Transcutaneous Bone Conduction Devices Research Articles

Comparison of Quality of Life Outcomes for Percutaneous Versus Transcutaneous Implantable Hearing Devices: A Systematic Review and Meta-analysis.

To compare quality of life (QOL) outcomes of percutaneous and transcutaneous bone conduction devices (pBCD and tBCD, respectively). Pubmed, Scopus, CINAHL. A systematic review was performed searching for English language articles from inception to March 15, 2023. Studies reporting QOL outcomes measured using a validated tool following implantation of either pBCDs or tBCDs were considered for inclusion. QOL outcomes included scores for Glasgow Benefit Inventory, Glasgow Children's Benefit Inventory, Abbreviated Profile of Hearing Aid Benefit, and the Speech, Spatial, and Qualities of Hearing Scale. A meta-analysis of continuous measures was performed. A total of 52 articles with 1,469 patients were included. Six hundred eighty-nine patients were implanted with pBCDs, and the remaining 780 were implanted with tBCDs. Average Glasgow Benefit Inventory scores for the tBCD group (33.0, 95% confidence interval [22.7-43.3]) were significantly higher than the pBCD group (30.9 [25.2-36.6]) (Δ2.1 [1.4-2.8], p < 0.0001). Mean Glasgow Children's Benefit Inventory scores (Δ3.9 [2.0-5.8], p = 0.0001) and mean gain in Abbreviated Profile of Hearing Aid Benefit scores (Δ5.6 [4.8-6.4], p < 0.0001) were significantly higher among patients implanted with tBCDs than those implanted with pBCDs. Patients implanted with tBCDs also had significantly higher gains on the Speech (Δ1.1 [0.9-1.3], p < 0.0001), Spatial (Δ0.8 [0.7-0.9], p < 0.0001), and Qualities of Hearing (Δ1.2 [1.1-1.3], p < 0.0001) portions of the Speech, Spatial, and Qualities of Hearing Scale than those implanted with pBCDs. Patients implanted with transcutaneous devices had better QOL outcomes than those implanted with percutaneous devices.

Post-implantation clinical cost analysis between transcutaneous and percutaneous bone conduction devices

IntroductionBone conduction devices (BCD) are effective for hearing rehabilitation in patients with conductive and mixed hearing loss or single-sided deafness. Transcutaneous bone conduction devices (tBCD) seem to lead to fewer soft tissue complications than percutaneous BCDs (pBCD) but have other drawbacks such as MRI incompatibility and higher costs. Previous cost analyses have shown a cost advantage of tBCDs. The purpose of this study is to compare long-term post-implantations costs between percutaneous and transcutaneous BCDs.Materials and methodsRetrospective data from 77 patients implanted in a tertiary referral centre with a pBCD (n = 34), tBCD (n = 43; passive (tpasBCD; n = 34) and active (tactBCD; n = 9) and a reference group who underwent cochlear implantation (CI; n = 34), were included in a clinical cost analysis. Post-implantation costs were determined as the sum of consultation (medical and audiological) and additional (all post-operative care) costs. Median (cumulative) costs per device incurred for the different cohorts were compared at 1, 3 and 5 years after implantation.ResultsAfter 5 years, the total post-implantation costs of the pBCD vs tpasBCD were not significantly different (€1550.7 [IQR 1174.6–2797.4] vs €2266.9 [IQR 1314.1–3535.3], p = 0.185), nor was there a significant difference between pBCD vs tactBCD (€1550.7 [1174.6–2797.4] vs €1428.8 [1277.3–1760.4], p = 0.550). Additional post-implantation costs were significantly highest in the tpasBCD cohort at all moments of follow-up.ConclusionTotal costs related to post-operative rehabilitation and treatments are comparable between percutaneous and transcutaneous BCDs up to 5 years after implantation. Complications related to passive transcutaneous bone conduction devices appeared significantly more expensive after implantation due to more frequent explantations.

