Surgery for Temporal Bone Encephaloceles: A Review of 85 Cases

Objective: To describe the presentation, etiology, and surgical management of brain involvement of the temporal bone.

Materials and Methods: A retrospective chart review was conducted of 85 patients with tegmen dehiscence, meningoencephalocele, or cerebrospinal fluid leak in the middle ear.

Results: The most common etiology was chronic ear disease with or without cholesteatoma (67%). In 61%, potential iatrogenic cause for the problem existed due to previous surgery for chronic ear disease. Twenty-one of the 85 had extensive dural exposure alone, 49 had a meningoencephaloceles, and 15 had CSF leak. The majority of patients required a minicraniotomy, mid-fossa approach for repair (61%), grafting with cartilage or calvarium (94%) and soft tissue reconstruction (53%). Dural exposure alone was largely amenable to transmastoid repair (70%), whereas meningoencephaloceles were more likely to require minicraniotomy mid-fossa approaches (73%). Facial nerve involvement by chronic ear disease often required a minicraniotomy mid-fossa approach. Approximately half needed a soft tissue flap for reconstruction. Flaps used were pedicle fascia flaps: temporoparietal fascia flap or superficial temporalis fascia flap. Only 17% of patients who had undergone a prior procedure were amenable to transmastoid repair.

Conclusions: Tegmen defects are most commonly due to chronic ear disease. Dural exposure alone may be repaired via a transmastoid approach, whereas herniation of intracranial contents into the mastoid will likely need a more extensive approach. Facial nerve involvement, spontaneous lesions, and history of prior surgery may require a minicraniotomy mid-fossa approach. Grafts are often needed for support. Soft tissue flaps frequently are required for appropriate repair, especially in patients with facial nerve involvement.