1. What is microtia?
Microtia is a congenital malformation with a prevalence of about 1 in 5,000-7,000, and the prevalence varies by country and ethnicity. A typical Grade III microtia is a curly bologna-like tissue, a Grade II microtia is a milder deformity that looks like a small ear, and a Grade I microtia is a minimal deformity of the ear. Ninety percent of microtia is unilateral, with the right side being about twice as affected as the left; males account for about 65% of patients and females only 35%.
2. What is atresia of the external auditory canal?
Microtia, atresia and middle ear malformations often occur together because the outer ear and middle ear originate from the same germ layer during embryonic development. In 15% of patients with microtia, it looks like there is an “external auditory canal”, but in reality it is only a “blind end” and there is no real external auditory canal.
3. What are the causes of microtia? Are parents responsible for the occurrence of microtia in their children?
The cause of microtia is not known for sure, but one thing is certain: it is not the parents’ fault that caused the child’s microtia, and they do not need to feel guilty about it. It is very common for parents of children with microtia to feel guilty, but there is nothing they can do to prevent their child’s microtia from occurring.
4. What is the probability that both parents of a child with microtia will have another child with microtia?
If a normal couple wants to have a child, the probability of having a child with microtia is 1 in 5,000-7,000, however, if both parents of a child with microtia want to have a child again, the probability of having a child with microtia increases to 5%, or 1 in 20. 5% of the immediate family members of a child with microtia have a family history of microtia, and the probability of a child with microtia having a child with microtia themselves is also 1 in 20.
5. Is there a drug-related cause for microtia?
Most children with microtia do not have other malformations. One third of children have hemifacial microsomia (short hemifacial) and 15% have facial nerve dysplasia. Other malformations such as harelip, cardiovascular malformations or urinary problems are not as likely.
6. When do children start to be concerned about microtia?
Children start to be concerned about their malformed ears around the age of 3 to 3.5 years. They begin to compare their bilateral ears in front of a mirror and begin to refer to their “little ears”.
7. What do parents tell their children when they notice that they are “different”?
When children are concerned about their little ears, parents should tell them that they are born with them and that when they grow up, doctors will let their little ears “grow up” and then treat them as completely normal children. If a child is stressed by their microtia before the age of 7 or 8, it is mainly because family members are overly concerned about it and pass this concern on to the child.
8. When is the best time to repair a microtia?
I generally do not advocate surgery for microtia before the age of 6 for two reasons: First, for technical reasons. Firstly, technical reasons, until the child is 6 years old, the rib cage is long enough to be sculpted into an ear brace in the size of the normal ear on the opposite side. Second, for psychological reasons, children are not particularly concerned about their abnormal ears until they are 6 years old, thus causing no serious psychological trauma, and they are not very cooperative with post-operative care, while after 6 years of age children begin to have a stronger will of their own for surgical repair and can actively cooperate with the surgeon during and after surgery.
9. Why is microtia repair surgery with living tissue a very challenging task?
The surgeon must sculpt the rib cartilage into a three-dimensional auricular shape in an operating room setting and then create a “capsule” under the skin and place it into the sculpted framework without disrupting the blood supply to the skin in a limited amount of time. This is like putting a 5-pound object into a space that can hold a 2-pound object, and doing this in vivo! In addition, because cartilage cannot be shown on x-ray in the same way as mature bone, it is impossible for the surgeon to know how well the rib cartilage is developing before the surgery. No matter how difficult it is, the surgeon must do his best to sculpt an auricular scaffold that is as realistic as possible.
10. What methods are currently available for microtia revision?
There are two methods of microtia repair according to the source of the auricular scaffold material: one is to use the patient’s own living tissue to sculpt the implant (e.g. rib cartilage) and the other is to use artificial material.
11. Does the surgically reconstructed ear grow with age, or does the child need to reconstruct the ear again when he/she grows up?
An ear made from one’s own rib cartilage is “living” and therefore can grow with age, whereas an ear made from artificial material obviously cannot grow with age.
