Transcutaneous bone-conduction hearing device: audiological and surgical aspects in a first series of patients with mixed hearing loss

Evaluating temporal bone column density for optimized bone conduction implant placement

Introduction

An optimal placement of bone conduction implants can provide more efficient mechanical transmission to the cochlea if placed in regions with greater bone column density. The aim of this study was to test this hypothesis and to determine the clinical potential of preoperative bone column density assessment for optimal implant placement.

Methods

Five complete cadaver heads were scanned with quantitative computed tomography imaging to create topographic maps of bone density based on the column density index (CODI). Laser Doppler vibrometry was used to measure cochlear promontory acceleration under bone conduction stimulation in different locations on the temporal bone, using a bone-anchored hearing aid transducer at frequencies ranging from 355 Hz to 10 kHz.

Results

We found a statistically significant association between CODI levels and the accelerance of the cochlear promontory throughout the frequency spectrum, with an average increase of 0.6 dB per unit of CODI. The distance between the transducer and the cochlear promontory had no statistically significant effect on the overall spectrum.

Discussion

We highlight the importance of bone column density in relation to the mechanical transmission efficiency of bone conduction implants. It may be worthwhile to consider column density in preoperative planning in clinical practice.

Surgical and audiological outcomes with a new transcutaneous bone conduction device with reduced transducer thickness in children

PURPOSE

Due to smaller bone thickness, young children with conductive or mixed hearing loss or single-sided deafness were previously most commonly treated with a percutaneous osseointegrated bone-anchored hearing aid (BAHA) or an active middle-ear implant. While the BAHA increases the risk of implant infections, skin infection, overgrowth of the screw or involvement of the implant in head trauma, middle-ear implant surgery involves manipulation of the ossicles with possible risk of surgical trauma. These complications can be omitted with transcutaneous bone conduction implant systems like the MED-EL Bonebridge system. The purpose of this study was to analyze whether the second generation of the Bonebridge (BCI 602) that features a decreased implant thickness with a reduced surgical drilling depth can be implanted safely in young children with good postoperative hearing performance.

METHODS

In this study, 14 patients under 12 years were implanted with the second generation of the Bonebridge. Preoperative workup comprised a CT scan, an MRI scan, pure tone audiometry, or alternatively a BERA (bone conduction, air conduction). Since children under 12 years often have a lower bone thickness, the CT was performed to determine the suitability of the temporal bone for optimal implant placement using the Otoplan software.

RESULTS

All patients (including three under the age of five) were successfully implanted and showed a good postoperative hearing performance.

CONCLUSION

With adequate preoperative workup, this device can be safely implanted in children and even children under 5 years of age and allows for an extension of indication criteria toward younger children.

Bonebridge® bone conduction implant. Hearing outcomes and quality of life in patients with conductive/mixed hearing loss

PURPOSE

The aim of this study was to analyze the hearing outcomes and quality of life in a series of 52 patients affected by conductive or mixed hearing loss and treated with Bonebridge^®.

METHODS

52 of 71 patients implanted with Bonebridge^® between October 2012 and January 2022, were included in the study. We compared the air conduction thresholds at the frequencies 500, 1000, 2000, 3000, 4000 Hz, the SRT50% and the World Recognition Score at an intensity of 50 dB with and without the implant. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was employed to assess the quality of life of patients.

RESULTS

The liminal tone audiometry (free field) pure tone average for air conduction after 6 months with the implant was 35.12 dB, obtaining a mean gain of 31.83 dB. With Bonebridge^®, the mean SRT was 34.17 dB, whereas before the surgery no patient achieved 50% of correct answers at a sound intensity of 50 dB. The world recognition score at 50 dB changed from 11% without the implant to 85% with it. We observed one case of implant failure and one case of implant exposure. The APHAB questionnaire showed an improvement after implantation in practically all the subscales.

CONCLUSIONS

The hearing outcomes and the subjective benefits reported by patients obtained in our study are similar to those published in the literature. Bonebridge^® represents an excellent method for the rehabilitation of patients with conductive and mixed hearing loss, showing a low rate of complications.

Comparison of passive versus active transcutaneous bone anchored hearing devices in the pediatric population

Objective

Transcutaneous bone anchored hearing devices (BAHDs) were introduced in an effort to avoid potential complications associated with the abutment of percutaneous BAHDs. Transcutaneous BAHDs can be active or passive. While studies have demonstrated good outcomes with both, a direct comparison of audiological and clinical outcomes of these devices in the pediatric population has not yet been studied.

Study design

Retrospective, multicenter study.

Setting

Two tertiary academic centers.

Methods

Between 2015 and 2019, all patients who received an active transcutaneous BAHD (Bonebridge, BB) at one center, and patients that received a passive transcutaneous BAHD (Attract, AT) at another center, were included in this study. Exclusion criteria included age > 18 years, and mixed hearing loss or single-sided deafness. Study outcomes included patient demographics, indications, complications and preoperative and one-year postoperative audiometric data.

Results

Eighteen BB and eight AT patients met the inclusion criteria. The age range was 5–16 years. There were no significant differences in complication outcomes. Both devices demonstrated similar mean improvements in hearing thresholds at frequencies of 250 Hz (38 dB Active vs. 38 dB Passive), 500 Hz (34 dB vs. 42 dB), 1000 Hz (34 dB vs. 40 dB) and 2000 Hz (31 dB vs. 22 dB). The BB was significantly more effective at frequencies of 4000 Hz (28 dB vs. 7 dB) and 8000 Hz (29 dB vs. 6 dB) (p < 0.05).

Conclusion

This is the first study comparing audiological outcomes between an active and a passive transcutaneous BAHD in the pediatric population. While both devices improved audiometric outcomes in the low and mid frequencies, the active BAHD demonstrated significantly better outcomes in the higher frequencies.

Graphical Abstract

Novel Surgical Technique in Active Bone Conduction: Minimally Invasive Approach to Fully Implantable Osseointegrated Implant

We report our experience using a novel minimally invasive surgical technique for implantation of a fully implantable active bone conduction implant. This was a retrospective review of 16 adults, including 10 women and 6 men. The mean age was 54 years. Hearing loss profiles included 8 with mixed hearing loss, 5 with conductive hearing loss, and 3 with single-sided deafness. Nine patients underwent placement through the standard approach and 7 with the minimally invasive approach. There were no postoperative complications at a mean follow-up of 6.5 months (SD, 4; range, 1.5-12), and all patients received audiologic benefit with objective improvement in sound-field thresholds upon activation. Mean operative time was shorter with the minimally invasive approach (64 vs 41 minutes, P = .01). The fully implantable bone-anchored auditory implant can be effectively placed via a minimally invasive incision, with potential benefits of decreased operative time, low risk for intra- and postoperative complications, and rapid healing.

