Repair of cerebrospinal fluid leak of the temporal bone via a Trans-Mastoid Approach: A single center’s experience

Objectives: To evaluate the outcomes of spontaneous temporal bone cerebrospinal fluid (sCSF) leak repairs performed via the transmastoid (TM) approach, with specific emphasis on recurrence rates and post-operative hearing outcomes. Methods: This is a retrospective case series in a single tertiary center including 24 consecutive patients who underwent TM repair for sCSF leaks between 2018 and 2024. Patients with non-spontaneous CSF leaks were excluded. The primary outcome was recurrence of CSF leak at 12 months. Secondary outcomes included post-operative audiometric changes (air-bone gap, pure tone average, speech reception threshold) and post-operative complications such as infection, cranial nerve injury, or seizures. Results: The mean patient age was 59.5 years (SD 11.0), with 45.8% female and an average BMI of 35.9. 45.8% of cases were left sided. Recurrence occurred in two patients (8.2%). There were no post-operative infections, cranial nerve injuries, or seizures. Audiometric data (n=19) demonstrated stable or improved hearing thresholds across most parameters, though statistical significance was limited by sample size. The average interval between surgery and post-operative audiogram was 15.5 weeks. Conclusions: The TM approach is non-inferior for the repair of spontaneous temporal bone CSF leaks, offering recurrence rates comparable to the middle cranial fossa (MCF) approach while minimizing morbidity associated with craniotomy and temporal lobe retraction. Hearing preservation was achieved in most patients. Larger, multi-institutional studies with long-term follow-up are warranted to further validate these findings and refine surgical selection criteria.