Surgical Outcomes of Modified Technique for Transcutaneous Bone Conduction Hearing Aid Implantation

OBJECTIVE

To detail a modified surgical technique for implantation of the Osia 2 Bone Conduction Hearing Aid (BCHA) system and to assess intra- and postoperative outcomes of this technique.

METHODS

A retrospective review was performed for cases undergoing implantation of an Osia 2 BCHA at a tertiary academic medical center. Modifications were made to the surgical procedure including: horizontal or curvilinear incisions, placement of the osseointegrated screw slightly superior to the plane of the external auditory canal, and double layer wound closure. Data regarding outcomes including demographics, incision type, surgical time, drilling requirements, and complications were collected using the electronic medical record.

RESULTS

A total of twenty-eight cases were evaluated with 57.1% and 42.9% utilizing horizontal and curved incisions, respectively. The median age for recipients was 43.1 years with six pediatric cases included in the study. Median operative time was 58 min (43-126 min). The majority of cases required minimal (60.7%) or no drilling (28.6%) with a significant increase in operative time for those requiring moderate drilling versus minimal to no drilling (F = 8.02, p = 0.002). There were no intraoperative complications. One (3.6%) postoperative seroma occurred which resolved with conservative management.

CONCLUSION

The proposed modified surgical technique is a safe and effective method for implantation of the transcutaneous BCHA system with a low complication rate. Keys include incision design, implant placement, and two-layered closure to minimize wound tension. These modifications can improve ease of the procedure and reduce operative time. These techniques also appear to be applicable to the pediatric population.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:2401-2404, 2024.

Binaural hearing in monaural conductive or mixed hearing loss fitted with unilateral Bonebridge

Objective

To determine the benefits of binaural hearing rehabilitation in patients with monaural conductive or mixed hearing loss treated with a unilateral bone conduction implant (BCI).

Methods

This monocentric study includes 7 patients with monaural conductive or mixed hearing loss who underwent surgical implantation of a unilateral BCI (Bonebridge, Med-El). An ITA Matrix test was performed by each patient included in the study - without and with the BCI and in three different settings - to determine the summation effect, squelch effect and head shadow effect. Subjective hearing benefits were assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire.

Results

The difference in signal to noise ratio of patients without and with BCI was 0.79 dB in the summation setting (p < 0.05), 4.62 dB in the head shadow setting (p < 0.05) and 1.53 dB (p = 0.063) in the squelch setting. The APHAB questionnaire revealed a subjective discomfort in the presence of unexpected sounds in patients using a unilateral BCI (aversiveness score) compared to the same environmental situations without BCI, with a mean discomfort score of 69.00% (SD ± 21.24%) with monaural BCI versus 25.67% (SD ± 16.70%) without BCI (difference: -43.33%, p < 0.05). In terms of global score, patients wearing a unilateral Bonebridge implant did not show any significant differences compared to those without hearing aid (difference: -4.00%, p = 0.310).

Conclusions

Our study shows that the use of a unilateral BCI in patients affected by monaural conductive or mixed hearing loss can improve speech perception under noise conditions due to the summation effect and to the decrease of the head shadow effect. However, since monaural BCIs might lead to discomfort under noise conditions in some subjects, a pre-operative assessment of the possible individual benefit of a monaural BCI should be carried out in patients affected by unilateral conductive or mixed hearing loss in order to investigate the possible additional effect of the fitting of hearing aids.

Precise selection of bone conduction hearing devices for congenital malformation of the middle and outer ear (CMMOE)

Background: No selection criteria for the four bone conduction hearing devices yet.Aims/Objectives: To compare effectiveness of four bone conduction hearing devices in patients with bilateral Congenital Malformation of the Middle and Outer Ear (CMMOE).Material and Methods: 24 Patients (25 ears) were divided into five groups: 1) Bone Anchored Hearing Aid softband (BAHA-s), 2) BAHA implant (BAHA-i nested within group 1), 3) Vibration Sound Bridge implant (VSB-i), 4) Bone Bridge implant (BB-i), and 5) Bone Conduction Hearing Aid softband (BCHA-s). One patient implanted VSB and BB. Auditory parameters were compared: 1. Communication, 2. Average Air Conduction Thresholds (ACT) of pure tone, 3. Sentence Recognition Scores in quiet (SRS-q) and noisy (SRS-n) settings. The one-way analysis of variance (ANOVA) were employed to compare the differences in ACT and SRS-q/n among the groups, a statistical significance level of P < 0.05 was applied.Results: After hearing aid usage, all 24 patients (25 ears) reached or approached the normal in communication (i.e. from difficult to smooth), average ACT and SRS-q/SRS-n (no difference among groups, p > 0 .05). However, there was the difference in the optimal frequency of ACT and the absolute value of SRS-q/SRS-n for VSB/BAHA implants was higher than that for BB and BAHA softband.Conclusions and Significance: The precise selection of the four hearing devices mainly depends on patient's hearing level, the optimal frequency of ACT and absolute values of SRS-q/SRS-n.

Evaluation of the Bonebridge BCI 602 active bone conductive implant in adults: efficacy and stability of audiological, surgical, and functional outcomes

PURPOSE

(1) To assess the effectiveness and safety of a bone-conduction implant, the Bonebridge BCI 602, in adults with conductive or mixed hearing loss. (2) To investigate whether the Bonebridge BCI 602 is at least as effective as the Bonebridge BCI 601 in such patients.

METHODS

The study group included 42 adults who had either conductive or mixed hearing loss. All patients underwent Bonebridge BCI 602 implant surgery. Before and after implantation, pure-tone audiometry, speech recognition tests (in quiet and noise), and free-field audiometry were performed. Word recognition scores were evaluated using the Polish Monosyllabic Word Test. Speech reception thresholds in noise were assessed using the Polish Sentence Matrix Test. Subjective assessment of benefits was done using the APHAB (Abbreviated Profile of Hearing Aid Benefit) questionnaire.

RESULTS

The APHAB questionnaire showed that difficulties in hearing decreased after BCI 602 implantation. Both word recognition in quiet and speech reception threshold in noise were significantly better after BCI 602 implantation and remained stable for at least 12 months. A significant advantage of the device is a reduced time for surgery while maintaining safety. In this study, the mean time for BCI 602 implantation was 28.3 min ± 9.4.

CONCLUSIONS

The second-generation Bonebridge BCI 602 implant is an effective hearing rehabilitation device for patients with conductive or mixed hearing loss. Patient satisfaction and audiological results confirm its efficacy and safety. Its new shape and dimensions allow it to be used in patients previously excluded due to insufficient or difficult anatomical conditions. The new BCI 602 implant is as effective as its predecessor, the BCI 601.

The Baha® Attract System Implantations Significantly Improve the Quality of Life of Hearing-Impaired Patients in Long-Term Observations

BACKGROUND

The aim of this study was to assess the impact of the Baha® Attract system implantation on the quality of life of hearing-impaired patients, who were qualified for surgery due to various audiological indications.

METHODS

A total of 96 patients implanted with the Baha® Attract system were asked to fill in the set of questionnaires: the Glasgow Benefit Inventory, the Abbreviated Profile of Hearing-Aid Benefit, and the BAHA Aesthetic, Hygiene, and Use. Totally 79 patients responded and were then analyzed. Patients were divided into 4 groups: A: with bilateral mixed or conductive hearing loss, B: with single-sided deafness, C: with unilateral mixed or conductive hearing loss, and D: others.

