Benefits of active middle ear implants in mixed hearing loss: Stapes versus round window

Long-term results and quality of life after vibrant soundbridge implantation (VSBs) in children and adults with aural atresia

PURPOSE

The aim of this study was to evaluate the long-term effectiveness and acceptance of the active middle ear implant system Vibrant Soundbridge (VSB®, MED-EL, Austria) in patients with aural atresia or aplasia (children and adults).

METHODS

Data from 51 patients (mean age 13.9 ± 11.3 years), 42 (79.2%) children and adolescents, and 11 (20.8%) adults) who received a VSB implant between 2009 and 2019 at the Department of Otolaryngology at LMU Clinic Großhadern, Munich were included in the study. Pure-tone audiometry, speech recognition in a quiet environment and in a noisy environment were performed preoperatively, during the first fitting of the audio processor, after 1-3 years, after 3-5 years, and after 5 years (if possible). The follow-up period ranged from 11 to 157 months with a mean of 58.6 months (4.8 years). Furthermore, the benefit of the VSB was evaluated by self-assessment questionnaires (Speech, Spatial, and Qualities of Hearing Scale, respectively, for parents).

RESULTS

Significant improvements were observed in hearing and speech comprehension immediately after the initial fitting of the VSB system (mean hearing gain 38.4 ± 9.4 dB HL) and at follow-up intervals (1-3, 3-5 and after 5 years) for children and adults (p < 0.01). The values remained stable over the long-term, indicating a sustained functional gain from the VSB (mean hearing gain 38.9 ± 9.2 dB HL). The results of the self-assessments affirm the positive influence on hearing and speech comprehension with the VSB. With the VSB, there was an improvement of 41.3 ± 13.7% in the Freiburg monosyllable test.

CONCLUSION

These results (a stable hearing gain over the long term, a good tolerance of the implant and an improvement in quality of life) affirm the recommendation for using the active middle ear implant VSB as early as permitted for aural atresia and aplasia patients. This study represents the audiometric results with the (to date) largest collective of aural atresia patients and with a long follow-up period.

Round-Window Vibroplasty: Systematic Review and Meta-Analysis of Audiological Effectiveness With Different Round-Window Coupling Techniques

OBJECTIVE

Active middle ear implants can be directly coupled to the round-window (RW) membrane via RW Vibroplasty. The objectives of this systematic review were to summarize data on different RW coupling techniques and to investigate their effect on audiological and safety outcomes using meta-analyses.

DATABASES REVIEWED

PubMed (MEDLINE), Cochrane Library, and Embase (DIMDI).

METHODS

All publications reporting on audiological outcomes in human patients after RW Vibroplasty were included. Two independent reviewers carried out screening and data extraction. Meta-analyses and meta-regression were used to evaluate the potential effects of surgical and demographic parameters on primary audiological outcomes. Adverse events were extracted and tabulated for qualitative analysis.

RESULTS

Fourteen different combinations of surgical coupling parameters were identified in 61 included publications. Overall, data from 23 publications could be used for meta-analyses. Significantly better aided sound-field thresholds were reported for RW Vibroplasty performed without a dedicated coupler and using fascia as interponate, compared with RW Vibroplasty with an RW coupler or without an interponate. These effects were not found in other outcomes (i.e., functional gain, word recognition score). Reporting of adverse events was relatively heterogeneous, with 32 explicit mentions of revision surgery after the loss of coupling efficacy.

CONCLUSION

There are numerous publications investigating the effectiveness of coupling active middle ear implants to the RW membrane. However, studies are typically undersampled and of low evidence level. Using meta-analyses, weighted means, and qualitative analyses enabled a summary of the existing literature on audiological and safety outcomes after RW Vibroplasty. Individual selection of the most appropriate coupling modality with standardized intraoperative measurement and careful patient follow-up may be considered key factors for achieving effective RW coupling.

Congenital aural atresia: hearing rehabilitation using active middle-ear implants

OBJECTIVE

To assess hearing rehabilitation in patients with congenital aural atresia using an active middle-ear implant (Vibrant Soundbridge).

METHODS

Of a cohort of 70 microtia and atresia patients, 10 underwent Vibrant Soundbridge implantation between 2008 and 2021. Two of the 10 patients had binaural implantation, resulting in 12 ears for analysis. Pre- and post-operative audiometry data were analysed, and patient satisfaction was evaluated. Surgical issues regarding coupling sites and outcomes were analysed.

