Bone-anchored Hearing Systems Research Articles

Three-week loading of the 4.5 mm wide titanium implant in bone anchored hearing systems

PurposeThe purpose of this study is to assess implant stability, implant loss, adverse skin reactions and quality of life benefit following surgical implantation and early processor loading (3-weeks post-implantation) of the Oticon Ponto 4.5mm osseointegrated auditory implant. This study also investigates the relationship between the type of post-operative skin reactions and the gender, BMI and medical co-morbidities of participants. Materials/MethodsUsing a prospective, multicenter design, thirty adult patients 18years or older who met medical and audiological candidacy for an osseointegrated auditory bone-anchored hearing device were evaluated. They underwent simultaneous implantation of the Oticon 4.5mm wide implant and a 3.75mm sleeper implant. Sound processor loading occurred at three weeks post-implantation. Implant stability was measured using Radio Frequency Analysis (RFA) at surgery, 1, 3, 6, 12, 26 and 52weeks. The Glasgow Benefit Inventory was used to assess quality of life benefit at 12 and 52weeks following implantation. ResultsThe results show a positive linear trend in implant stability measures in all subjects over time. There have been no implant losses with early 3-week loading. Skin reactions were limited to grade 0 and 1 of the modified Holger's grading scale.Due to the limited incidence of complications, no conclusion can be made regarding the relationship between patient demographic data and soft tissue reaction. ConclusionOur findings confirm the safety and efficacy of early loading of the Oticon 4.5mm wide implant. Participants showed satisfaction with the earlier use of their processor with no added complications after one year post-implantation.

Bone-Conduction Hearing Aids

Bone-Conduction Hearing Aids

Sound location modulation of electrocochleographic responses in chinchilla with single-sided deafness and fitted with an osseointegrated bone-conducting hearing prosthesis.

Bone-anchored hearing systems (BAHSs) provide sound location-dependent input to the normal ear for reducing the head shadow effect in the case of single-sided deafness (SSD). Patients with SSD can be fit with a BAHS positioned on the impaired side. Despite successful outcomes and some reports of spatial hearing capabilities, little data are available regarding the physiologic performance of BAHSs in response to free-field sounds. Cochlear microphonics (CMs) were recorded from five chinchillas before and after destruction of one cochlea. A BAHS (Cochlear Baha) was fitted on the deafened side. CM measurements were made in response to tones, with and without the BAHS, to free-field sounds presented ipsilateral to the SSD, on the side of the normal ear, and along the midline. Stimuli were also presented directly through the BAHS and an earphone to generate sounds with interaural time and level differences approximating free-field sounds. With the BAHS, CM thresholds were decreased (re: no BAHS) by approximately 10 dB for sources ipsilateral to the SSD, approximately 14 dB for midline sources, and approximately 5 dB for sources contralateral to the SSD. Changes in CM amplitudes and thresholds were sound location dependent. CM amplitudes were modulated by interaural time and level differences generated by the linear interaction of BAHS and acoustic signals. This study suggests that BAHS can provide input to the normal ear that is modulated by sound location, which serves to reduce the head shadow effect and may also offer cues to sound location.

Recent breakthroughs on surgically implanted hearing devices: Cochlear implants and bone anchored hearing systems

Recent breakthroughs on surgically implanted hearing devices: Cochlear implants and bone anchored hearing systems

Site for bone-anchored hearing system for children younger than 5 years.

To describe in children younger than the present US FDA-approved 5 years of age the thickest part of the temporal bone available for placement of a bone-anchored hearing system. Children with unilateral hearing loss, as with aural atresia, have deficits in at least language comprehension and oral expression. The early provision of hearing to the atretic ear may minimize the potential for auditory deprivation. Point prevalence descriptive study. Tertiary referral pediatric hospital. Thirty-eight patients less than 6 years old with congenital aural atresia had undergone temporal bone computed tomography (CT). Bone thickness lateral (ie, superficial) to the sinodural angle, in the topmost axial CT slice that included any adjacent petrous ridge, was measured. The mean bone thicknesses lateral to the sinodural angles of the atretic ears were 5.1, 5.0, 5.9, 5.2, 5.2, and 4.8 mm for the <1, 1-, 2-, 3-, 4-, 5-year-olds, respectively; of the non-atretic ears, thicknesses were 4.1, 4.9, 5.5, 6.7, 4.3, and 4.7 mm. Based on this small case series, bone thickness lateral (ie, superficial) to the sinodural angle is sufficient for many children suffering from aural atresia to have bone-anchored hearing devices implanted younger than age 5 years. Use of the sinodural site would require a magnetic bone-anchored hearing system, which could be repositioned posteriorly at age 5 years when pinna construction and atresiaplasty endeavors typically begin.