RESULTS

There was a significant improvement in quality of life measured by the Glasgow Benefit Inventory in all the analyzed groups, with a mean total score of 29.4 points (P < .001). Similarly, the evaluation by the Abbreviated Profile of Hearing Aid Benefit questionnaire showed a significant improvement in terms of the global score in all the analyzed groups, with a mean gain of 38.6% (P < .001). There were no differences between the groups. More than 90% of patients found the Baha® Attract system easy to place on their heads and maintain good hygiene. Of all the implant users, 81% were satisfied with the final aesthetic effect.

CONCLUSION

The implantation of the Baha® Attract system significantly improves the quality of life of hearing-impaired patients in all subjec- tive scales used. The system is effective for all audiological indications when strictly adhered to. The majority of patients are very satisfied with the aesthetic, hygienic, and utility aspects of the device.

Efficient Bone Conduction Hearing Device with a Novel Piezoelectric Transducer Using Skin as an Electrode

OBJECTIVE

Bone conduction hearing aids are the only non-surgical devices used for conductive hearing loss. However, they are impractical for lifelong use since they require close contact of the transducer with the head skin, causing skin erosion and discomfort. Bone conduction hearing implants and active middle ear implants do not present these issues; however, they require surgery and can sometimes cause issues in the skin surrounding the devices. This study aimed to develop a new bone conduction hearing device that does not exert pressure on the skin or require surgery.

METHODS

Our device modified a piezoelectric element by using the skin of a pinna as one of the two electrodes of a conventional piezoelectric device. We compared the sound transmission of a speaker, a conventional piezoelectric device, or the new device to the guinea pig cochlea, a physiological sound transducer to the auditory nerve, in normal and air-conductive hearing loss conditions.

RESULTS

The novel device transmitted sound to the cochlea even after causing air-conductive hearing loss. Its bone conduction was more efficient than the speaker and the conventional piezoelectric device.

CONCLUSION

We developed a novel type of bone conduction device that efficiently transmits sound to the cochlea by skipping the external auditory canal, tympanic membrane, and middle ear ossicles. This device does not exert pressure on the skin that can result in skin damage, an adverse effect of a conventional bone conduction hearing aid.

SIGNIFICANCE

Our novel hearing device can be used as a substitute for current bone-conduction hearing devices.

ADHEAR device in bone conduction audiometry

ADHEAR is a bone conduction hearing aid that uses an adhesive skin adapter. In the current study, the use of ADHEAR as an audiometric bone stimulator was investigated in normal-hearing subjects by comparing it to the standard Radio-Ear B71. Bone conduction thresholds of 15 normal-hearing subjects (aged 21-36 years) were measured four times in a randomized order, twice with the B71 and twice with the ADHEAR. There were no significant differences in test-retest reliability between the two devices. Subjectively rated comfort was better for the ADHEAR. The development of a specific audiometric adhesive bone stimulator may be warranted.

Early Osia® 2 bone conduction hearing implant experience: Nationwide controlled-market release data and single-center outcomes

PURPOSE

Bone conduction hearing devices are a well-established treatment option for conductive or mixed hearing losses as well as single-sided deafness. The Osia® 2 System is an active osseointegrated device where a surgically implanted titanium fixture supports a newly developed piezoelectric actuator that is placed under the skin.

METHODS

Nationwide data collected during a controlled-market release (CMR) of the Cochlear™ Osia® 2 System as well as outcomes at single, tertiary-level private practice Otology/Neurotology center were retrospectively reviewed. Key learnings from surgeons and audiologists are discussed.

RESULTS

During the CMR period, 23 surgeons performed 44 operations on 43 recipients. The mean age of recipients was 44 years and mean surgery duration was 52 min. The most commonly used incision was postauricular but anterior to the device (78%). Five complications were observed during the CMR, none of which were device related. Twenty-one audiologists performed 33 Osia® 2 activations during the CMR. The mean age of this group was 47 years, and the mean duration of each activation appointment was 55 min. Single-center data at the authors' institution demonstrated an average additional PTA4 gain with the Osia® 2 patients of 9.6 dB compared to Baha Attract and 10.2 dB compared to Baha Connect.

CONCLUSION

The Cochlear™ Osia® 2 System represents a significant advance in auditory osseointegrated implant technology. Digital piezoelectric stimulation delivers high power outputs, improves high frequency gain for optimal speech perception, and maintains safety while providing excellent patient satisfaction.

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

Purpose

To evaluate the long-term benefits in hearing-related quality of life, patient satisfaction and wearing time of patients rehabilitated with an active transcutaneous bone-conduction device. Adverse events and audiological outcomes are reported as secondary outcomes.

Methods

This retrospective, mono-centric cohort analysis involves 16 adults with conductive or mixed hearing loss with a mean device experience of 51.25 months. Patient-reported outcome measures were assessed using the short version of the Speech, Spatial and Qualities of Hearing Scale (SSQ12-B) and the German version of the Audio Processor Satisfaction Questionnaire (APSQ). Audiological outcomes as well as incidence of adverse events were obtained from patients´ charts.

Results

The hearing-related quality of life improved significantly within all subscales of the SSQ12-B scoring a mean overall of 2.95 points. Patient satisfaction measured with the APSQ scored 8.8 points on average. Wearing times differed considerably and patients with lower levels of education seemed to use their device longer compared to patients with academic education. Eight minor adverse events were documented, all of which resolved during follow-up. The mean gain in word recognition score at the last follow-up measured at 65 dB was 75.9%, while speech reception threshold was lowered by 35.1 dB.

Conclusion

Even after several years, patients report significant benefits in hearing-related quality of life and device satisfaction. In combination with a low rate of minor adverse events and significantly improved audiological outcomes, the device is considered as a comfortable and effective option in hearing rehabilitation.

The BONEBRIDGE active transcutaneous bone conduction implant: effects of location, lifts and screws on sound transmission

BACKGROUND

The BONEBRIDGE (MED-EL, Innsbruck, Austria) is a bone-conduction implant used in the treatment of conductive and mixed hearing loss. The BONEBRIDGE consists of an external audio processor and a bone-conduction floating mass transducer that is surgically implanted into the skull in either the transmastoid, retrosigmoid or middle fossa regions. The manufacturer includes self-tapping screws to secure the transducer; however, self-drilling screws have also been used with success. In cases where the skull is not thick enough to house the transducer, lifts are available in a variety of sizes to elevate the transducer away from the skull. The objective of the present study was to investigate the effects of screw type, lift thickness, and implant location on the sound transmission of the BONEBRIDGE.

METHOD

Six cadaveric temporal bones were embalmed and dried for use in this study. In each sample, a hole was drilled in each of the three implant locations to house the implant transducer. At the middle fossa, six pairs of screw holes were pre-drilled; four pairs to be used with self-tapping screws and lifts (1, 2, 3, and 4 mm thick lifts, respectively), one pair with self-tapping screws and no lifts, and one pair with self-drilling screws and no lifts. At the transmastoid and retrosigmoid locations, one pair of screw holes were pre-drilled in each for the use of the self-tapping screws. The vibration of transmitted sound to the cochlea was measured using a laser Doppler vibrometry technique. The measurements were performed on the cochlear promontory at eight discrete frequencies (0.5, 0.75, 1, 1.5, 2, 3, 4 and 6 kHz). Vibration velocity of the cochlear wall was measured in all samples. Measurements were analyzed using a single-factor ANOVA to investigate the effect of each modification.

RESULTS

No significant differences were found related to either screw type, lift thickness, or implant location.

CONCLUSIONS

This is the first known study to evaluate the effect of screw type, lift thickness, and implant location on the sound transmission produced by the BONEBRIDGE bone-conduction implant. Further studies may benefit from analysis using fresh cadaveric samples or in-vivo measurements.