RESULTS

Pure tone average (0.5, 1, 2 and 4 kHz) improved from a pre-operative mean (standard deviation) of 65.3 (8.7) dB HL to a post-operative mean of 26.8 (4.9) dB HL. This resulted in a mean pure tone average gain of 38.5 dB HL. The results indicate no obvious difference between stapes (n = 8) and incus (n = 4) coupling. The mean effective gain for 0.5, 1, 2 and 4 kHz was -17.8 dB HL (standard deviation = 4.3). Concerning effective gain, Vibrant Soundbridge performed best at 2 kHz. Patients reported high overall satisfaction, good sound quality and strongly improved directional hearing.

CONCLUSION

An active middle-ear implant (Vibrant Soundbridge) allows hearing rehabilitation in selected atretic ears, and provides long-term hearing stability in children and adults.

Advances in auditory implants

Auditory implants are classified into bone conduction (BAHA and Bonebridge; BB) and active middle ear implants (Vibrant Soundbridge; VSB) that stimulate cochlear hair cells, and cochlear implants (CIs) that stimulate neural structures. CIs should be performed as early as possible, and bilateral CIs have become popular because sound localization and speech recognition can be improved. CI is also considered a desirable treatment option for patients with single-sided deafness. VSB provides a safe and effective option for patients with conductive or mixed hearing loss and moderate to severe sensorineural hearing loss (SNHL); however, it use in patients with conductive or mixed hearing loss have only been approved in Japan. BAHA and BB implants have been approved by national insurance in Japan as bone conduction implants for patients with conductive or mixed hearing loss. Two fully implantable devices (Cochlear Carina and Envoy Esteem) are provided for patients with SNHL.

Modified Power Piston Versus Simultaneous Stapedotomy With Hearing Aids in Otosclerosis: A Follow-Up Study Exploring Speech Recognition, Quality of Life and Usage of Device

OBJECTIVE

To compare audiologic outcomes, quality-of-life (QoL) and usage-of-device (UoD) between case-matched, otosclerotic patients with mixed hearing loss (MHL) which received (a) stapedotomy and postoperative amplification with hearing aids (SDT+HA) or (b) short-incudial process coupled active middle ear implant with simultaneous stapedotomy (mPP).

STUDY DESIGN, SETTING, AND PATIENTS

Prospective, matched case-control, follow-up study conducted at two tertiary otologic referral centers. Eligible were all otosclerotic patients with MHL, which received mPP at either of the two institutions. A case-matched-cohort of SDT+HA-patients was generated from the hospitals database based on preoperative audiologic findings.

MAIN OUTCOME MEASURES

For sound- and speech perception, primary outcome parameters were the mean postoperative, aided air-conduction pure tone average (mpa-AC-PTA) and word recognition score at 80 dB speech level (mpa-WRS), for QoL the mean Nijmegen-Cochlear-Implant-Questionnaire (NCIQ) total-score, and for UoD the mean score rated on a 10-point Likert-scale.

RESULTS

A total of 28 patients were included; 14 received mPP; mpa-AC-PTA and mpa-WRS significantly improved from 47.1 dB-HL to 34.3 dB-HL (-12.8 dB-HL; p < 0.001) and from 75.0% to 93.2% (+18.2%; p = 0.002) compared to 46.5 dB-HL to 31.9 dB-HL (-14.8 dB-HL; p < 0.008) and 75.0% to 93.2% (+18.2%; p = 0.002) for SDT+HA. No significant difference between groups was observed (all p > 0.1). NCIQ total-score between groups did not significantly differ (70.4 vs. 69.9; p = 0.93). UoD for mPP was significantly higher (6.1 vs. 3.0; p < 0.001).

CONCLUSIONS

If medical/technical problems prevent usage of HA in otosclerosis with MHL, mPP can be considered as effective treatment option with similar audiological outcome and QoL. A significantly higher UoD for mPP was observed.

