Baha Dermalock and Implant Stability

By Guest Author: Lisa Christensen, AuD

Lisa Christensen, AuD, is the Audiology Program Manager at Cook Children’s Medical Center in Fort Worth, Texas and currently serves as President of the American Academy of Audiology (AAA).  We recently connected for a discussion on her use of bone conduction solutions as part of her clinical practice.

Q: Describe your process for fitting and using bone conduction technology in cases of atresia or microtia?

A: If the baby has atresia/microtia and traditional amplification is not an option, we follow the Joint Commission on Infant Hearing (JCIH) 1-3-6 Guidelines.  These babies are the easiest and most straight-forward cases, especially with bilateral atresia/microtia.  The cause of the hearing loss is visible, which helps with family motivation, and we fit the bone conduction scores instead of a potential fluctuating air conduction score.  These babies are also easy to obtain the JCIH new suggestions of 1-2-3 Guidelines.  In cases of bilateral losses, bilateral fittings should be fit bilaterally.

Q: How about for cases of unilateral hearing loss?

A: In cases of unilateral atresia/microtia or SSD, when-to-fit is a little more complex.  In order to put a Baha® processor behind and/or near the affected ear to obtain the best microphone placement, it creates a bit of an issue with babies and head control.  My recommendation with these patients is to obtain good, reliable diagnostic results and proceed with the Baha Softband order.  Wear-time may be limited until the baby has established good head control, and full-time wear-time may therefore be delayed.  However, parents can use tummy time and other times when the baby is upright to begin using the Baha on a Softband.  For most families, although a proper wear-time goal might not be obtained until 7-9 months of age when the baby spends a majority of their day sitting up, earlier use can still be beneficial.

Q: How do you choose between treatments using traditional air conduction, such as hearing aids, and treatments using bone conduction?

A: When choosing between traditional air conduction aids and bone conduction, first and foremost anatomy plays the biggest part.  If the ear can support an earmold and hearing aid, then it should at least be discussed with the family.  I often list out the advantages of each solution in the initial diagnosis or fitting appointment.  Some of the important things to discuss are if there is fluctuating air conduction due to middle ear status, such as in many patients with Down syndrome. Another notable thought is sound quality, do we overdrive an ear with a conductive loss and a traditional hearing aid? Or do we use the good bone conduction with a Baha for a better sound quality?

Q: What about deciding between a traditional CROS and Baha solution?

A: When comparing traditional CROS to Baha for SSD, age is a very important factor.  Fitting children with unilateral losses with a CROS should be given great consideration. As the AAA Pediatric Amplification Guidelines point out, attention to the child’s age and the ability to control their environment must be considered.  There is currently a very limited set of data to inform audiologists about this decision. As the Baha doesn’t ‘amplify’ by air conduction, I feel this is a safer option for young children with SSD.

Q: What is the earliest age you would fit a child with a Softband and are there any special considerations or tips for fitting Softband on very small children?

A: I have fit a two-week old with bilateral atresia with a Softband.  The mother of the baby had Treacher Collins and was a Baha user so when Treacher Collins with atresia was noted at birth we did a diagnostic ABR bedside in the NICU at one week of age and fit as soon as insurance was approved and the Bahas and Softband arrived in the clinic a week later.  As for tips or special considerations, bilateral loss equals bilateral Baha Softband.  Much like unilateral/SSD losses, you will most likely not get full-time wear with both Bahas for a period of time but that does not mean just order one and see what happens.  Get a bilateral Softband. Start with one Baha and as head control gets better start to add the second Baha during tummy time or times where the baby is sitting up.  I do recommend that parents switch out the Baha sound processors every few days to ensure both sides get wear time.  I also recommend not programming a right versus left until the time when the family is ready to start to use two at a time.  This will allow proper directional microphone usage. Lastly, I recommend for infants that the parents switch sides or places on the head every few hours to decrease chances of irritation and therefore lack of use.

Q: How do you test and verify a Softband fitting for a young child (baby or toddler)? 

A: Testing young children is the ‘easy’ part in this process when utilizing ABR tonebursts and bone conduction.  The harder part for most audiologists is verifying, especially for those who do not routinely see babies and toddlers.  Like most days working with kids, some of the following will be easily obtained….and the others will take some repeat visits. To start the verification process, I like to utilize BC Direct in the Cochlear™ Baha software.  This can be done just like behavior testing and will be based on developmental status of the patient.  You can use behavioral observation audiometry and/or visual reinforcement audiometry for BC Direct.  Some clinics will mount a video VRA screen on the wall or you can create a box with traditional VRA reinforcers that can be used to train these patients where VRA is most appropriate.  For BOA, it is like standard BOA testing so make sure you families bring in the infant hungry so that you can look for sucking responses.  Once BC Direct is completed you can take this show to the sound booth for verification using the same developmentally appropriate testing techniques to obtain aided thresholds and speech perception testing for verification of the device.

