Clinical experience with the Vibrant Soundbridge implant device

Adverse events associated with Vibrant Soundbridge: A MAUDE study

OBJECTIVE

To summarize adverse events and their root causes reported to the United States Food and Drug Administration (FDA) on Vibrant Soundbridge (VSB) hearing device (Med-El, Innsbruck, Austria), an active middle ear implant for patients with moderate to severe hearing loss.

MATERIALS AND METHODS

The FDA's Manufacturer and User Facility Device Experience (MAUDE) database was queried for reports of VSB adverse events from January 1, 2012, to July 27, 2022.

RESULTS

Six hundred sixty-three total medical device reports were identified, from which 913 adverse events were extracted. Of these, 498 (54.5 %) were adverse events to patients (AEPs), while 415 (45.5 %) were device malfunctions (DMs). The most common AEPs were hearing performance issues 428 (85.9 %). The most common DMs were compromised conductive link 125 (30.1 %). Root causes identified for DMs were iatrogenic 85 (58.6 %), patient-related 28 (19.3 %), and trauma and external causes 32 (22.1 %). The most common iatrogenic root cause 12 (14.1 %) involved damage to the conductive link during revision surgery. The most common patient-related causes of DMs were excessive middle ear tissue growth 16 (57 %), and abrupt body movements 5 (28.6 %). The most common external cause of DM was cleaning of the ear canal or mastoid cavity 20 (62.5 %).

CONCLUSIONS

Despite its well-known limitations, the MAUDE database provides valuable information on possible complications of VSB as it relates to device malfunction or adverse events for patients. Implementation of standardized reports with relevant and well-defined categories could certainly allow for a more meaningful analysis.

The Stapes Head Coupler-A Flexible and Safe Option for Vibroplasty

OBJECTIVE

To investigate the surgical approach and the audiological outcome of a stapes head coupler in active middle ear implant surgery.

STUDY DESIGN

Retrospective data analysis.

SETTING

Tertiary referral center with a large active middle ear implant program.

PATIENTS

Twelve patients with active middle ear implant surgery.

INTERVENTIONS

Therapeutic surgical approach for hearing rehabilitation in human subjects.

MAIN OUTCOME MEASURES

Auditory brainstem response, sound field thresholds, vibrogram, speech perception in the Freiburger monosyllabic word test.

RESULTS

The stapes head was attached safely in different coupling situations. Audiological outcomes were similar to the audiological performance of established vibroplasty couplers presented in the literature.

CONCLUSION

The stapes head coupler is a new and safe tool for vibroplasty with a good audiological outcome.

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.

Using Stapes Velocity to Estimate the Efficacy of Mechanical Stimulation of the Round Window With an Active Middle Ear Implant

OBJECTIVE

To test a method to measure the efficacy of active middle ear implants when coupled to the round window.

METHODS

Data previously published in Koka et al. ( Hear Res 2010;263:128-137) were used in this study. Simultaneous measurements of cochlear microphonics (CM) and stapes velocity in response to both acoustic stimulation (forward direction) and round window (RW) stimulation (reverse direction) with an active middle ear implant (AMEI) were made in seven ears in five chinchillas. For each stimulus frequency, the amplitude of the CM was measured separately as a function of intensity (dB SPL or dB mV). Equivalent vibrational input to the cochlea was determined by equating the acoustic and AMEI-generated CM amplitudes for a given intensity. In the condition of equivalent CM amplitude between acoustic and RW stimulation-generated output, we assume that the same vibrational input to the cochlea was present regardless of the route of stimulation.

RESULTS

The measured stapes velocities for equivalent CM output from the two types of input were not significantly different for low and medium frequencies (0.25-4 kHz); however, the velocities for AMEI-RW drive were significantly lower for higher frequencies (4-14 kHz). Thus, for RM stimulation with an AMEI, stapes velocities can underestimate the mechanical input to the cochlea by ~20 dB for frequencies greater than ~4 kHz.

CONCLUSIONS

This study confirms that stapes velocity (with the assumption of equivalent stapes velocity for forward and reverse stimulation) cannot be used as a proxy for effective input to the cochlea when it is stimulated in the reverse direction. Future research on application of intraoperative electrophysiological measurements during surgery (CM, compound action potential, or auditory brainstem response) for estimating efficacy and optimizing device coupling and performance is warranted.

Comparison between incus short process and long process coupling of the vibrant soundbridge in human temporal bones

OBJECTIVE

The Vibrant Soundbridge (VSB) is one of the most widely used implantable hearing devices. It consists of a vibrating floating mass transducer (FMT) that is connected to a middle ear structure. The standard coupling devices for sensorineural hearing loss are short process (SP) or long process (LP) couplers.

DESIGN AND STUDY SAMPLE

This study directly compared the electro-mechanical performance of the SP- and LP-coupled FMT of the VSB in the same temporal bone specimen (n = 10). We measured velocity magnitudes and total harmonic distortions (THD) of the stapes (ST) and the round window (RW) using laser Doppler Vibrometry (LDV).

RESULTS

Comparison shows a maximally 10 dB higher magnitude for the LP coupler at ST and RW for frequencies below 600 Hz, whereas the SP coupler shows a maximally 20 dB higher magnitude at the ST and RW for frequencies above 600 Hz. THD show similar behaviour with less distortion at 500 Hz for the LP coupler and less distortions for the SP coupler in higher frequencies.

CONCLUSIONS

Our experiments showed that the SP coupling may be mechanically favourable, in terms of magnitude and distortion, for the transmission of FMT vibrations at higher frequencies.

Hearing rehabilitation and microbial shift after middle ear surgery with Vibrant Soundbridge in patients with chronic otitis media

INTRODUCTION

Patients with otitis media (OM) encounter significant functional hearing impairment with conductive, or a combined hearing loss and long-term sequelae involving impaired speech/language development in children, reduced academic achievement and irreversible disorders of middle and inner ear requiring a long time therapy and/or multiple surgeries. In its persistent chronic form, Otitis media (COM) can often only be treated by undergoing ear surgery for hearing restoration. The persistent inflammatory reaction plays a major role, often caused by multi-resistant pathogens in the ear. Herein, we present outcomes of patients implanted with currently the only FDA approved active Middle Ear Implant Vibrant Soundbridge (VSB), suffering from persistent COM.

METHODS

The study enrolled 42 patients, treated by performing middle ear (ME) surgery to different extents and implanted with the VSB to various structures in the ME. Included were 17 children and 25 adults that had recurrent and/or persisting OM and significant hearing loss. Preoperative and postoperative patients' audiometric data were evaluated and the benefit with VSB assessed using the Glasgow Benefit Inventory for adults and pediatric cohorts. The microbial spectrum of pathogens was assessed before and after surgery, exploring the colonization of the otopathogens, as well as the intestinal microbiome from individually burdened patients.

RESULTS

The mean functional gain is 29.7 dB HL (range from 10 to 56.2 dB HL) with a significant improvement in speech intelligibility in quiet. Following VSB implantation, no significant differences in coupling were observed at low complication rates. Postoperatively patients showed significantly increased benefit with VSB compared to the untreated situation, including less otorrhea, pain, medical visits, and medication intake, with no recurrent OM and significant bacterial shift in otopathogens. The analysis of the intestinal microbiome displayed a high abundance of bacterial strains that might be linked to chronic and persistent inflammation.