An alternative to percutaneous bone-anchored hearing systems

An alternative to percutaneous bone-anchored hearing systems

Measurement of implant stability and auditory pure-tone thresholds of Baha patients comparing osteosysthesis and osseointegrated systems

With bone-anchored hearing systems the implant-bone junction is critical for the transmission of mechanical vibrations to the skull. The implant stability might differ between available and widely applied implants and can be estimated by resonance frequency analysis.The implant stability and the audiological performance of ten adult long-time users where a bone-anchored hearing system was connected by an Baha osseointegrated implant (Cochlear Ltd, Mölnlycke, Sweden) were compared with the implant stability of fourteen adult patients provided with a Ti-epiplating osteosysthesis system (Medicon, Tuttlingen, Germany). The acute implant stability was compared between these two implants with one cadaveric skull.The results show higher resonance frequencies and thus higher implant stability for the osseointegrating system of both, measuring acute and after long-time use of the implants. The audiological outcomes show frequency dependent differences between both systems as determined by comparing pure-tone bone-conduction audiometry. However, measuring thresholds by a direct stimulation of the implant reveals better hearing with low frequencies for the osseointegrated system and for high frequencies with the osteosysthesis system. At all, the implant selection has an impact on the implant stability and on the pure-tone hearing.

The bonebridge as a transcutaneous bone conduction hearing system: preliminary surgical and audiological results in children and adolescents.

The Bonebridge (®) (BB, Med-El) is a newly designed transcutaneous active bone conductive implant with functional outcome similar to percutaneous bone-anchored hearing systems (BAHS). It is currently approved only for patients ≥18 years. Since the BB allows the skin to remain intact and therefore should be able to overcome some of the issues related to percutaneous BAHS including skin reactions, wound infection and implant extrusion, it would be especially attractive for use in children. We present a preliminary series of the first three cases of BB implantation in children/adolescents (10-16 years). Two subjects were affected by conductive hearing loss (CHL) and one subject by single-sided deafness (SSD). The surgical procedure with transmastoid approach was completed in all cases without complications. Both subjects with CHL showed an increase in speech perception thresholds in quiet from preoperative unaided to 6 months postoperatively with BB of 37 dB, respectively, of 12 dB. The adolescent with SSD attained -3.1 dB unaided vs. -5.6 dB with the BB in the "speech and noise from the front" presentation and +0.5 unaided vs. -5.0 dB with the BB in the "speech from the unilateral deaf side/noise from the normal hearing side" presentation using the adaptive Oldenburg Sentence Test. The results show a straightforward surgical procedure and satisfactory functional gain after BB implantation also in children/adolescents. BB implantation in patients ≤18 years is currently an "off-label use" so that detailed information about alternative treatment options, operation risks and the lack of approval for use in children is essential.

Initial experience of a rapid-insertion bone-anchored hearing system: series of 20 consecutive implants.

Objective: The loading of bone-anchored hearing system sound processors usually occurs two to three months after surgical implant. This study examined a new bone-anchored hearing system coupling mechanism that permits loading at two weeks post-implantation without compromising osseointegration. Methods: Twenty implants were implanted into 15 patients. The interval between operation and time of processor loading was recorded, along with the cause of any delay and any late complications. Results: Two patients were fitted with implants at seven and nine weeks. The delay was a result of administrative errors; the patients reported no skin problems. Of the remaining 17 implants, 8 processors were fitted at 2 weeks, 1 at 3 weeks, 4 at 4 weeks, 3 at 7 weeks and 1 at 8 weeks. For those nine implants fitted later than two weeks, the delay was because of incomplete skin healing. Conclusion: The Oticon Medical Xpress system allowed processor loading at two weeks post-operatively, providing skin healing was adequate. Early loading occurred in approximately half of the patients. All patients were fitted within the two to three months traditionally allowed. Prolonged skin healing time was the main reason for the delayed fitting of sound processors.

