Strategies of Active Middle Ear Implants for Hearing Rehabilitation in Congenital Aural Atresia

Efficacy of vibrant sound bridge in congenital aural atresia: an updated systematic review

PURPOSE

The indications of Vibrant Soundbridge (VSB) have been expanded to include patients with conductive and mixed hearing loss due to congenital aural atresia (CAA). However, the current evidence supporting the auditory outcomes of VSB is based mainly on case reports and retrospective chart reviews. Therefore, the present systematic review aims to summarize and critically appraise the current evidence regarding the safety and effectiveness of VSB in children and adult patients with CAA.

METHODS

A systematic literature search retrieved studies that evaluated the outcomes of unilateral or bilateral implantation of VSB in patients with CAA. The bibliographic search was conducted in PubMed, Scopus, EBSCO, and Cochrane Central Register of Controlled Trials (CENTRAL) databases from January 2000 to December 2022.

RESULTS

Twenty-seven studies were included in the present systematic review. Overall, the speech perception after VSB was good, with a mean word recognition score (WRS) score ranging from 60 to 96.7%. The mean postoperative speech recognition threshold (SRT) after implantation ranged from 20.8 to 50 dB. The effective gain was reported in 15 studies, ranging from 31.3 to 45.5 dB. In terms of user satisfaction with VSB, the included studies showed significant improvements in the patient-reported outcomes, such as the Speech Spatial and Qualities of Hearing scale and Glasgow Hearing Aid Benefit Profile. The VSB implantation was generally safe with low incidence of postoperative complications.

CONCLUSION

VSB provides significant benefits to individuals with hearing loss owing to CAA, with very good subjective outcomes and a low risk of complications.

Role of early hearing aid experience in speech recognition in patients with bilateral congenital microtia following Bonebridge implantation: a retrospective cohort study

PURPOSE

To identify audiological and demographic variables that predict speech recognition abilities in patients with bilateral microtia who underwent Bonebridge (BB) implantation.

METHODS

Fifty patients with bilateral microtia and bilateral conductive hearing loss (CHL) who underwent BB implantation were included. Demographic data, preoperative hearing aid use experience, and audiological outcomes (including pure-tone hearing threshold, sound field hearing threshold [SFHT], and speech recognition ability) for each participant were obtained. The Chinese-Mandarin Speech Test Materials were used to test speech recognition ability. The word recognition score (WRS) of disyllabic words at 65 dB SPL signals was measured before and after BB implantation in quiet and noisy conditions.

RESULTS

The mean preoperative WRS under quiet and noisy conditions was 10.44 ± 12.73% and 5.90 ± 8.76%, which was significantly improved to 86.38 ± 9.03% and 80.70 ± 11.34%, respectively, following BB fitting. Multiple linear regression analysis revealed that lower preoperative SFHT suggested higher preoperative WRS under both quiet and noisy conditions. Higher age at implantation predicted higher preoperative WRS under quiet conditions. Furthermore, patients with more preoperative hearing aid experience and lower postoperative SFHT were more likely to have higher postoperative WRS under both quiet and noisy testing conditions.

CONCLUSIONS

This study represents the first attempt to identify predictors of preoperative and postoperative speech recognition abilities in patients with bilateral microtia with BB implantation. These findings emphasize that early hearing intervention before implantation surgery, combined with appropriate postoperative fitting, contributes to optimal benefits in terms of postoperative speech recognition ability.

Comparison of Transcutaneous and Percutaneous Implantable Hearing Devices for the Management of Congenital Aural Atresia: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare audiometric outcomes, complications, and revisions required for percutaneous (pBCD) versus transcutaneous (tBCD) implantable bone-conduction devices for the treatment of hearing loss associated with congenital aural atresia (CAA).Databases Reviewed.PubMed, Scopus, CINAHL.

METHODS

A systematic review was performed searching for English language articles from inception to December 14, 2022. Studies reporting audiometric outcomes or complications for either pBCDs or tBCDs for the treatment of CAA were selected for inclusion. A meta-analysis of single means and meta-analysis of proportions with comparison (Δ) of weighted proportions was conducted.

RESULTS

A total of 56 articles with 756 patients were selected for inclusion. One hundred ninety patients were implanted with pBCDs, whereas the remaining 566 were implanted with tBCDs. Mean pure-tone audiometry improvement in the pBCD group (39.1 ± 1.1 dB) was significantly higher than in the tBCD group (34.6 ± 1.6 dB; Δ4.5 dB; 95% confidence interval, 4.2-4.7 dB; p < 0.0001). The average improvement in speech reception threshold was 38.6 ± 2.5 dB in the percutaneous group as compared with 32.7 ± 1.6 dB in the transcutaneous group (Δ5.9 dB [5.3-6.5 dB], p < 0.0001). Overall complication rates for patients implanted with pBCDs and tBCDs were 29.0% (15.7-44.4%) and 9.4% (6.5%-13.0%), respectively (Δ19.6% [12.0-27.7%], p < 0.0001).

