The middle fossa approach with self-drilling screws: a novel technique for BONEBRIDGE implantation

Abstract

Background Bone conduction implants can be used in the treatment of conductive or mixed hearing loss. The BONEBRIDGE bone conduction implant (BB-BCI) is an active, transcutaneous device. BB-BCI implantation can be performed through either the transmastoid or retrosigmoid approach with their respective limitations. Here, we present a third, novel approach for BB-BCI implantation. Objective Describe the detailed surgical technique of BB-BCI implantation through a middle fossa approach with self-drilling screws and present preliminary audiometric outcome data following this approach. Methods A single institution, retrospective chart review was completed for patients implanted with the BB-BCI via the middle fossa approach. Preoperative planning and modelling were performed using 3D Slicer. Audiological testing was performed pre- and post-operatively following standard audiometric techniques. Results Forty patients underwent BB-BCI implantation using the middle fossa approach. Modelling techniques allowed for implantation through the use of external landmarks, obviating the need for intraoperative image guidance. The surgical technique was refined over time through experience and adaptation. Mean follow-up was 29 months (range 3–71 months) with no surgical complications, favourable cosmesis, and expected audiometric outcomes. An average functional gain of 39.6 dB (± 14.7 SD) was found. Conclusion The middle fossa technique with self-drilling screws is a safe and effective option for BONEBRIDGE implantation. As a reference for other groups considering this approach, an annotated video has been included as a supplement to the study. Electronic supplementary material The online version of this article (10.1186/s40463-019-0354-7) contains supplementary material, which is available to authorized users.

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

“…The BB-BCI is the first active, transcutaneous BCI and multiple studies have shown it to be an effective device to treat hearing loss in patients with mixed or conductive hearing loss [10][11][12][13][14][15]. 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]. Since then, other groups have also used the MF approach with or without self-drilling screws with clinical success [1].…”

“…The transmitted vibration to the cochlea using BCIs has been widely studied in the literature using accelerometers [8][9][10] and laser Doppler vibrometry (LDV) techniques. A broad range of studies have focused on the effect of implant location on the transmitted sound to the cochlear promontory [11][12][13][14][15][16][17][18].…”

“…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].…”

The effect of anatomical variables and use of the Lifts system on hearing outcomes after implantation of an active transcutaneous bone conduction device in bilateral congenital conductive hearing loss

“…For patients with a bone thickness of less than 8.7 mm or other abnormal temporal bone structure, the Lifts system can help avoid excessive pressure on the dura or sigmoid sinus. Dedicated BB Lifts have been developed by MED-EL and are available in 1, 2, 3, and 4-mm sizes [ 18 ]. The use of Lifts allows implantation in younger children, and facilitates implantation in difficult cases [ 19 , 20 ].…”