CONCLUSIONS

Functional ear surgery including rehabilitation with a VSB in patients suffering from COM present to be safe and effective. The successful acceptance accompanied by the improved audiological performance resulted in significant benefit with VSB, with a shift in the ear pathogens and altered microbiome and thus is a great opportunity to be treated.

Subjective Sound Quality Detection (HISQUI) over Time after Vibrant Soundbridge Implantation

Background: To evaluate the long-term audiological outcomes combined with the Hearing Implant Sound Quality Index (HISQUI) after Vibrant Soundbridge (VSB) implantation. Methods: Prospective recall cohort study of patients who received a VSB in a tertiary academic medical center between 1996 and 2017. Air conduction (AC) and bone conduction (BC), sound field thresholds in aided and unaided conditions, and speech discrimination in noise (Oldenburger sentence test) were measured. Postoperative results were compared with preoperative audiograms. Furthermore, the HISQUI was evaluated. Results: Ten patients (eleven implants) were included, the mean follow up period was nine years. The mean AC threshold preoperatively was between 63 and 70 dB, and the BC was between 38 and 49 dB from 500 to 4000 Hz. In the free-field audiogram, the mean threshold was between 61 and 77 dB unaided vs. between 28 and 52 dB in the aided condition. The average signal to noise ratio (SNR) in the Oldenburger sentence test in the unaided condition was 10 dB ± 6.7 dB vs. 2 dB ± 5.4 dB in the aided condition. Three patients reported a good to very good hearing result, four patients a moderate, and three patients a poor hearing result. There was a significant association between the years of implantation and the HISQUI (p = 0.013), as well as a significant decrease by 14 HISQUI points per 10 dB SPL decline (SE 5.2, p = 0.023). There was a significant difference between the change of BC over the years and the HISQUI, as well as the number of years after implantation and the HISQUI. On average, per dB decrease in BC, the HISQUI decreases by 1.4 points, and every year after implantation the HISQUI decreases by 2.7 points. Conclusions: The aided threshold in free field and speech understanding in noise improved significantly with VSB. An increase over time of BC thresholds was observed as well as a decrease in HISQUI score. This decrease in BC thresholds over time may be due to presbycusis. Therefore, monitoring of these patients over time should be considered to discuss alternative hearing rehabilitation measures in a timely manner.

Active Middle Ear Implant Evoked Auditory Brainstem Response Intensity-Latency Characteristics

Objective

To analyze intensity-latency functions of intraoperative auditory evoked brainstem responses (ABRs) to stimulation by the Vibrant Soundbridge (VSB) active middle ear implant with respect to coupling efficiency, VSB evoked ABR thresholds, and coupling modality [oval window (OW) placement vs. Incus placement and vs. round window (RW) placement].

Study Design

Exploratory study.

Setting

Bi-centric study at tertiary referral centers.

Patients

Twenty-four patients (10 female, 14 male, mean age: 58 years) who received a VSB.

Outcome Measures

Wave-V intensity-latency functions of intraoperative VSB evoked ABRs using a modified audio processor programmed to preoperative bone conduction thresholds for stimulation. Threshold level correction to coupling efficiency and ABR thresholds. Individual plots and exponential function fits.

Results

After ABR threshold level correction, the latency functions could be aligned. A large variance of latencies was observed at individual threshold level. Wave-V latency was longest in the Incus placement subgroup (9.73 ms, SD: 1.04) as compared to OW placement subgroup (9.47 ms, SD: 1.05), with the shortest latency in the RW placement subgroup (8.99 ms, SD: 0.68). For increasing stimulation levels, the variance decreased with intensity-latency function slopes converging toward a steady-state (saturation) latency caused by saturation of audio processor (stimulation) gain. Latency saturation was reached at a stimulation level of 50 dB nHL for the OW placement subgroup, 35 dB nHL for the Incus placement subgroup, and 30 dB nHL for the RW placement subgroup. The latency and saturation results indicated decreased dynamic range for RW placement, i.e., reverse stimulation.

Conclusions

VSB evoked ABR wave-V intensity-latency function slopes were similar to acoustic stimulation at high stimulation levels with a shift toward longer latencies caused by audio processor signal delay. Saturation of latencies occurred for higher stimulation levels due to saturation of audio processor gain. Thus, the analysis of VSB evoked intensity-latency functions appears to allow for the objective assessment of a patient's individual dynamic range. This can further improve diagnostics as well as intraoperative and postoperative quality control.

Machine Learning Technique Reveals Prognostic Factors of Vibrant Soundbridge for Conductive or Mixed Hearing Loss Patients

OBJECTIVES

Vibrant Soundbridge (VSB) was developed for treatment of hearing loss, but clinical outcomes vary and prognostic factors predicting the success of the treatment remain unknown. We examined clinical outcomes of VSB for conductive or mixed hearing loss, prognostic factors by analyzing prediction models, and cut-off values to predict the outcomes.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care hospital.

PATIENTS

Thirty patients who underwent VSB surgery from January 2017 to December 2019 at our hospital.

INTERVENTION

Audiological tests were performed prior to and 3 months after surgery; patients completed questionnaires 3 months after surgery.

MAIN OUTCOME MEASURES

We used a multiregression and the random forest algorithm for predictions. Mean absolute errors and coefficient of determinations were calculated to estimate prediction accuracies. Coefficient values in the multiregression model and the importance of features in the random forest model were calculated to clarify prognostic factors. Receiver operation characteristic curves were plotted.

RESULTS

All audiological outcomes improved after surgery. The random forest model (mean absolute error: 0.06) recorded more accuracy than the multiregression model (mean absolute error: 0.12). Speech discrimination score in a silent context in patients with hearing aids was the most influential factor (coefficient value: 0.51, featured value: 0.71). The candidate cut-off value was 36% (sensitivity: 89%, specificity: 75%).

CONCLUSIONS

VSB is an effective treatment for conductive or mixed hearing loss. Machine learning demonstrated more precise predictions, and speech discrimination scores in a silent context in patients with hearing aids were the most important factor in predicting clinical outcomes.

Combination of Direct Oval Window Vibroplasty With Customized Partial Ossicular Replacement Prosthesis (PORP): A Novel Reconstruction Technique to Rehabilitate Mixed Hearing Loss

OBJECTIVE

Hearing rehabilitation with an active middle ear implant (AMEI) in patients with mixed hearing loss (MHL) after multiple ear surgeries is surgically challenging and requires individual solutions in some cases. Our objective was to introduce a feasible novel technique for direct oval window vibroplasty (OW vibroplasty) using a partial ossicular replacement prosthesis (PORP) to ensure stability and enable active and passive sound transmission.

DESIGN

Four patients with MHL following multiple middle ear surgeries and indication for an AMEI received direct OW vibroplasty in combination with a customized PORP between the enwrapped actuator and reconstructed tympanic membrane (TM).

RESULTS

Postoperative bone conduction was stable in all patients. All patients benefitted from the AMEI in combination with PORP with a mean functional gain of 31.5 ± 17.0 dB. Mean aided postoperative pure tone average was 27.3 ± 2.6 dB. Speech discrimination in quiet at 65 dB with the German Language Freiburg Monosyllabic Test improved for all patients to 68.8 ± 6.3% and in noise with the German Language Oldenburger Sentence Test to -10.4 ± 3.3 dB SNR. No complications were observed.