Long-term audiological benefit with an active transcutaneous bone-conduction device: a retrospective cohort analysis

PURPOSE

To evaluate long-term audiological, surgical and safety outcomes of a complex patient cohort treated with an active transcutaneous bone-conduction device (tBCD).

METHODS

This retrospective, monocentric cohort analysis involves 31 adults with conductive (CHL) and mixed hearing loss (MHL). For outcome analysis, study results were divided into short-term follow-up data (< 12 months) and long-term follow-up data (> 12 months).

RESULTS

31 patients with a total person-time of 90.4 years and an average number of 3.2 ± 1.5 preoperatively performed surgeries on the implanted side were investigated. Mean BCD-aided PTA₄ thresholds were significantly lower than unaided PTA_4AC before surgery (64.7 ± 16.1 dB HL; CHL 50.6 ± 10.6 dB HL; MHL 72.8 ± 12.8 dB HL) and did not change between short-term (42.3 ± 13.1 dB HL; CHL 35.8 ± 6.8 dB HL; MHL 45.2 ± 14.3 dB HL) and long-term (43.4 ± 10.0 dB HL; CHL 35.8 ± 4.3 dB HL; MHL 48.1 ± 9.6 dB HL) follow-up periods. Speech intelligibility in the Freiburg monosyllables test at 65 dB improved significantly, from 16.3 ± 21.5% (CHL 26.8 ± 19.0%; MHL 8.7 ± 20.5%) in the unaided condition to 82.7 ± 15.5% (CHL 90.0 ± 12.2%; MHL 79.4 ± 16.3%) in the short-term and 85.5 ± 13.2% (CHL 93.8 ± 7.9%; MHL 79.5 ± 13.3%) BCD-aided in the long-term follow-up periods. Ten minor procedure-related and 6 implant-related (5 minor, 1 major) AEs occurred over the total follow-up period.

CONCLUSION

The device provides satisfactory audiological and speech benefit over long-term follow-up periods, up to 7 years. Explant rates were very low, while the overall rate of manageable AEs was high in this complex patient cohort. The device is considered a safe and effective option in the long-term hearing rehabilitation of patients with CHL and MHL.

Retrosigmoidal placement of an active transcutaneous bone conduction implant: surgical and audiological perspectives in a multicentre study

Introduction

The retrosigmoidal (RS) placement of the Bonebridge system (BB) has been advocated for cases of unfavourable anatomical or clinical conditions which contraindicate transmastoid-presigmoidal positioning. However, these disadvantageous conditions, combined with the considerable dimensions of the implant, may represent a challenge, especially for surgeons with no skull base experience. Moreover, the literature reports only limited experience concerning RS implantation of the BB system.

Methods

A multicentre, retrospective study was conducted to analyse the surgical and functional outcomes of a wide population of patients undergoing RS placement of the BB system by means of a surgical technique specifically developed to overcome the intraoperative issues related to this surgery. Twenty patients with conductive or mixed hearing loss and single sided deafness were submitted to RS implantation of the BB system.

Results

Audiological assessment concerning the measurement of the functional and effective gain by pure-tone audiometry (28 dB HL and -12.25 dB HL, respectively) and speech audiometry (24.7 dB HL and -21 dB HL, respectively) was conducted. A high overall subjective improvement of quality of life was recorded with the Glasgow Benefit Inventory questionnaire. No major complications, such as device extrusions or other conditions requiring revision surgery, were reported during the follow-up period (median: 42 months).

Conclusions

In our study, which has one of the largest cohort of patients reported in the literature, RS placement of the BB system was safe and effective. Our functional results showed comparable hearing outcomes with presigmoidal placement. The effective gain, rarely investigated in this field, may be the object of further research to improve our understanding of bone conduction mechanisms exploited by bone conduction hearing implants.

Active Versus Passive Transcutaneous Bone Conduction Hearing Devices: A Systematic Review and Meta-Analysis

OBJECTIVES

Active and passive transcutaneous devices (tBCHDs) have been introduced in an effort to address complication concerns with percutaneous devices. Direct comparison of active and passive devices through evidence synthesis practices is incomplete. This systematic review and meta-analysis sought to synthesize and compare available evidence on audiological, quality of life, and complication-related outcomes of active and passive tBCHDs.

DESIGN

MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL were searched from inception to September 23, 2019. Observational and experimental studies investigating active or passive tBCHDs in adults were eligible. Studies were screened independently in duplicate. This study is reported in accordance with the PRISMA guidelines. Risk of bias and quality assessments were completed using the Newcastle-Ottawa Scale and the Quality Appraisal Tool for Case Series. Meta-analysis was performed with random-effects models. Audiological outcomes included changes in pure-tone average, functional hearing, and high-frequency hearing. Quality of life outcomes included patient-reported results. Complications included minor, major, and total complications experienced.

RESULTS

One thousand five hundred forty-two nonduplicate articles were screened. Twenty-eight studies were included. Quality of included studies was low overall. The pooled complication rate for active devices was 14.8% (95% confidence interval: 0.09-0.21, I2: 0%). The pooled improvement in functional hearing for active devices among those with mixed or conductive hearing loss was 31.8 dB (95% confidence interval: 27.7-35.9, I2: 44.6). Improvement in functional hearing ranged from 25.2 to 44.3 dB for passive devices. Active devices provided improved high-frequency hearing compared to passive devices: the weighted average hearing gains at 2, 3, 4, and 6 kHz were 26.5, 25.7, 31.8, and 34.3 dB for active devices and 26.2, 21.1, 16.8, and 6.4 dB for passive devices, respectively. Both device types demonstrated improvement in ease of communication, reverberation, and understandability in background noise.

CONCLUSIONS

Both active and passive tBCHDs demonstrate acceptable safety profiles and QoL improvements. Active devices may provide better hearing outcomes, especially in high frequencies, but high-quality comparative studies are lacking. Future work is needed in this regard.

A New Active Osseointegrated Implant System in Patients with Single-Sided Deafness

OBJECTIVE

The Cochlear™ Osia® System (Osia) is an active transcutaneous bone conduction implant system intended for patients with conductive and mixed hearing loss but can also be used in cases of single-sided deafness (SSD) for the contralateral routing of signal (CROS). The Osia implant is placed subcutaneously under the intact skin behind the ear with the piezoelectric actuator connected to an osseointegrated BI300 implant - a titanium screw used for a 2-stage Baha surgery - on the mastoid. The external processor is magnetically attached to the subcutaneous implant receiver coil. As the Osia has recently been CE certified and is new on the market, with limited patient outcome data for SSD available, the objective of this study was the evaluation of surgical procedure, audiological results, and patient satisfaction for the Osia in SSD patients.