Ten-year retrospective evaluation of therapeutic choices and related satisfaction in patients with auricular deformities

To adequately counsel future patients with auricular abnormalities, this study aimed to analyze the therapeutic choices patients make after consultation concerning their auricle and/or hearing. All patients who visited the auricle consultation between January 2010 and January 2020 were included. This comprises patients with all types of auricular anomalies of both congenital and acquired etiology. Follow-up was performed by telephone to obtain informed consent and to take a short nonvalidated questionnaire regarding their therapeutic choices and satisfaction with these choices. Patient characteristics and information regarding therapeutic choices after consultation were subsequently obtained from the patients' medical files. The main outcome parameters were the patients’ therapeutic choices regarding the auricle and hearing. A total of 134 patients (61.2%) were included with a mean follow-up of 3.85 years. For congenital and acquired etiologies, 72.8% and 18.2% declined reconstruction, 14.0% and 18.2% chose autologous, 5.3% and 0% chose alloplastic, 6.1% and 45.4% chose prosthetic, and 1.8% and 18.2% chose another type of reconstruction, respectively. A total of 54.9% declined hearing rehabilitation, while 38.2% chose percutaneous bone conduction device (BCD), 2.0% transcutaneous BCD, and 4.9% BCD on a softband. The overall satisfaction score was 8.7/10 concerning the auricle and 8.3/10 regarding hearing. In conclusion, most patients with a congenital etiology chose to wait or decided against auricular reconstruction, while patients with acquired etiologies mostly opted for reconstruction by a prosthesis. Patients or their caregivers were very satisfied with their choice, regardless of whether this implies reconstruction or no reconstruction, which emphasizes the importance of shared decision-making and thorough counseling.

Transcutaneous Bone Conduction Implants in Patients With Single-Sided Deafness: Objective and Subjective Evaluation.

This study aimed to investigate the audiological outcomes and subjective benefits of transcutaneous bone conduction implants (BCIs) in patients with single-sided deafness (SSD). This retrospective study was conducted on 11 patients with SSD implantations between 2015 and 2018 at a tertiary center. Pure-tone audiometry, speech reception threshold (SRT), and speech-in-noise (SPIN) tests were performed. Preoperative and postoperative performances were compared. Subjective satisfaction level was assessed using validated questionnaires. A PubMed search was conducted to identify the relevant studies published to date. All patients demonstrated significant audiological improvements compared with their preoperative condition. The mean SRT improved significantly (p = 0.001) from 109dB to 23dB after implantation. The mean SPIN score improved significantly after implantation. The questionnaires showed an overall positive benefit of transcutaneous bone conduction devices (BCDs). A literature search revealed 21 articles, of which 14 reported the use of BCIs in patients with SSD. Our results agree with the published evidence showing the overall benefit of BCI in patients with SSD. Transcutaneous BCDs could be considered as an alternative treatment option for patients with SSD, it could show good audiological outcomes and high satisfaction levels. Further studies should be conducted on patients with SSD to determine the most appropriate hearing solutions.

The Impact of Location and Device Coupling on the Performance of the Osia System Actuator.

Active transcutaneous bone conduction (BC) devices offer the benefit of improved power output compared to passive transcutaneous devices and remove the risk of skin infections that are more common in traditional percutaneous BC devices. Despite these advantages, more research is needed on implant location, device coupling, and their influence on device performance. This study is aimed at quantifying the extent to which certain parameters affect device output when using the Osia® system actuator. Parameters under study are (1) implant location, (2) comparison with the actuator of a state-of-the-art BC device, (3) bone undergrowth simulation, and (4) skull fixation. Five human cadaveric heads were implanted with the actuator at three different implant locations: (1) recommended, (2) posterior Osia® positions, and (3) standard Baha® position. At each location, the cochlear promontory velocity and the intracochlear pressure difference were measured. A percutaneous bone conduction actuator was used as a reference for the obtained measurements. Stimulation levels corresponded to a hearing level of 60 dB HL for frequencies between 250 and 6000 Hz. In addition, bone cement was used as a simulation for reactive bone growth. Results obtained in four heads indicate an improved power transmission of the transcutaneous actuator when implanted at the recommended position compared to the actuator of the percutaneous device on its respective recommended location when stimulating at an identical force level. A correlation was found between the promontory vibration and the actuator position, indicating that the same level of stimulation leads to higher promontory vibrations when the device is implanted closer to the ear canal. This is mainly reflected at frequencies higher than 1 kHz, where an increase was observed in both measurement modalities. At lower frequencies (<1 kHz), the power transmission is less influenced by the implant position and differences between the acquired responses are limited. In addition, when no rigid coupling to the skull is provided, power transfer losses of up to 30 dB can be expected.