Three-Year Follow-Up with the Bone Conduction Implant

BACKGROUND

The bone conduction implant (BCI) is an active transcutaneous bone conduction device where the transducer has direct contact to the bone, and the skin is intact. Sixteen patients have been implanted with the BCI with a planned follow-up of 5 years. This study reports on hearing, quality of life, and objective measures up to 36 months of follow-up in 10 patients.

METHOD

Repeated measures were performed at fitting and after 1, 3, 6, 12, and 36 months including sound field warble tone thresholds, speech recognition thresholds in quiet, speech recognition score in noise, and speech-to-noise thresholds for 50% correct words with adaptive noise. Three quality of life questionnaires were used to capture the benefit from the intervention, appreciation from different listening situations, and the ability to interact with other people when using the BCI. The results were compared to the unaided situation and a Ponto Pro Power on a soft band. The implant functionality was measured by nasal sound pressure, and the retention force from the audio processor against the skin was measured using a specially designed audio processor and a force gauge.

RESULTS

Audiometry and quality of life questionnaires using the BCI or the Ponto Pro Power on a soft band were significantly improved compared to the unaided situation and the results were statistically supported. There was generally no significant difference between the two devices. The nasal sound pressure remained stable over the study period and the force on the skin from the audio processor was 0.71 ± 0.22 N (mean ± 1 SD).

CONCLUSION

The BCI improves the hearing ability for tones and speech perception in quiet and in noise for the indicated patients. The results are stable over a 3-year period, and the patients subjectively report a beneficial experience from using the BCI. The transducer performance and contact to the bone is unchanged over time, and the skin area under the audio processor remains without complications during the 3-year follow-up.

Hearing Aid Uptake in Children with Unilateral Microtia and Canal Atresia: A Comparison between a Tertiary Center and Peripheral Centers

OBJECTIVES

To review the trialing and uptake of hearing aids in children with unilateral microtia or canal atresia, known collectively as congenital unilateral conductive hearing loss (CUCHL), observed in a tertiary hospital and local peripheral services.

MATERIALS AND METHODS

A retrospective review of medical records for patients with CUCHL was conducted using data from a shared audiology database at a tertiary children's hospital.

RESULTS

We identified 45 patients with CUCHL and excluded seven of them due to missing data. Of the 38 patients, 16 (16/38, 42%) did not have any subjective hearing complaints. Furthermore, 32% (12/38) of patients attended audiology at a tertiary centre and 83% (10/12) from this group trialled a hearing aid. In comparison, 46% (12/46) whose audiology care was delivered peripherally trialled aiding. Of the patients from the tertiary center, 58% (7/12) are still using a hearing aid compared to 27% (7/26) of patients from peripheral centers.

CONCLUSION

Our analysis shows that patients with CUCHL are more likely to try hearing aids and continue using them if their audiology care is in a tertiary center. Allowing for a small sample size, this may indicate a health inequality. Agreeing on minimum standards for the management of patients with CUCHL or managing them in a designated center could increase consistency.

First experiences with a new adhesive bone conduction hearing device in children

OBJECTIVES

To evaluate the hearing benefit, advantages, and disadvantages in a series of children using a new, nonimplantable, pressure-free, adhesive bone conduction hearing aid.

METHODS

Seventeen children were included in the study. 5 children suffered from bilateral conductive hearing loss (CHL), 6 children with unilateral CHL and 6 children with unilateral sensorineural hearing loss. An audiological tests were provide. Additionally, sound quality (SSQ10) and quality of life (AQoL-6D) were assessed using questionnaires.

RESULTS

The average value of speech audiometry with bubble noise in children with SNHL is 21.33 (±5.72) dB HL with the device and 27.67 (±4.59) dB HL without the device, which is a statistically significant gain (p = 0.027). The analysis showed the average value of hearing threshold in sound field in the group of children with CHL supported 20.23 (±16.84) dB HL and not supported 33.52 (±27.27) by the hearing aid for bone conduction, which i a statistically significant gain (p = 0.008). The average value of speech audiometry is 23.45 (±14.45) dB HL with the device and 37.27 (±26.65) dB HL without the device, which is a statistically significant gain (p = 0.012). The average value of speech audiometry with bubble noise is 30.55 (±10.03) dB HL with the device and 45.45 (±18.41) dB HL without the device, which is a statistically significant gain (p = 0.008). No patient referred pain or irritation.

CONCLUSION

This new device for bone conduction show a hearing benefit for a paediatric patient, without any concomitant aesthetic and other complications.

Objective and subjective results of the Bonebridge transcutaneous active direct-drive bone conduction hearing implant

Objectives:

To investigate the effectiveness of a bone-anchored hearing implant system (Bonebridge implant technology) as a rehabilitation treatment for individuals with conductive or mixed hearing losses.

Methods:

This is a retrospective cohort study. Twelve implanted ears with conductive or mixed hearing losses were implanted with this device at a tertiary university hospital between 2012 and 2016. Audiological tests included pure tone air conduction (AC) and bone conduction (BC) measurements and unaided and aided sound-field thresholds. To evaluate the speech intelligibility in a quiet environment, the speech discrimination score (SDS) was tested using Arabic monosyllabic words, and the speech reception threshold (SRT) was measured using Arabic disyllabic words spoken in front of them. The subjective sound quality was assessed with the Hearing Implant Sound Quality Index (HISQUI).

Results:

In comparison with the unaided condition, there was a significant improvement in the aided thresholds, SDS, and SRT. Comparing the aided and unaided thresholds, the average AC threshold improved with an average functional gain of 40±6.3dB. The unaided SRT improved from 72.5 dB hearing levels (HL)(median) to 27.5 dB HL (median) when aided, and patients performed 71% better, on average, based on the SDS with the help of the device. The HISQUI questionnaire revealed high satisfaction with the device sound quality.

Conclusion:

Patients with conductive and mixed hearing loss substantially benefit from the Bonebridge active transcutaneous BC hearing implant.

Improved directional hearing of children with congenital unilateral conductive hearing loss implanted with an active bone-conduction implant or an active middle ear implant

Different amplification options are available for listeners with congenital unilateral conductive hearing loss (UCHL). For example, bone-conduction devices (BCDs) and middle ear implants. The present study investigated whether intervention with an active BCD, the Bonebridge, or a middle ear implant, the Vibrant Soundbridge (VSB), affected sound-localization performance of listeners with congenital UCHL. Listening with a Bonebridge or VSB might provide access to binaural cues. However, when fitted with the Bonebridge, but not with a VSB, binaural processing might be affected through cross stimulation of the contralateral normal hearing ear, and could interfere with processing of binaural cues. In the present study twenty-three listeners with congenital UCHL were included. To assess processing of binaural cues, we investigated localization abilities of broadband (BB, 0.5-20 kHz) filtered noise presented at varying sound levels. Sound localization abilities were analyzed separately for stimuli presented at the side of the normal-hearing ear, and for stimuli presented at the side of the hearing-impaired ear. Twenty-six normal hearing children and young adults were tested as control listeners. Sound localization abilities were measured under open-loop conditions by recording head-movement responses. We demonstrate improved sound localization abilities of children with congenital UCHL, when listening with a Bonebridge or VSB, predominantly for stimuli presented at the impaired (aided) side. Our results suggest that the improvement is not related to accurate processing of binaural cues. When listening with the Bonebridge, despite cross stimulation of the contralateral cochlea, localization performance was not deteriorated compared to listening with a VSB.