STUDY DESIGN

In a prospective, monocentric clinical observation study, 6 patients (18 years of age or older) with SSD and bone conduction thresholds pure tone average 0.5, 1, 2, and 4 kHz ≤25 dB HL on the contralateral side were implanted with an Osia. Analysis of clinical outcome data with respect to surgical technique, adverse events, audiological measurement, and subjective benefit for SSD patients was conducted. Audiological measurements performed included hearing thresholds, sound field thresholds, word recognition scores (WRS; in %) in quiet, and speech recognition thresholds in noise (in dB SNR). All tests were performed unaided and aided with the Osia. The subjective benefit with the Osia was determined by using 2 questionnaires; the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Bern Benefit in Single-Sided Deafness (BBSSD).

RESULTS

Preliminary results indicate a straightforward surgical procedure with a low rate of complications and an improvement in speech perception in quiet, listening performance in everyday situations and patient satisfaction. However, in one of 6 subjects, a revision surgery had to be performed.

CONCLUSION

Provided that SSD patients are open for CROS hearing, they can benefit from the Osia by reduced head shadow effects and better speech recognition. Special caution should be given to the skin at the site of implantation to avoid complications.

Performance With an Adhesive Bone Conduction Device in Active Transcutaneous Bone Conduction Implant Users

OBJECTIVES

The aim of this study was to evaluate the performance and limits of an adhesive bone conduction hearing aid in patients implanted with an active transcutaneous bone conduction implant. Therefore, hearing performance and subjective benefit of patients with mixed and conductive hearing loss were assessed with both bone conduction devices.

STUDY DESIGN AND PATIENTS

This cohort study was conducted at a tertiary care center. Fifteen subjects, who had been implanted with an active transcutaneous device previously, were included and used the adhesive hearing device for 3 weeks instead of the implant. Subjects underwent two sets of audiological tests as well as assessments of quality of life at the beginning and at the end of the testing period.

RESULTS

Audiological results showed a significantly greater improvement in regards to functional hearing gain and word recognition scores with the transcutaneous bone conduction device than the nonimplantable adhesive device. Regression analysis showed a trend toward greater improvement with the transcutaneous device compared with the adhesive device in patients with an increasing bone conduction threshold. Hearing-specific and general quality-of-life questionnaires revealed no significant difference between the two devices.

CONCLUSION

Patients with mixed or conductive hearing loss experience hearing gain with both, the adhesive device and the active transcutaneous device. The adhesive device may be a valuable alternative to the active transcutaneous device, depending on the individual bone conduction threshold.

Systematic review of outcome domains and instruments used in designs of clinical trials for interventions that seek to restore bilateral and binaural hearing in adults with unilateral severe to profound sensorineural hearing loss ('single-sided deafness')

BACKGROUND

This systematic review aimed to identify, compare and contrast outcome domains and outcome instruments reported in studies investigating interventions that seek to restore bilateral (two-sided) and/or binaural (both ears) hearing in adults with single-sided deafness (SSD). Findings can inform the development of evidence-based guidance to facilitate design decisions for confirmatory trials.

METHODS

Records were identified by searching MEDLINE, EMBASE, PubMed, CINAHL, ClinicalTrials.gov, ISRCTN, CENTRAL, WHO ICTRP and the NIHR UK clinical trials gateway. The search included records published from 1946 to March 2020. Included studies were those as follows: (a) recruiting adults aged 18 years or older diagnosed with SSD of average threshold severity worse than 70 dB HL in the worse-hearing ear and normal (or near-normal) hearing in the better-hearing ear, (b) evaluating interventions to restore bilateral and/or binaural hearing and (c) enrolling those adults in a controlled trial, before-and-after study or cross-over study. Studies that fell just short of the participant eligibility criteria were included in a separate sensitivity analysis.

RESULTS

Ninety-six studies were included (72 full inclusion, 24 sensitivity analysis). For fully included studies, 37 exclusively evaluated interventions to re-establish bilateral hearing and 29 exclusively evaluated interventions to restore binaural hearing. Overall, 520 outcome domains were identified (350 primary and 170 secondary). Speech-related outcome domains were the most common (74% of studies), followed by spatial-related domains (60% of studies). A total of 344 unique outcome instruments were reported. Speech-related outcome domains were measured by 73 different instruments and spatial-related domains by 43 different instruments. There was considerable variability in duration of follow-up, ranging from acute (baseline) testing to 10 years after the intervention. The sensitivity analysis identified no additional outcome domains.

CONCLUSIONS

This review identified large variability in the reporting of outcome domains and instruments in studies evaluating the therapeutic benefits and harms of SSD interventions. Reports frequently omitted information on what domains the study intended to assess, and on what instruments were used to measure which domains.

TRIAL REGISTRATION

The systematic review protocol is registered on PROSPERO (International Prospective Register of Systematic Reviews): Registration Number CRD42018084274 . Registered on 13 March 2018, last revised on 7th of May 2019.

Clinical and functional results after implantation of the bonebridge, a semi-implantable, active transcutaneous bone conduction device, in children and adults

Purpose

Aim of the study was to evaluate the surgical, clinical and audiological outcome of 32 implantations of the Bonebridge, a semi-implantable transcutaneous active bone conduction implant.

Methods

In a retrospective cohort study, we analyzed data for 32 implantations in 31 patients (one bilateral case; seven age < 16 years) with conductive or mixed hearing loss, malformations, after multiple ear surgery, or with single-sided deafness as contralateral routing of signal (CROS).

Results

Four implantations were done as CROS. Five cases were simultaneously planned with ear prosthesis anchors, and 23 implantations (72%) were planned through three-dimensional (3D) “virtual surgery.” In all 3D-planned cases, the implant could be placed as expected. For implant-related complications, rates were 12.5% for minor and 3.1% for major complications. Implantation significantly improved mean sound field thresholds from a preoperative 60 dB HL (SD 12) to 33 dB HL (SD 6) at 3 postoperative months and 34 dB HL (SD 6) at > 11 postoperative months (p < 0.0001). Word recognition score in quiet at 65 dB SPL improved from 11% (SD 20) preoperatively to 74% (SD 19) at 3 months and 83% (SD 15) at > 11 months (p < 0.0001). The speech reception threshold in noise improved from − 1.01 dB unaided to − 2.69 dB best-aided (p = 0.0018).

