Repair of iatrogenic temporal lobe encephalocele after canal wall down mastoidectomy in the presence of active cholesteatoma

Objective: Although mastoid and middle ear obliteration provides the ultimate repair of an encephalocele, retained squamous epithelium may result in the occult recurrence of cholesteatoma. For most patients, a preferable technique is to perform a canal-wall-up mastoidectomy with middle fossa craniotomy. However, temporal lobe encephaloceles are occasionally found in patients with canal-wall-down cavities along with active cholesteatoma. We sought to describe our management strategy for this dilemma. Study Design: Retrospective review. Setting: Tertiary referral center. Patients: We reviewed all patients with encephaloceles treated by the primary surgeon. Patients without active cholesteatoma and a canal-wall-down cavity were excluded. Intervention: Surgical management of the encephalocele and cholesteatoma. Main Outcome Measure: Successful repair and a noninfected ear. Results: Three patients met the inclusion criteria. All had previous canal-wall-down surgery for cholesteatoma by outside surgeons and presented with chronic otorrhea, large tegmen defects, and brain herniation into the mastoid cavity. All had incomplete removal of their posterior canal wall. Our management strategy involved completing the canal-wall-down mastoidectomy and repairing the temporal floor defect using a three-layer closure via a middle fossa craniotomy. This included Suture repair of the dural defect with or without a graft, a temporalis muscle rotation flap, and a split-calvarial bone graft. All patients recovered from their surgery without evidence of further cerebrospinal fluid leak, encephalocele, or cholesteatoma with a minimum follow-up time of 6 months. Conclusions: A temporal lobe encephalocele can be safely repaired while maintaining a mastoid bowl. This may be the safest treatment option for patients with active cholesteatoma.