Analysis of design parameters of round-window stimulating type electromagnetic transducer by a nonlinear lumped parameter model of implanted human ear

Round-window stimulating transducer is a new solution to treat mixed hearing loss. To uncover the factors affecting the round-window stimulation's performance, we investigated the influence of four main design parameters of round-window stimulating type electromagnetic transducer. Firstly, we constructed a human ear nonlinear lumped parameter model and confirmed its validity by comparing the stapes responses predicted by the model with the experimental data. Following this, an electromagnetic transducer's mechanical model, which simulates the floating mass transducer, was built and coupled to the human ear model; thereby, we established a nonlinear lumped parameter model of implanted human ear under round-window stimulation and verified its reliability. Finally, based on this model, the influences of the four main design parameters, i.e., the excitation voltage, the electromechanical coupling coefficient, the support stiffness, and the preload force, were analyzed. The results show that the change of excitation voltage does not alter the system's natural frequency. Chaotic motion occurs when the electromechanical coupling coefficient is small. Meanwhile, the stapes displacement appears to increase firstly and then decrease with the increase of the electromechanical coupling coefficient. The increase of the support stiffness enlarges the resonance frequency of the stapes displacement and reduces the stapes displacement near the resonance frequency, deteriorating the transducer's hearing compensation at low frequency. The preload force can improve the transducer's hearing compensation performance in mid-high frequency region.

Effects of design and coupling parameters on the performance of electromagnetic transducers in round-window stimulation

Many studies have investigated factors contributing to large variations in the outcomes of round-window (RW) stimulation but most have focused on the floating mass transducer (FMT). To determine whether results for the FMT hold for a fixed-type transducer (FTT), this study constructs two coupled finite element models of the transducer and the human ear that incorporate the cochlear third windows and inner structures of these two electromagnetic transducers. We use these FE models of the human ear and transducers to investigate the influence of four design parameters and coupling conditions for the transducers, i.e., the support's Young's modulus, the coupling layer's cross sectional area and Young's modulus, and the transducer's cross sectional area. The results show that an increase in the support's Young's modulus reduces the output of the FMT but increases that of the FTT. Reducing the cross sectional area and Young's modulus of the coupling layer significantly increases the low-frequency response of the FMT but slightly reduces that of the FTT. Reducing the cross sectional area of the transducer increases the output of the FMT but reduces that of the FTT. This shows that inner structures of electromagnetic transducers should be considered in the optimal design parameters and coupling conditions for RW stimulation.

Development and Validation of a Prognostic Model to Predict Hearing Recovery for Patients With Chronic Otitis Media

OBJECTIVE

To explore the factors affecting postoperative hearing recovery in chronic otitis media (COM) patients, establish a clinical prediction model for hearing recovery, and verify the accuracy of the model.

METHODS

Data of patients with COM who were admitted to our hospital between January 1, 2012 and September 30, 2020 were retrospectively analyzed. We collected data on relevant clinicopathological characteristics of patients. The patients were randomly divided into the development cohort and validation cohorts. A postoperative air-bone gap (ABG) ≤20 dB was defined as successful hearing recovery. Univariate and multivariable logistic regression analyses were used to investigate the association of several prognostic factors with hearing recovery. These factors were then used to establish a nomogram. The model was subjected to bootstrap internal validation and performance evaluation in terms of discrimination, calibration, and clinical validity.

RESULTS

This study included 2146 patients with COM: the development cohort comprised 1610 patients (mean [standard deviation; SD] age, 44.1 [14.7] years; 733 men [45.5%]) and the validation cohort included 536 patients (mean [SD] age, 42.9 [14.4] years; 234 men [43.7%]). Multivariable logistic regression analysis showed that age, duration of onset, styles of surgery (tympanoplasty, canal wall up-CWU, or canal wall down-CWD), ossicular prosthesis, granulation or calcified blocks around the ossicular chain, ossicular chain integrity, duration of drilling, eustachian tube dysfunction, mixed hearing loss, semicircular canal fistula, and second surgery were associated with hearing recovery. A nomogram based on these variables was constructed. The area under the curve was 0.797 (95% confidence interval [CI], 0.778-0.812) in the development cohort and 0.798 (95% CI, 0.7605-0.8355) in the validation cohort.

CONCLUSIONS

This study demonstrated the various clinical factors correlated with hearing recovery in patients with COM. The nomogram developed with these data could provide personalized risk estimates of hearing recovery to enhance preoperative counseling and help to set realistic expectations in patients.