Conclusion

We found a clinically relevant audiological benefit with Bonebridge. To overcome anatomical challenges, we recommend preoperative 3D planning in small and hypoplastic mastoids, children, ear malformation, and simultaneous implantation of ear prosthesis anchors and after multiple ear surgery.

Application of retrosigmoid sinus approach in Bonebridge implantation

BACKGROUND

Bonebridge is an suitable option for conductive hearing loss, however, the traditional approach cannot accomplished a satisfying implantation for patients with congenital malformation or radical mastoidectomy.

OBJECTIVES

To evaluate the clinical application of retrosigmoid sinus approach in Bonebridge implantation and postoperative evaluation.

MATERIALS AND METHODS

11 patients who underwent retrosigmoid sinus approach Bonebridge implantation from March 2016 to September 2019 were retrospectively analyzed, including 6 males and 5 females, aged 12-54 years old (30.6 in average). Among them, 4 cases had undergone bilateral radical mastoidectomy, 6 cases had bilateral congenital aural atresia or stenosis, and 1 case had unilateral congenital aural atresia.

RESULTS

All patients underwent Bonebridge implantation through retrosigmoid sinus approach according to the preoperative image reconstruction and plan. There was no surgical injury of sigmoid sinus or cerebrospinal fluid leakage during the operation. The aided threshold obtained an increase of 32.32 dB HL; the speech recognition rates of bisyllabic words, monosyllabic words and sentence were 79.6%, 67.8% and 75.0%, respectively. After 11-53 months of follow-up, the hearing effect was stable and no long-term complications occurred.

CONCLUSION

The retrosigmoid sinus approach is an effective surgical approach for patients with congenital ear deformities or radical cavity after mastoidectomy.

Patient-reported long-term benefit with an active transcutaneous bone-conduction device

Purpose

To evaluate the long-term benefits in hearing-related quality of life, patient satisfaction and wearing time of patients rehabilitated with an active transcutaneous bone-conduction device. Adverse events and audiological outcomes are reported as secondary outcomes.

Methods

This retrospective, mono-centric cohort analysis involves 16 adults with conductive or mixed hearing loss with a mean device experience of 51.25 months. Patient-reported outcome measures were assessed using the short version of the Speech, Spatial and Qualities of Hearing Scale (SSQ12-B) and the German version of the Audio Processor Satisfaction Questionnaire (APSQ). Audiological outcomes as well as incidence of adverse events were obtained from patients´ charts.

Results

The hearing-related quality of life improved significantly within all subscales of the SSQ12-B scoring a mean overall of 2.95 points. Patient satisfaction measured with the APSQ scored 8.8 points on average. Wearing times differed considerably and patients with lower levels of education seemed to use their device longer compared to patients with academic education. Eight minor adverse events were documented, all of which resolved during follow-up. The mean gain in word recognition score at the last follow-up measured at 65 dB was 75.9%, while speech reception threshold was lowered by 35.1 dB.

Conclusion

Even after several years, patients report significant benefits in hearing-related quality of life and device satisfaction. In combination with a low rate of minor adverse events and significantly improved audiological outcomes, the device is considered as a comfortable and effective option in hearing rehabilitation.

Device profile of the Bonebridge bone conduction implant system in hearing loss: an overview of its safety and efficacy

INTRODUCTION

The Bonebridge is an active transcutaneous semi-implantable bone conduction hearing device suitable for several types of hearing loss. It has unique benefits over some more established technologies. It consists of an internal active implant and an external sound processor. It was first launched in 2012, with a newer model released in late 2019.

AREAS COVERED

The structure and features of the device are described. Indications, audiological criteria, and contraindications to implantation are discussed. The planning and procedure of implantation surgery are also described. Research outlining the outcomes of implant use and risk of adverse events is highlighted.

EXPERT OPINION

The evidence included in this article demonstrates the successful audiological outcomes and patient satisfaction with Bonebridge implantation. The rate of adverse events following surgery is low and compares well with other devices which may be considered for Bonebridge candidates. The device should be considered as an option for suitable candidates and in many cases may be the better option available, given the low incidence of skin complications and the absence of a skin penetrating abutment. Future advances are likely to affect sound processor technology, connectivity, and possibly further reduction in implant size and gain.

Bonebridge implantation for mixed hearing loss in a patient with Kabuki syndrome

The high prevalence of middle ear disease with related hearing loss in Kabuki syndrome requires the diagnostic and treatment expertise of otologists. This case report describes outcomes and changes in the quality of life of a patient affected by Kabuki syndrome with a history of recalcitrant chronic otitis media and mixed hearing loss who had undergone several unsuccessful surgical procedures before solving his problems by means of subtotal petrosectomy and active middle ear implant.

Auditory Performance and Subjective Satisfaction with the ADHEAR System

BACKGROUND

The ADHEAR device, a new nonsurgical bone conduction hearing device, has been developed for patients with conductive hearing loss.

OBJECTIVES

This study aims to assess the impact of the ADHEAR device on the audiological performance and satisfaction level in subjects with conductive hearing loss.

METHODS

Twelve patients with conductive hearing loss were included. All patients received the device for 3 months. The audiological outcomes were determined using basic audiological assessments, including pure tone audiometry and sound field measurements of pure tone and speech audiometry with the contralateral ear occluded with a specific earplug. Additionally, the patients were subjectively evaluated using (1) the Speech, Spatial, and Qualities Questionnaire (SSQ), and (2) the custom-made ADHEAR questionnaire.

RESULTS

Analysis of the measured audiological outcomes revealed an average improvement in pure tone thresholds (functional gain) of 23 (± 4.4) dB HL when the ADHEAR system was used compared to the unaided condition in the sound field. Moreover, speech reception thresholds improved by an average of 23 (± 15.3) dB SPL in the aided condition with plugged contralateral ear. Additionally, when using ADHEAR in the sound field, subjects' speech recognition scores improved by 32% (± 17.7) in quiet and 21% (± 15.1) in the presence of interfering noise. The average SSQ questionnaire scores improved from 3.9 at the study initiation to 6.6 after 3 months of device usage. ADHEAR custom questionnaire assessments revealed high satisfaction and acceptance of the device with no pain or skin irritation.

CONCLUSION

During the study period, this new adhesive system yielded improved audiological outcomes with high patient satisfaction and acceptance and no reported skin irritation or pain.