Comparison of Speech Discrimination in Noise and Directional Hearing With 2 Different Sound Processors of a Bone-Anchored Hearing System in Adults With Unilateral Severe or Profound Sensorineural Hearing Loss

To evaluate and compare the benefit of a bone-anchored hearing implant with 2 different sound processors in adult patients with unilateral severe to profound sensorineural hearing loss (UHL). Prospective crossover design. Tertiary referral center. Eleven adults with UHL and normal hearing in the contralateral ear were assigned to 2 groups. All subjects were unilaterally implanted with a bone-anchored hearing implant and were initially fitted with 2 different sound processors (SP-1 and SP-2). SP-1 is a multichannel device equipped with an omnidirectional microphone and relatively simple digital signal-processing technology and provides a user-adjustable overall gain and tone control with compression limiting. SP-2 is a fully channel-by-channel programmable device, which can be set with nonlinear dynamic range compression or linear amplification. In addition, SP-2 features automatic noise management, an automatic multichannel directional microphone, microphone position compensation, and an implementation of prescription rules for different types of hearing losses, one of them unilateral deafness. After at least 1-month use of the initial processor, both groups were fitted with the alternative processor. Speech discrimination in noise and localization tests were performed at baseline visit before surgery, after at least 1-month use of the initial processor, and after at least 2-week use of the alternative processor. Relative to unaided baseline, SP-2 enabled significantly better overall speech discrimination results, whereas there was no overall improvement with SP-1. There was no difference in speech discrimination between SP-1 and SP-2 in all spatial settings. Sound localization was comparably poor at baseline and with both processors but significantly better than chance level for all 3 conditions. Patients with UHL have an overall objective benefit for speech discrimination in noise using a bone-anchored hearing implant with SP-2. In contrast, there is no overall objective benefit from SP-1. Depending on the speech-in-noise presentation setting, the difference between objective benefit from SP-2 and SP-1 might be mainly attributed to the new technological features in SP-2 unavailable in SP-1 such as 1) automatic noise management reducing the noise in the speech signal and thus improving the signal-to-noise ratio of the resulting signal on the better ear, 2) programmable multichannel sound-processing and nonlinear dynamic range compression offering considerably greater control over signal amplification compared to SP-1, and 3) implementation of a prescription rule for unilateral deafness addressing the specific amplification needs of patients with UHL by reducing amplification in the low frequencies and applying additional gain in the high frequencies. Sound localization is poor but better than chance level in the unaided condition as well as in both bone-anchored hearing system-aided conditions.

The Punch Method for Bone‐Anchored Hearing Aid Placement

Objective: Various techniques have been described for bone anchored hearing system placement. Alterations to the initial technique have helped lower complication rates. Additional modifications can...

Outcomes after Usage of Ponto Implant System

Objective: Bone-anchored hearing systems have proven to be an effective amplification solution for conductive, mixed, and profound unilateral sensorineural hearing losses. The Ponto bone-anchored hearing system has been available in the United States for 2 years. Method: This multicenter study was performed to review our experience with the Ponto system in 99 patients from 3 medical centers. The mean follow-up was 6 months and the average loading time was 80 days. The linear surgical technique was used in 95% of cases. Clinical outcomes were measured. Results: Of the 99 cases, there were no implant losses. Factors such as gender, hypertension, diabetes, body mass index (BMI), and smoking were investigated to determine any correlation between skin reactions that were found. Smoking was the only factor to be found significant in correlating to skin reactions ( P &lt; .05). Conclusion: The Ponto bone-anchored hearing system is an effective and successful treatment option for conductive and single sided deafness. Factors were evaluated to determine skin reactions and implant survival. These include gender, hypertension, diabetes, tobacco usage, and BMI. Only tobacco usage seemed to be a significant factor in skin reactions.