Vibrant Soundbridge Implantation: Floating Mass Transducer Coupled with the Stapes Head and Embedded in Fat

Subtotal petrosectomy may be performed for refractory chronic middle ear diseases, such as massive cholesteatoma or recurrent otitis media. It involves permanent obliteration of the operative cavity, thus precluding the chance to restore conductive hearing via traditional inertial ossicular prostheses. The Vibrant Soundbridge (VSB) is an alternative option for hearing rehabilitation. Vibrant energy is delivered into the inner ear via a floating mass transducer (FMT), which can be coupled with any part of the middle ear acoustic transmission structure. To restore the hearing of a young woman with cholesteatoma, we combined subtotal petrosectomy with obliteration of the cavity and VSB implantation with an FMT coupled to the stapes head. Two years of follow-up demonstrated excellent auditory rehabilitation, improved sound source localization ability, and a lower speech recognition threshold. This study showed that the FMT works well in an obliterated cavity, and the experience acquired through this successful exploration is worth disseminating.

Hearing Rehabilitation in Congenital Middle Ear Malformation

Microtia and atresia cause significant conductive hearing loss of up to 60 dB HL. The bilateral cases suffer from severely restricted communication abilities and require immediate acoustic stimulation. There is also growing evidence that unilateral cases benefit from an early and selective stimulation of the affected side. Hearing restoration can be performed in selected cases of minor malformation by classic middle ear reconstruction. However, the majority of patients presumably benefit better from a hearing aid. There are 3 main types: active middle ear implants, active bone conduction implants and passive bone conduction implants. All implants improve speech perception, speech recognition, the signal-to-noise ratio and directional hearing. The extent varies among implants and requires further studies. Decision making on the implant type depends on the extent of malformation and hence the preoperative imaging. New scoring systems provide reliable risk stratification. Second it depends on the age of the patient. The active middle ear implants provide a selective stimulation of the affected side and are beneficial if implanted in the first years of life during the maturation period of the auditory system. In conclusion, hearing rehabilitation of congenital atresia should be performed as early as possible. This includes not only the bilateral but also the unilateral affected patients.

The role of bone conduction hearing aids in congenital unilateral hearing loss: A systematic review

OBJECTIVES

To systematically review the literature on the audiological and/or quality of life benefits of a bone conduction hearing aid (BCHA) in children with congenital unilateral conductive or sensorineural deafness.

METHODS

A systematic search was performed according to the PRISMA guidelines using the PubMed, Medline, and Embase databases. Data were collected on the following outcomes of interest: speech reception threshold, speech discrimination, sound localization, and quality of life measures. Given the heterogeneity of the data for quantitative analysis, the results are qualitatively summarized.

RESULTS

Eight studies were included in the review. Four studies examined the audiological outcomes associated with bone conduction hearing aid implantation. There was a consistent gain in speech reception thresholds and speech discrimination, especially in noisy environments. Results pertaining to sound localization was inconsistent. The studies that examined quality of life measures reported a high usage rate of BCHAs among children. Quality of life improvements are reported with suggested benefit in the subdomain of learning.

CONCLUSION

Given the potential benefits of a BCHA, along with the fact that it can be safely trialed using a headband, it is reasonable to trial a BCHA in children with congenital unilateral deafness. Should the trial offer audiological and/or quality of life benefits for the individual child, then BCHA implantation can be considered.

Intermediate outcomes of a transcutaneous bone conduction hearing device in a paediatric population

OBJECTIVE

The aim of this study was to review the outcomes of Bone Anchored Hearing Aid (BAHA^®) Attract implantation in a cohort of paediatric patients.

METHODS

Prospective data collection and case review were undertaken in a paediatric tertiary referral centre. We have included patients under the age of 16 years with unilateral or bilateral hearing loss that met the criteria for BAHA^® Attract implantation. The main outcome measures were surgical complications and Patient Reported Outcomes including the 'Speech, Spatial and Qualities of Hearing scale' (SSQ-12) and 'Qualitative Feedback for BAHA^® 5 Hearing Aids'.

RESULTS

Twenty-five paediatric patients were implanted with the BAHA^® Attract between June 2014 and July 2016. Nine of them had a conversion from a percutaneous Bone Conduction Hearing Device (BCHD). Four children had minor skin problems that settled with conservative measures. Two children with a previous percutaneous BCHD developed skin dehiscence over the magnet after conversion to the transcutaneous version. The SSQ-12 was completed by 6 children and an improvement of 22% was noted between the unaided and aided condition. The patients and their parents were generally satisfied with the BAHA^® Attract.

CONCLUSIONS

The BAHA^® Attract offers a good solution for hearing rehabilitation in appropriately selected and counseled patients. The complication rate was low for primary surgery but higher in cases of conversion from a percutaneous device. Large, prospective data is needed to evaluate the relative risks and benefits of this BCHD.

Hearing devices for children with unilateral hearing loss: Patient- and parent-reported perspectives

OBJECTIVE

Management of children with unilateral hearing loss is not standardized. The primary goal of this study was to elicit patient- and parent-reported perspectives regarding usage of hearing devices in pediatric UHL and to suggest a basic algorithmic approach to management.

METHODS

Our tertiary care center recruited families of youth ages 5-19 years with unilateral hearing loss from January 2014 through October 2015. Parents of all youths completed a 36-item survey, and some youth ages 11-19 years participated in hour-long interviews. We assessed patterns of hearing device usage among participants, and performed qualitative data analysis to understand factors considered by youths when deciding whether or not to use a hearing device.

RESULTS

Survey information was collected for 50 patients. Distribution of hearing loss severity in affected ear was mild 14%, moderate 26%, severe 22%, and profound 38%. The majority of children had sensorineural hearing loss (57%), followed by mixed (32%), and then conductive (11%). 34 children (68%) had tried a hearing device; 20 continued to use the device. Retention rates were similar among children with different degrees of hearing loss: mild 66%, moderate 50%, severe 60%, profound 64%. Sixteen children tried a wireless contralateral routing of signal (CROS) device, and 15 tried a behind-the-ear (BTE) hearing aid. Retention rates for CROS and BTE devices were 69% and 47%, respectively. The most common reason for cessation of use was discomfort, followed by lack of benefit.

CONCLUSION

A majority of children with unilateral hearing loss who tried a hearing device continued to use it, and retention rates were similar across all degrees of hearing loss. These findings suggest that personal hearing devices should be included in management protocols.

[Multicenter Clinical Study of Vibrant Soundbridge in Japan: Analysis of Subjective Questionnaires]

The Vibrant Soundbridge (VSB) is an active middle ear implant with the Floating Mass Transducer (FMT). We performed a multicenter study to study the efficacy of the VSB by means of "the 10 Questionnaire on Hearing 2002" and "the APHAB questionnaire" at 13 hospitals between 2011 and 2013. In all, 23 patients with mixed or conductive hearing loss received VSB implantation by the round window placement technique. These individuals were generally unable to use, or gained little from conventional hearing aids or bone conduction hearing aids. Two questionnaires were administrated before the surgery and 20 weeks after the VSB implantation. Scores on every item of "the 10 Questionnaire on Hearing 2002" showed significant improvement under noise after VSB implantation. On the APHAB, the scores for Ease of Communication, Reverberation, and Background subscales improved significantly after the VSB implantation, while the score for the Aversiveness subscale alone failed to show a positive improvement from the inexperience to the new sound. Analysis of the responses to these subjective questionnaires revealed better results after VSB implantation as compared to the preoperative data. In conclusion, RW vibroplasty with the use of VSB provided subjective benefit in patients with conductive and mixed hearing loss.

Accuracy and precision of direct bone conduction measurements

OBJECTIVES

Variability in Baha® sound processor fittings arise from several sources including the nature of the implant-to-bone transmission and transcranial attenuation in patients with single-sided sensorineural deafness. One method of improving the predictability of Baha fittings is to measure the individual patient's actual bone conduction thresholds via the implant, thereby removing the influence of skin thickness and/or implant location site.

