The incidence of brain herniation into the mastoid is a rare complication of mastoid surgery. However, we should not overlook the seriousness of the complication and the potential for its prevention.
A 6-year-old boy presented with a temporal lobe herniation (meningoencephalocele) originated from mastoid surgery for middle ear cholesteatoma. The herniation might expand into mastoid cavity so slowly that it might have developed without any clinical symptoms such as the cerebrospinal fluid leakage. The herniation had at first been treated by transmastoid approach in the revision tympanoplasty.
One and half year after that repir of the tegmen defect, a head trauma by a fall accident brought him reccurence of the temporal herniation by chance.
The tegmen defect was too large to close primarily, a middle fossa approach was added to the transmasid approach.
A satisfactory technique by using the fascia-bone-fascia graft (sandwich) was also reported.
The dura and arachnoid may be easily damaged during mastoidectomy, therefore it is always neccessary to inspect carefully any area of dural exposure.