Comparative study of efficiency and characteristics of FMT and DRT installed in human cadavers for round-window stimulation

Acoustic hearing aids generate amplified sound in the ear canal, and they are the standard of care for patients with mild to moderate sensorineural hearing loss. However, because of their limited frequency bandwidth, gain, and feedback, there is substantial room for improvement. Active middle ear implants, which directly vibrate the middle ear and cochlea, are an alternative approach to conventional acoustic hearing aids. They provide an opportunity to improve sound quality and speech understanding with amplification rehabilitation. For floating-mass type and direct-rod type (DRT) middle ear transducers, a differential floating-mass transducer (DFMT) and a tri-coil bellows transducer (TCBT), respectively, were fabricated to measure the output characteristics in four human temporal bones. Both were fabricated to have similar output forces per unit input and were placed in four human temporal bones to measure their output performances. The TCBT resulted in higher output than did the DFMT throughout the audible frequency range, and the output was more prominent at lower frequency ranges. In this study, we showed that DRT was a more effective method for round window stimulation. Because of its frequency characteristics and vibration efficiency, this implantation method can be utilized as a driving solution for middle ear implants.

Results of the Active Middle Ear Implantation in Patients With Mixed Hearing Loss After the Middle Ear Surgery: Prospective Multicenter Study (ROMEO Study)

Objectives

This study was conducted to evaluate the user satisfaction, efficacy, and safety of round window (RW) vibroplasty using the Vibrant Soundbridge (VSB) in patients with persistent mixed hearing loss after mastoidectomy.

Methods

The study included 27 patients (mean age, 58.7 years; age range, 28–76 years; 11 men and 16 women) with mixed hearing loss after mastoidectomy from 15 tertiary referral centers in Korea. The VSB was implanted at the RW. The Korean translation of the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire and the Korean version of the International Outcome Inventory for Hearing Aids (K-IOI-HA) questionnaire were used to evaluate user satisfaction as the primary outcome. The secondary outcome measures were audiological test results and complication rates.

Results

The mean scores for ease of communication (61.3% to 29.7% to 30.2%), reverberation (62.1% to 43.1% to 37.4%), and background noise (63.3% to 37.7% to 34.3%) subscales of the APHAB questionnaire significantly decreased after VSB surgery. The mean K-IOI-HA scores at 3 and 6 months after surgery were significantly higher than the mean preoperative score (18.6 to 27.2 to 28.1). The postoperative VSB-aided thresholds were significantly lower than the preoperative unaided and hearing aid (HA)-aided thresholds. There was no significant difference between preoperative unaided, preoperative HA-aided, and postoperative VSB-aided maximum phonetically balanced word-recognition scores. None of the 27 patients experienced a change in postoperative bone conduction pure tone average. One patient developed temporary facial palsy and two developed surgical wound infections.

Conclusion

RW vibroplasty resulted in improved satisfaction and audiological test results in patients with mixed hearing loss after mastoidectomy, and the complication rate was tolerable.

Hearing Rehabilitation with Combined Electroacoustic Stimulation and Ossiculoplasty

We report a case of hearing rehabilitation following combined cochlear implantation and ossiculoplasty. A 71-year-old patient visited the clinic for right-sided mixed hearing loss. We targeted neural and conductive components, performing two different operations simultaneously. At two months post-operative, the patient showed satisfactory results with respect to hearing threshold and speech comprehension. Our experience suggests that careful evaluation of patients and consideration of the diverse array of available treatment strategies can be used to provide personalized rehabilitation with maximal effectiveness. To the best of our knowledge, this is the first report to take such an integrated approach to treat hearing impairment and is thus likely to have clinical importance for otologists.

Long-term Outcomes of Clip Coupler Implantation in Patients with Unilateral Congenital Aural Atresia

OBJECTIVE

To evaluate the long-term safety and efficacy of the Clip coupler attached to the stapes head in patients with unilateral congenital aural atresia (CAA).