Long-term Outcomes of Bone Conduction Hearing Implants in Patients With Bilateral Microtia-atresia

Supplemental Digital Content is available in the text

To evaluate the long-term outcomes of three different types of bone conduction hearing implants (BCHI)—BAHA, Ponto, and Bonebridge—in Mandarin-speaking patients with bilateral microtia-atresia.

A Precision Driver Device for Intraoperative Stimulation of a Bone Conduction Implant

Semi-implantable bone conduction implants (BCI) and active middle ear implants (AMEI) for patients with sensorineural, conductive or mixed hearing loss commonly use an amplitude modulation technology to transmit power and sound signals from an external audio processor to the implant. In patients, the distance dependence of the signal amplitude is of minor importance as the skin thickness is constant and only varies between 3–7 mm. In this range, critical coupling transmission technique sufficiently reduces the variability in amplitude, but fails to provide well-defined amplitudes in many research and clinical applications such as intraoperative integrity tests where the distance range is exceeded by using sterile covers. Here we used the BCI Bonebridge (BB, Med-El, Austria) as an example to develop and demonstrate a system that synthesizes the transmission signal, determines the distance between the transmitter and the receiver implant coil and compensates transmission losses. When compared to an external audio processor (AP304) on an artificial mastoid, our system mainly decreased amplitude variability from over 11 dB to less than 3 dB for audio frequencies (0.1–10 kHz) at distances up to 15 mm, making it adequate for intraoperative and audiometric tests.

Characteristics of Bone-Conduction Devices Simulated in a Finite-Element Model of a Whole Human Head

Nowadays, many different kinds of bone-conduction devices (BCDs) are available for hearing rehabilitation. Most studies of these devices fail to compare the different types of BCDs under the same conditions. Moreover, most results are between two BCDs in the same subject, or two BCDs in different subjects failing to provide an overview of the results between several of the BCDs. Another issue is that some BCDs require surgical procedures that prevent comparison of the BCDs in the same persons. In this study, four types of skin-drive BCDs, three direct-drive BCDs, and one oral device were evaluated in a finite-element model of the human head that was able to simulate all BCDs under the same conditions. The evaluation was conducted using both a dynamic force as input and an electric voltage to a model of a BCD vibrator unit. The results showed that the direct-drive BCDs and the oral device gave vibration responses within 10 dB at the cochlea. The skin-drive BCDs had similar or even better cochlear vibration responses than the direct-drive BCDs at low frequencies, but the direct-drive BCDs gave up to 30 dB higher cochlear vibration responses at high frequencies. The study also investigated the mechanical point impedance at the interface between the BCD and the head, providing information that explains some of the differences seen in the results. For example, when the skin-drive BCD attachment area becomes too small, the transducer cannot provide an output force similar to the devices with larger attachment surfaces.

Response to commentary on "the middle fossa approach with self-drilling screws: a novel technique for BONEBRIDGE implantation"

The aim of this letter is to respond to a commentary on a published article on the middle fossa approach to BONEBRIDGE implantation with self-drilling screws published by the senior authors.

Active transcutaneous bone conduction hearing implants: Systematic review and meta-analysis

BACKGROUND

In July 2018 the active transcutaneous bone conduction hearing implant received FDA approval in the US (for patients 12 years and older with conductive and/or mixed hearing loss or single-sided deafness), reflecting the current trend of moving away from percutaneous hearing solutions towards intact skin systems.

OBJECTIVES

To critically assess the current literature on safety, efficacy and subjective benefit after implantation with an active transcutaneous bone conduction hearing device.

DATA SOURCES

Literature investigation was performed by electronic database search including PubMed and Cochrane Central Register of Controlled Trials, and manual search of relevant journals and reference lists of included studies.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials, clinical controlled trials and cohort studies, case series and case reports investigating subjective and objective outcomes.

STUDY APPRAISAL AND SYNTHESIS METHODS

Retrieved literature was screened and extracted by two reviewers independently. Subgroup analysis of indications (conductive and/or mixed hearing loss, single-sided deafness) and participant ages (pediatric vs. adults) was conducted on patients with active transcutaneous bone conduction devices. Sensitivity analysis was performed to test the stability of the results in meta-analysis.

RESULTS

39 citations reporting on pre- and postoperative audiological results, speech performance in quiet and in noise, localization testing as well as subjective outcomes were included in this systematic review. Functional gain as well as word recognition score outcomes could be further investigated via meta-analysis. All outcomes reported and summarized here reflect beneficial audiological performance and high patient satisfaction, accompanied with a low complications rate (minor event incidence rate: 9.9 person-years; major incidence rate: 148.9 person-years) for the indications of conductive and mixed hearing loss as well as in individuals suffering from single-sided deafness for all age groups of subjects who underwent active transcutaneous bone conduction hearing device implantation.

LIMITATIONS

A limiting factor of this systematic review was the Level of Evidence of the reviewed literature, comprising 2a/3a studies (cohort studies and case-control studies). Furthermore, the reporting standards, especially in outcomes such as word recognition scores in quiet and in noise, vary across study cites from various countries, which impedes comparisons. Last but not least, no other comparable other device was retrieved as the active transcutaneous bone conduction hearing device is the only available at the moment.

CONCLUSION

The device's transcutaneous technology results in a minor event incidence rate of one in 9.9 person-years and a major incidence rate of one in 148.9 person-years. Based on the audiological outcomes, high patient satisfaction as well as the low complication rate, the authors recommend the active transcutaneous bone conduction hearing device as a safe and effective treatment for patients suffering from hearing loss within the device's indication criteria (conductive and/or mixed hearing loss or single-sided deafness).

Objective and subjective results of the Bonebridge transcutaneous active direct-drive bone conduction hearing implant

Objectives:

To investigate the effectiveness of a bone-anchored hearing implant system (Bonebridge implant technology) as a rehabilitation treatment for individuals with conductive or mixed hearing losses.

Methods:

This is a retrospective cohort study. Twelve implanted ears with conductive or mixed hearing losses were implanted with this device at a tertiary university hospital between 2012 and 2016. Audiological tests included pure tone air conduction (AC) and bone conduction (BC) measurements and unaided and aided sound-field thresholds. To evaluate the speech intelligibility in a quiet environment, the speech discrimination score (SDS) was tested using Arabic monosyllabic words, and the speech reception threshold (SRT) was measured using Arabic disyllabic words spoken in front of them. The subjective sound quality was assessed with the Hearing Implant Sound Quality Index (HISQUI).