“Punch” Method for Bone‐Anchored Hearing Aid Placement

ObjectiveVarious techniques have been described for bone anchored hearing system placement. Alterations to the initial technique have helped lower complication rates. Additional modifications can continue to improve postoperative results. A safe, streamlined approach for bone anchored hearing system placement to limit these known complication rates will be presented.MethodA retrospective chart review of 15 consecutive adult patients from an otology/neurotology practice was performed. Patients underwent the “Punch” method for placement using a 4‐mm implant with the longer 9‐mm abutment. The initial incision is performed using a 12‐mm punch biopsy with variations to the standard procedure.ResultsFifteen of 15 patients had successful placement of the bone anchored device. Ten were Oticon Ponto® systems, and 5 were the Cochlear BAHA® systems. There were no cases of tissue overgrowth, failure of osseointegration, or major postoperative infections. The only complications were minor skin infections that were treated with oral and topical antibiotic. All operative times were recorded and found to be less than 15 minutes. Postoperative follow‐up ranged from 10 to 24 months. All implants were found to be well integrated.ConclusionBone‐anchored hearing system placement with longer abutments may reduce postoperative tissue overgrowth. Using the “Punch” method decreases major postoperative infections, reduces incision length, improves cosmesis, and decreases operative time. Larger studies are needed to determine if the low complication rate demonstrated in this study will continue.

Computed Tomographic Analysis of Outer Calvarial Thickness for Osseointegrated Bone-Anchored Hearing System Insertion

Osseointegrated bone-anchored hearing systems (BAHSs) are a useful tool in auditory rehabilitation for single-sided deafness and conductive/mixed hearing loss. They rely on adequate osseointegration of titanium implants, which can be limited by calvarial thickness. This study examines adult computed tomographic (CT) temporal bone normative data for calvarial thickness in the areas commonly recommended for BAHS insertion and identifies hazards that may compromise the osseointegration process. Prospective analysis of 100 consecutive adult helical CT scans. Calvarial thickness was measured in axial and coronal planes 5.5 cm posterior to the superior external auditory canal at 6 vertical points (EAC, +1 cm, +2 cm, +3 cm, +4 cm, and +5 cm). Other parameters measured include temporal bone pneumatization and the presence of suture lines, bone marrow, and vascular structures. A total of 195 temporal bones were examined in 100 patients. Mean patient age was 60.9 years, of whom 54.4% were men and 45.6% were women. Mean calvarial thickness was greatest at +1 cm above the EAC level (6.3 mm) and thinnest at +4 cm (5.1 mm). Of temporal bones, 55% had at least 1 site thinner than 4 mm and 21% had at least 1 site thinner than 3 mm. Air cells and suture lines were more likely to be encountered within 2 cm above the EAC level, and marrow space is more likely to be encountered 3 to 4 cm above the EAC level. Selecting a position 3 to 4 cm above the level of the EAC is more likely to result in dural exposure for a 3-mm BAHS abutment, especially in men. Selecting a position near the level of the EAC provides thicker bone, but the surgeon is more likely to encounter suture line or enter mastoid air cells. Preoperative CT imaging may be a useful tool in evaluating calvarial thickness and hazards when planning BAHS insertion in the adult population.

Ten Years of Experience with the Swedish Bone-Anchored Hearing System

In 1977, a new phase began in hearing rehabilitation of patients with chronic middle and external ear diseases and atresias. Thus far, these patients have had to rely on conventional bone conduction and air conduction devices that for various reasons give poor rehabilitation. The principle of the new treatment, made possible by the Swedish bone-anchored hearing system, is simple: sound vibrations are directly transmitted to the skull bone via a skin-penetrating titanium implant and then are further transmitted to the cochlea, bypassing the middle ear. The present paper summarizes our results in 147 patients over 10 years, including a total of 6,334 follow-up months. No significant rate of skin infections was observed. In over 93% of the observations, no sign of adverse skin reaction was seen. When herein-suggested indications for treatment with the bone-anchored sound processor HC-200 are followed, the success rate is over 90%. The improved quality of life reported by the patients is a combination of improved quality of sound, improved comfort, and relief from middle ear and ear canal disease occasioned by conventional hearing aids.