Intradural Repair of Temporal Bone Encephalocele and Cerebrospinal Fluid Leak: Results from a Single Institution

Abstract

Background: Lateral temporal bone encephaloceles incidence is increasing with obesity rates. Middle fossa(MF) craniotomy, transmastoid(TM), or combined MF+TM access can be used for repair. Methods: Retrospective review of MF or MF+TM repair with an intradural graft. Sex, age, and BMI were collected. Pre/postoperative audiometric results were included. Postoperative complications were reported. Results: 49 patients(50 repairs) were included. 74% were women(p < 0.05). 10 patients had a history of chronic otitis media and surgery. Average BMI was 35.8, and average age was 59. 54% had multiple skull base defects. 18(36%) patients had a MF approach. 32(64%) patients had a MF+TM approach for repair; 13(40.1%) of these patients had a concurrent tympanoplasty. Hearing improved for 74%. Air-conduction pure tone average(PTA) improved by an average of 5dB(p0.27). No differences in hearing outcomes between the MF vs. MF+TM groups. 2 patients(6%) had hearing decline. Eight complications were reported [1(2%) skin infection, 4(8%) recurrent/persistent CSF leaks requiring lumbar drain or shunt, and 3(6%) episodes of aphasia or mental status change]. Age(>65) was not associated with risk of postoperative complication. Conclusion: Intradural repair of encephalocele and CSF leak is a safe and effective surgical approach. Intradural reinforcement along the entire middle fossa floor is beneficial for multiple areas of dehiscence and thin dura. Complication rates including recurrent/persistent CSF leak and aphasia related to temporal lobe retraction were similar to previously published reports and not associated with older patient age. Hearing was stable or improved in 94% with no difference noted between MF or MF+TM repair.