Endoscopic Middle Fossa Repair of Temporal Lobe Encephaloceles and Cerebrospinal Fluid Otorrhea

Temporal lobe encephaloceles and cerebrospinal fluid otorrhea are relatively rare conditions involving the tegmen tympani and mastoideum. These conditions have become more frequent in recent years due to increases in average body mass index and prevalence of sleep apnea in the United States. When either condition is present, surgical repair of the skull base defects is recommended to circumvent severe complications, such as meningitis, brain abscess, conductive hearing loss, and chronic middle ear effusion. The traditional surgical approach used to repair middle fossa encephaloceles and cerebrospinal fluid leaks includes a middle fossa craniotomy. A standard middle fossa craniotomy approach requires a sizable skin incision, a large craniotomy on the lateral aspect of the skull, and considerable retraction on the brain. Unfortunately, such procedures place patients at risk of temporary deficits in cognitive function and an increased risk of cerebrovascular accident. Repairs of encephaloceles and cerebrospinal fluid leaks originating from other areas of the skull base have been successfully performed using endoscopes. Success rates after a single procedure were estimated at >90% for CSF leaks and >93% for encephaloceles. The use of endoscopes for visualization of the tegmen allows for a smaller skin incision, a small craniotomy, and less retraction on the temporal lobe than with a traditional middle fossa craniotomy approach. Such endoscopic procedures have relatively low morbidity and mortality and are increasing in popularity. At our institution, six cases of endoscope-assisted middle fossa repairs of tegmen deficiencies have been performed. A retrospective analysis of these cases has been performed to assess patient outcomes, including operative times, postoperative complications, recurrences of encephaloceles, or cerebrospinal fluid otorrhea. Both short-term and long-term follow-up (>18 months) data has been collected. Our findings demonstrate that there was no increase in surgical times or in major postoperative complications, recurrences of encephaloceles, or cerebrospinal fluid otorrhea. This study provides preliminary data demonstrating the efficacy of an endoscopic middle fossa repair of temporal lobe encephaloceles and cerebrospinal fluid otorrhea.

No conflict of interest has been declared by the author(s).