Results:

In comparison with the unaided condition, there was a significant improvement in the aided thresholds, SDS, and SRT. Comparing the aided and unaided thresholds, the average AC threshold improved with an average functional gain of 40±6.3dB. The unaided SRT improved from 72.5 dB hearing levels (HL)(median) to 27.5 dB HL (median) when aided, and patients performed 71% better, on average, based on the SDS with the help of the device. The HISQUI questionnaire revealed high satisfaction with the device sound quality.

Conclusion:

Patients with conductive and mixed hearing loss substantially benefit from the Bonebridge active transcutaneous BC hearing implant.

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

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.

Comparison of Satisfaction Between Patients Using Percutaneous and Transcutaneous Bone Conduction Devices

BACKGROUND

Bone conduction devices are widely used to treat conductive and mixed hearing loss as well as single-sided deafness (SSD). A transcutaneous system was introduced recently with the clear advantage of fewer local reactions. Our goal was to evaluate and compare the satisfaction of patients with percutaneous and transcutaneous bone conduction devices.

METHODS

We divided a cohort of 72 patients into groups by type of hearing loss and their relation to the use of the percutaneous or transcutaneous system. The Glasgow Benefit Inventory (GBI) questionnaire, adapted for hearing aids, was employed to assess patient satisfaction, along with an additional questionnaire covering the general usefulness of the devices.

RESULTS

Overall median daily wearing time was 12 hours for the percutaneous and seven for the transcutaneous groups (p < 0.001). We found no correlation between the bone conduction level at any frequency and the GBI satisfaction score. The median total GBI score of the entire patient cohort was 30.1; median values for general, social support, and physical health subscales were 0, 37.5, and 16.7, respectively. People suffering from SSD had the lowest satisfaction rates, and these were significantly lower for the patients who used transcutaneous aids than for those with percutaneous devices (p = 0.033). Similarly, the percutaneous system brought more satisfaction to combined hearing loss patients than did the transcutaneous (p = 0.010).

CONCLUSION

Both types of bone conduction devices provide a safe and efficient way to improve hearing for candidates within correct indications. Our study revealed that patients wore the transcutaneous device less than they did the percutaneous. Satisfaction was the lowest among SSD patients who used the transcutaneous device; hence it is especially important to carry out preoperative counseling for such patients.

Outcomes of the Baha Attract System combined with auricle reconstruction in mandarin speaking patients with bilateral microtia-atresia

BACKGROUND

A transcutaneous bone-conduction hearing device (tBCHD), the Baha Attract System has been recently introduced to China, and very few studies have assessed the efficacy of this system in speakers of mandarin.

OBJECTIVES

This study aims to analyze the functional and cosmetic outcomes of this system.

MATERIALS AND METHODS

This prospective study included 11 patients (nine males, two females), of mean age 16 years (range 9-32 years). Seven patients were conducted the implantation simultaneously with auricle reconstruction, and the other four were before it. Auditory results were compared between unaided patients and implanted patients. Subjective satisfaction was analyzed using three questionnaires.

RESULTS

The mean sound field thresholds were 65.9 ± 5.1 dB SPL unaided and 30.9 ± 4.7 dB SPL with an implanted Baha Attract System, resulting in a mean hearing gain of 35.0 ± 6.7 dB. The mean WRS scores were 47.8 ± 8.7% unaided and 92.1 ± 2.0% with the Baha Attract System, resulting in a mean improvement of 47.8 ± 8.7%. No adverse events were reported and questionnaires showed good patients satisfaction.

CONCLUSIONS

The transcutaneous Baha Attract System is effective in mandarin speaking patients, and the combination of hearing rehabilitation and auricle reconstruction surgery is promising for patients with bilateral microtia-atresia.

The Bonebridge active bone conduction system: a fast and safe technique for a middle fossa approach

BACKGROUND

The transmastoid pre-sigmoid approach is always the preferred choice for implantation of the Bonebridge active bone conduction system in patients with a normal anatomy. When an anatomical variant exists or a previous surgery has been performed, a retrosigmoid approach or middle fossa approach can be performed.

METHODS

The preferred surgical technique for a middle fossa approach is described. A 14 mm drill head (Neuro Drill) was used to create the bed at the squamous portion of the temporal bone. Surgical time and complication rate were analysed.

RESULTS

The surgical time was shorter than 30 minutes in all cases, and only 14 seconds were needed to create a 14 mm bone bed. No complications were observed during the follow-up period (6-45 months).

CONCLUSION

Use of the Neuro Drill for the middle fossa approach is an easy technique. It significantly decreases the surgical time, without increasing the complication rate.

Application of Implantable Hearing Aids and Bone Conduction Implant System in patients with bilateral congenital deformation of the external and middle ear

OBJECTIVE

To determine the efficacy of the application of the Implantable Hearing Aids and Bone Conduction Implant System in patients with bilateral congenital deformation of the external and middle ear.

METHODS

twenty patients with bilateral congenital malformation of the external and middle ear were included in the study. Implantable Hearing Aids implantation was performed in ten patients, and Bone Conduction Implant System implantation was performed in ten patients. Audiometric tests, including pure-tone audiometry and speech discrimination in the free field were performed pre-operatively and post-operatively.

RESULTS

Implantable Hearing Aids and Bone Conduction Implant System implantation were performed successfully in all patients. The mean pure-tone threshold improvement with Implantable Hearing Aids or Bone Conduction Implant System activation in the free filed pure tone audiometry was 25 dB and ranged from 0.25 to 4 kHz. Mean free field speech discrimination in quiet was 80% at 65 dB compared to 18% pre-operatively. The mean pure-tone threshold improvement with Bone Conduction Implant System was 25.5 dB better than 18.2 dB with Implantable Hearing Aids. The mean free filed speech discrimination in quite improvement with Bone Conduction Implant System was 66% better than 58% with Implantable Hearing Aids.

CONCLUSION

Implantable Hearing Aids or Bone Conduction Implant System are effective options for improving hearing in patients with bilateral congenital deformation of the external and middle ear. The procedure is safe and effective, and its indications are wider than those of tympanoplasty for such cases. Furthermore, the Bone Conduction Implant System is better than Implantable Hearing Aids, tympanoplasty and hearing aids.

A functional and anatomical comparison between two passive transcutaneous bone conduction implants in children

OBJECTIVE

To compare anatomical and functional outcomes of two passive transcutaneous bone conduction implant systems: Sophono™ and BAHA Attract™.