Output performance of the novel active transcutaneous bone conduction implant Sentio at different stimulation sites

ObjectivesThe output performance of a novel semi–implantable transcutaneous bone conduction device was compared to an established percutaneous bone-anchored hearing system device using cadaver heads. The influence of actuator position, tissue growth below the actuator and mounting it on the surface or in a flattened bone bed on the performance of the implanted actuator was investigated. Materials and MethodsThe percutaneous and the new transcutaneous device were sequentially implanted at two sites in five human cadaver heads: 55 mm superior-posterior to the ear canal opening (position A) and, closer to the cochlea, about 20 mm inferior-posterior to the ear canal opening behind the pinna on the mastoid (position B). The ipsi- and contralateral cochlear promontory (CP) velocity magnitude responses to percutaneous and transcutaneous stimulation were measured using laser Doppler vibrometry. In addition, the CP vibration of the transcutaneous device placed directly on the skull bone surface was compared with the placement in a flattened bone bed at a depth of about 3 mm. Finally, the influence of placing a thin silicone interposition layer under the implanted transducer was also explored. ResultsThe percutaneous device provided about an 11 dB higher average CP vibration level than the transcutaneous device at frequencies between 0.5 and 10 kHz. The ipsilateral CP vibration responses with stimulations at position B were on average 13 dB higher compared to stimulation at position A. The placement of the transcutaneous transducer at position B provided similar or higher average vibration magnitudes than the percutaneous transducer at position A. The 3 mm deep flattened bone bed had no significant effects on the output performance. Placing a thin silicone layer under the transcutaneous transducer had no significant influence on the output of the transcutaneous device. ConclusionsOur results using the CP vibration responses show that at frequencies above 500 Hz the new transcutaneous device at position B provides similar output levels as the percutaneous device at position A. The results also indicated that neither a bone bed for the placement of the transcutaneous transducer nor a simulated tissue growth between the actuator and the bone affect the output performance of the device.

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

To evaluate long-term audiological, surgical and safety outcomes of a complex patient cohort treated with an active transcutaneous bone-conduction device (tBCD). 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 (< 12months) and long-term follow-up data (> 12months). 31 patients with a total person-time of 90.4years 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 PTA4AC before surgery (64.7 ± 16.1dB HL; CHL 50.6 ± 10.6dB HL; MHL 72.8 ± 12.8dB HL) and did not change between short-term (42.3 ± 13.1dB HL; CHL 35.8 ± 6.8dB HL; MHL 45.2 ± 14.3dB HL) and long-term (43.4 ± 10.0dB HL; CHL 35.8 ± 4.3dB HL; MHL 48.1 ± 9.6dB HL) follow-up periods. Speech intelligibility in the Freiburg monosyllables test at 65dB 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. The device provides satisfactory audiological and speech benefit over long-term follow-up periods, up to 7years. 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.

Audiological results and subjective benefit of an active transcutaneous bone-conduction device in patients with congenital aural atresia.

PurposeTo review functional and subjective benefit after implantation of an active transcutaneous bone conduction device (BCD) in patients with congenital microtia with atresia or stenosis of the external auditory canal.MethodsRetrospective chart analysis and questionnaire on the subjective impression of hearing ( Speech, Spatial and Qualities of Hearing Scale (SSQ-B) of patients treated between 2012 and 2015.ResultsResults18 patients (24 ears) with conductive or mixed hearing loss in unilateral (n = 10) or bilateral (n = 8) atresia were implanted with a BCD. No major complications occurred after implantation. Preoperative unaided air conduction pure tone average at 0.5, 1, 2 and 4 kHz (PTA 4 ) was 69.2 ± 11.7 dB, while postoperative aided PTA 4 was 33.4 ± 6.3 dB, resulting in a mean functional hearing gain of 35.9 +/- 15.6 dB. Preoperatively, the mean monosyllabic word recognition score was 22.9 % ± 22.3 %, which increased to 87.1 % +/- 15.1 % in the aided condition. The Oldenburger Sentence Test at S0N0 revealed a decrease in signal-to-noise-ratio from − 0.58 ± 4.40 dB in the unaided to − 5.67 ± 3.21 dB in the postoperative aided condition for all patients investigated. 15 of 18 patients had a subjective benefit showing a positive SSQ-B score (mean 1.7).ConclusionThe implantation of an active bone conduction device brings along subjective and functional benefit for patients with conductive or combined hearing loss.