CONCLUSIONS

Patients with CAA implanted with pBCDs had significantly better audiometric outcomes than those implanted with tBCDs. However, complication rates were significantly higher among the pBCD group.

Task force Guideline of Brazilian Society of Otology - hearing loss in children - Part II - Treatment

OBJECTIVES

To provide an overview of the main evidence-based recommendations for the diagnosis of hearing loss in children and adolescents aged 0-18 years.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on childhood hearing loss were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) treatment of sensorineural hearing loss: individual hearing aids, bilateral cochlear implants, cochlear implants in young children, unilateral hearing loss, and auditory neuropathy spectrum disorder; and (2) treatment of conductive/mixed hearing loss: external/middle ear malformations, ventilation tube insertion, and tympanoplasty in children.

CONCLUSIONS

In children with hearing loss, in addition to speech therapy, Hearing AIDS (HAs) or implantable systems may be indicated. Even in children with profound hearing loss, both the use of HAs and behavioral assessments while using the device are important.

Vibrant soundbridge implantation prior to auricular reconstruction with unilateral microtia-atresia

We presented the first successful application of VSB implantation prior to auriculoplasty, which can provide hearing improvement in safe conditions and open new strategies for earlier hearing rehabilitation in unilateral microtia-atresia children.

Psychosocial outcome measures for conductive and mixed hearing loss treatment: An overview of the relevant literature

OBJECTIVE

To identify the psychosocial assessments utilized with individuals with conductive and/or mixed hearing loss as part of a broader effort by the Auditory Rehabilitation Outcomes Network (AURONET) group to develop a core set of patient-centred outcome measures.

DESIGN

A review of articles published between 2006 and 2016 was completed. Included studies had more than three adult participants, were available in English, and reported a psychosocial outcome from any treatment of mixed and/or conductive hearing loss.

STUDY SAMPLE

Sixty-six articles from seven databases.

RESULTS

Sixty-six articles met our inclusion/exclusion criteria. Within this set, 15 unique psychosocial or patient-reported outcome measures (PROs) were identified, with the Abbreviated Profile of Hearing Aid Benefit (APHAB) and Glasgow Benefit Inventory (GBI) being the most frequently dispensed. Five of the fifteen were only administered in one study. In-house questionnaires (IHQs) were reported in 19 articles.

CONCLUSIONS

Only 66 (22%) of the 300 articles with outcomes contained a PRO. Some of the mostly frequently employed PROs (e.g., APHAB) were judged to include only social items and no psychological items. Lack of PRO standardization and the use of IHQs make psychosocial comparisons across treatments in this population difficult for patients, clinicians and stakeholders.

Auricular prostheses attached to osseointegrated implants: multidisciplinary work-up and clinical evaluation

PURPOSE

Not long after the introduction of osseointegrated implants outside the oral cavity, auricular prostheses are retrained on osseointegrated implants. New insights have been gained with the next-generation percutaneous osseointegrated titanium implants for bone conduction hearing since its introduction in 2010. As a result, the same technology was introduced in the Vistafix^® system (VXI implant) to retain auricular prostheses. The aim of this study is to evaluate the surgical procedure, clinical outcome, and satisfaction of the patient of osseointegration-retained auricular prosthesis using VXI implants.

MATERIALS AND METHODS

11 patients who received an auricular prosthesis using VXI implants between December 2012 and November 2017 were evaluated retrospectively. The patient's medical files were reviewed to assess clinical complications and the necessity for revision surgery. The subjective outcome was measured using the Glasgow benefit inventory (GBI).

RESULTS

In total, 31 implants were placed in 11 patients. None of these implants were lost nor revision surgery needed. An adverse skin reaction was observed in 13.0% of the implants and in 27.2% of the patients, adequately treated with an antibiotic ointment. The average follow-up time was 2 years and 7 months. The GBI displayed a positive score in every patient.

CONCLUSIONS

The VXI implants used are a safe and reliable treatment option for retaining auricular prostheses in patients with an absent auricle. Patients were satisfied with their auricular prosthesis and showed benefit in quality of life. Studies with larger numbers and preferably a prospective character are needed to draw statistically significant conclusions.

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.

Direct Acoustic Stimulation at the Lateral Canal: An Alternative Route to the Inner Ear?