12. What are the advantages of sculpting ear scaffolds from living tissue?
The benefits of using your own living tissue to repair the ear are obvious. The auricle is “living” and can grow with age, and can repair itself after damage. Brent has performed this method on 1,500 patients, some of whom have been followed up for 20 years, and has shown that the results are excellent and can last a lifetime.
13. Do I need to restrict certain exercises after microtia repair?
Basically, there is no need to restrict any movement in particular. As mentioned above, because it is a living tissue reconstruction, the child can participate in sports and swimming up to 5 weeks after surgery without any particular concern for the operated ear or chest wall.
14. If the ear is reconstructed with rib cartilage, does it have any effect on the child?
The discomfort in the chest after surgery is mainly due to the intravenous medication the night before the surgery, while there is no discomfort in the ear. Only hydroxyphenylacetamide and codeine syrup are needed after the rib cartilage surgery and the chest wall discomfort can be resolved after a few days. If there is postoperative discomfort in the next II and III procedures, it is also mainly in the ear, and these can be resolved on an outpatient basis.
15.Is it possible to use the mother’s rib cartilage or other people’s tissues for implantation? Why is it possible to perform kidney transplant, heart transplant and liver transplant but not cartilage transplant?
In order to ensure the success of the transplant, the patient needs to apply medication for the rest of his life to prevent his own rejection, and these medications have very serious side effects, such as causing heart or kidney problems. And in fact, the doctor only needs to spend 20 minutes more to take the patient’s rib cartilage and another 30 minutes to sculpt it, using allogeneic tissue is not necessary.
16. Do all patients with microtia have hearing problems?
Ninety percent of patients with microtia have unilateral disease, have a normal ear, and have adapted to hearing in one ear. The functional problems of these microtia patients are mainly sound localization problems and hearing problems in noisy environments. Children should talk to the appropriate teacher when they enter school so that they can be placed in an appropriate position. In the case of binaural malformations, the problem is more severe and these children must be fitted with bone conduction hearing aids in the first few months of life in order to facilitate their speech development.
17. How can I hear with a microtia?
Patients with microtia and external atresia transmit sound to the inner ear through a bone conduction pathway. Patients often have normal inner ear structures because they originate from a different germ layer than the middle and outer ears. Bone conduction hearing aids are fitted to the bone in the posterior region of the ear, creating a bypass for the abnormal middle ear to amplify sound and channel it into the normal inner ear. This allows a child with a binaural deformity to hear sound and does not interfere with his or her speech development.
18. How long after birth can we tell if a child with microtia and external atresia has a hearing problem?
Brainstem auditory evoked potentials (BAER) can be performed within a few days or 2 weeks after birth, and BAER can detect hearing problems earlier than electrical audiometry. For bilateral malformations, this test is even more important. I have also seen patients with unilateral microtia who have abnormal hearing on the opposite side.
Children with monaural hearing do not need hearing aids, but those with bilateral microtia need hearing aids to help with their speech development. They need bone-conduction hearing aids for a few months after birth, and then they need to see a speech therapist when the child begins to speak.
19. How do I protect my normal ear from microtia?
Ninety percent of children with microtia are unilateral, and these children do not need hearing aids and have good speech development. Children (with or without microtia) are susceptible to ear infections and must be especially aggressive in treating infections in the healthy ear of microtia. If ear infections occur frequently in these children, it is important to monitor hearing and speech development frequently.
20. Are there any other tests that need to be done for microtia?
Because the urinary tract develops at the same time as the ear, malformations of the urinary tract are more common in patients with microtia (about 4%). A renal ultrasound can give us information about the kidneys. a CT scan can give us information about the development of the middle ear and help us decide if the patient is a candidate for hearing reconstruction, and a CT scan can be used to rule out cholesteatoma (15% prevalence in patients with atresia)
21. What is BAHA? In what cases can it be used in children with microtia with atresia?
BAHA (Bone Anchored Hearing Aid) is a box shaped device that is attached to a metal fixator which is anchored to the skull by two surgical methods, this hearing device can provide better sound quality than traditional bone conduction hearing aids. It needs to be surgically placed and requires scalp care during the hearing aid application. If a bone-anchored hearing aid is placed prior to auricular contouring, it is required to be placed very far back in the skull to prevent the resulting scar from interfering with the later auricular reconstruction. Many BAHAs are placed improperly resulting in missed opportunities for auricular reconstruction.