METHODOLOGY

One hundred thirty eight adult wearers of the Baha System participated in the study. Direct bone conduction thresholds were obtained through the BC Direct feature of the Cochlear™ Baha Fitting Software combined with the CochlearBaha BP100 sound processor. Test-retest reliability measurement was performed in 58 participants.

RESULTS

Improved transmission of sound through the implant rather than transcutaneously through the skin was confirmed. On average, the BC Direct thresholds were closer to the patient's unmasked thresholds than the masked values. In patients with single-sided sensorineural deafness, BC Direct results were elevated compared to the contralateral bone conduction thresholds due to transcranial attenuation. The test-retest reliability for the BC Direct measurements was within ±5 dB, which is in within the accepted variability for audiometric test measurements.

CONCLUSIONS

Direct bone conduction measurement provides a validated method of comparing the transcutaneous thresholds as measured through audiometry with the percutaneous responses from the Baha sound processor. The Baha fitting based on direct measurements of bone conduction may require less fine-tuning and provide a greater understanding of the variability of the bone conduction sound pathway.

Is complex signal processing for bone conduction hearing aids useful?

OBJECTIVES

To establish whether complex signal processing is beneficial for users of bone anchored hearing aids.

METHODS

Review and analysis of two studies from our own group, each comparing a speech processor with basic digital signal processing (either Baha Divino or Baha Intenso) and a processor with complex digital signal processing (either Baha BP100 or Baha BP110 power). The main differences between basic and complex signal processing are the number of audiologist accessible frequency channels and the availability and complexity of the directional multi-microphone noise reduction and loudness compression systems.

RESULTS

Both studies show a small, statistically non-significant improvement of speech understanding in quiet with the complex digital signal processing. The average improvement for speech in noise is +0.9 dB, if speech and noise are emitted both from the front of the listener. If noise is emitted from the rear and speech from the front of the listener, the advantage of the devices with complex digital signal processing as opposed to those with basic signal processing increases, on average, to +3.2 dB (range +2.3 … +5.1 dB, p ≤ 0.0032).

DISCUSSION

Complex digital signal processing does indeed improve speech understanding, especially in noise coming from the rear. This finding has been supported by another study, which has been published recently by a different research group.

CONCLUSIONS

When compared to basic digital signal processing, complex digital signal processing can increase speech understanding of users of bone anchored hearing aids. The benefit is most significant for speech understanding in noise.

Cochlear implantation in patients with chronic otitis media and radical mastoidectomy: A single-stage procedure

BACKGROUND

We conducted a retrospective case review of patients with mastoid cavity and active or inactive chronic otitis media (COM) who underwent cochlear implantation and ear obliteration in a single-stage procedure. The objectives of this review are to assess the rates of complications and postoperative infections and to evaluate post-implantation audiologic performance.

MATERIALS AND METHODS

All patients with COM and mastoid cavity, associated or not with active disease, who undergo cochlear implantation and obliteration of the ear as a single-stage procedure from November 2004 to April 2013, were included in the review. All the complications were recorded. Open-set sentence scores were used to evaluate the audiologic gain after implantation.

RESULTS

Twenty-seven patients were included in our review: Ten with active COM and seventeen with inactive COM. Overall, nine patients (9/27) presented post-operative complications (7/9 were minor): three were amongst active COM patients (30%) as compared to six amongst inactive COM patients (35%), which included the two major complications. A mean gain of 55.9% on open-set sentence scores was obtained after cochlear implantation.

DISCUSSION

We found that complications rate of the one-stage cochlear implantation was higher in patients with COM than in global implant population, but most complications were minors and there was no statistical difference between active and inactive COM. In addition, these patients had audiologic scores similar to those found in patients with normal temporal bone anatomy.

CONCLUSION

Cochlear implantation performed as a one-stage procedure could be considered as an option of treatment to avoid staging in patients with active and inactive COM. Although these patients need a regular follow-up, they present good post-implantation audiometric scores.

Functional outcomes of Vibrant Soundbridge applied on the middle ear windows in comparison with conventional hearing aids

CONCLUSION

Vibrant Soundbridge (VSB) application to the middle ear windows yields better functional outcomes than conventional hearing aids. However, speech discrimination scores obtained with VSB and conventional hearing aids are similar.

OBJECTIVE

To assess audiological outcomes of round and oval window applications of VSB in comparison with conventional hearing aids.

METHODS

Nineteen adult patients were included in the study. The patients had mild to moderate, moderate or moderate to profound conductive or mixed hearing loss. During surgery the floating mass transducer (FMT) was placed on the round (n = 14) or oval (n = 5) window. After the surgery, audiometric evaluation and free field audiometric evaluation of both ears was carried out.

RESULTS

The hearing thresholds in the low frequencies were not significantly different between the conventional hearing aids and VSB. The functional gains obtained with oval and round window approaches were similar except for 500 Hz. The hearing thresholds in the mid and high frequencies were significantly better with VSB than the conventional hearing aids. The functional gain in the low frequencies was not significantly different between VSB and conventional hearing aids. The functional gain in the other frequencies was significantly better with VSB than conventional hearing aids.

Automated hearing tests: applying the otogram to patients who are difficult to test

OBJECTIVE

The Otogram is an automated audiometer capable of determining air and bone conduction thresholds with masking when appropriate. The manufacturer claims that testing can be done in a quiet physician's consultation room without a sound-treated booth. We aimed to test the validity of the Otogram on "difficult-to-test" patients, all of whom require masking.

METHODS

Twenty-eight difficult-to-test patients underwent three audiograms: two by an audiologist and one by the Otogram. First, audiograms performed by the audiologists were compared, establishing test-retest reliability. Second, audiograms performed by the Otogram were compared to those of the audiologists. We calculated the percentage of pure-tone thresholds that were in agreement by 10 dB. Weighted kappa statistical analyses demonstrated levels of agreement.

RESULTS

Comparisons between audiologists demonstrated a very high degree of agreement. More than 90% of air and bone conduction thresholds fell within 10 dB of each other. Comparisons between audiologists and the Otogram also demonstrated a high degree of agreement.

CONCLUSIONS

The Otogram has the capability to accurately ascertain air and bone conduction thresholds. It appropriately used masking when indicated. The Otogram has great potential as a diagnostic tool to improve access to health care, especially where hearing test facilities are limited or unavailable.

Bone-anchored hearing aids versus conventional hearing aids

Hearing amplification technology has been evolving since the 19th century. Currently in most audiology departments, the mainstay of hearing rehabilitation is performed with conventional air and bone conduction aids. These are cost-effective, non-invasive hearing aids but are not without their drawbacks. This chapter explores the advantages and disadvantages of conventional hearing aids compared with the bone-anchored hearing aids. Although the bone-anchored hearing aids are a more expensive invasive option, there is increasing evidence that the benefits outweigh the disadvantages. Users report improved quality of life, health status and audiological rehabilitation.

Audiological results with Baha in conductive and mixed hearing loss

The level of improvement in the audiological results of Baha(®) users mainly depends on the patient's preoperative hearing thresholds and the type of Baha sound processor used. This investigation shows correlations between the preoperative hearing threshold and postoperative aided thresholds and audiological results in speech understanding in quiet of 84 Baha users with unilateral conductive hearing loss, bilateral conductive hearing loss and bilateral mixed hearing loss. Secondly, speech understanding in noise of 26 Baha users with different Baha sound processors (Compact, Divino, and BP100) is investigated. Linear regression between aided sound field thresholds and bone conduction (BC) thresholds of the better ear shows highest correlation coefficients and the steepest slope. Differences between better BC thresholds and aided sound field thresholds are smallest for mid-frequencies (1 and 2 kHz) and become larger at 0.5 and 4 kHz. For Baha users, the gain in speech recognition in quiet can be expected to lie in the order of magnitude of the gain in their hearing threshold. Compared to its predecessor sound processors Baha(®) Compact and Baha(®) Divino, Baha(®) BP100 improves speech understanding in noise significantly by +0.9 to +4.6 dB signal-to-noise ratio, depending on the setting and the use of directional microphone. For Baha users with unilateral and bilateral conductive hearing loss and bilateral mixed hearing loss, audiological results in aided sound field thresholds can be estimated with the better BC hearing threshold. The benefit in speech understanding in quiet can be expected to be similar to the gain in their sound field hearing threshold. The most recent technology of Baha sound processor improves speech understanding in noise by an order of magnitude that is well perceived by users and which can be very useful in everyday life.