CONCLUSIONS

This novel technique of direct OW vibroplasty extends the portfolio of reconstructive middle ear procedures by combining an intraoperatively customized "off-the-shelf" PORP as a coupler between floating mass transducer (FMT) and a cartilage TM. We found satisfying functional hearing results. Benefits of the reported technique comprise 1) stabilization and optimized coupling of the reconstruction, 2) possibility of passive sound transmission, 3) general feasibility due to great availability of a regular PORP, and 4) flexibility in bridging of large gaps between TM and actuator.

Long-Term Safety and Quality of Life after Vibroplasty in Sensorineural Hearing Loss: Short/Long Incus Process Coupler

OBJECTIVE

The study shows the long-term effectiveness, safety, and quality of life after Vibrant Soundbridge (VSB) implantation in sensorineural hearing loss (SNHL) using the short process coupler (SP) or the long process coupler (LP).

METHODS

This retrospective study evaluated 77 VSB cases. Follow-up (F/U) time-dependent objective measurements (audiological outcomes), subjective data collection (quality-of-life questionnaire), and safety measures are presented.

RESULTS

Sixty-two ears were included in the analysis with up to 116 months of postsurgical F/U data (mean 32.15 ± 37.97 months LP and SP coupler). Fifty-three ears (13 bilateral cases) received the LP coupler and 9 subjects the SP coupler. The post-operative bone conduction thresholds remained stable and, in both groups, <10 dB. The benefit in word recognition scores measured at 65 dB SPL and 80 dB SPL showed no significant difference between the couplers (p = 0.559 and p = 0.088, respectively). The functional gain was not significantly different (p > 0.05) with a mean of 20.91 ± 9.77 and 17.19 ± 5.75 for LP and SP coupler, respectively. The utility score deciphered from the Assessment of Quality-of-life Questionnaire-8 dimensions revealed a mean score of 0.75 ± 0.16 which is not significantly different to the age- and sex-matched healthy control group with 0.81 ± 0.02 (p = 0.3547).

CONCLUSION

The Incus Vibroplasty utilizing both couplers is a safe and effective method to treat mild-to-severe SNHL. Both fixation methods of the floating mass transducer exhibit good clinical and audiological outcomes with high patient quality of life. The SP coupling method can be a good alternative when the long process is anatomically inaccessible, or the approach is limited due to anatomical reasons.

[Simultaneous implantation of epithesis anchors and Bonebridge to treat severe ear malformations]

OBJECTIVE

 Surgical treatment with bone conduction hearing implants and epitheses for ear malformations offer the right combination of hearing rehabilitation and cosmetic reconstruction. The surgical procedure is often performed in two-stage surgical steps. This project aimed to gain experience with a procedure in which the hearing implant and the epithesis anchors are inserted simultaneously.

MATERIAL AND METHODS

 Four ears of three patients (n_f = 1, n_m = 2) with severe ear malformations (type III, according to Weerda) received a Bonebridge and an epithesis anchor with three base posts in one operation each. Previously, the indication for the use of a bone conduction implant using the active middle ear implant (aMEI) score, according to Frenzel (2013), had been established.

RESULTS

 All patients scored 4 points each in the aMEI score, indicating an unfavorable prognosis for successful implantation of an active middle ear implant. The treatment with a Bonebridge and an epithesis anchor was performed without complications. Postoperatively, the initial audiological fitting and the application of the magnetic abutment were performed after 4 weeks. Audiometry showed a functional gain of up to 30 dB and an improved speech comprehension. The epithesis was shaped like the contralateral ear. After treatment, patients were satisfied with the audiological and cosmetic results.

CONCLUSIONS

 The simultaneous surgical procedure with a bone conduction hearing implant and epithesis anchor is a good option for the treatment of ear malformations. The aMEI-score was a helpful instrument for the indication. The procedure reduced the surgical risk and the time and effort required for treatment.

[Laser Doppler vibrometric measurements on human temporal bones]

Laser Doppler vibrometric (LDV) measurements on human temporal bones represent the standard method for predicting the performance of active middle ear implants (AMEI) and are used as preclinical tests in the development, approval process, and indication expansion of AMEI. The quality of the coupling of the floating mass transducer to the mobile structures of the middle ear is decisive for the performance of the implant and patients' hearing perception. The cochlea can be stimulated via the oval window (forward stimulation) or the round window (reverse stimulation). For forward stimulation, the ASTM standard F2504-05 defines a method to ensure physiologically normal properties of the temporal bones used in the experiments. For reverse stimulation, which depends even more critically on the quality of the temporal bone, a comparable standard method is lacking. Appropriate preparation and storage of the human petrous bone as well as suitable LDV test setups with respect to calibration and reproducibility of measuring positions and angles provide results that allow a comparison of different types of coupling and also correlate well with clinical data.

Implementation of a fully implantable middle-ear hearing device chip

BACKGROUND AND OBJECTIVE

Recently, with the increase in the population of hearing impaired people, various types of hearing aids have been rapidly developed. In particular, a fully implantable middle ear hearing device (F-IMEHD) is developed for people with sensorineural hearing loss. The F-IMEHD system comprises an implantable microphone, a transducer, and a signal processor. The signal processor should have a small size and consume less power for implantation in a human body.

METHODS

In this study, we designed and fabricated a signal-processing chip using the modified FFT algorithm. This algorithm was developed focusing on eliminating time delay and system complexity in the transform process. The designed signal-processing chip comprises a 4-channel WDRC, a fitting memory, a communication 1control part, and a pulse density modulator. Each channel is separated using a 64-point fast Fourier transform (FFT) method and the gain value is matched using the fitting table in the fitting memory.

RESULTS AND CONCLUSION

The chip was designed by Verilog-HDL and the designed HDL codes were verified by Modelsim-PE 10.3 (Mentor graphics, USA). The chip was fabricated using a 0.18 μm CMOS process (SMIC, China). Experiments were performed on a cadaver to verify the performance of the fabricated chip.

Intraoperative quantification of floating mass transducer coupling quality in active middle ear implants: a multicenter study

Purpose

Evaluating the effectiveness of intraoperative auditory brainstem responses (ABRs) to stimulation by the Vibrant Soundbridge (VSB) active middle ear implant for quantifying the implant’s floating mass transducer (FMT) coupling quality.

Methods

In a diagnostic multicentric study, patients (> 18 years) who received a VSB with different coupling modalities were included. Pre- and postoperative bone conduction thresholds, intraoperative VSB-evoked ABR thresholds (VSB-ABR) using a modified audio processor programmed to preoperative bone conduction thresholds, postoperative vibrogram thresholds, and postoperative VSB-ABR thresholds were measured. Coupling quality was calculated from the difference between the pure tone average at 1000, 2000, and 4000 Hz (3PTA) vibrogram and postoperative 3PTA bone conduction thresholds.

Results

Twenty-three patients (13 males, 10 females, mean age 56.6 (± 12.5) years) were included in the study. Intraoperative VSB-ABR response thresholds could be obtained in all except one patient where the threshold was > 30 dB nHL. Postoperatively, an insufficient coupling of 36.7 dB was confirmed in this patient. In a Bland–Altman analysis of the intraoperative VSB-ABRs and coupling quality, the limits of agreement exceeded ± 10 dB, i.e., the maximum allowed difference considered as not clinically important but the variation was within the general precision of auditory brainstem responses to predict behavioral thresholds. Five outliers were identified. In two patients, the postoperative VSB-ABR thresholds were in agreement with the coupling quality, indicating a change of coupling before the postoperative testing.

