Active Transcutaneous Bone Conduction Implant: Audiometric Outcomes Following a Novel Middle Fossa Approach With Self-Drilling Screws

Abstract

Objective: To present surgical and audiometric outcomes of patients implanted with an active transcutaneous bone conduction implant following the novel middle fossa surgical approach with self-drilling screws. Study Design: Retrospective review. Setting: Tertiary care center. Patients: Thirty-seven adults with either conductive or mixed hearing loss that met indications for an active transcutaneous bone conduction implant were consecutively implanted from April, 2013 to May, 2018. Intervention: Unilateral middle fossa implantation of an active transcutaneous bone conduction implant. Main Outcome Measures: Patient charts were reviewed for surgical outcomes and complications over the 6-year period. Preoperative air conduction, preoperative bone conduction, and 3-month postoperative aided thresholds were recorded. Speech perception was assessed using CNC words and AzBio sentences. Pure-tone averages (PTAs; measured at 0.5, 1.0, 2.0 and 3.0 kHz), air-bone gap, and functional gain were calculated. Results: Mean air conduction and bone conduction PTAs (±standard deviation) of the implanted ear were 66.8 dB (±14.9 dB) and 21.9 dB (±14.0 dB), respectively. Mean aided PTA was 26.5 dB (± 8.5 dB). The average functional gain was 40.3 dB (±19.0 dB). Favorable speech perception outcomes were observed. No complications or instances of revision surgery were reported, with a mean follow-up time of 32 months (range, 9–71 mo). Conclusions: This is the first paper to describe outcomes of patients implanted with an active transcutaneous bone conduction implant via the middle fossa with self-drilling screws. Favorable surgical outcomes were observed with a follow-up of up to 6 years.

The BONEBRIDGE active transcutaneous bone conduction implant: effects of location, lifts and screws on sound transmission

“…The BB-BCI can be implanted under a variety of surgical techniques, with the implant housed in either the TM or RF, and recently the MF location. The MF location is associated with improvements such as reduced operating time and a smaller skin incision [ 1 ]. The MF approach was first performed at London Health Sciences Centre (LHSC), London, ON, Canada in 2013 [ 10 ] with favorable surgical results reported with a follow-up of up to 6 years [ 1 ].…”

“…The MF location is associated with improvements such as reduced operating time and a smaller skin incision [ 1 ]. The MF approach was first performed at London Health Sciences Centre (LHSC), London, ON, Canada in 2013 [ 10 ] with favorable surgical results reported with a follow-up of up to 6 years [ 1 ]. Since then, other groups have also used the MF approach with or without self-drilling screws with clinical success [ 1 ].…”

“…The MF approach was first performed at London Health Sciences Centre (LHSC), London, ON, Canada in 2013 [ 10 ] with favorable surgical results reported with a follow-up of up to 6 years [ 1 ]. Since then, other groups have also used the MF approach with or without self-drilling screws with clinical success [ 1 ]. At our centre (LHSC), self-drilling screws are used in place of the self-tapping screws included in the implant kit and lifts are used; however, there have not been any empirical studies of the effects of these modifications.…”

“…The BB-BCI is commonly implanted at the transmastoid (TM), retrosigmoid (RS) or recently-introduced middle fossa (MF) locations [1,10,11]. The BB-BCI comes with self-tapping screws included in the implant kit; however, due to incompatibility with most North American drills, has been shown to work successfully with self-drilling screws [6].…”

“…Bone conduction implants (BCIs) stimulate the cochlea through vibratory excitation of the temporal bone using an actuator [ 1 ]. Bone conduction implants are used to treat hearing loss when conventional hearing aids cannot be worn because of medical or anatomic conditions such as recurrent otitis externa, aural atresia, or unilateral hearing loss, among others [ 2 ].…”