Microtia | Testing & Diagnosis
How is microtia diagnosed?
Because microtia is a congenital condition, your child's malformed ear will be obvious at birth, and therefore diagnosed by the doctor immediately upon physical examination.
Doctors also recommend an Auditory Brainstem Response Evaluation soon after every child’s birth to evaluate babies’ inner ear function on both sides.
What is an Auditory Brainstem Response Evaluation (ABR)?
An ABR is a type of test that evaluates how well sounds travel along the hearing nerve pathways from the ear to the brainstem.
There are two main types of hearing loss:
Conductive hearing loss—problems transmitting sound from the outer ear (where sound is collected) to the inner ear.
This is the predominant type of hearing loss that’s associated with microtia.
Sensorineural hearing loss—problems with the nerves connecting the inner ear to the brain. In the inner ear, tiny hairs on the cochlea act as a neural pathway, transmitting through the inner ear. Usually, problems with these hairs on the cochlea are responsible for sensorineural hearing loss.
Sensorineural hearing loss is present in 10 to 15 percent of children with microtia.
How does it work?
An ABR test is a sleep EEG hearing test, which shows the softest sounds your child's ears can detect at various pitches. The ABR compares changes in brain activity to the timing of repetitive sounds to determine whether the particular intensity of sound can be heard.
How is the test performed?
There will be three or four small stickers on your child's head, connected to leads going into a computer. Sounds will be presented through an earphone to each ear separately while a computer analyzes the changes in the brain wave pattern in response to sounds.
Your child should be sleeping for the duration of the test. Young children under the age of 6 months are not usually sedated, and the test is performed while your baby is naturally sleeping, following a feeding. Children older than 6 months are usually sedated.
The test is not painful or uncomfortable in any way, but it is necessary for your child to be asleep in order to obtain clear recordings during the test.
You will be in the room with your child during the test, and the results will be explained immediately afterward.
How long does an ABR test take?
ABR evaluations, both sedated and unsedated, take two to three hours to complete.
Important: Please follow these feeding instructions before your child’s ABR test.
Under 6 months of age:
no solid food, milk or formula for four hours before the test
6 months or older:
no solid food, milk or formula for six hours before the test
For all children:
Clear liquids such as water, breast milk or apple juice should be given until two hours before the test.
Please bring your child awake but very sleepy.
Microtia | Treatments
The care and treatment of a child with microtia depends on the severity of the case. Some children will need a series of operations, while others might not need any treatment at all.
Though the prospect of your child needing a surgical procedure is worrisome, it’s important to remember that these procedures have excellent success rates.
What surgical treatment is usually used for microtia?
The most common type of operation for microtia we perform at Boston Children’s is called autologous auricular construction. During this operation, specially trained pediatric plastic surgeons will take cartilage from your child’s ribcage and use it to “plant” a new ear on the affected side of the head. The process uses your child’s own tissue, so if the new ear is ever injured it can heal itself just as a natural ear would. Autologous construction is performed when a child is 6 years of age or older. He/she needs to be old enough to have sufficient rib cartilage to “spare”, and 6 years is about the age when the ear on the other side (if applicable) will reach its approximate adult size—so the surgeons can be sure to line up the new ear to match it.
Will my child need further operations as he/she ages?
Yes. Autologous construction usually requires three procedures in total, depending on the type and severity of your child’s microtia. Procedures are typically scheduled six months apart to allow your child time to heal.
First procedure Surgeons remove some cartilage from the ribcage to build a new ear.
Second procedure Surgeons refine and reposition the new earlobe.
Third procedure Surgeons lift the new ear for better alignment and perform “touch-ups” as needed.
It is possible that your child also may need an operation on the middle or inner ear. In that case, surgeons will perform the procedure after the last operation is done.
How will my child look after the reconstruction?
While your child’s reconstructed ear will not look exactly like his other ear, it will greatly improve his/her appearance (and will allow practical things like wearing eyeglasses or sunglasses).
Are there alternatives to surgical treatment for microtia?
In general, we recommend autologous construction as the most effective treatment for microtia. It offers children a comfortable new ear that feels natural, facilitates the use of eyewear, boosts self-esteem and improves their quality of life. At the same time, we understand that every child and family is different. Your doctors will work with you to decide on the right option.
Alternatives to autologous construction include:
- No treatment You may opt not to have any treatment at all. Talk to your child’s care team for guidance and advice.
- Ear implant An artificial ear made from synthetic materials can be used instead of cartilage. Advantages include no chest scar and ear construction as early as age three. Disadvantages include a higher complication rate and potential long-term problems compared to autologous construction.
- Ear prosthesis This type of artificial ear, made from a synthetic material, can be attached to the side of your child’s head with a minimally invasive procedure. Disadvantages include the need for daily care.
What happens if my child has hearing loss related to his/her microtia?
If your child has a hearing problem related to microtia, she/he will be followed by an audiologist (hearing specialist) and an otolaryngologist (ear, nose and throat expert). Together, the team will:
- monitor the hearing loss with regularly scheduled hearing tests (audiograms)
- recommend hearing aids and other ways to maximize the use of the remaining hearing • suggest a hearing aid (either worn as a headband or implanted into the bone) in the event of serious hearing loss
- offer surgery to recreate a missing ear canal (called atresia repair) and improve hearing. Alternatively, a bone anchored hearing aid (BAHA) may be offered.
- recommend additional language or developmental assessments for your child, as needed
- direct you to community resources for educational or financial assistance
Timeline of care
- Infancy: Possible headband hearing aid
- 6 years of age or older: First stage autologous reconstruction
- 6 months later: Second stage autologous reconstruction
- 6 months later: Third stage autologous reconstruction
- 6 months later: Possible bone anchored hearing aid (BAHA), possible atresia repair