Historical background of bone conduction hearing devices and bone conduction hearing aids

During the last 20 years, bone-anchored hearing aids (Baha(®)) became a familiar solution in the treatment of some types of hearing loss. The aim of this chapter is to present the different historical steps which have permitted the production of this new bone conduction hearing device. The recognition of bone conduction hearing is old and was known at least in Antiquity. During the Renaissance, Girolamo Cardano demonstrated a method by which sound may be transmitted to the ear by means of a rod or the shaft of a spear held between one's teeth: this was the beginning of teeth stimulators to improve hearing, firstly in connection with a musical instrument and then, in the second part of the 19th century, with the speaker. The development of the carbon microphone at the beginning of the 20th century allowed the construction of the bone conduction vibrator placed on the mastoid area, notably supported by eyeglasses since the 1950s. Confronted by various problems, and notably the loss of part of sound in the soft tissue of the external mastoid, the idea to implant the vibrator into the mastoid bone was developed in Göteborg, and the first Baha was implanted in 1977 by Anders Tjellström. From that date, various improvements allowed the development of the actual Baha. These different steps are presented in this study, supported by original documentation.

Surgery for the bone-anchored hearing aid

INTRODUCTION

This review covers the surgery for the bone-anchored hearing aid (Baha(®)). PREOPERATIVE WORKUP: A review of the indications and preoperative diagnostics shows that best results are generally obtained in patients with conductive or mixed hearing loss rehabilitation when surgery is not applicable or has failed and in patients that suffer from single-sided deafness. An audiogram must confirm that the bone conduction hearing is within the inclusion criteria. A computed tomography scan is performed in cases of malformation to assure sufficient bone thickness at the site of screw implantation.

PROCEDURE

The steps of the Baha implantation are described step by step including the setting and anesthesia, skin work with regard to different techniques, correct resection of subcutaneous tissue, preparation of the implant site, drilling and placement of the fixture and wound closure.

POSTOPERATIVE CARE

After wound healing (6-8 weeks), the bone conduction aid is fitted on the abutment. Regular cleaning of the fixture is important to avoid irritations and infections.

CONCLUSION

If performed carefully, the surgery for the Baha has a favorable outcome, regardless of the technique used.

Bone-anchored devices in single-sided deafness

Single sided deafness (SSD) implies sensorineural hearing loss in one ear with normal contralateral hearing function. Traditionally, SSD patients have been overlooked due to a belief that the preserved functioning of the contralateral ear compensates for the nonhearing side. SSD patients however experience multiple audiological difficulties, particularly when the sound source is situated on the non-hearing side or in the presence of competing sounds. Through reviewing current literature, we describe the role of bone-anchored devices (Baha) in the management of SSD patients. Recent publications for Baha in SSD have demonstrated consistent objective and subjective improvement in audiologic metrics when compared to unaided conditions. There is also evidence of benefit provided by Baha by the Abbreviated Profile of Hearing Aid Benefit, in global measures of ease of communication, reverberation, and background noise, but not typically in aversiveness to sounds. Interestingly, despite some patients gaining minimal objective or subjective benefits, the majority of these patients still report improved quality of life and would recommend the procedure. Despite increasing evidence for the role of Baha in the management of SSD in the literature, much of these data are based on older technology. Further reports should specify the processor type used and the etiology of the hearing loss to ensure accuracy of future data.

Challenges and recent developments in sound processing for Baha®

Osseointegrated auditory implants such as Baha(®) provide an efficient pathway for sound delivery and an excellent amplification choice for patients with conductive or mixed hearing loss or single-sided sensorineural deafness. But at the same time, bone conduction hearing provides a number of key challenges that need to be addressed. One solution is computer-based fitting software to measure in-situ thresholds directly through the Baha sound processor and to individually prescribe amplification settings based on the patient's hearing loss and degree of transcranial attenuation. Additionally, technologies such as automatic directional microphones and noise reduction systems further improve hearing performance in noisy situations. This paper highlights recent technological innovations and summarizes data on the advantages for the Baha patient population using the sound processing capabilities available in the latest Baha sound processors.

Conductive hearing loss and bone conduction devices: restored binaural hearing?

An important aspect of binaural hearing is the proper detection of interaural sound level differences and interaural timing differences. Assessments of binaural hearing were made in patients with acquired unilateral conductive hearing loss (UCHL, n = 11) or congenital UCHL (n = 10) after unilateral application of a bone conduction device (BCD), and in patients with bilateral conductive or mixed hearing loss after bilateral BCD application. Benefit (bilateral versus unilateral listening) was assessed by measuring directional hearing, compensation of the acoustic head shadow, binaural summation and binaural squelch. Measurements were performed after an acclimatization time of at least 10 weeks. Unilateral BCD application was beneficial, but there was less benefit in the patients with congenital UCHL as compared to patients with acquired UCHL. In adults with bilateral hearing loss, bilateral BCD application was clearly beneficial as compared to unilateral BCD application. Binaural summation was present, but binaural squelch could not be proven. To explain the poor results in the patients with congenital UCHL, two factors seemed to be important. First, a critical period in the development of binaural hearing might affect the binaural hearing abilities. Second, crossover stimulation, referring to additional stimulation of the cochlea contralateral to the BCD side, might deteriorate binaural hearing in patients with UCHL.

An overview of different systems: the bone-anchored hearing aid

In the past 30 years, a large amount of clinical and audiological research on bone conduction hearing devices has been performed. In this review, we give a brief history of the developments in indications, surgical techniques and sound processors with respect to implantable bone conduction devices like the bone-anchored hearing aid or Baha. Starting with the use of Baha in patients with bilateral conductive or mixed hearing loss (HL), the indications for such devices have been extended to patients with unilateral HL, children and moderate mentally retarded patients. Bilateral fitting has been shown to be beneficial in restoring binaural hearing in patients with bilateral acquired or congenital conductive HL. In addition, the surgical techniques used to implant the titanium fixture for Baha application have been modified and further developed to reach two main goals: (a) optimal osseointegration, and (b) preparation of the implant site to minimize the occurrence of soft tissue reactions. Currently, the most used techniques are the pedicled skin flap, dermatome and linear incision techniques. Several generations of the Baha(®) sound processor have been developed by Cochlear(TM) to provide sufficient amplification in different hearing situations. Improvements in sound quality, aesthetics and handling have been major points of interest. The Baha sound processors most often used today are the Baha(®) Divino, the Baha(®) Intenso and the Baha(®) Cordelle. Recently, the more flexible Baha(®) BP100 sound processor was launched.

Paediatric Baha

Bone-anchored hearing aids (Baha(®)) are a well-established and readily available option for aural rehabilitation for children. Audiological outcomes and paediatric quality of life results have added to the evidence of benefit of Baha. Recent years have seen an increase in the number of centres worldwide providing a Baha service for children. Indications for Baha have evolved. The paediatric population present a variety of challenges for clinicians who undertake Baha surgery. Complex medical conditions, social and educational issues, and trauma are such examples. The surgical techniques are now varied and the timing of surgery varies between surgeons and Baha centres. Fortunately, serious complications are very rare, and to date there are no more than six significant such case reports in the literature. Careful patient selection and a multidisciplinary team approach with an understanding of the problems that present in children should result in a successful outcome for the child.