Conclusion

The response thresholds recorded in this set-up have the potential to predict the VSB coupling quality and optimize postoperative audiological results.

A retrospective European multicenter analysis of the functional outcomes after active middle ear implant surgery using the third generation vibroplasty couplers

Purpose

To evaluate the safety and performance of three novel vibroplasty couplers that allow attachment of the floating mass transducer of a transcutaneous active middle ear implant (AMEI) to the round window (RW) membrane, the long process (LP), or the incus body and the short process (SP) of the incus.

Methods

Retrospective multicenter cohort study of 25 AMEI users with sensorineural or mixed hearing loss that were among the first implanted with an AMEI vibrating ossicular prosthesis in combination with the third generation of vibroplasty couplers between 2014 and 2016. Main Outcome Measures were bone-conduction pure-tone and vibroplasty thresholds, postoperative aided sound field thresholds and postoperative aided word recognition score (WRS).

Results

Bone conduction threshold changes of more than 10 dB in 4PTA_BC were observed in two subjects. A mean improvement of 57.8% in speech recognition was observed with a mean WRS at 65 dB SPL improving from 14.8% (SD 21.9%) preoperatively to a mean aided score of 72.6% (SD 18.6%). Sound field thresholds improved from an average 4PTA_SF of 64.1 dB HL (SD 9.8 dB HL) to 37.0 dB HL (SD 8.9 dB HL), resulting in a mean functional gain of 27.1 dB. There was no significant difference in WRS or functional gain between the coupler types.

Conclusion

Initial experience shows that all three third generation vibroplasty couplers represent safe and efficient attachment options for the FMT allowing the surgeon to choose the coupling type based on the present pathology.

Direct Drive Simulation-Preoperative Sound Simulation of "Vibroplasty-Hearing" in Patients With Mixed Hearing Loss

OBJECTIVE

Validation of the preoperative sound simulation test for vibroplasty-hearing so-called "Direct Drive Simulation" (DDS) in case of mixed hearing loss.

STUDY DESIGN

Retrospective data analysis.

SETTING

Tertiary referral center with a large hearing implant program.

MAIN OUTCOME MEASURE

Comparison of sound impression during preoperative Direct Drive Simulation, and postoperative testing with the activated active middle ear implant (AMEI) under free-field condition and in daily routine.

PATIENTS

Fifty-four data sets from 18 patients with mixed hearing loss with a mean age of 60.78 ± 3.18 were included.

RESULTS

Comparing the sound impression during DDS preoperatively versus free-field testing with the implanted AMEI, no significant differences were found. DDS offers a slightly better sound quality than the AMEI in daily routine, fitting well to the ideal listening situation in DDS versus some background noise in daily routine.

CONCLUSION

The DDS offers the possibility of a realistic preoperative sound simulation of the "vibroplasty-hearing" in cases of mixed hearing loss. This probably facilitates patient's decision towards a vibroplasty. The audiologist as well as the surgeon get additional information regarding the indication especially when audiologic inclusion criteria are critical. Thus, the DDS is a useful extension of preoperative diagnostics before vibroplasty.

Audiological Results with the SAMBA Audio Processor in Comparison to the Amadé for the Vibrant Soundbridge

BACKGROUND

Since its introduction in 1996, the Vibrant Soundbridge (VSB) has been upgraded with several improved generations of processors. As all systems are compatible, implanted patients can benefit from new technologies by upgrading to the newest processor type available.

OBJECTIVES

The aim of this study was to compare the performance of the new (current) SAMBA processor with the previous Amadé processor.

METHODS

Twenty subjects monaurally implanted with a VSB and the Amadé processor tested the new SAMBA processor for a trial period of 4 weeks. We measured air conduction and bone conduction thresholds, unaided thresholds, and aided free field thresholds with both devices. Speech performance in quiet using the Freiburg monosyllabic test at 65 dB SPL (S0) was compared. The speech intelligibility in noise was determined using the Oldenburg sentence test measured in different listening conditions (S0NVSB/S0Ncontra) and microphone settings (omni/directional vs. adaptive directivity).

RESULTS

Word recognition scores in quiet with the SAMBA were still significantly lower than with the Amadé after the 4 weeks trial period but improved over the following year. Speech intelligibility with the SAMBA was significantly better than with the Amadé in omnidirectional mode and comparable with the Amadé in directional mode. Hence, the adaptive directionality provides an advantage in difficult hearing situations such as noisy environments. The subjective benefit was evaluated using the Abbreviated Profile of Hearing Aid Benefit and the Speech, Spatial and Qualities-C questionnaire. Results of the questionnaires demonstrate an overall higher level of satisfaction with the new SAMBA speech processor than with the older processor.

CONCLUSION

The SAMBA enables similar speech perception in quiet but more flexible adaptation in acoustically challenging environments compared to the previous Amadé processor.

Long-Term Stability and Functional Outcome of an Active Middle Ear Implant Regarding Different Coupling Sites

OBJECTIVES

Indication and implantation of active middle ear implants (AMEI) are well established. Choice of the coupling site depends from the individual anatomical situation. Long-term stability of different coupling sites in terms of functional outcome and complications are rare and were investigated in this study.

DESIGN

Retrospective analysis of 41 consecutive patients (45 ears) with coupling of the AMEI at the incus, stapes, and round window. Analysis of preoperative, postoperative, and long-term results of pure-tone average, speech discrimination in quiet at 65 dB (German language Freiburg Monosyllabic Test) and noise (German language Oldenburger Sentence Test), rate of revision surgeries as well as explantations and the novel parameter patient years (py).

RESULTS

Mean of follow-up was 3.0 ± 1.7 years resulting in a total of 135.6 py. Bone conduction was stable in all patients pre- to postoperatively as well as preoperatively to the long-term. Round window patients had the broadest air-bone gap (31.4 ± 19.4 dB HL) benefitting the most from the AMEI (functional gain = 39.0 ± 12.8 dB HL). Regarding speech discrimination, incus patients performed the best both in quiet (77.7 ± 22.8%) and noise (3.4 ± 2.9 dB SNR). In terms of revision surgery and explantations, round window patients exhibited the highest rates (20%).

CONCLUSIONS

Regarding all coupling sites, satisfying long-term stability results and comparable complication rates were reported with best performance of coupling to the incus. Implementation of patient years might be a novel parameter for the comparison of revisions and explantations.

Intraoperative Estimation of the Coupling Efficiency and Clinical Outcomes of the Vibrant Soundbridge Active Middle Ear Implant Using Auditory Brainstem Response Measurements

Purpose This study intraoperatively measured the coupling efficiency of the Vibrant Soundbridge (VSB), with the aim of avoiding revision surgery due to insufficient outcome. This method can also be used to test the integrity of the implant at the end of the implantation surgery and to evaluate aided thresholds. In addition, this method makes it possible to objectively test how well the VSB has been fitted, provide assistance in fitting handicapped patients or children, evaluate hearing degradation, or test for a drop in coupling efficiency before revision surgeries. In order to analyze the feasibility of these new VSB-aided auditory brainstem response (ABR) thresholds, they were compared to behavioral thresholds from the Vibrogram and the preoperative bone conduction thresholds. Method The study included 30 patients with mild-to-severe hearing loss implanted with a VSB (VORP503). Intraoperative ABR thresholds during the VSB implantation were recorded using a VSB-optimized chirp stimulus. The new method is compared to the bone conduction threshold of the study sample and the aided Vibrogram thresholds. Speech intelligibility results up to 24 months after surgery are also presented. Results A reliable correlation between the bone conduction thresholds and the intraoperative ABRs was found and was higher in comparison to the Vibrogram. Furthermore, speech intelligibility outcomes were stable over time. Conclusion ABR measurements can be used intraoperatively to estimate the coupling efficiency of the VSB and test the integrity of the implant at the end of surgery.