METHODS

This single-center retrospective study included 16 Mandarin-speaking patients who had unilateral microtia accompanied by CAA. All patients were divided into two groups: the short-term follow-up group (n = 9) and the long-term follow-up group (n = 7). The floating mass transducer of the Vibrant Soundbridge (VSB) was positioned in the stapes head by the Clip coupler. The safety of the VSB was investigated by comparing preoperative and postoperative bone-conduction (BC) thresholds as well as by complications. The effectiveness was evaluated by functional gain (FG), word recognition score (WRS), speech reception threshold (SRT) and signal-to-noise ratio (SNR).

RESULTS

Pre- and post-operative BC thresholds were no different in all patients. And no complications developed. VSB-aided thresholds in the free-field had improved significantly in both short- and long-term follow-up groups. The improvements of WRS were observed in two groups. The monosyllabic VSB-aided WRS in the long-term follow-up group was significantly higher than that in the short-term follow-up group. When speech was from the impaired ear and noise presented to the side of normal ear (S_VSBN_CL), lower SNRs were found in two groups after VSB implantation. However, there was no statistical difference in aided SNR between the two groups at S_VSBN_CL status.

CONCLUSIONS

Our results show that the FMT connected to the stapes head is a secure and useful device for patients with unilateral CHL/MHL, not only in terms of improved hearing thresholds, but also improved speech intelligibility in quiet and noisy environments.

Modified-Power-Piston: Short-Incudial-Process-Vibroplasty and Simultaneous Stapedotomy in Otosclerosis

OBJECTIVE

If mixed-hearing-loss (MHL) occurs in otosclerosis, hearing-aids (HA) in addition to conventional-stapedotomy (SDT) may be necessary. If otosclerosis progresses or technical or medical problems prevent use of HA, combining active-middle-ear-implants (AMEI) with SDT ("power-piston") may be considered. Previously, AMEI-coupling to the long-incudial-process was suggested. Here, a "modified-power-piston" surgery (mPP) coupling to the short-incudial-process was proposed, so no coupling over the positioned stapes-piston is required. We questioned whether mPP is as safe and effective as SDT.

METHODS

Otosclerotic patients with MHL and limited satisfaction with previously worn HA receiving mPP were retrospectively reviewed at two Austrian tertiary otologic referral centers. Patients, receiving stapedotomy, were case-matched for preoperative pure-tone averages (PTA), bone-conduction (BC-PTA), air-conduction (AC-PTA), and air-bone gap (ABG-PTA). Postoperative changes in BC-PTA and in AC-PTA and ABG-PTA were defined as safety- and as efficacy outcome parameter.

RESULTS

Of 160 patients, 14 received mPP and 14 stapedotomy. Preoperative findings were comparable (all p = 1.000). BC-PTA improved from 38.0 to 36.7 and from 37.1 to 36.9 dB-HL for mPP and SDT, respectively (Δ -1.3 versus -0.2 dB-HL; p = 0.077). AC-PTA improved from 66.8 to 47.1 and from 66.3 to 46.5 dB-HL for mPP and SDT, respectively (Δ -19.6 versus -19.7 dB-HL; p = 0.991). ABG-PTA improved from 28.8 to 10.4 and from 29.1 to 9.6 dB-HL for mPP and SDT, respectively (Δ -18.3 versus -19.5 dB-HL; p = 0.771).

CONCLUSION

In otosclerosis with MHL and limited satisfaction with HA, mPP appeared as safe and effective as SDT and may be considered a treatment alternative in these patients.

Effects of Vibrant Soundbridge on tinnitus accompanied by sensorineural hearing loss

OBJECTIVES

Tinnitus is a common symptom among patients with hearing loss, and many studies have reported successful tinnitus suppression with hearing devices. Active middle ear implantation of the Vibrant Soundbridge (VSB) is a good alternative to existing hearing devices. This study evaluated the effects of VSB implantation on tinnitus and sought to identify the main audiological factor that affects tinnitus suppression.

METHODS

The study participants were 16 adults who had tinnitus with sensorineural hearing loss, and who underwent VSB implantations. Pure-tone audiometry; word recognition test; tinnitus handicap inventory (THI); and visual analog scale (VAS) assessment of loudness, awareness, and annoyance were performed before and 12 months after surgery. Changes in hearing threshold, word recognition scores (WRS), THI scores, and VAS scores were analyzed.