Complications of bone-anchored hearing devices

Complications of bone-anchored hearing devices occur with both soft tissue and bone. Soft tissue complications are much more common and most often involve irritation of the skin surrounding the implant. Other complications include: skin flap necrosis, wound dehiscence, bleeding or hematoma formation, and persistent pain. Bone complications are classified as either early or late. Early complications are due to failure of osseointegration, while late complications are usually the result of either chronic infection or trauma. Pediatric patients are a unique group of implant patients and are more likely to have complications of both soft tissue and bone. Most complications can be managed in the office with topical therapy and wound care, although revision surgery may be required in extensive skin overgrowth cases. Proper patient selection, meticulous surgical technique, and patient hygiene around the implant are the most critical aspects in minimizing complications in patients with osseointegrated implants.

Hearing rehabilitation in congenital aural atresia using the bone-anchored hearing aid: audiological and satisfaction results

CONCLUSION

The BAHA (bone-anchored hearing aid) remains the most reliable method of auditory rehabilitation for patients with congenital aural atresia and improves hearing outcome and quality of life in these patients who are otherwise unable to benefit from traditional hearing aids. New techniques are being developed, such as fully implantable hearing devices, and will have to prove their efficacy and safety in this indication.

OBJECTIVE

To evaluate the audiological results and patient satisfaction after rehabilitation of congenital aural atresia using the BAHA.

METHODS

Sixteen patients suffering from bilateral congenital aural atresia were implanted with unilateral BAHA. Preoperative air- and bone-conduction thresholds and air-bone gap (ABG), preoperative sound reception threshold (SRT), postoperative aided thresholds, implantation complications, patient satisfaction, and the APHAB questionnaire were collected.

RESULTS

After a mean follow-up period of 6.5 years, 15 patients were still using their device. Each patient had an average improvement of 33 ± 7 dB. Closure of the ABG within 15 dB of the preoperative bone-conduction thresholds occurred in 10 patients. Adverse skin reactions appeared in 50% of patients over 6.5 years of follow-up. Eleven of the 12 patients used their BAHA for more than 8 h per day.

Hearing loss in Pompe disease revisited: results from a study of 24 children

Little information is available regarding the auditory function in Pompe patients. Hearing loss has been reported in classic infantile patients, but it is still unknown whether central nervous system involvement interferes with auditory function and whether enzyme replacement therapy can improve hearing. Auditory function has not been studied in children with milder forms of the disease. We analyzed repetitive auditory brainstem response measurements and pure tone audiometry in 24 children with Pompe disease. Only 1 of 13 patients with milder phenotypes showed recurrent conductive hearing loss, while 10 out of 11 classic infantile patients had sensorineural hearing defects. These patients also had a high prevalence of conductive hearing loss. Five patients showed evidence of mild retrocochlear pathology, suggestive of glycogen accumulation in the central nervous system. Hearing loss persisted during therapy in all patients. The results emphasize the need for careful monitoring of auditory function in classic infantile Pompe patients, and for early implementation of hearing aids to protect speech and language development.

Otosclerosis: mid-term results of cochlear implantation

INTRODUCTION

Constant histological changes in otosclerosis lead to progressive hearing loss which may end up in a profound hearing loss and then be treated by means of cochlear implants. These progressive changes could be followed by changes in cochlear implants fitting and speech discrimination results over the years.

OBJECTIVES

The aim of the study is to correlate the progressive histological changes to the cochlear implant clinical outcomes (fitting and speech discrimination results). Also main complications (facial nerve stimulation and difficulties at insertion) and new complications will be discussed.

DESIGN

A 5-year prospective case-control study was performed in order to compare cochlear implant results in otosclerosis patients to those in a matched-pair control group.

MATERIALS AND METHODS

Fifteen otosclerosis patients were followed throughout the study. Preoperatively temporal bone high-resolution computed tomography, electrically evoked auditory brainstem responses and speech discrimination tests were performed in order to select the patients to be implanted.

RESULTS

Not only difficulties with electrode guide insertion were reported, but also difficulties with fitting over the years, due to increasing difficulties to spread the electrical stimuli, which provokes increasing thresholds, maximum comfort levels and charges needed to stimulate hearing cells in basal and medial turn electrodes (p < 0.05), which required deactivating some basal and medial turn electrodes in order to improve cochlear implant effectiveness. The results demonstrated no statistical differences in speech discrimination in otosclerosis patients compared to the control group (p > 0.05). Several complications were reported: facial nerve stimulation (7.14%) and sudden episodes of tinnitus and headaches (14.28%).

CONCLUSIONS

Although progressive histological changes in otosclerosis lead to increasing thresholds, maximum comfort levels and charges needed to stimulate hearing cells, speech discrimination results support the cochlear implantation in otosclerosis.

Osseointegration Timing for Baha System Loading

OBJECTIVES

The process of osseointegration for creating a biological bond between titanium oxide and bone is time dependent. However, different surgeons have used very varied time frames before loading the implant. The waiting time in dental implant loading ranged from immediate to 6 months. The Baha system (Cochlear Limited, Englewood, CO) traditional waiting period consisted of 3 months for adults and 4 to 6 months for children. The purpose of the study was to evaluate the safety of reducing the waiting time to 6 weeks in adults.

STUDY DESIGN

Retrospective study of patients who underwent Baha implantation and exteriorization between March, 2004 and July 2005.

METHODS

Twenty-six adult patients underwent Baha titanium implantation and exteriorization in a single stage. They were loaded with the external processor after an average of 6.5 weeks. The etiology of their hearing loss (HL) included conductive HL, mixed HL, and unilateral sensorineural HL. Follow-up period ranged between 6 and 20 months.

RESULTS

All patients were successfully implanted with the titanium implants, loaded at the 6 week interval, and have safely retained their prosthesis. The only reported complication was dermatitis, which occurred in three patients. Patients were pleased to receive the external processor earlier.

CONCLUSION

The reduction of the waiting period from 3 months to 6 weeks did not result in any failure of osseointegration of the titanium implants. The earlier activation resulted in enhanced patient satisfaction. A larger series would be needed to definitively recommend shortening of the interval between Baha implantation and device loading.

Integration des aktiven Mittelohrimplantates in die plastische Ohrmuschelrekonstruktion

BACKGROUND

Patients with high-grade microtia and atresia require a sophisticated and specific treatment. Apart from the plastic reconstruction of the auricle, in some cases hearing rehabilitation is medically indicated or is desired by the patients. The long-term results of simultaneous middle ear reconstruction with tympanoplasty are often inadequate owing to a persisting air-bone gap, and new techniques in hearing rehabilitation are needed for these patients.

METHODS

We present three cases of unilateral atresia to illustrate a combined approach integrating hearing rehabilitation using the active middle ear implant Vibrant Soundbridge (VSB) into plastic auricular reconstruction. The VSB was attached to the stapes suprastructure via the titanium clip in two of these cases and in the third case a subfacial approach was used to attach it directly to the membrane of the round window.

RESULTS

The air-bone gap was reduced to 17 dB, 14 dB and 0.25 dB HL. In free-field speech recognition tests at 65 dB SPL the patients achieved 100%, 90% and 100% recognition with the activated implant. No postoperative complications such as facial nerve paresis, vertigo or inner ear damage were found.

CONCLUSIONS

The integration of active middle ear implants in auricular reconstruction opens up a new approach in complete hearing rehabilitation. The additional implantation of the VSB does not have any negative effect on the healing process or the cosmetic outcome of the auricular reconstruction.

