Audiometric Outcomes After Surgery for Spontaneous CSF Otorrhea and Temporal Bone Encephaloceles: A Systematic Review and Meta-Analysis.

BACKGROUND

Spontaneous cerebrospinal fluid (CSF) otorrhea and temporal bone encephaloceles are rare but potentially serious conditions that can lead to meningitis if left untreated. Surgical intervention is the primary treatment, with approaches including transmastoid (TM), middle cranial fossa (MCF), or combined. Although these procedures aim to prevent complications, their impact on hearing outcomes remains unclear.

OBJECTIVE

To compare hearing outcomes of different surgical approaches for spontaneous CSF otorrhea and temporal bone encephaloceles.

METHODS

A systematic review following PRISMA guidelines was conducted. PubMed, Medline (OVID), and Cochrane library were searched for studies on spontaneous CSF otorrhea and temporal bone encephaloceles. Case reports, non-English studies, and those including trauma or previous surgery patients were excluded. Primary outcomes were pooled pure-tone average (PTA) and air-bone gap (ABG) differences. Random-effects meta-analysis was performed.

RESULTS

Eleven studies with audiometric data (307 ears) were analyzed. Overall pooled PTA difference was -9.06 dB (95% CI, -1.86 to -16.26; p = 0.014), and ABG difference was -10.09 dB (95% CI, -3.96 to -16.22; p = 0.001). Subgroup analysis showed the following: TM approach (three studies)-PTA difference: -4.4 dB (p = 0.43), ABG difference: -7.3 dB (p = 0.17); MCF approach (six studies)-PTA difference: -10.33 dB (p = 0.006), ABG difference: -9.9 dB (p = 0.012); and combined approach (three studies)-PTA difference: -4 dB (p = 0.64), ABG difference: -6.71 dB (p = 0.27).

CONCLUSION

Surgical treatment improves hearing outcomes, with the MCF approach showing the greatest improvement. However, limited data precluded meaningful comparisons between approaches. Further research comparing surgical techniques and materials is needed, as current studies predominantly focus on recurrence rather than audiometric outcomes.