Implantability of endaurally insertable active vibratory middle-ear implants - an anatomical study

Background: Hearing loss is often treated with an acoustic hearing aid. However, distortion and insufficient gain may cause problems. Active non-acoustic vibratory middle-ear implants (AMEI) may contribute to solve this problem. We recently developed an AMEI which is to be implanted completely through the patient's external auditory canal. The device uses a light-emitting diode (LED) in the external auditory canal that stimulates a photovoltaic sensor, placed in the middle ear, through the intact tympanic membrane. This results in activation of a vibratory miniaturized piezoelectric displacement transducer (MDT) (actuator) coupled to the auditory organ. Aims/objectives: The aim of this study was to evaluate the anatomical implantability of the novel AMEI using an exclusively endaural approach. Materials and methods: The internal components of our AMEI were implanted into 39 human temporal bones. The surgical procedure and the optimal size and anatomical fitting were systematically evaluated. Results: We can show here that implantation of all components of this novel AMEI into anatomical specimens proves to be a quick and easy procedure, performed using an endaural approach. Conclusions and significance: The anatomical data of this study establish the basis for further technical development of our AMEI and other future implantable hearing systems.

ACTIVE MIDDLE EAR VIBRANT SOUNDBRIDGE SOUND IMPLANT

The Vibrant Soundbridge represents a new approach to hearing improvement in the form of active implantable middle ear hearing device. Unlike conventional acoustic hearing aids, which increase the volume of sound that goes to the eardrum, the Vibrant Soundbridge bypasses the ear canal and eardrum by directly vibrating the small bones in the middle ear. Because of its design, no portion of the device is placed in the ear canal itself. The Vibrant Soundbridge has been approved by the FDA as a safe and effective treatment option for adults with moderate to severe sensorineural, conductive or mixed hearing losses who desire an alternative to the acoustic hearing aids, for better hearing. The paper presents a review of the active middle ear implant Vibrant Soundbridge, which has been also implanted at the Department of Otorhinolaryngology and Head and Neck Surgery, Sestre milosrdnice University Hospital Center, which is the Referral Center for Cochlear Implantation and Surgery of Hearing Impairment and Deafness of the Ministry of Health, Republic of Croatia.

Stapedotomy with incus vibroplasty - A novel surgical solution of advanced otosclerosis and its place among existing therapeutic modalities - Hungarian single institutional experiences

OBJECTIVE

To delineate the advantages and steps of stapedotomy with incus vibroplasty, to assess the safety and efficacy of this method via the authors' experiences, and to overview the literature regarding other surgical options in advanced otosclerosis determining the place of stapedotomy with incus vibroplasty in the therapeutic range.

METHODS

Four patients were enrolled in the study presenting severe mixed hearing loss of at least one side on pure tone audiometry. Based on complementary audiological examinations including stapedial reflex test and multifrequency tympanometry, all cases were suspected as advanced otosclerosis. Stapedotomy with incus vibroplasty - the combination of laser stapedotomy and simultaneous Vibrant Soundbridge implantation - was performed in each patient. Preoperative pure tone average, speech recognition thresholds and word recognition scores were compared to one-year postoperative free-field values with the implant switched on focusing on functional gain.

RESULTS

Among 4 participants (3 females, 1 male) the mean age (SD) was 66 years (35). In three cases Nitinol, in one case NitiBond piston was inserted. One-year postoperative free-field functional gains were 30 dB, 34 dB, 42 dB and 51 dB, respectively. One-year postoperative free-field speech recognition thresholds were 45 dB, 45 dB, 49 dB and 50 dB, respectively, while word recognition scores were 70%, 70%, 70% and 75%, respectively.

CONCLUSION

Postoperative results in our serie regarding pure tone average and word recognition score proved to be better than those found in the literature. Stapedotomy with incus vibroplasty - through sufficient air-bone gap closure and simultaneous sensorineural component management - seems to be a promising surgical solution in advanced otosclerosis, requiring further investigation.

Frequency-specific activation of the peripheral auditory system using optoacoustic laser stimulation

Hearing impairment is one of the most common sensory deficits in humans. Hearing aids are helpful to patients but can have poor sound quality or transmission due to insufficient output or acoustic feedback, such as for high frequencies. Implantable devices partially overcome these issues but require surgery with limited locations for device attachment. Here, we investigate a new optoacoustic approach to vibrate the hearing organ with laser stimulation to improve frequency bandwidth, not requiring attachment to specific vibratory structures, and potentially reduce acoustic feedback. We developed a laser pulse modulation strategy and simulated its response at the umbo (1-10 kHz) based on a convolution-based model. We achieved frequency-specific activation in which non-contact laser stimulation of the umbo, as well as within the middle ear at the round window and otic capsule, induced precise shifts in the maximal vibratory response of the umbo and neural activation within the inferior colliculus of guinea pigs, corresponding to the targeted, modelled and then stimulated frequency. There was also no acoustic feedback detected from laser stimulation with our experimental setup. These findings open up the potential for using a convolution-based optoacoustic approach as a new type of laser hearing aid or middle ear implant.

The Vibrant Soundbridge: A Global Overview

The Vibrant Soundbridge is a semi-implantable, active middle ear implant that is a safe and effective treatment for patients with sensorineural hearing loss. Since Food and Drug Administration approval for this indication, many international investigators have expanded its use for conductive and mixed hearing losses. This article reviews the author's experience and the international uses of this versatile device.

The development of active middle ear implants: A historical perspective and clinical outcomes

Objective s

Energy emitting, active middle ear implants (aMEI) have taken more than two decades of research to reach technological sophistication, medical safety, and regulatory approval to become a powerful tool in treating sensorineural, conductive, and mixed hearing loss. The present review covers this era.

Data Source

Literature found from searching Pubmed (MEDLINE); EMBASE, SciSearch, German Medical Science Journals and Meetings, and The Cochrane Library; and published as of February 2017. Study bibliographies were hand-searched to find further materials.

Methods

A systematic literature review was conducted to identify studies evaluating the safety, efficacy, effectiveness, and subjective outcomes of partially implantable aMEIs. Data were extracted on systems with regulatory approval and summarized narratively. Meta-analyses were conducted for aMEIs with more than 25 publications. Study selection, data extraction, and quality appraisal for quantitative data synthesis was carried out by two reviewers.

Results

Four hundred thirty-one studies included in narrative synthesis describe that albeit good audiological outcomes, clinical safety and (dis)investment are major barriers to continued market access. The synthesised risk of adverse events was three fold with the MET than with the VIBRANT SOUNDBRIDGE. With the latter system, audiological outcomes were stable and similar for all indications and age groups.