I believe it is best to wait until after auricular reconstruction if considering BAHA implantation for a child. For children with bilateral ear deformities, traditional bone-conduction hearing aids can be used first, and then BAHA surgery can be performed after the auricular deformity has been repaired.
22. Should I perform auricular repair first or external canalplasty and tympanoplasty?
If the surgeon wants to use rib cartilage sculpted into an auricular scaffold for implantation, the result of the auricular deformity repair relies on a pristine, scar-free skin in the area of the ear implant. Reconstructing the auricle first to repair the microtia does not interfere with the external auditory canal surgery for canal atresia, but the reverse is not true. If external otoplasty is done first, the skin in the area is no longer suitable for auricular reconstruction and the surgeon must replace the original good skin with a fascial flap to cover the ear scaffold.
23. Why not do the surgery earlier, for example, at the age of 2 or 3, to rebuild function and avoid psychological trauma?
As mentioned above, children at an early age are not overly concerned about their abnormal ears and do not cooperate well with post-operative care. As for the repair of external atresia, the younger the child, the stronger the tissue repair ability, which is actually a disadvantage for the repair of external atresia. The bone regeneration capacity of such a young child is very high and the probability of postoperative atresia reattachment is higher. As an example, in a child with a cholesteatoma, removal of that cholesteatoma involves grinding away the bone to reveal and remove the cholesteatoma, and then reoperating a few months later to reconstruct the middle ear. When the otologist does the reconstructive surgery again 9-12 months later, he finds that the area of the mastoid that was previously removed has been filled with new bone. If external atresia is done at a young age (e.g., 2-4 years), the risk of reattachment of the external auditory canal mentioned above is real. Even at the age of 7-8 years, the risk of reoperation exists because the incidence of bone regeneration or external auditory canal restenosis is in the range of 15-20%. In younger patients, this probability is higher because of their significant regenerative capacity.
If the atretic external auditory canal is not opened at an early age, will the auditory center fail to understand the information it receives again when hearing reconstruction is performed at an older age? While this concern is perfectly valid for the visual system, fortunately it is completely unnecessary for the auditory system. In the visual system, if the brain fails to receive information from one side of the eye, the center “shuts down” the ability to understand and process that information, which we call amblyopia, or lazy eye, which is essentially a blind eye. Fortunately, this is not the case in the auditory system. Signals from one ear are transmitted to the same side of the brain and to the other side of the brain early in the entire auditory reflex pathway, in other words, from birth (and even earlier) both auditory centers work together to collect and process the information coming from both ears. This means that regardless of when the external auditory atresia opens, the bilateral auditory center can process and understand the new signals it receives.
For these reasons, we recommend delaying microtia/atresia surgery until 6 or 7 years of age.
24. Is it wise to perform external otolaryngoplasty for unilateral microtia?
In patients with unilateral external atresia, opening the atretic canal may improve the child’s hearing in noisy environments (noisy classrooms, playgrounds, etc.) as well as spatial localization of sound. We are currently conducting research. Approximately 50% of patients with microtia/atresia have a well-developed middle ear, making them suitable for hearing reconstruction surgery, which will require a CT scan to determine.
25. Do I need a CT scan of the ear for microtia?
CT examinations are usually required for the following purposes
(1) To detect the presence of congenital cholesteatoma.
(2) To understand the development of the middle ear mastoid.
(3) To detect malformations of the auditory chain.
(4) To understand the development of the inner ear. Because there is not much damage in the middle ear and external auditory canal in the early stage even if there is a cholesteatoma present, CT examination of the middle ear mastoid is required only at the age of 3-4 years. CT examination is also needed again before the 6-7 water surgery.