Bone anchored hearing aids: a second fixture reduces auditory deprivation in Cambridge

Bone anchored hearing aids are well established for canal atresia, otosclerosis and chronic suppurative otitis media. Refinements in technique to maximise gain while keeping the complications to a minimum are desirable. This study was taken up in order to explore the potential advantage of a second or spare fixture placed at the time of primary surgery. A group of patients who underwent BAHA insertion at The Emmeline Centre for Cochlear Implants and Bone Anchored Hearing Aids, Addenbrookes hospital, Cambridge, UK with the placement of a spare fixture between 1999 and 2002 were compared to those patients with one fixture BAHA undertaken from 1991. Main outcome measures were complications encountered and duration of disability, (i.e. loss of hearing while waiting for new fixture placement). Both groups had similar incidence of complications, but the group with two fixtures suffered a shorter period of disability when a fixture failed. In our experience the use of second or spare fixture reduces the duration of disability. It engenders no additional complications with minimal extra cost.

Initial experiments to develop a MEMS transducer for a new implantable audioprosthesis to substitute the tympanic-ossicular system

CONCLUSION

We tested one prototype of a new audioprosthesis including the audioprocessor, the implemented algorithms and fitting platform in a small group of selected patients with mixed hypoacusis due to earlier bilateral radical mastoidectomy. It was effective to compensate the conductive and the neurosensory components of those patients. Results regarding the energy, frequency and other requirements of the output transduction make it possible to develop a suitable actuator with the available Micro-Electromechanic-Machine-System (MEMS) technology to substitute the conventional transducer of the prototype.

OBJECTIVES

The objectives were: a) to evaluate the effectiveness of the whole fitting system, and b) to obtain information about the required energy to design the MEMS actuator.

MATERIALS AND METHODS

The experiments were conducted with the A prototype of the prosthesis equipped with an output transducer coupled to the oval window. Two algorithms and three cases were tested.

RESULTS

The audioprocessor with the implemented FIR filter-67 coefficients paradigm algorithms, and the fitting system were shown to be adequate for clinical use. Effectiveness parameters were: pure tone average gains 20-33.3 dB; gap closure 25.5-31.8 dB; speech reception thresholds improvement 15-20 dB. Required gain: 5-40 dB. Subjectively, patients considered the results very satisfactory.

Das Ti-Epiplating-System für die Knochenverankerung von Hörhilfen

The advent of bone-anchored hearing aids with titanium implants has markedly improved patient management. There are two systems on the market for performing the requisite osseointegration. The aim of our study was to evaluate the Ti-Epiplating system, since no data have been published on this in the literature thus far. Between November 2002 and March 2005, we anchored the BAHA snap coupling via the Ti-Epiplating system in 8 patients in a single session. The patients were followed-up at regular intervals to assess clinical and audiometric results and subjective satisfaction. The postoperative hearing threshold with the BAHA was in the former bone conduction range. In the Freiburg speech test, a significant improvement was found for monosyllables (free-field), and the hearing loss for numbers showed a mean reduction from 75 to 30 dB. There has been no implant loss in our collective thus far. Good to very good results were evaluated for the quality of life in the "International Inventory of evaluation of hearing aids" (IIEH). Clinics that use Medicon's osteosynthesis system can safely and reliably achieve inexpensive and audiometrically successful BAHA management by a comparatively simple surgical procedure.

Bone-Anchored Hearing Aids in Infants and Children Younger Than 5 Years

OBJECTIVE

While bone-anchored hearing aids (BAHAs) are currently indicated for rehabilitation in children older than 5 years with bilateral maximal conductive hearing loss, our objective was to capitalize on potentially important stages of auditory and speech-language development by providing BAHAs to children younger than 5 years.

DESIGN

A retrospective review of surgical data of children receiving BAHA implants over a 10-year period.

SETTING

The Hospital for Sick Children, Toronto, Ontario.

PATIENTS

Twenty children 5 years or younger (mean +/- SD age, 3.21 +/- 1.65 years) served as the study group, while 20 older children (mean +/- SD age, 7.63 +/- 1.55 years) served as the comparison group.

INTERVENTIONS

All patients received BAHA implants. Children with cortical bone thickness less than 2.5 mm underwent a 2-stage procedure; children with cortical bone thickness greater than 4 mm underwent a single-stage procedure.

MAIN OUTCOME MEASURES

Traumatic and skin revision complication rates and implantation interstage intervals were compared between groups.

RESULTS

The mean +/- SD interstage interval was 7.72 +/- 3.81 months for the younger children, which was significantly longer than for the older children (4.41 +/- 2.51 months) (P<.003). Two traumatic fixture losses occurred in the younger children, while 4 occurred in the older children. Skin site revision was required in 3 younger children. All children are currently wearing their BAHAs.

CONCLUSION

Two-stage BAHA implantation with a prolonged interval between stages yields surgical success in younger children comparable to that routinely observed in older children.

Rehabilitation of Patients with Conductive Hearing Loss and Moderate Mental Retardation by Means of a Bone-Anchored Hearing Aid

OBJECTIVE

To evaluate whether the bone-anchored hearing aid (BAHA) can be applied successfully to patients with conductive hearing loss and moderate mental retardation.

STUDY DESIGN

Retrospective clinical evaluation.

SETTING

Tertiary referral center.

PATIENTS

Twenty-two patients with congenital moderate mental retardation and conductive or mixed hearing loss were selected to receive a BAHA at the University Medical Centre Nijmegen, the Netherlands. Four of them were fitted despite a limited air-bone gap.

INTERVENTION

Rehabilitative BAHA application.

MAIN OUTCOME MEASURES

Implantation results, skin reactions, and audiological data were evaluated during a mean follow-up of 36 months.

RESULTS

All the patients were still using the BAHA 7 days a week and for more than 8 hours a day after a follow-up period between 5 and 96 months. Two implants (9%) were lost due to insufficient integration but were reimplanted successfully. With the BAHA, mean free-field thresholds showed a clear mean improvement of 9 dB compared with the previous hearing aid. Considerable improvements in daily activities were seen in at least five patients.

CONCLUSION

Moderate mental retardation should no longer be considered as a contraindication for BAHA application. Although implant loss was low, extra attention may be required from the personal care providers to maintain the percutaneous implant. The BAHA was well-accepted by the patients with moderate mental retardation and was being used for most of the day. Implementation of the BAHA as hearing aid treatment in patients with moderate mental retardation proved to be sufficiently effective and may have strongly positive effects on activities at school or at work.

UK and Ireland experience of bone anchored hearing aids (BAHA) in individuals with Down syndrome

OBJECTIVE

To evaluate the indications, surgical techniques and post-operative problems seen in children with Down syndrome fitted with bone anchored hearing aids (BAHA).

METHODS

A postal survey of all registered United Kingdom and Ireland BAHA centres.

RESULTS

There was a 98% response rate to the survey. Eighty-one centres in the United Kingdom and Ireland undertake BAHA surgery. Eighteen centres were identified to have undertaken BAHA surgery on individuals with Down syndrome. A total of 43 individuals were implanted. Twenty-four cases were under the age of 16. Soft tissue complications were encountered in 21 patients (49%). Osseointegration failures were encountered in four cases (9%). There was a high level of satisfaction with the BAHA system amongst patients, parents and carers.

CONCLUSIONS

BAHA is a valuable method of hearing amplification in children with Down syndrome. It should be considered not as a primary method of amplification, but in the overall management of individuals with Down syndrome after conventional hearing aids and/or ventilation tubes have been considered or already failed. The survey shows a high patient and carer satisfaction with the system, despite short term early soft tissue complications.