Safety and Efficacy of Implantation of the Bonebridge Active Transcutaneous Bone-Conduction Device Using Implant Lifts.

Implant lifts were recently introduced to facilitate implantation of the Bonebridge and to reduce the risk of uncovering the sigmoid sinus and/or dura. The current study analyzed medical, technical, and audiological outcomes of implantation with the Bonebridge implant using lifts. This was a retrospective study on all consecutive patients implanted with a bone-conduction hearing implant at a tertiary medical referral center between March 2012 and October 2018. Outcome measures were complications, explantations, and revisions and the mean time of implant use. Audiological results were assessed as well. Outcomes were evaluated for devices implanted with BCI Lifts and compared with those implanted without lifts. In the study period, 13 out of a total of 54 implantations were conducted using one or two 1- to 4-mm BCI Lifts. During the follow-up period, two complications occurred and both in patients implanted without lifts (2/41; 4.9%). All patients in the lifts group were using the implant at the end of observation period. No statistically significant difference was observed in functional hearing gain or word-recognition improvement at 65 dB between two groups. The use of BCI Lifts in Bonebridge implantations was not associated with adverse events during the observation period. The clinical follow-up revealed no complications in implantations requiring lifts. Furthermore, the functional hearing gain and the word-recognition improvement did not differ from those of devices implanted without lifts. Data indicate safety and efficacy for Bonebridge implantations using lifts.

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

PurposeAim 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.MethodsIn 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).ResultsFour 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).ConclusionWe 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.

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

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. 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. 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. 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.

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

PurposeTo 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.MethodsThis 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.ResultsThe 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.ConclusionEven 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.

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

BackgroundMalformations of the temporal bone present different challenges to the implantation of a transcutaneous active bone conduction device, such as Bonebridge (Med-el, Innsbruck, Austria). This study aims to describe the benefits of high-resolution computed tomography (HRCT) in preoperative assessment and to analyze whether characteristics of the mastoid process, intraoperative compression of the dura or sigmoid sinus, and the use of the Lifts system, lead to differences in audiological performance after implantation.MethodsWe examined 110 cases of congenital microtia. The structure of the temporal bone was examined using HRCT and a 3D simulation software program. The mean anteroposterior mastoid bone thickness from the external auditory canal to the sigmoid sinus was measured (a measurement referred to as “AP”, hereafter). Sound field threshold (SFT), speech reception threshold (SRT) in noise, and word recognition score (WRS) in quiet, before and after implantation, were also measured. Independent variables were recorded in all patients: mastoid type (well pneumatized or poorly pneumatized), the presence of dural or sigmoid sinus compression, and the use of the Lifts system.ResultsWe found that the mean AP in the non-compression group was 16.2 ± 2.3 mm and in the compression group, 13.1 ± 2.9 mm (p < 0.001). We analyzed the hearing improvement of patients grouped by mastoid development, dural or sigmoid sinus compression, and use of the Lifts system, and found that these factors did not interact and that they had no influence on the hearing outcomes (p > 0.05).ConclusionsThe AP dimension in the non-compression group was significantly larger than that in the compression group. This finding combined with the ROC curve analysis revealed the AP dimension was a high-accuracy predictor of potential surgical complications involving the dura and sigmoid sinus compression. Further analysis revealed that there was no interaction between the chosen variables: mastoid type, dural or sigmoid sinus compression, and the use of the Lifts system, and that all of these factors had no significant impact on hearing performance. Bonebridge was shown to produce effective and stable bone conduction and to improve patients’ hearing performance.

Audiological and subjective outcomes of 100 implanted transcutaneous bone conduction devices and preoperative bone conduction hearing aids in patients with bilateral microtia-atresia

Background: Bonebridge (BB) and bone conduction hearing aid (BCHA) are effective in patients with bilateral congenital microtia-atresia (CMA).Objectives: To investigate and compare the outcomes of these devices in a large sample size.Materials and methods: This single center prospective study involved 100 patients with bilateral CMA who were implanted with BBs and used BCHAs before implantation. Sound field threshold (SFT), speech reception thresholds (SRTs) and word recognition scores (WRSs) were compared between unaided, BCHA used and implanted patients. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was used to evaluate subjective satisfaction.Results: Compared to unaided condition, the SFT, WRS and SRT of BCHA and BB were significantly improved. With BCHA or BB, the three subscale scores of the APHAB (ease of communication, background noise and reverberation) significantly reduced. However, the aversiveness subscale scored significantly higher than unaided condition. All outcomes were better in BB condition than BCHA.Conclusions: BB or BCHA use can be considered as effective methods to improve audiological outcomes and subjective satisfaction. Although not as good as BB, BCHA use is critical for improving hearing in the early period of language and auditory pathway development before the skull is suitable for BB implantation.