Conclusion

To date, the majority of the literature covers the clinical application of the VIBRANT SOUNDBRIDGE system as it is applicable to a wide range of otologic and audiological conditions, particularly with the introduction of couplers to extend its clinical reach. The MAXUM and MET still have to find their way into surgical routine.Level of Evidence.

Long-Term Outcome of Hearing Rehabilitation With An Active Middle Ear Implant

Objective

To assess the audiological and long‐term medical and technical follow‐up outcomes of an active middle ear implant.

Methods

This was a retrospective medical chart analysis of all patients provided with an active middle ear implant in a tertiary academic medical referral center between September 1, 1998, and July 31, 2015. Main outcome measures were medical and technical complications, revisions, reimplantations, explantations, coupling approaches, mean time of use, pre‐ and postoperative hearing thresholds, functional hearing gain across frequencies (250–4,000 Hz), and Freiburg monosyllablic word test at 65 dB.

Results

One hundred and three patients were identified. Fifteen were implanted bilaterally (n = 118 Vibrant Soundbridge devices [MED‐EL, Innsbruck, Austria]). Seventy‐seven devices were implanted for sensorineural and 41 for mixed and conductive hearing loss. Patients used the implant for 6.7 years (range 0.7 months–17.9 years) on average. Ninety‐one patients (77.12%) were using the device at the end of the observation period. An overall complication rate of 16.1% was observed. The revision and explantation rates were higher for devices implanted between 2004 and 2006. The device failure rate was 3.4%. Audiological evaluation showed significant hearing gains for both hearing loss patient groups.

Conclusion

This long‐term follow‐up reveals the reliability of the active middle ear implant in a single center. Overall complication rate and device failure rate are acceptable. The complication rate was higher during implementation of alternative coupling approaches. The audiological benefit was satisfactory in patients with all hearing loss types. The majority of implanted patients used the implant at the end of the observation period.

Level of Evidence

4 Laryngoscope, 129:477–481, 2019

Piezoelectric Actuator with Frequency Characteristics for a Middle-Ear Implant

The design and implementation of a novel piezoelectric-based actuator for an implantable middle-ear hearing aid is described in this paper. The proposed actuator has excellent low-frequency output characteristics, and can generate high output in a specific frequency band by adjusting the mechanical resonance. The actuator consists of a piezoelectric element, a miniature bellows, a cantilever membrane, a metal ring support, a ceramic tip, and titanium housing. The optimal structure of the cantilever-membrane design, which determines the frequency characteristics of the piezoelectric actuator, was derived through finite element analysis. Based on the results, the piezoelectric actuator was implemented, and its performance was verified through a cadaveric experiment. It was confirmed that the proposed actuator provides better performance than currently used actuators, in terms of frequency characteristics.

Evaluation of Maximal Speech Intelligibility With Vibrant Soundbridge in Patients With Sensorineural Hearing Loss

OBJECTIVE

The study investigated improvements in maximal speech intelligibility after Vibrant Soundbridge (VSB) implantation and analyzed the effect of the hearing loss pattern on maximal speech intelligibility represented by a phonetically balanced word score (PBmax). The effect of middle ear implants on PBmax has not been evaluated yet.

STUDY DESIGN

Study.

SETTING

Tertiary academic medical center.

PATIENTS/INTERVENTIONS

Sixty patients who underwent VSB from December 2011 to January 2016 were retrospectively reviewed. All the patients had hearing aids preoperatively.

MAIN OUTCOME MEASURES

Pure-tone and speech audiometry were checked with and without hearing aids and then with the VSB. The patients were divided into two groups: flat and down-sloping type of hearing loss. PBmax score was evaluated at the most comfortable listening level before and after VSB implantation and compared with scores with/without HA.

RESULTS

PBmax for both conventional HA and VSB were significantly higher compared with the unaided condition. The improvement in speech recognition was significantly better using VSB than using HA (p = 0.003). However, there was no significant difference in the improvement provided by VSB and HA in patients with a flat hearing loss. Patients with a down-sloping audiogram showed significantly better improvement with VSB than with HA (p = 0.003). Moreover, patients with greater preoperative high-frequency hearing loss had greater improvement in PBmax after VSB implantation.

CONCLUSION

Speech intelligibility can be significantly improved by VSB implantation, especially in patients with a down-sloping hearing loss. This finding can help select patients who will benefit most from VSB implantation.

Round and Oval Window Anatomic Variability: Its Implication for the Vibroplasty Technique

OBJECTIVE

The objective of this study is to evaluate the anatomical variability of round and oval window regions and its relationship with their closest structures, to determine its implication on the fitting and stabilization of the middle ear implant Vibrant Soundbridge.

METHODS

Variations of the anatomy of round and oval window regions were assessed in a total of 85 human dissected temporal bones. Afterward, we evaluated the adaptation and subsequent stabilization of the floating mass transducer (FMT) of the Vibrant Soundbridge in 67 cases in round window (RW) and in 22 cases in oval window (OW), and the influence that the variability of the different anatomical features examined had on this stabilization. We also assessed access and surgeon's view of the RW niche through the facial recess approach.

RESULTS

Stabilization of the FMT in the RW was achieved in 53 (79%) of the 67 cases; we found that the less favorable anatomical conditions for stabilization were: membrane smaller than 1.5 mm, presence of a high jugular bulb and a narrow or very narrow RW niche. Frequently, two or more of these conditions happened simultaneously. In seven cases (22%) access to the RW through facial recess approach did not allow positioning the FMT in place. OW stabilization succeeded in 18 (82%) of the 22 cases.

CONCLUSION

Round and oval window vibroplasty are difficult surgical techniques. To place the FMT directly on the OW may be easier as we do not have to drill the niche. In both regions there are some anatomical conditions that hinder fitting the FMT and even make it impossible. Once fitted, the main problem is to achieve good stabilization of the device.

Active Middle Ear Implantation: Long-term Medical and Technical Follow-up, Implant Survival, and Complications

OBJECTIVE

To evaluate the long-term medical and technical results, implant survival, and complications of the semi-implantable vibrant soundbridge (VSB), otologics middle ear transducer (MET), and the otologics fully implantable ossicular stimulator (FIMOS).

STUDY DESIGN

Retrospective cohort study.

PATIENTS

Patients with chronic external otitis and either moderate to severe sensorineural or conductive/mixed hearing loss.

SETTING

Tertiary referral center.

INTERVENTION

Implantation with the VSB, MET, or FIMOS.

MAIN OUTCOME MEASURES

Medical complications, number of reimplantations, and explantations.

RESULTS

Ninety-four patients were implanted, 12 patients with a round window or stapes application. 28 patients were lost to follow-up. The average follow-up duration was 4.4 years (range, 1 month-15 years). 128 devices were evaluated: (92 VSB, 32 MET, 4 FIMOS). 36 devices (28%) have been explanted or replaced (18 VSB, 14 MET, 4 FIMOS). Device failure was 7% for VSB, 28% for MET, and 100% for FIMOS. In 16 patients (17%) revision surgery (n = 20) was performed. Twenty patients (21%) suffered any medical complication.

CONCLUSION

Medical and technical complications and device failures have mostly occurred in the initial period of active middle ear implants (AMEI) implementation and during clinical trials or experimental procedures. All four FIMOS had technical difficulties. An important decrease in the occurrence of both medical and technical complications was observed. Application in more recent years did not show any complications and the recent device failure rates are acceptable. Magnetic resonance imaging (MRI) incompatibility should be taken into account when indicating AMEI.