MATERIALS AND METHODS

Twenty patients, affected by bilateral conductive hearing loss, underwent unilateral transcutaneous bone conduction implant surgery. Ten children received a Sophono™ implant (6 males, 4 females, mean age 11 years, mean unaided Pure Tone Average (PTA) 0.25-4kHz = 69.70dB HL) and 10 a BAHA Attract™ system (7 males, 3 females, mean age 19 years, mean unaided PTA0.25-4kHz = 66.40dB HL). The following outcomes were considered: incidence of local complications, hearing aid benefit, hearing aid gain and changes in quality of life (QOL), as measured by the Glasgow Children's Benefit Inventory (GCBI).

RESULTS

One patient in the Sophono group experienced magnet-related skin decubitus, while two patients (one per group) had skin hyperemia in the area overlying the magnet. The mean BAHA-aided threshold was 23.70dB, whereas the mean Sophono-aided threshold was 31.60dB. The mean gain was significantly different for lower frequencies, the BAHA having better functional outcomes. All patients reported an improvement in their QOL.

CONCLUSION

Given the lower thickness of the internal magnet, the Sophono™ system might be more suitable for younger children, whereas BAHA offered better functional results. Both systems can be considered valid and safe options for the functional rehabilitation of conductive hearing loss in children, provided that precautions are observed, such as a gradual use of the device and use of the least powerful magnets in the first months after the activation.

A Bone Conduction Implantable Device as a Functional Treatment Option in Unilateral Microtia with Bilateral Stapes Ankylosis: A Report of Two Cases

BACKGROUND Implantable devices have been proposed as an alternative to hearing aids and auditory canal reconstruction in patients with microtia (congenital aural atresia), which includes a malformation of the external and middle ear. This report is of two rare cases of microtia associated with congenital stapes ankylosis treated with an implantable device and describes the treatment outcomes. CASE REPORT Two siblings from Ecuador, a 29-year-old woman, and her 35-year-old brother, were born with unilateral type II microtia with bilateral external auditory canal atresia and conductive hearing loss. Pre-operatively, high-resolution computed tomography (HRCT) imaging was performed using FastView software to allow placement of a bone conduction-floating mass transducer (BC-FMT) to couple a Bonebridge bone conduction implant (BCI) system in both patients. Pure-tone audiometry (PTA) testing and speech audiology were performed. The Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Speech, Spatial and Qualities (SSQ) of hearing scale questionnaires and scoring systems were used. Following activation of the implantable device, both patients achieved improved bilateral conductive hearing with sound-field (field-free) thresholds >25 dB, and speech recognition scores >90%. In both cases, hearing improvement remained at three years following surgery. CONCLUSIONS To our knowledge, these are the first reported cases of microtia with congenital stapes ankylosis successfully treated with a bone conduction implantable device. Patients with microtia and stapes ankylosis who are reluctant to undergo surgery may benefit from unilateral or bilateral, short-term or long-term use of a Bonebridge bone conduction implantable device.

Implantable hearing devices

Combined hearing loss is an essential indication for implantable hearing systems. Depending on the bone conduction threshold, various options are available. Patients with mild sensorineural deafness usually benefit from transcutaneous bone conduction implants (BCI), while percutaneous BCI systems are recommended also for moderate hearing loss. For combined hearing losses with moderate and high-grade cochlear hearing loss, active middle ear implants are recommended. For patients with incompatibilities or middle ear surgery, implants are a valuable and proven addition to the therapeutic options.

Preliminary audiologic and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device: A systematic review

OBJECTIVE

To delineate the auditory functional improvement and peri-operative outcomes of the Sophono™ transcutaneous bone conduction device.

METHODS

Eligible articles presenting patients implanted with the Sophono™ were identified through a comprehensive search of PubMed and Embase electronic databases. All relevant articles were reviewed to justify inclusion independently by 2 authors. Studies that successfully passed critical appraisal for directness of evidence and risk of bias were included.

RESULTS

From a total of 125 articles, 8 studies encompassing 86 patients using 99 implants were selected. Most patients (79.1%) were children. Ear atresia (67.5%) was the most frequently reported indication for Sophono™ implantation. Overall pure tone average auditory improvement was 31.10 (±8.29) decibel. During a mean follow-up time of 12.48 months, 25 patients (29%) presented with post-operative complications from which 3 were deemed as serious implant-related adverse events (3.5%).

CONCLUSIONS

The Sophono™ transcutaneous bone conduction device shows promising functional improvement, no intra-operative complications and minor post-operative skin related complications. If suitable, the device could be a proposed solution for the rehabilitation of hearing in children meeting eligibility criteria. A wearing schedule must be implemented in order to reduce magnet-related skin complications.

A New Transcutaneous Bone Conduction Hearing Implant: Short-term Safety and Efficacy in Children

OBJECTIVE

To investigate the safety and efficacy of a new bone conduction hearing implant in children, during a 3-month follow-up period.

STUDY DESIGN

Prospective, single-subject repeated-measures design in which each subject serves as his/her own control.

SETTING

Otolaryngology departments of four Austrian hospitals.

PATIENTS

Twelve German-speaking children aged 5 to 17 suffering from conductive or mixed hearing loss, with an upper bone conduction threshold limit of 45 dB HL at frequencies between 500 and 4000 Hz.

INTERVENTION

Implantation of the Bonebridge transcutaneous bone conduction hearing implant (tBCI).

MAIN OUTCOME MEASURES

The subjects' audiometric thresholds (air conduction, bone conduction, and sound field at frequencies 500 Hz to 8 kHz) and speech perception (word recognition scores [WRS] and 50% word intelligibility in sentences [SRT50%]) were tested preoperatively and at 1 and 3 months postoperatively. The patients were also monitored for adverse events and they or their parents filled out questionnaires to analyze satisfaction levels.

RESULTS

Speech perception as measured by WRS and SRT50% improved on average approximately 67.6% and 27.5 dB, respectively, 3 months after implantation. Aided thresholds also improved postoperatively, showing statistical significance at all tested frequencies. Air conduction and bone conduction thresholds showed no significant changes, confirming that subjects' residual unaided hearing was not damaged by the treatment. Only minor adverse events were reported and resolved by the end of the study.

CONCLUSION

Safety and efficacy of the new bone conduction implant was demonstrated in children followed up to 3 months postoperatively.

Sound Localization in Patients With Congenital Unilateral Conductive Hearing Loss With a Transcutaneous Bone Conduction Implant

OBJECTIVE

There is no consensus regarding the benefit of implantable hearing aids in congenital unilateral conductive hearing loss (UCHL). This study aimed to measure sound source localization performance in patients with congenital UCHL and contralateral normal hearing who received a new bone conduction implant.

