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

Brazilian Society of Otology task force - Otosclerosis: evaluation and treatment

OBJECTIVES

To review and provide evidence-based recommendations for the diagnosis and treatment of otosclerosis.

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 otosclerosis 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) Diagnosis - audiologic and radiologic; 2) Treatment - hearing AIDS, pharmacological therapy, stapes surgery, and implantable devices - bone-anchored devices, active middle ear implants, and Cochlear Implants (CI).

CONCLUSIONS

The pathophysiology of otosclerosis has not yet been fully elucidated, but environmental factors and unidentified genes are likely to play a significant role in it. Women with otosclerosis are not at increased risk of worsening clinical condition due to the use of contraceptives or during pregnancy. Drug treatment has shown little benefit. If the patient does not want to undergo stapedotomy, the use of hearing aids is well indicated. Implantable systems should be indicated only in rare cases, and the CI should be indicated in cases of profound deafness.

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.

Results and Quality of Life after Implantation of Active Middle Ear Implants

The provision of implantable hearing aids represents an area with high development and innovation potential. On the one hand, this review article provides an overview of current indication criteria for the treatment with active middle ear implants. On the other hand, outcome parameters as well as functional results after implantation of active middle ear implants are demonstrated and discussed. The focus is mainly placed on audiological results as well as the subjective health status. "Patient Reported Outcome Measures" (PROMs) have become an integral part of the evaluation of hearing implant treatment. Due to low evidence level criteria, the study situation regarding audiological as well as subjective outcome parameters is not satisfactory. The lack of an international consensus on accepted outcome parameters makes a meta-analytical analysis of results immensely difficult. In the studies published to date, patients with sensorineural hearing loss and patients with conductive or mixed hearing loss offered better speech recognition after implantation of an active middle ear implant compared to conventional hearing aids. Current analyses show a significant improvement in general as well as hearing-specific quality of life after implantation of an active middle ear implant. To date, no validated, hearing-specific quality-of-life measurement instruments exist for assessing the success of fitting in children. Especially in children with complex malformations of the outer ear and the middle ear, excellent audiological results were shown. However, these results need to be substantiated by quality-of-life measurements in future.

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.

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.

Subjective Hearing Impression and Quality of Life in Patients With Bilateral Active Middle Ear Implants

OBJECTIVE

This study compared the quality of life in patients with bilateral active middle ear implants to their quality of life when they were unilaterally implanted.

DESIGN

Twenty-one patients implanted sequentially with the Vibrant Soundbridge (VSB) active middle ear implant completed quality-of-life surveys. The patients were asked to rate whether and to what extent their quality of life has changed upon receiving a second VSB. Hearing-specific quality of life was assessed with the Speech, Spatial, and Qualities of Hearing Scale (SSQ12-B), and general quality of life was with the Glasgow Benefit Inventory (GBI). In addition, the patients completed a health-related quality-of-life questionnaire (AQoL-8D). Finally, the changes in hearing-related and general quality of life were correlated to the change in word recognition ability after implantation of the second VSB (Freiburg monosyllabic word test; unilateral VSB versus bilateral VSB at 65 dB SPL).

RESULTS

On the SSQ12, subjects scored a median of + 2.73 (p < 0.001; significantly different from zero) on a scale of -5 to + 5 where 0 indicates no change. All three subscores showed significant improvement. On the GBI, patients reached a median overall score of + 23.6 (p < 0.001; significantly different from zero) on a scale of -100 to + 100 where 0 indicates no change. Here, the improvement was mainly visible in the general subscore, whereas the social support and physical health subscores did not change due to the intervention. Both subjective benefit rating scores strongly correlated with the change in word recognition scores, suggesting that both hearing and general quality of life improved with increased word recognition due to bilateral VSB use. No significant correlation was found between the subjects' general health (as measured by AQoL-8D utility scores) and SSQ12-B or GBI overall scores.

CONCLUSION

Usage of a second active middle ear implant substantially improved our patients' subjective hearing and general quality of life compared with unilateral use. The increase in quality of life may be linked to improved speech understanding due to bilateral use of a middle ear implant. Furthermore, these outcomes were not influenced by our patients' general health state at the time of survey.

[Coupling of active middle ear implants-biomechanical aspects]

Active middle ear implants or implantable hearing aids are used to treat sensorineural or combined hearing loss. Their coupling to the middle ear structures has a large impact on the success of rehabilitation. Practical issues such as the coupling site, influence of middle ear status, and forward and backward excitation of the inner ear are discussed in the context of biomechanics. For this purpose, experimental studies, model simulations, and current literature data are evaluated. The explanations are intended to contribute to a better understanding of certain procedures in hearing rehabilitation with active implants.

Three-year audiological outcomes of the latest generation middle ear transducer (MET) implant

PURPOSE

To evaluate the long-term audiological outcomes and safety of the latest generation of middle ear transducer (MET) among a group of Polish patients.

METHODS

Ten patients aged 48-72 years with bilateral sensorineural hearing loss (n = 8) and mixed hearing loss (n = 2) were included in this study. Pure tone audiometry, sound thresholds, word recognition scores in quiet and speech reception thresholds in noise were assessed. Medical and technical complication information was gathered.

RESULTS

All the patients underwent unilateral implantation with the latest generation Cochlear MET between 2014 and 2016. Mean length of follow-up was 3.7 years. Compared to the unaided condition, the implant provided significant functional gain (mean M = 26.1 dB) at 12 months follow-up. Compared to before surgery, average word recognition in quiet at 65 dB and at 80 dB SPL, as well as speech reception threshold in noise, were significantly better at 12 months. However, postoperative air conduction thresholds 6 months after implantation worsened by 10.3 dB (standard deviation SD = 5.8 dB). Postoperatively, three patients had skin problems around the processor, and one of them completely resigned from using the device 5 months after activation. Technical failures occurred in 4 cases. There were 9 out of 10 patients who still used the MET, but only 5 of them used the processor regularly (every day).

CONCLUSION

Despite changes in the transducer implemented by the manufacturer, we observed a significant number of adverse events in users of the latest generation of MET.