Comparison of Alternative Coupling Methods of the Vibrant Soundbridge Floating Mass Transducer

The active middle ear implant Vibrant Soundbridge© provides a variety of coupling modalities of the floating mass transducer (FMT) to various structures of the ossicular chain and the round window. A retrospective analysis was performed on 125 subjects (n = 137 ears) (1) to compare the efficacy of the different FMT coupling modalities with increasing degree of hearing loss, (2) to compare the performance in speech outcome and the effective gain between the coupling types, and (3) to evaluate the risk of additional hearing loss of each coupling procedure. The patients were grouped according to their type of FMT coupling into incus vibroplasty (incus group, n = 59), round window vibroplasty with coupler (RWC group, n = 23), round window vibroplasty without coupler (RW group, n = 22), and oval window vibroplasty with coupler (OWC group, n = 33). For each coupling group, pre- and postoperative thresholds, the results of the Freiburg monosyllable test at 65 dB SPL, and the effective gain across frequencies (0.5-6 kHz) were evaluated. A logistic regression function was used to describe the relationship between word recognition scores (WRS, in % correct) and the mean bone conduction (BC) hearing loss. The surgical procedure had no clinically relevant effect on BC thresholds of patients in each coupling group. The BC pure tone average (PTA4) for 50% WRS predicted by the model function was similar for the incus (48.2 dB nHL), RW (47.8 dB nHL), and OWC (49.0 dB nHL) groups, but higher for the RWC group (67.9 dB nHL). However, the median WRS was 80% or better with no significant differences in speech perception between coupling types (Kruskal-Wallis test, p = 0.229). The effective gain shows an advantage for the incus coupling between 0.5 and 2 kHz over the other coupling types. The performance of the FMT coupling modalities is equally good for patients with a mild-to-moderate hearing loss, but the efficacy of coupling types differs for patients with greater hearing loss (>48 dB BC HL).

Systematic review to evaluate the safety, efficacy and economical outcomes of the Vibrant Soundbridge for the treatment of sensorineural hearing loss

Introduced in the late 90s, the active middle ear implant Vibrant Soundbridge (VSB) is nowadays used for hearing rehabilitation in patients with mild to severe sensorineural hearing loss (SNHL) unable to tolerate conventional hearing aids. In experienced hands, the surgical implantation is fast done, safe and highly standardized. Here, we present a systematic review, after more than 15 years of application, to determine the efficacy/effectiveness and cost-effectiveness, as well as patient satisfaction with the VSB active middle ear implant in the treatment of mild to severe SNHL. A systematic search of electronic databases, investigating the safety and effectiveness of the VSB in SNHL plus medical condition resulted in a total of 1640 papers. After removing duplicates, unrelated articles, screening against inclusion criteria and after in-depth screening, the number decreased to 37 articles. 13 articles were further excluded due to insufficient outcome data. 24 studies remained to be systematically reviewed. Data was searched on safety, efficacy and economical outcomes with the VSB. Safety-oriented outcomes included complication/adverse event rates, damage to the middle/inner ear, revision surgery/explant rate/device failure and mortality. Efficacy outcomes were divided into audiological outcomes, including hearing thresholds, functional gain, speech perception in quiet and noise, speech recognition thresholds, real ear insertion gain and subjective outcomes determined by questionnaires and patient-oriented scales. Data related to quality of life (QALY, ICER) were considered under economical outcomes. The VSB turns out to be a highly reliable and a safe device which significantly improves perception of speech in noisy situations with a high sound quality. In addition, the subjective benefit of the VSB was found to be mostly significant in all studies. Finally, implantation with the VSB proved to be a cost-effective and justified health care intervention.

Long-term Stability of the Active Middle-ear Implant with Floating-mass Transducer Technology: A Single-center Study

OBJECTIVE

To examine the long-term results of an active middle-ear implant (AMEI) with floating-mass transducer (FMT) technology.

STUDY DESIGN

Prospective cohort study of German-speaking patients implanted with an AMEI between 2006 and 2013.

SETTING

Single-center study.

PATIENTS

Eighty-three patients.

INTERVENTION

AMEI with FMT technology implantation.

MAIN OUTCOME MEASURES

Long-term outcome (27 mo; range, 12-84 mo) for FMT position in correlation with pure-tone audiometry, auditory thresholds for frequency-modulated (warble) tones, vibroplasty thresholds for pure tones, and speech audiometry in quiet and noise.

RESULTS

In 15.6% of patients, a revision surgery was necessary to improve functional performance of the AMEI, and the highest revision rate was found with FMT coupling to the round window not using couplers. A peak number of revision surgeries were observed 3 years after the initial surgery. Stable audiological results (pure-tone audiometry and speech audiometry in quiet and noise) were observed up to 84-month post-surgery. Incus vibroplasty (classic indication) showed a significantly lower functional gain compared with oval and round window vibroplasty. Vibroplasty in combined or conductive hearing loss showed no functional difference between forward and reverse stimulation of the cochlea; however, significantly lower vibroplasty thresholds were detected when using a coupler.

CONCLUSIONS

The AMEI with FMT technology can be safely used in treatment of patients with mild-to-severe sensorineural, conductive, or mixed hearing loss. Optimized coupling, especially in incus vibroplasty, has to be developed to achieve enhanced audiological results.

A tri-coil bellows-type round window transducer with improved frequency characteristics for middle-ear implants

A number of methods to drive the round window (RW) using a floating mass transducer (FMT) have been reported. This method has attracted attention because the FMT is relatively easy to implant in the RW niche. However, the use of an FMT to drive the RW has been proven to produce low outputs at frequencies below approximately 1 kHz. In this study, a new tri-coil bellows-type transducer (TCBT), which has excellent low frequency output and is easy to implant, is proposed. To design the frequency characteristics of the TCBT, mechanical and electrical simulations were performed, and then a comparative analysis was conducted between a floating mass type transducer (like the FMT) and a fixed type transducer (like the TCBT). The features of the proposed TCBT are as follows. First, the TCBT's housing is fixed to the RW niche so that it does not vibrate. Second, the internal end of a tiny bellows is connected to a vibrating three-pole permanent magnet located within three field coils. Finally, the rim of the bellows bottom is attached to the end of the housing that hermetically encloses the three field coils. In this design, the only vibrating element is the bellows itself, which efficiently drives the RW membrane. To evaluate the characteristics of this newly developed TCBT, the transducer was installed in the RW niche of temporal bones and the velocity of the stapes was measured using a laser Doppler vibrometer. The experimental results indicate that the TCBT can produce 100, 111, and 129 dB SPL equivalent pressure outputs at below 1 kHz, 1-3 kHz, and above 3 kHz, respectively. Thus, the TCBT with one side coupled to the RW via a bellows will be easy to implant and offer better performance than an FMT.