Severe to profound mixed hearing loss is associated with hearing rehabilitation difficulties. Recently, promising results for speech understanding were obtained with a direct acoustic cochlear implant (DACI). The surgical implantation of a DACI with standard coupling through a stapedotomy can however be regarded as challenging. Therefore, in this experimental study, the feasibility of direct acoustic stimulation was investigated at an anatomically and surgically more accessible inner ear site. DACI stimulation of the intact, blue-lined and opened lateral semicircular canal (LC) was investigated and compared with standard oval window (OW) coupling. Additionally, stapes footplate fixation was induced. Round window (RW) velocity, as a measure of the performance of the device and its coupling efficiency, was determined in fresh-frozen human cadaver heads. Using single point laser Doppler vibrometry, RW velocity could reliably be measured in low and middle frequency range, and equivalent sound pressure level (L_E) output was calculated. Results for the different conditions obtained in five heads were analyzed in subsequent frequency ranges. Comparing the difference in RW membrane velocity showed higher L_E in the LC opened condition [mean: 103 equivalent dB SPL], than in LC intact or blue-lined conditions [63 and 74 equivalent dB SPL, respectively]. No difference was observed between the LC opened and the standard OW condition. Inducing stapes fixation, however, led to a difference in the low frequency range of L_E compared to LC opened. In conclusion, this feasibility study showed promising results for direct acoustic stimulation at this specific anatomically and surgically more accessible inner ear site. Future studies are needed to address the impact of LC stimulation on cochlear micromechanics and on the vestibular system like dizziness and risks of hearing loss.

The Vibrant Soundbridge in Children and Adolescents: Preliminary European Multicenter Results

OBJECTIVE

Evaluation of safety and efficacy of the Vibrant Soundbridge in the treatment of hearing loss in children and adolescents with primary focus on improvement in speech discrimination.

STUDY DESIGN

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

SETTING

Tertiary referral center.

PATIENTS

Nineteen patients aged 5 to 17 years.

INTERVENTION

Implantation of an active middle ear implant.

MAIN OUTCOME MEASURE

Improvement in word recognition scores, speech reception thresholds, and signal-to-noise ratios (SNRs) were evaluated, in addition to air and bone conduction. Oldenburger Kids Satztest/Oldenburger Satztest sentences and Göttinger/Freiburger monosyllables at 65-dB hearing level were tested in two age groups.

RESULTS

Significant speech discrimination improvement was seen in all patients after 6 months. In children 5 to 9 years old, mean monosyllable recognition improved from 28.9% (unaided) to 95.5% (Soundbridge-aided). Aided 50% sentence discrimination at 44.1 dB and SNR of -4.9 dB were measured. In patients 10 to 17 years old, mean word recognition improved from 18.5% to 89.0%, sentence reception threshold improved to 40.2 dB, and SNR to -3.6 dB. Comparison between age groups indicated a slight trend toward quicker adaptation by older subjects. However, after initial adjustment, a higher level of overall benefit was seen at 6 months in younger children.

CONCLUSIONS

Currently, the only middle ear implant approved for pediatric patients, the Vibrant Soundbridge, provides an option in cases of congenital aural atresia or disease-induced defects, when surgical intervention and reconstruction is indicated. The 6-month results in this comparatively large study population validated conclusions found in previous trials.

The image variations in mastoid segment of facial nerve and sinus tympani in congenital aural atresia by HRCT and 3D VR CT

OBJECTIVE

To find the variations of middle ear structures including the spatial pattern of mastoid segment of facial nerve and the shapes of the sinus tympani in patients with congenital aural atresia (CAA) by using the high-resolution (HR) CT and 3D volume rendered (VR) CT images.

METHODS

HRCT was performed in 25 patients with congenital aural atresia including six bilateral atresia patients (n=25, 21 males, 4 females, mean age 13.8 years, range 6-19). Along the long axis of the posterior semicircular canal ampulla, the oblique axial multiplanar reconstruction (MPR) was set to view the depiction of the round window and the mastoid segment of facial nerve. Volumetric rending technique was used to demonstrate the morphologic features. HRCT and 3D VR findings in atresia ears were compared with those in 19 normal ears of the unilateral ears of atresia patients.

RESULTS

On the basic plane, the horizontal line distances between the mastoid segment of the facial nerve and the round window (h-RF) in atresia ears significantly decreased compared to the control ears (P<0.05). There was a significant negative correlation between the sinus tympani area (a-ST) and the distance between the horizontal lines of FN and RW midpoint (h-RF) (P<0.05). The mean area of sinus tympani in atresia group is larger (P<0.05). The shapes of the sinus tympani were classified into three categories: the cup-shaped, the pear-shaped and the boot-shaped. Area measurement indicated that the boot-shaped sinus tympani was a special variation with a large area, which only appears in CAA group. There were a significant difference between the area of the boot-shaped group and the other two groups (P<0.05). The morphologic differences of ST and other middle ear structures can also be observed visually in 3D VR CT images.

