[Magnetic coupling of partially implantable bone conduction hearing aids without open implants]

Clinical guideline on bone conduction implants

INTRODUCTION AND GOALS

During the last decade there have been multiple and relevant advances in conduction and mixed hearing loss treatment. These advances and the appearance of new devices have extended the indications for bone-conduction implants. The Scientific Committee of Audiology of the Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello SEORL-CCC (Spanish Society of Otolaryngology and Head and Neck Surgery), together with the Otology and Otoneurology Committees, have undertaken a review of the current state of bone-conduction devices with updated information, to provide a clinical guideline on bone-conduction implants for otorhinolaryngology specialists, health professionals, health authorities and society in general.

METHODS

This clinical guideline on bone-conduction implants contains information on the following: 1) Definition and description of bone-conduction devices; 2) Current and upcoming indications for bone conduction devices: Magnetic resonance compatibility; 3) Organization requirements for a bone-conduction implant programme.

RESULTS AND CONCLUSIONS

The purpose of this guideline is to describe the different bone-conduction implants, their characteristics and their indications, and to provide coordinated instructions for all the above-mentioned agents for decision making within their specific work areas.

Implantable hearing devices

Combined hearing loss is an essential indication for implantable hearing systems. Depending on the bone conduction threshold, various options are available. Patients with mild sensorineural deafness usually benefit from transcutaneous bone conduction implants (BCI), while percutaneous BCI systems are recommended also for moderate hearing loss. For combined hearing losses with moderate and high-grade cochlear hearing loss, active middle ear implants are recommended. For patients with incompatibilities or middle ear surgery, implants are a valuable and proven addition to the therapeutic options.

[Treatment of nasal valve stenosis]

Nasal valve dysfunction is one of the most common causes of obstructed nasal ventilation. In most cases the cause is congenital, but iatrogenic occurrence after functional-aesthetic rhinoplasty is not infrequent. To diagnose nasal valve dysfunction, a thorough anamnesis, inspection, endoscopy, and palpation is required. If conservative therapy using rhinologic substances, as well as outer and inner stenting do not achieve the desired outcome, and the dysfunctional site can be localized, surgical procedures are indicated to improve nasal valve function. Numerous procedures and techniques are available, amongst which the most important ones shall be elucidated and discussed in the present article. These include septoplasty, septorhinoplasty, and enlargement of pyriform aperture stenosis, as well as corrections of the upper and lower lateral cartilages.

New developments in bone-conduction hearing implants: a review

The different kinds of bone-conduction devices (BCDs) available for hearing rehabilitation are growing. In this paper, all BCDs currently available or in clinical trials will be described in categories according to their principles. BCDs that vibrate the bone via the skin are referred to as skin-drive devices, and are divided into conventional devices, which are attached with softbands, for example, and passive transcutaneous devices, which have implanted magnets. BCDs that directly stimulate the bone are referred to as direct-drive devices, and are further divided into percutaneous and active transcutaneous devices; the latter have implanted transducers directly stimulating the bone under intact skin. The percutaneous direct-drive device is known as a bone-anchored hearing aid, which is the BCD that has the largest part of the market today. Because of some issues associated with the percutaneous implant, and to some extent because of esthetics, more transcutaneous solutions with intact skin are being developed today, both in the skin-drive and in the direct-drive category. Challenges in developing transcutaneous BCDs are mostly to do with power, attachment, invasiveness, and magnetic resonance imaging compatibility. In the future, the authors assume that the existing percutaneous direct-drive BCD will be retained as an important rehabilitation alternative, while the transcutaneous solutions will increase their part of the market, especially for patients with bone-conduction thresholds better than 35 dB HL (hearing level). Furthermore, the active transcutaneous direct-drive BCDs appear to be the most promising systems, but to establish more detailed inclusion criteria, and potential benefits and drawbacks, more extensive clinical studies are needed.

Malformation and plastic surgery in childhood

Malformations of the head and neck show a huge variety of clinical symptoms with functional and esthetic consequences. Often times its rehabilitation requires multi-staged and multi-disciplinary procedures and concepts. These must consider eating, speech, mimic expression, hearing and "esthetics" or at least "normality". A survey of the most common head and neck malformations and their treatment options are presented here.

Comparison between a new implantable transcutaneous bone conductor and percutaneous bone-conduction hearing implant

OBJECTIVES

Despite good results on osseointegration and limited skin reactions with percutaneous bone conductors, there remains room for improvement. Especially in children, adverse events with percutaneous bone conductors might occur more frequently. Transcutaneous bone conductors, if powerful enough, can provide a solution that minimizes adverse events and implant loss. This study compares a new transcutaneous bone conduction hearing aid, the Sophono Alpha 1 (Sophono), with the percutaneous BAHA system (BAHA).

METHODS

In our tertiary referral center, 12 patients (age 5-12 yr) with congenital unilateral conductive hearing loss were enrolled in the study as follows: 6 patients with the Sophono and 6 with the BAHA. Both clinical results and audiologic data were gathered. For an objective audiologic comparison between both systems, we used a skull simulator.

RESULTS

The skin reactions were comparable between both groups, in 1 implant was lost 1 month after second phase surgery (BAHA). The users received audiologic benefits from both systems. The BAHA-based outcome was slightly better compared with Sophono-based results in sound field thresholds, speech recognition threshold, and speech comprehension at 65 dB. The skull simulator demonstrated that the BAHA device has an output that is 10 to 15 dB higher compared with the Sophono device.

CONCLUSION

The Sophono offers appealing clinical benefits of transcutaneous bone conduction hearing; however, the audiologic challenges of transcutaneous application remain, as the Sophono does not exceed percutaneous application regarding audiologic output.