Middle Cranial Fossa Encephalocele and Cerebrospinal Fluid Leakage: Etiology, Approach, Outcomes

Objective To compare outcome data for surgical approaches in the management of a middle cranial fossa encephalocele or cerebrospinal fluid (CSF) leak and, secondarily, to evaluate the role of obesity and the etiology of the defect. Design Retrospective Setting Quaternary referral center Participants The study included 73 patients who underwent surgical repair of middle cranial fossa tegmen defects, two of which underwent bilateral repair. Outcome Measures Demographic characteristics, clinical presentation, etiology, imaging, audiometry, surgical findings, method and material for repair, and postoperative course. Results Fifty cases were spontaneous in origin, 2 were iatrogenic, and 23 were because of chronic otitis media. Of the 50, 18 underwent middle fossa craniotomy, 29 underwent a transmastoid approach, and 28 underwent a combined approach for repair. A postoperative CSF leak was seen in five patients: one who had undergone a transmastoid approach and four after a combined approach. There was no significant difference between the three approaches and risk of postoperative CSF fistulae. Two of the CSF fistulae resolved after a lumbar drain, and the remaining three patients required revision surgery. Conclusions Middle cranial fossa tegmen defects are most commonly seen in obese females and are spontaneous in origin. The most common location was the tegmen mastoideum, and these defects were most commonly repaired through the transmastoid approach, with no greater risk of recurrence.

Keywords: cerebrospinal fluid leakage; encephalocele; middle cranial fossa; obesity.