Hearing Improvement Following Middle Cranial Fossa Floor Defect Repair Utilizing a Modified Middle Fossa Approach and Reconstructive Techniques

Abstract

Background: Few studies report hearing preservation following middle cranial fossa (MCF) floor defect repair. Objective: To investigate audiological outcomes following MCF floor defect repair using a modified MCF suprapetrous approach. Study Design: Retrospective cohort. Setting: Tertiary referral center. Patients: Eleven patients, with MCF floor defects. Interventions: MCF floor defect surgical repairs with either fascia or fascia and bone graft. Main Outcome Measured: Hearing outcomes. Results: Eleven patients (two men) aged 34 to 82 years (median, 62 yrs) were identified. All patients were operated on by the same two senior surgeons (M.P. and M.G.). One patient with conductive hearing loss (based on tuning fork test) was excluded from the analysis due to missing preoperative audiogram data. All patients had middle fossa plate defects leading to cerebrospinal fluid (CSF) otorrhoea, rhinorrhoea, or meningitis. Nine patients had retrieval of herniated contents from the defect. Five patients had repair with temporalis fascia and split calvarial bone graft, and six patients had repair with fascia only. Follow up audiogram was performed at a mean 7.5 months (range, 0.5–24 mo). There was no recurrent CSF leak during the follow up period. The 10 patients (90.9%, 95% confidence interval [CI] 60.1–100.6) who had complete audiologic data sets demonstrated a mean improvement of 18.86 dB (range, –7.5 to 33.75 dB) in hearing postoperatively. One of these patients acquired a 7.5 dB reduction in postoperative hearing due to post-procedural middle ear effusion which subsequently resolved. Hearing improvement following fascial graft alone versus fascial graft with bone was 12.5 and 26.5 dB, respectively (p < 0.01). Conclusion: Middle fossa craniotomy with or without retrieval of herniated contents and floor reconstruction with fascia and bone is associated with improved hearing. Clinical efficacy of this technique, however, can be only fully established when a statistically meaningful number of cases have been performed.

Audiometric Outcomes and Middle Ear Disease following Cerebrospinal Fluid Leak Repair

“…Only a handful of prior reports have evaluated audiometric outcomes in detail following a multilayer, lateral skull base repair of spontaneous CSF leaks. 5,[12][13][14] To our knowledge, this is the second and largest series describing a combined approach. Overall, hearing was preserved and the mean airbone gap improved 7.23 dB in patients with spontaneous CSF leaks.…”

“…Only a handful of prior reports have evaluated audiometric outcomes in detail following a multilayer, lateral skull base repair of spontaneous CSF leaks 5,12–14 . To our knowledge, this is the second and largest series describing a combined approach.…”

“…Following a transmastoid approach, Kim et al 5 found a multilayer repair yielded a mean improvement of 12 dB in air-bone gap and 13 dB in PTA in 14 sCSF leak patients. Alwan et al 14 found a mean improvement of 2.5 dB and 18.9 dB in ABG and PTA, respectively, in 10 patients who underwent a middle cranial fossa approach.…”

Is Septal Cartilage Graft via Transmastoid Approach Safe Enough in the Repair of Large Tegmen Defects?

“…A split-thickness bone graft is mostly harvested from the inner cortical side of the temporal bone squamosal part. Thus, there is a need of titanium mini-plate fixation of the bone flap during wound closure, which can prolong the operation time and increase the surgical and the harvest site complications [14, 26-29]. Furthermore the bone graft has a resorption risk which was shown by a study about the repair of orbital floor fracture [26].…”

Spontaneous Tegmen Tympani Dehiscence: Causes and Treatment of Conductive Hearing Loss

“…Up to 93% of patients have conductive hearing loss (CHL) at presentation (3,8,9). CHL in this situation commonly arises due to CSF effusion in the tympanomastoid space and prolapse of encephalocele onto the ossicular chain resulting in impaired movement (1,3,(9)(10)(11)(12)(13)(14)(15). In addition, synchronous SSCCD may also cause CHL (16).…”