RESULTS

VAS scores for loudness (mean difference: 1.9, 95% CI: 0.6, 3.1), awareness (mean difference: 1.6, 95% CI: 0.4, 2.8), and annoyance (mean difference: 1.7, 95% CI: 0.7, 2.8) showed significant improvements from baseline to 12 months after surgery. In addition, THI scores showed a significant decrease (mean difference: 13.8, 95% CI: 2.9, 24.9). The average hearing threshold level, WRS, and most comfortable level (MCL) also showed significant improvements at 12 months after surgery (mean difference: 17.3, 95% CI: 13.3, 21.3; mean difference: -7.6, 95% CI: -15.1, -0.1; mean difference: 26.3, 95% CI: 22.9, 29.6, respectively). Among the aforementioned factors, changes in MCL were best correlated with those in THI scores (mean difference: 2.55, 95% CI: 0.90, 4.21).

CONCLUSION

A VSB implant is beneficial to subjects with tinnitus accompanied by sensorineural hearing loss. The changes in THI scores best correlated with those in MCL. This improvement may represent a masking effect that contributes to tinnitus suppression in patients with VSB implants.

Clinical Experience of Vibroplasty With Direct Coupling to the Oval Window Without Use of a Coupler

OBJECTIVES/HYPOTHESIS

To investigate the efficacy of direct implantation of a Vibrant Soundbridge (VSB) implant in the oval window (OW) without the use of an OW coupler in patients with severe mixed hearing loss.

STUDY DESIGN

Retrospective chart review METHODS: A total of 62 patients underwent VSB implantation between July 2016 and December 2018 at Severance Hospital in Seoul, South Korea. Among them, eight patients (nine ears) with moderate-to-severe mixed hearing loss were implanted with a VSB directly in the OW. A floating mass transducer (FMT) was attached to the stapes footplate and covered with tragal cartilage. The outcomes were evaluated using pure-tone audiogram and speech audiogram preoperatively and postoperatively. Word recognition score (WRS; % correct) were measured at the most comfortable loudness (MCL) level to evaluate speech perception.

RESULTS

All cases posed difficulty with round window vibroplasty during surgery, and eventually, an FMT was appropriately placed in the OW without a coupler. Preoperative and postoperative bone conduction thresholds were not different. VSB-aided threshold improved in terms of functional and effective gains. Interestingly, four cases showed improved air conduction thresholds without the use of a VSB. In addition, MCL level with a VSB was significantly lower than that with a hearing aid, and VSB-aided WRS improved over time.

CONCLUSIONS

Direct implantation of a VSB in the OW without the use of a coupler showed favorable hearing outcomes, and the OW vibroplasty was safe. Direct OW vibroplasty without a coupler is a reliable procedure and can be a good option for hearing rehabilitation in patients with severe mixed hearing loss.

LEVEL OF EVIDENCE

4 Laryngoscope, 2020.

Benefits of active middle ear implants over hearing aids in patients with sloping high tone hearing loss: comparison with hearing aids

In this retrospective chart review we compared the subjective and objective benefits of active middle ear implants (AMEIs) with conventional hearing aids (HAs) in patients with sloping high tone hearing loss. Thirty-four patients with sensorineural hearing loss were treated with AMEIs. Of these, six had sloping high tone hearing loss and had worn an HA for more than 6 months. Objective assessments, a pure-tone audiogram, as well as a word recognition test, and the Korean version of the Hearing in Noise Test (K-HINT), and a subjective assessment, the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire, were performed. Tests were conducted under three circumstances: 1) the unaided state before surgery; 2) the HA-aided state before surgery; and 3) the AMEI-aided state 3 months after surgery. The average high-frequency hearing gain (≥ 2 kHz) was significantly better with AMEIs than with HAs. Although the result had no statistical significance, AMEIs showed a superior word recognition score (WRS) compared to HAs. However, the most comfortable hearing level at which the WRS was tested was significantly decreased with an AMEI compared to an HA. In the K-HINT, patients with an AMEI showed greater recognition than those fitted with an HA under both quiet and noisy conditions. The APAHB scores revealed that patients were more satisfied with an AMEI rather than an HA on all subscales. The use of vibroplasty in patients with sloping high tone loss resulted in positive hearing outcomes when compared to conventional HAs. Based on the data from this study, AMEIs provided better objective and subjective results and could, therefore, be a better alternative for the treatment of sloping hearing loss.