STUDY DESIGN

Evaluation of within-subject performance differences for sound source localization in a horizontal plane.

SETTING

Tertiary referral center.

PATIENTS

Five patients with atresia of the external auditory canal and contralateral normal hearing implanted with transcutaneous bone conduction implant at the Medical University of Vienna were tested.

INTERVENTION

Activated/deactivated implant.

MAIN OUTCOME MEASURE

Sound source localization test; localization performance quantified using the root mean square (RMS) error.

RESULTS

Sound source localization ability was highly variable among individual subjects, with RMS errors ranging from 21 to 40 degrees. Horizontal plane localization performance in aided conditions showed statistically significant improvement compared with the unaided conditions, with RMS errors ranging from 17 to 27 degrees. The mean RMS error decreased by a factor of 0.71 (p < 0.001).

CONCLUSION

Analysis revealed improved sound localization performance in a horizontal plane with the activated transcutaneous bone conduction implant. Some patients with congenital UCHL might be capable of developing improved horizontal plane localization abilities with the binaural cues provided by this device.

Active transcutaneous bone conduction implant: audiological results in paediatric patients with bilateral microtia associated with external auditory canal atresia

OBJECTIVE

To describe, in terms of functional gain and word recognition, the audiological results of patients under 18 years of age implanted with the active bone conduction implant, Bonebridge™.

DESIGN

Retrospective case studies conducted by reviewing the medical records of patients receiving implants between 2014 and 2016 in the public health sector in Chile.

STUDY SAMPLE

All patients implanted with the Bonebridge were included (N = 15). Individuals who had bilateral conductive hearing loss, secondary to external ear malformations, were considered as candidates.

RESULTS

The average hearing threshold one month after switch on was 25.2 dB (95%CI 23.5-26.9). Hearing thresholds between 0.5 and 4 kHz were better when compared with bone conduction hearing aids. Best performance was observed at 4 kHz, where improvements to hearing were observed throughout the adaptation process. There was evidence of a significant increase in the recognition of monosyllables.

CONCLUSIONS

The Bonebridge implant showed improvements to hearing thresholds and word recognition in paediatric patients with congenital conductive hearing loss.

Image-guided implantation of the Bonebridge™ with a surgical navigation: A feasibility study

OBJECTIVE

To access a method of fitting a designated location on the patient's temporal bone by surgically navigating to the Bonebridge implantation.

STUDY DESIGN

A patient with unilateral profound hearing loss received early intervention with the Bonebridge implant for binaural hearing. The optimal implant site was determined from computed tomography (CT) images using a three-dimensional (3D) simulation software program before the surgery. The pre-calculated coordinates from the 3D simulation software program were moved to the Scopis Hybrid Navigation System. After using the surgical navigation system for the surgery, we evaluated the degree of mismatch of the center of the bone conduction-floating mass transducer (BC-FMT) between the computer simulation and the actual drilling.

RESULTS

The time required to determine the implant location on the surface of the patient's temporal bone was shortened, and the accuracy of the implantation was high. The coordinates on the 3D simulation system were comparable to the surgical navigation system. The predicted coordinates were replicated exactly upon actual drilling during the surgery, and we could confirm this in preoperative and postoperative images.

CONCLUSIONS

Using an image-guided surgical navigation system to aid in the placement of the BC-FMT on the simulated location is a simple procedure and is more effective that finding the exact coordinates. It also shortens the decision time for applying the implant.

The Prediction of Speech Recognition in Noise With a Semi-Implantable Bone Conduction Hearing System by External Bone Conduction Stimulation With Headband: A Prospective Study

Semi-implantable transcutaneous bone conduction devices are treatment options for conductive and mixed hearing loss (CHL/MHL). For counseling of patients, realistic simulation of the functional result is desirable. This study compared speech recognition in noise with a semi-implantable transcutaneous bone conduction device to external stimulation with a bone conduction device fixed by a headband. Eight German-language adult patients were enrolled after a semi-implantable transcutaneous bone conduction device (Bonebridge, Med-El) was implanted and fitted. Patients received a bone conduction device for external stimulation (Baha BP110, Cochlear) fixed by a headband for comparison. The main outcome measure was speech recognition in noise (Oldenburg Sentence Test). Pure-tone audiometry was performed and subjective benefit was assessed using the Glasgow Benefit Inventory and Abbreviated Profile of Hearing Aid Benefit questionnaires. Unaided, patients showed a mean signal-to-noise ratio threshold of 4.6 ± 4.2 dB S/N for speech recognition. The aided results were -3.3 ± 7.2 dB S/N by external bone conduction stimulation and -1.2 ± 4.0 dB S/N by the semi-implantable bone conduction device. The difference between the two devices was not statistically significant, while the difference was significant between unaided and aided situation for both devices. Both questionnaires for subjective benefit favored the semi-implantable device over external stimulation. We conclude that it is possible to simulate the result of speech recognition in noise with a semi-implantable transcutaneous bone conduction device by external stimulation. This should be part of preoperative counseling of patients with CHL/MHL before implantation of a bone conduction device.

Active Bone Conduction Prosthesis: Bonebridge(TM)

Introduction Bone conduction implants are indicated for patients with conductive and mixed hearing loss, as well as for patients with single-sided deafness (SSD). The transcutaneous technology avoids several complications of the percutaneous bone conduction implants including skin reaction, skin growth over the abutment, and wound infection. The Bonebridge (MED-EL, Austria) prosthesis is a semi-implantable hearing system: the BCI (Bone Conduction Implant) is the implantable part that contains the Bone Conduction-Floating Mass Transducer (BC-FMT), which applies the vibrations directly to the bone; the external component is the audio processor Amadé BB (MED-EL, Austria), which digitally processes the sound and sends the information through the coil to the internal part. Bonebridge may be implanted through three different approaches: the transmastoid, the retrosigmoid, or the middle fossa approach. Objective This systematic review aims to describe the world́s first active bone conduction implant system, Bonebridge, as well as describe the surgical techniques in the three possible approaches, showing results from implant centers in the world in terms of functional gain, speech reception thresholds and word recognition scores. Data Synthesis The authors searched the MEDLINE database using the key term Bonebridge. They selected only five publications to include in this systematic review. The review analyzes 20 patients that received Bonebridge implants with different approaches and pathologies. Conclusion Bonebridge is a solution for patients with conductive/mixed hearing loss and SSD with different surgical approaches, depending on their anatomy. The system imparts fewer complications than percutaneous bone conduction implants and shows proven benefits in speech discrimination and functional gain.