May 29, 2024
Carter McDonald (now age 10) was six years old in June 2020 when he became the first Canadian patient to receive a BONEBRIDGE 602 implant - a bone conduction device that is implanted under the skin and into the skull - to aid his hearing. At the time the surgery was completed at London Health Sciences Centre (LHSC), the BONEBRIDGE 602 was the only implant device of its kind available for paediatric patients.
Carter’s diagnosis and early intervention
Carter, who was born at LHSC in April 2014, failed his newborn hearing screening test.
“One of his ears was fine, but the other canal was blocked by what looked like a wall where there is normally an ear canal,” shares Marzena McDonald, Carter’s mother. “It was something we weren’t prepared for, and it started us on a journey of learning and interventions.”
Carter was diagnosed with atresia of his right ear canal soon afterwards, meaning that his ear canal lacked an opening. This meant that he could not use a conventional hearing aid. It was too risky to correct surgically, so other hearing interventions needed to be considered to ensure Carter reached hearing and speech milestones as he grew. At six months old, Carter received a temporary external bone conduction device that was worn on a softband or headband.
“We had the regular worries any parent has for their child and had a lot of our own learning to do to ensure we were supporting Carter the best we could,” says Reid McDonald, Carter’s father.
Marzena and Reid explored surgical bone conduction options, but they were not interested in a traditional percutaneous device, where a post attached to the skull protrudes through the skin.
Dr. Josee Paradis, Paediatric Otolaryngologist, LHSC, referred Carter to Dr. Sumit Agrawal, Otologist Neurotologist and Interim Physician Department Head of Otolaryngology/Head & Neck Surgery, LHSC, after learning about the opportunity for a paediatric patient to receive the first BONEBRIDGE 602 implant in Canada. Dr. Paradis identified Carter as a good candidate to experience this Canadian first, kickstarting the surgery process.
The family, and Carter, shared enthusiasm and excitement over this option that was available for Carter’s hearing.
About the implant
Dr. Agrawal and Kim Zimmerman, Audiologist, LHSC were both very familiar with the BONEBRIDGE implant. They were part of the team that performed the first BONEBRIDGE implant in North America in 2013 using the original BONEBRIDGE 601 model.
BONEBRIDGE is predominantly used for conductive hearing loss when sound waves are unable to penetrate the external or middle ear to reach the inner ear, such as in atresia. An external processor is connected magnetically to the implant, and together they enable hearing by creating vibrations to the surrounding bone. When the bone vibrations reach the inner ear, they are converted into nerve signals that the brain then interprets as sound.
The BONEBRIDGE was the first active transcutaneous implant, meaning that the entire implant could be placed under the skin without the need for a protruding post.
“There are a number of factors to consider prior to proceeding with implantation,” shares Zimmerman. “One of the main factors is skull thickness, which can impact device placement.”
The skull needs to be able to accommodate the implant, which is why paediatric patients were not able to receive this implant until recently. Compared to the 601 model, the BONEBRIDGE 602 is thinner and easier to place in paediatric patients and in adult patients with thin skulls.
“After the implant site heals and the processor is activated, the device itself is relatively low maintenance,” explains Zimmerman. “The external equipment can be updated with future improvements to allow Carter access to the most up to date technology.”
The surgery
“Having BONEBRIDGE as an option for paediatric patients was a gamechanger. Since Carter’s surgery, we now routinely use this new transcutaneous device in children and adults, and it has become standard of care for most patients unable to use a hearing aid for conductive hearing loss,” says Dr. Agrawal.
The surgery with Dr. Agrawal was unfortunately delayed due to the pandemic. As a result, Dr. Agrawal, who had started the consultation process with the McDonald family, referred Carter to Dr. Lorne Parnes, Otologist Neurotologist, Site Chief and Implant Program Director, LHSC. “I felt confident about the surgery, the implant and the positive impact this would have on Carter’s life” said Dr. Parnes.
The device was implanted into a part of Carter’s skull that was thick enough to support the implant. This was determined through imaging and 3D modeling performed by Dr. Agrawal. The surgery and Carter’s recovery went smoothly.
After recovery, Carter met with Zimmerman for “activation day” - the day he received his hearing device, which was activated and calibrated for his hearing.
Carter today
Marzena and Reid are proud of Carter and incredibly grateful for his health-care team who helped make his surgery and adaptation to his new device a success.
Carter is thriving in school and his extracurriculars. In terms of development, due to early diagnosis and intervention, his hearing and speech development are where they should be for his age.
He has been responsible with his device and wears it when he can, knowing that he can’t wear it while swimming or doing activities that require a helmet.
“It’s so easy to put on and take off,” says Carter as he takes the magnetized hearing device, removes it and puts it back on the magnetized implant. “I also get to change the cover. It’s a pirate – I like the detail.”
“Carter makes my job easy. He’s so appreciative of having the device and being able to see him grow and be a part of his hearing journey has been a pleasure,” shares Zimmerman. “It’s been wonderful to witness the improvement in Carter’s confidence in his hearing because of the device.”
It was clear that Marzena and Reid wanted what was best for Carter long-term. Adds Dr. Agrawal, “When we mentioned Carter was a candidate to receive the first BONEBRIDGE 602 device in Canada, you could see how excited the entire family was to be able to improve his hearing and, in turn, his quality of life.”
Dr. Parnes expresses profound fulfillment in conducting this type of surgery. “Witnessing the excitement and gratitude of families underscores the privilege I feel in facilitating such substantial improvements in patients’ hearing losses.”