversy related to the approach best suited to address them.

Objective: The purpose of this study is to evaluate the use and efficacy of different surgical options for the treatment of encephaloceles according to their location. We present our experience as a case series.

Methods: Twenty-one consecutive patients with skull base encephaloceles were surgically treated by a multidisciplinary skull base team including the senior author (DMP). Preoperative symptoms, encephalocele location, surgical technique, postoperative complications, and recurrence were assessed. The AF encephaloceles were treated using the EEA and reconstruction with vascularized flap. The MF encephaloceles were subdivided in two groups. The sphenoidal lesions were treated by EEA with vidian nerve transposition and reconstruction using a vascularized flap. The tegmental ones were treated by a craniotomy with extradural approach and reconstruction with temporalis muscle rotation. On the second postoperative day, all patients underwent a lumbar puncture to assess opening pressure. When elevated intracranial pressure (ICP) was diagnosed, a ventriculoperitoneal (VP) shunt was performed.

Results: Nine patients had AF and 12 had MF encephaloceles. The presenting symptoms were CSF leakage, convulsions, conductive hearing loss, and recurrent meningitis. All of the sphenoidal encephaloceles treated with EEA and vidian nerve transposition (five patients) had preserved nerve function. One patient that had a craniotomy for MF encephalocele repair needed reoperation because of persistent CSF leakage through a previous mastoidectomy. Ten patients underwent a VP shunt due to elevated ICP (47.6%). No complications were observed.

Conclusion: Both endoscopic technique and craniotomy may be used to repair skull base encephaloceles with good results. A thorough evaluation of the encephalocele location and anatomical characteristics must be performed to choose the best surgical option.