Post-market clinical follow-up of a magnetic bone conduction implant (Cochlear Baha® Attract System)

Bone conduction implants such as the Baha® system were first clinically
described in 1977 by
Tjellström et al.1, and since then more than 100.000 patients have been treated
with this technique.
The traditional Baha system consists of a titanium implant, which connects to a
sound processor via a
skin-penetrating abutment. The sound processor transforms sound into vibrations
that are transmitted
via the abutment and titanium implant to the skull bone and then to the
cochlea. Although Baha
treatment has been proven to be a safe and effective treatment for patients
with a mixed or conductive
hearing loss or single-sided sensorineural deafness, a large proportion of Baha
candidates refuse to
undergo Baha surgery, mainly due to aesthetic concerns related to the
percutaneous abutment. Other
candidates may not be suitable for a percutaneous Baha due to being - for
medical reasons or other -
unable to perform the daily cleaning that the percutaneous abutment requires.
This clinical investigation will assess the usability and clinical performance
of a magnetic bone conduction implant, Cochlear**Baha**Attract System. The
device aims to reduce the perceived barriers for Baha candidates by providing a
non-skin penetrating bone anchored hearing device. This gives Baha candidates a
treatment option with improved cosmetic outcomes and minimal aftercare. In the
Baha Attract System, the sound processor connects to a nonpercutaneous implant
through a transcutaneous coupling. The transcutaneous coupling consists of an
implanted magnet, which is fixated to the osseointegrating titanium implant
underneath the soft tissues, and an external magnet placed on top of the skin.
The sound processor attaches to the external magnet via a snap coupling. The
transducer of the sound processor transforms sound into vibrations which are
conducted through the soft tissues and via the titanium implant to the skull
and onwards to the cochlea.


The Baha Attract System is CE-marked and has been in clinical use in Europe
since September 2013,
and received FDA clearance in the US in November 2013.

The Baha Attract System is intended for patients (adults and children) with
conductive or mixed hearing loss or single-sided sensorineural deafness.
Patients should have sufficient bone quality and quantity to support successful
implant placement.

While the Baha Attract System is approved for use in both adults and children,
this investigation is
limited to adult subjects. The paediatric population constitutes an
inhomogeneous patient group (agerelated), and currently there are no
audiological tests that are suitable for comparisons across age
ranges and across multiple countries/languages. Performance evaluation of the
Baha Attract System
in children should be performed as separate investigations.

The rationale behind this post-market clinical follow-up investigation is to
collect data regarding the usability and clinical performance of the Baha
Attract System in subjects with hearing impairment that are
candidates for Baha surgery:
•*to evaluate the efficacy of the Baha Attract System in terms of hearing
performance compared to the unaided situation and compared to a pre-operative
test situation using the sound processor on a Baha Softband;
•*to evaluate the mid- and long-term safety of the Baha Attract System.

This investigation is expected to demonstrate that the Baha Attract System
performs within its
intended use and is a suitable treatment for patients with a conductive or
mixed hearing loss or single sided sensorineural deafness.

This post-market clinical follow-up investigation aims to evaluate the
usability and the mid- to long-term performance of the Baha Attract System in
terms of hearing outcomes and safety. The objective is to compare the hearing
performance with the Baha Attract System (aided) and the unaided hearing
performance.
The investigation will also provide input to future product developments in the
area of transcutaneous bone conduction hearing.

The investigation is designed as an international multicentre, open,
prospective clinical investigation. The investigation comprises a 6-month
investigation with an additional 18-month follow-up period. The investigation
will be performed in an open design, since it is not possible to perform the
investigation in a blinded fashion. The main evaluations of the investigation,
i.e. free-field hearing tests, are relevant and objective methods.

As with any surgical products, there is a risk that unanticipated Adverse
Events may occur. The
subjects will be closely monitored in the investigation and instructed to
contact the responsible
investigator if they experience any untoward effect.

Risks associated with the transcutaneous coupling that cannot be completely
eliminated include
magnetic retention difficulties, pressure-related skin complications and
pain/discomfort. The system
has been designed to minimise these risks. Tests have demonstrated that the
Implant Magnet in combination with the BI300 Implant is MRI conditional for up
to 1.5 Tesla. Subjects that receive the Baha Attract System will receive an MRI
card, for use by radiologists to evaluate and plan any MRI examination.

Subjects that have received radiation therapy at the same side of the skull
where the Baha Attract will be positioned are excluded from the investigation.
Participation in the investigation requires slightly more frequent follow-up
visits for the subject than what is normally required, and the duration of the
visits will be slightly longer than normal. After surgery subjects are asked to
return to the hospital for 7 follow up visits (day 10, week 4, 6, 12, month 6,
12 and 24). The more frequent visits will provide the subject the opportunity
to more frequently interact with the treating physician.

With the Baha Attract System, the subjects will be able to benefit from the
Baha sound processor without an abutment penetrating the skin, thus providing
cosmetic advantages compared to a traditional Baha. In addition, with the Baha
Attract System, there is reduced need for daily cleaning to maintain a healthy
implant site compared to a percutaneous Baha, and risk of adverse tissue
reactions related to the percutaneous passage are eliminated.

It is expected that the audiological performance of the Baha Attract System
will be similar to, or somewhat better than, Baha on a Softband. The
performance in the high frequency range are likely to be slightly lower for
subjects with the Baha Attract System compared to the percutaneous solution,
due to transcutaneous attenuation of the vibrations through the skin.

Subjects will receive compensation for travelling expenses made for extra
visits to the clinic.