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

Background: Lateral temporal bone encephaloceles and CSF leaks may present with otorrhea or effusion, conductive hearing loss, and meningitis. Spontaneous CSF otorrhea with or without encephalocele may be a result of prolonged intracranial hypertension, trauma (including iatrogenic injury), or may be idiopathic. Repair is recommended to decrease risk of meningitis, resolve otorrhea, and improve hearing. Multiple approaches including middle fossa (MF) craniotomy and transmastoid (TM) or combined MF + TM access have been described. We report here on a series of consecutive patients with tegmen defects who all had intradural repair combined with middle fossa floor reconstruction. Patients who had middle fossa repair alone and those with combined MF + TM approaches were included.

Methods: Single-institution, retrospective review of all patients who underwent MF or MF + TM lateral skull base repair utilizing an intradural graft by the corresponding author. Patient characteristics including sex, age, and BMI were collected. Pre- and postoperative audiometric results were included when available. Postoperative complications including recurrent or persistent CSF leak were reported. Statistical analysis was performed in Excel.

Results: A total of 49 patients undergoing 50 repairs were included. 74% were performed in women (p < 0.05). 10 patients had a history of chronic otitis media and prior mastoid surgery. Average BMI was 35.8, and average age was 59 years. 54% of patients had multiple skull base defects that involved the tegmen mastoideum (82%), tegmen tympani (62%), and petrous apex (14%). 18 (36%) patients had a MF approach for repair. 32 (64%) patients had a MF + TM approach for repair; 13 (40.1%) of these patients had a concurrent tympanoplasty or myringoplasty. Postoperative audiograms were available for 31 patients (62%). Hearing improved in 74% of patients. Pure tone average (PTA) improved by an average of 5 dB (p = 0.27). No difference in hearing preservation between patients in the MF versus MF + TM groups was noted. Only two patients (6%) had hearing decline. Eight complications were reported including 1 (2%) skin infection, 4 (8%) recurrent or persistent CSF leaks requiring lumbar drain or shunt, and 3 (6%) episodes of aphasia or mental status change which were self-limited. 44% of our cohort was over the age of 65 years, and age was not associated with risk of postoperative complication.

Conclusion: Intradural repair of temporal bone encephalocele and CSF leak is a safe and effective surgical approach and allows access to the entire skull base including petrous apex and tegmen tympani. We believe that intradural reinforcement of the dura along the entire middle fossa floor may be beneficial for patients with multiple areas of dehiscence and thin dura. Complications 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% of our cohort, with no difference noted between those patients undergoing mastoidectomy and those treated only with a craniotomy ([Fig. 1]; [Tables 1]–[3]).

Table 1

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Fig. 1

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Artikel online veröffentlicht:
05. Februar 2024