Q: How about an older child (pre-school or school age)?

A: For testing an older children, as always it starts with an accurate hearing evaluation that is done at the developmental status of the child.  So even for a 4 year old if behavioral testing isn’t achievable, you should obtain a sedated ABR to make sure your starting point is at the correct place.  BC Direct can also easily be achieved for this population with the proper tools aka toys.  Performing conditioned play audiometry through BC direct is easy and requires little preparation.  Again once the processor is programmed appropriately, take your show on the road to the booth and repeat for aided thresholds and speech perception testing to verify the device.

Q: What topics do you cover when counselling a family of a child that is getting a Softband? Are there differences depending on the child’s age?

A: I start fairly early on depending on the family’s readiness to learn explaining the anatomy of their child’s ear.  Through my experiences, I think this is a vital piece of information for them.  I utilize a clipboard with the ear anatomy on it and a dry eraser or a pad of ear anatomy paper.  This really helps them understand where the issue lies and helps them to understand why a Softband is the best, and many times only, option for the child.  When families understand why the Softband is needed, they are much more compliant in wearing it. 

Also, fairly early in the process I ask about their thoughts for surgical repairs. This might seem early to many but the sooner we start to discuss it the better knowledge the family will seek to make the best decision for their child.

Q: Do you ever fit Softband on a temporary basis (i.e. for children with Down Syndrome who have fluctuating middle ear problems)?  If so, what has your experience been with this?

A: This is one of the things I enjoy most about the Softband.  So many children, especially with conditions such as Down Syndrome, can benefit from something to help with a fluctuating conductive hearing loss.  Using the Softband has been life changing for these patients when so many times it was very hard and unreliable to fit a traditional hearing aid. 

Q: When would you consider a SoundArc for a child?  Have you ever switched a child from a Softband to a SoundArc?  If so, why and what were the considerations?

A: I would consider a SoundArc for a child as soon as they are about 3 years old.  By that point they can typically handle using the SoundArc and have many times started in a preschool program.  In my experience when a child begins a regular school program, many families start to have concerns about how the Softband will be received by peers.  So this tends to be when families are seeking out other options for the child.  I have switched many children from a Softband to SoundArc.  Most of these switches were done purely for cosmetic reasons and mostly preschool aged boys were the ones that were traded.  I always let kids wear the device how they will/want to wear it.  Then I verify it in the booth.  If I need to make changes to help them hear better how they like wearing it, then I do that.  If you put a Softband or a SoundArc where you think it should be clinically in the beginning, sometimes that lasts until surgical intervention.  However, sometimes kids find a specific place or device that feels better to them.  When this happens, I always try to work with them so that they wear their device as much as possible.

Q: When do you start discussing a surgical bone conduction option with a family who is using a non-surgical option like Softband?  How do you decide when a child might be ready to transition to a surgical option?

A: I begin discussing surgical options very soon in the process many times prior to fitting the actual Softband.  With atresia and microtia, you can see the loss and the process always seems to move along faster than with sensorineural losses.  I know these families search on the internet and I want to be there to help them find the best and most accurate information for their child.

For the most part, I have worked with very traditional surgeons, so deciding on when the child might be ready to transition is mostly based on the surgeon’s preference and the FDA-approved product indications.  I bring up the topic early so the family can read and make informed decisions but at the end of the day the surgical decision is left to the surgeon.

Q: Are there any future technologies you feel might change the way you work with children who need bone conduction solutions?

A: I believe that direct Bluetooth® streaming has changed the way we utilize hearing devices.  I think that anything that helps these children feel that their device has something fun for them they will want to wear them more and that is what I want as an audiologist – for children to hear the very best they can.  And now with more power options, it is easier to fit every child that needs a bone conduction solution.

Also, new technologies like the Osia® System will need to be added into the counseling topics early on.  This surgical solution is currently on the market for children 12 and older in the US and it will be something we discuss as families consider a surgical option.

As a pediatric audiologist, I think that we are starting to change the way verification and programming happens.  We are a rule driven group of pediatric audiologists. When there is a widely accepted protocol based on best practice we all get excited. So I feel that as we adopt more specific protocols related to bone conduction, more audiologists will get comfortable with the process.  And when more audiologists feel comfortable, more devices are fit and more individuals hear better.  It’s really a great time to be an audiologist as we watch so many exciting technologies get better and better.

In the United States and Canada, the placement of a bone-anchored implant is contraindicated in children below the age of 5

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