First United Kingdom experience of the novel Osia active transcutaneous piezoelectric bone conduction implant

Bone conduction hearing devices are widely used and indicated in cases of conductive, mixed or single-sided deafness where the conventional hearing aids are not indicated or tolerated. This prospective study aims to investigate the surgical and hearing outcomes of a novel active piezoelectric transcutaneous bone conduction device (t-BCD). Prospective data were collected from the first 10 patients who underwent implantation with the t-BCD Osia (Cochlear, Australia) (between Dec 2018 and March 2019) in a tertiary referral centre. The main outcome measures include: surgical outcome, free field speech testing with speech recognition thresholds, audiological gain and patient-reported outcomes including the 'Glasgow Benefit Inventory' (GBI) and the 'Client Oriented Scale of Improvement (COSI). The mean length of surgery was 70.6min (range 50-87, SD = 9.5). Mean skin thickness measured was 5.6mm (range 4-8, SD = 1.1). There were two post-operative wound infections which settled conservatively. One required revision surgery to thin skin. The average gain in hearing with the implant was + 39.4dB. Pre-implantation mean unaided SRT was 38.1dB (SD = 7.8) and the post-implantation mean-aided SRT was 22.7dB (SD = 4.6) (p = 0.000078). There was improvement in COSI domains. The mean Glasgow disability score dropped from 52% pre-implantation to 20% post-implantation (p = 0.001). This new active t-BCHD provides excellent audiological gain and improvement in speech recognition. Patient-reported outcomes have also been very positive. The surgery was straightforward with no major surgical complications reported. Further studies will be required to examine long-term outcomes in larger number of patients.

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

BackgroundIn 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.ObjectivesTo critically assess the current literature on safety, efficacy and subjective benefit after implantation with an active transcutaneous bone conduction hearing device.Data sourcesLiterature 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 criteriaRandomized controlled trials, clinical controlled trials and cohort studies, case series and case reports investigating subjective and objective outcomes.Study appraisal and synthesis methodsRetrieved 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.Results39 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.LimitationsA 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.ConclusionThe 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).

Audiologic, surgical and subjective outcomes of active transcutaneous bone conduction implant system (Bonebridge)

Objective: Our objective was to evaluate the surgical restrictions, audiologic benefits and satisfaction from using an active transcutaneous bone conduction device (BCD), Bonebridge® (BB) in patients with mixed/conductive hearing loss (MCHL) or single-sided deafness (SSD).Design: A retrospective review from all patients who underwent BB surgery at the Pusan National University Hospital from 2015 to 2017 for SSD or MCHL was performed.Study sample: Twenty-two patients with SSD and five with MCHL had a BB implanted and analysed.Results: Complete transmastoid implantation of the device was possible for all patients with an intact canal wall (ICW), using lifts if necessary. The overall functional hearing gain (FHG) in SSD and MCHL was 31.4 and 37.6 dB, respectively. The mean percentage of speech recognition in a quiet was 81% (vs. 11% unaided) for MCHL group and 82% (vs. 29% unaided) for SSD group. Mean speech recognition scores in noise improved significantly under various signal-to-noise ratio (SNR) for both groups. Questionnaires showed overall improvement, and there was no significant difference between the two groups.Conclusions: The BB provides improved functional gain, and there were no limitations during surgery despite the large device. Both MCHL and SSD group had benefit and improved quality of life with BB.