New Approach for Implantable Hearing Aids: A Feasibility Study

The objective of this study was to test the feasibility of a new kind of implantable hearing device based on a cerebrospinal fluid hydroacoustic pathway by which sound waves are conducted from the dura mater to the inner ear by cerebrospinal fluid. In this prospective animal study, a piezoelectric bimorph was implanted into 2 guinea pigs and 1 dog between the skull bone and the dura at the parietal area. The bimorph was connected transdermally by wires to a click generator. The auditory brain stem response was recorded after stimulation of the piezoelectric device by the click generator. In the 3 animals, the auditory brain stem response could be recorded in response to a stimulus intensity of 135 dB peak equivalent (pe) sound pressure level (SPL; instrument setting), corresponding to 3.8 V activating the device. The auditory brain stem response disappeared during white noise masking, proving that the origin of the response was in the inner ear. The threshold was 125 and 115 dB pe SPL in the 2 guinea pigs and 135 dB pe SPL in the dog (instrument setting). We conclude that transmission of sound waves by a cerebrospinal fluid hydroacoustic pathway to the inner ear is possible. Such a device would have advantages over more traditional implantable hearing devices: it would not be necessary to couple it to the ossicular chain, and it could be used in patients with infected middle ears.

Active middle-ear implant fixation in an unusual place: clinical and audiological outcomes

OBJECTIVE

The Vibrant Soundbridge is an active middle-ear implant for hearing rehabilitation that is usually placed in the long process of the incus or round window. This study reports on the unusual implant attachment to the short process of the incus in a patient with ear malformation, and describes their audiological and clinical outcomes.

METHODS

Case report and literature review.

RESULTS

Audiological evaluation with the Vibrant Soundbridge implant showed a pure tone average of 31 dB. The speech test, at 65 dB HL, revealed correct recognition of 92 per cent of disyllabic words. The Glasgow Hearing Aid Benefit Profile showed high levels of satisfaction, hearing aid use and benefit.

CONCLUSION

Fixation of the Vibrant Soundbridge implant on the short process of the incus is a feasible option, with good clinical and audiological outcomes. Coupling the floating mass transducer to the short process of the incus is a good surgical option, especially when the long process and the oval or round window are inaccessible.

Standardized Active Middle-Ear Implant Coupling to the Short Incus Process

INTRODUCTION

Active middle-ear implants with floating-mass transducer (FMT) technology are used to treat mild-to-severe sensorineural hearing losses. The standard surgical approach for incus vibroplasty is a mastoidectomy and a posterior tympanotomy, crimping the FMT to the long incus process. An alternative fixation side with less surgical trauma might be the short incus process and incus body.The aim of this study was to develop and test a short incus process coupling device for its functional properties in temporal bone preparations and clinical practice.

MATERIALS AND METHODS

An extended antrotomy and a posterior tympanotomy were performed in 10 fresh human temporal bones. As a control for normal middle-ear function, the tympanic membrane was stimulated acoustically, and the vibration of the stapes footplate was measured using laser Doppler vibrometry. FMT-induced vibration responses of the stapes were then measured for standard attachment at the long process and for 2 types of couplers designed for attachment at the short process of the incus (SP1 and SP2 coupler). Additionally, the functional outcome in 2 patients provided with an SP2 coupler was assessed postoperatively at 2 weeks, 3 months, and then 11 months, using pure-tone audiometry, auditory thresholds for frequency-modulated (warble) tones, vibroplasty thresholds, and speech audiometry in quiet and noise.

RESULTS

For the SP2 coupler, velocity-amplitude responses in temporal-bone preparations showed generally similar mean amplitudes as compared with the standard coupling of the FMT to the long process but with clearly increased mean amplitudes between 0.7 and 1.5 kHz and with reduced interindividual variation between 0.5 and 3 kHz. The clinical data of 2 patients with mild-to-severe sensory hearing loss showed good vibroplasty thresholds and convincing results for speech audiometry in quiet (Freiburger monosyllables at 65 dB SPL, 23 ± 31% unaided versus 83 ± 4% aided) and noise (Hochmair-Schulz-Moser-test at 65 dB SPL at 10 dB SNR, 32 ± 45% unaided and 42 ± 29% aided).

CONCLUSION

The attachment of the FMT to the short incus process with the SP2 coupler leads to good mechanical and functional coupling in an experimental setup and clinical practice.

Audiologic limitations of Vibrant Soundbridge device: Is the contralateral hearing aid fitting indispensable?

OBJECTIVES/HYPOTHESIS

The purpose of this study was to evaluate the audiologic limitations of the Vibrant Soundbridge (VSB) implant and the benefits of contralateral hearing aid (HA) fitting in VSB recipients.

STUDY DESIGN

Retrospective study.

METHODS

Twenty-three patients with symmetrical sensorineural or mixed hearing loss were enrolled in this study. The patients underwent VSB implantation in one ear and HA fitting in the other. Aided pure-tone audiometry was performed to measure the functional gains of each device. The Korean version of the Hearing in Noise Test (K-HINT) was used to determine the sentence speech perception in a quiet environment and the signal-to-noise ratio (SNR) in a noisy environment.

RESULTS

VSB implantation resulted in hearing gains comparable to that of conventional HAs at high frequencies, whereas the functional gains at low frequencies were not satisfactory in the mixed hearing loss group. In these patients, the contralateral HA sufficiently amplified the low frequencies. The results of the K-HINT of the SNR in the VSB-aided ear were not significantly improved when compared to HA-aided contralateral ear. However, binaural fitting of a VSB and HA resulted in substantially improved SNR when compared to the unaided condition. This improvement of the SNR strongly correlated with functional gains at low frequencies in the contralateral HA-aided ear.

CONCLUSIONS

Although unilateral VSB implantation is limited in terms of low-tone enhancement and speech perception in noisy environments, contralateral HA fitting can overcome these limitations and increase the efficacy of hearing rehabilitation.

LEVEL OF EVIDENCE

4 Laryngoscope, 126:2116-2123, 2016.

A Case of Incus Vibroplasty: Postoperative Changes in Residual Hearing

In patients with mild to severe hearing loss, conventional hearing aids offer limited benefits and several problems with feedback and cosmesis. Middle ear implants are a feasible option for patients with moderate to severe hearing loss who are unable to achieve adequate benefit from or cannot tolerate hearing aids for various reasons. Here we present a case of middle ear implant surgery using Vibrant Soundbridge with incus vibroplasty technique, and describe the hearing changes during postoperative follow-up.

The mechanism of direct stimulation of the cochlea by vibrating the round window

BACKGROUND

Active middle ear implants such as the vibrant sound bridge (VSB) have been placed on the round window (RW) in patients with conductive or mixed hearing loss, with satisfactory hearing results. Several observations show that the mechanism of RW stimulation is not completely understood. The purpose of the present study was to compare different coupling procedures between the transducer and the RW in order to contribute to an understanding of the mechanism of RW stimulation.

METHODS

Five fat sand rats underwent ablation of the left ear and opening of the right bulla, followed by baseline measurements of thresholds of auditory nerve brainstem evoked responses (ABR) to air and bone conduction click stimuli. Subsequently the malleus and incus were removed from the right middle ear, modeling a conductive hearing loss in which the VSB on the RW is indicated. In the next stage of the experiment, a rod attached to the bone vibrator was placed gently on the RW membrane and then on saline fluid applied to the RW niche. ABR thresholds were recorded following both placements.

RESULTS

Mean baseline ABR threshold in response to air conduction stimuli was 48 ± 4 dB; mean ABR threshold when the rod was placed on the dry RW membrane was 99 ± 12 dB; mean ABR threshold when the rod was in the saline on RW niche was 79 ± 7 dB.

CONCLUSIONS

ABR thresholds were better (lower) with stimulation of fluid on the RW membrane compared to direct stimulation of the RW, providing further evidence of a direct fluid pathway.