Combined Approach for Giant Temporal Meningoencephalocele

Abstract

Introduction: To present a complex case of giant meningoencephalocele after a canal wall down mastoidectomy and describe our preferred approach to repair meningoencephalic herniation of the temporal bone.

Case report: A 20-year-old patient, who had previously undergone type III tympanoplasty with total ossicular reconstruction prosthesis for an attic cholesteatoma, presents with clinical and imaging features compatible with the diagnosis of a giant temporal meningoencephalocele. We performed a combined approach -transmastoid plus minicraniotomy- to repair the skull base defect. A multilayer reconstruction of the defect with septal cartilage and temporal fascia was performed. After a 48 months follow-up, the patient remains symptom free without signs of tissue herniation.

Conclusions: Transmastoid plus minicraniotomy combined approach is a safe and feasible technique in case of large and anterior skull base defects with low surgical morbidity, allowing a safe and multilayered reconstruction, even in the context of a simultaneous active chronic otitis media.

Keywords: Acquired Encephalocele; Cholesteatoma; Middle ear; Skull base; Temporal bone.

Fig.1

A mass protruding into the external auditory meatus is identified

Fig. 2

CT scan. Coronal view. A right skull base defect is observed

Fig.3

MRI imaging. Coronal view. Brain tissue herniation is identified on the right side

Fig. 4

Dura is elevated from the middle cranial fossa floor in a lateral to medial direction and the bony defect is identified from above and from below

Fig. 5

Septal cartilage graft is disposed between the dura and the floor of middle fossa, covering the bony defect