Effect of transducer attachment on vibration transmission and transcranial attenuation for direct drive bone conduction stimulation

Direct drive bone conduction devices (BCDs) are used to rehabilitate patients with conductive or mixed hearing loss by stimulating the skull bone directly, either with an implanted transducer (active transcutaneous BCDs), or through a skin penetrating abutment rigidly coupled to an external vibrating transducer (percutaneous BCDs). Active transcutaneous BCDs have been under development to overcome limitations of the percutaneous bone anchored hearing aid (BAHA), mainly related to the skin penetration. The attachment of a direct drive BCD to the skull bone can differ significantly between devices, and possibly influence the vibrations’ transmission to the cochleae.In this study, four different attachments are considered: (A) small-sized flat surface, (B) extended flat surface, (C) bar with a screw at both ends, and (D) standard bone anchored hearing aid screw. A, B, and C represent three active transcutaneous options, while D is for percutaneous applications. The primary aim of this study was to investigate how the different transcutaneous attachments (A, B, and C) affect the transmission of vibrations to the cochleae to the ipsilateral and the contralateral side. A secondary aim was to evaluate and compare transcranial attenuation (TA, ipsilateral minus contralateral signal level) between transcutaneous (A, B, and C) and percutaneous attachments (D).Measurements were performed on four human heads, measuring cochlear promontory velocity with a LDV (laser Doppler vibrometer) and sound pressure in the ear canal (ECSP) with an inserted microphone. The stimulation signal was a swept sine between 0.1 and 10 kHz. The comparison of ipsilateral transmission between transcutaneous adaptors A, B, and C was in agreement with previous findings, confirming that: (1) Adaptor C seems to give the most effective transmission for frequencies around 6 kHz but somewhat lower in the mid frequency range, and (2) keeping a smaller contact area seems to provide advantages compared to a more extended one. The same trends were seen ipsilaterally and contralaterally. The observed TA was similar for adaptors A, B, and C at the mastoid position, ranging -10-0 dB below 500 Hz, and 10–20 dB above. A lower TA was seen above 500 Hz when using adaptor D at the parietal position.

Nasal sound pressure as objective verification of implant in active transcutaneous bone conduction devices.

Objective: Active transcutaneous bone conduction devices consist of an external audio processor and an internal implant under intact skin. During the surgical procedure, it is important to verify the functionality of the implant before the surgical wound is closed. In a clinical study with the new bone conduction implant (BCI), the functionality of the implant was tested with an electric transmission test, where the output was the nasal sound pressure (NSP) recorded in the ipsilateral nostril. The same measurement was performed in all follow-up visits to monitor the implant's functionality and transmission to bone over time. The objective of this study was to investigate the validity of the NSP method as a tool to objectively verify the implant's performance intraoperatively, as well as to follow-up the implant's performance over time.Design: Thirteen patients with the BCI were included, and the NSP measurement was part of the clinical study protocol. The implant was electrically stimulated with an amplitude-modulated signal generator using a swept sine 0.1–10 kHz. The NSP was measured with a probe tube microphone in the ipsilateral nostril.Results: The NSP during surgery was above the noise floor for most patients within the frequency interval 0.4–5 kHz, showing NSP values for expected normal transmission of a functioning implant. Inter-subject comparison showed large variability, but follow-up results showed only minor variability within each subject. Further investigation showed that the NSP was stable over time.Conclusion: The NSP method is considered applicable to verify the implant's functionality during and after surgery. Such a method is important for implantable devices, but should be simplified and clinically adapted. Large variations between subjects were found, as well as smaller variability in intra-subject comparisons. As the NSP was found to not change significantly over time, stable transmission to bone, and implant functionality, were indicated.

Transmastoid implantability of an active transcutaneous bone conduction implant in adults with regard to the underlying pathology: a radiological simulation study

Objectives: To compare the feasibility of transmastoid implantation of an active transcutaneous bone conduction device (BCD) in the most important pathologies of the temporal bone and the impact of implant lifts in adulthood.Methods: First, clinical predominant pathologies for implantation of this BCD were evaluated by a literature review. Then, high-resolution CT of 240 temporal bones with neuro-otologic diseases (NOD), chronic otitis media (COM), or cholesteatoma, respectively, were investigated regarding their implantability, using a radiological simulation program.Results: Chronic inflammatory diseases (CID) of the temporal bone with or without cholesteatoma account for most adults scheduled for an active BCD. Complete implantation was possible in almost all cases with NOD as well as COM, requiring an implant lift in 50% of COM and 20% of NOD (p = .025) cases. In contrast, in subjects with cholesteatoma, implantation required an additional tool in 92% of cases, leading to 59% implantability rate in these temporal bones.Conclusion: Adult subjects with CID of the temporal bone show more limiting anatomical conditions for transmastoid placement of an active transcutaneous BCD than those with single-sided deafness. Implant lifts increase the implantability significantly in subjects with COM and particularly in those with cholesteatoma.