CONCLUSION

HRCT and 3D VR CT could help a better understanding of different kinds of variations in mastoid segment of facial nerve and sinus tympani in CAA ears. And it may further help surgeons to make the correct decision for hearing rehabilitation.

Comparison of two different titanium couplers for an active middle ear implant

OBJECTIVE

To compare surgical methods, functional gain, and speech discrimination using two different coupling methods for an active middle ear implant. Of several couplers enabling placement of the active element at various locations, two function directly at a cochlear membrane, bypassing a missing or malformed ossicular chain. This study evaluates whether either of these methods is more beneficial.

STUDY DESIGN

Retrospective case review.

SETTING

ENT surgical clinic.

PATIENTS

Forty-seven German-speaking patients with moderate to severe mixed hearing loss.

INTERVENTIONS

Records of patients implanted with either a round window (RW) or oval window (OW) coupler and active implant were examined. Preoperative and postoperative bone and air-conduction thresholds, auditory gain, and speech perception were compared.

MAIN OUTCOME MEASURES

Functional gain, Freiburger monosyllables in quiet.

RESULTS

The range of hearing benefit shown by functional gain in patients implanted with the RW coupler (median) was between 22.5 dB (at 0.25 kHz) and 52.5 dB (2 and 3 kHz). In the OW group, improvement was similar, ranging from 21 dB (at 8 kHz) to 50 dB (1 and 2 kHz). Patients in both groups showed a similar improvement in speech recognition. Median preoperative unaided word recognition was 0% at 60 dB HL for both patient groups, improved postoperatively in both groups to median 85% correct at 65 dB HL and 95% at 80 dB HL.

CONCLUSION

Placement of an active middle ear implant using the RW and the OW coupler was found to be safe, although the surgical methods differ. Safety and efficacy of both couplers present no significant differences.

Grading system for the selection of patients with congenital aural atresia for active middle ear implants

INTRODUCTION

Active middle ear implants (aMEI) are being increasingly used for hearing restoration in congenital aural atresia. The existing gradings used for CT findings do not meet the requirements for these implants. Some items are expendable, whereas other important imaging factors are missing. We aimed to create a new grading system that could describe the extent of the malformation and predict the viability and challenges of implanting an aMEI.

METHODS

One hundred three malformed ears were evaluated using HRCT of the temporal bone. The qualitative items middle ear and mastoid pneumatization, oval window, stapes, round window, tegmen mastoideum displacement and facial nerve displacement were included. An anterior- and posterior round window corridor, oval window and stapes corridor were quantified and novelly included. They describe the size of the surgical field and the sight towards the windows.

RESULTS

The ears were graded on a 16-point scale (16-13 easy, 12-9 moderate, 8-5 difficult, 4-0 high risk). The strength of agreement between the calculated score and the performed implantations was good. The comparison of the new 16-point scale with the Jahrsdoerfer score showed that both were able to conclusively detect the high-risk group; however, the new 16-point scale was able to further determine which malformed ears were favorable for aMEI, which the Jahrsdoerfer score could not do.

CONCLUSION

The Active Middle Ear Implant Score for aural atresia (aMEI score) allows more precise risk stratification and decision making regarding the implantation. The use of operative corridors seems to have significantly better prognostic accuracy than the Jahrsdoerfer score.

Application of the Vibrant Soundbridge middle-ear implant for aural atresia in patients with Treacher Collins syndrome

OBJECTIVE

To present results for the auditory rehabilitation of patients with Treacher Collins syndrome with bilateral osseous atresia, using middle-ear implantation with a Vibrant Soundbridge.

METHODS

Three patients underwent vibroplasty for aural atresia with moderate to severe conductive hearing loss. The pre-operative Jahrsdoerfer radiological score was 4 for all patients. Patients underwent active middle-ear implantation of a Vibrant Soundbridge implant (coupling the floating mass transducer to the rudimentary stapes or footplate distally, and positioning it adjacent to the round window membrane proximally), with audiological analysis as follow up.

RESULTS

After implant activation, the mean air conduction threshold ± standard deviation decreased to 22.8 ± 5.5 dB HL, representing a mean functional gain of 44.5 dB. The mean word recognition score (for bisyllabic words at 65 dB SPL) increased from 0 to 97 per cent.

CONCLUSION

Vibrant Soundbridge implantation is an effective hearing rehabilitation procedure in patients with Treacher Collins syndrome with bilateral osseous atresia. This is a versatile implant which can achieve coupling even in cases of severe middle-ear malformation.