"Microtia" (small ear) : It is a condition characterized by impaired development of the external ear.
It generally occurs in one out of every 5000 - 6000 births and involves the external ear and middle part of the ear. The inner ear is essentially normal in function. As a result, the main problem lies in conduction of the sound to the inner part of the ear. Although the reconstruction of the external ear needs great surgical expertise, restoration of hearing could be easily done by bone conduction hearing aids. This may occur on one side (unilateral microtia) or on both sides (bilateral microtia).
The ear deformities in microtia could be of various types and one way to understand this is by simple classification system, based on the anatomy of the ear. This actually helps in choosing the right operation for a particular patient.
1. Lobule type microtia - Only the ear lobule is present along with the remnant of the ear
2. Small concha type microtia - Ear lobule is present along with small conchal indentation and remnant of the ear
3. Concha type microtia – Ear lobule, concha, external auditory meatus and tragus are present
4. Anotia- All the features of ear are missing
5. Atypical - Low hair line cases
Choosing the correct time for operation is one of the most important factors for achieving long lasting and stable results.
Various authors around the world choose 8 to 10 years as the correct time of operation or a chest circumference of at least 60 cm at xiphisternum. In Indian patients we have painstakingly analyzed our long term results in this age group and have come to understand that , for achieving a world class outcome it is rather prudent to further delay the reconstruction to at least teen age.
Our original research and audit in this field lead us to develop a first of its kind grading system for ear reconstruction in the world and on analysis of our patients it appears that long term stability of framework is lost in younger children ,at least in the Indian subcontinent and initial good results disappear with in few years.
We have published our results in Indian Journal of Plastic Surgery and have further refined our grading system to better assess the long term results.
Ear is reconstructed using one’s own rib cartilages in two stages.
Stage one - A small 5 to 6 cm horizontal incision is given in anterior chest wall. Rib cartilages are harvested leaving the covering (perichondrium) behind. Ear framework is reconstructed. Skin pocket is created at the correct designated position and reconstructed framework is placed in to it and the skin is sutured. Suction is applied to conform skin to the framework.
Stage two - After six months. Ear is lifted from its bed . Elevation is maintained by another piece of cartilage, which is fixed behind the ear. Framework is covered from behind by a thin layer of vascularized tissue, which is taken from under the scalp skin (temporoparietal fascial flap). Skin graft is placed on top of fascial flap to complete elevation.
Firstly, Titanium implants are drilled in to the skull. Abutments are provided and on top of that prosthetic ears are fixed.
Autogenous reconstruction – The current gold standard for ear reconstruction is autogenous reconstruction because of it’s overall low complication rate.
It involves a highly skilled and technically challenging task of harvesting the cartilage from the ribs and then carving out the framework of the ear from those pieces of rib cartilage.
The rib cartilage is harvested from 6th,7th,8th and 9th ribs. Firstly the skin elasticity and movement over the chest wall is judged and based on that a small 5-cm long transverse incision is given on the skin over the rib cartilages ( This gives the best possible cosmetic outcome for the patient and is specially useful in minimizing the scar in female children).
The chest muscles are not cut but split in the line of direction of muscle fibres, this helps in minimizing the post operative pain.
Once the rib cartilage is reached, specially designed instruments are used to gently separate the outer covering of the cartilage, known as perichondrium and after fully preserving it, the underlying cartilage is taken out.
This part of surgery needs great patience and technical knowledge on the part of the surgeon, but is very important to prevent future chest wall deformity.
This cartilage covering (perichondrium) keeps the rib tethered to the chest wall, preserving this covering helps in preventing injury to the underlying pleura (covering membrane of the lungs).
This preserved cartilage covering (perichondrium) for each cartilage is sutured together as a hollow tube, using absorbable sutures and at the end of the operation, all the cartilage pieces which remain after sculpting the ear framework are cut in to small bits and placed back in to perichondrial tube with the help of a small syringe which is cut from its front portion.
This step helps in formation of the cartilage again and prevents any chest wall deformity in the growing children.
After this, the muscles are approximated together, a bigger piece of remaining cartilage is banked in the chest wall under the skin (This cartilage piece is used again at the time of second stage of ear reconstruction for elevation of the ear framework).
The skin is sutured back using dissolving stitches avoiding the need of suture removal in the postoperative period.
A small tube is placed in the wound to remove the excess blood and secretions and is removed after two or three days.
At the time of completion of operation a local anesthetic nerve block is given to minimize the post operative pain and discomfort.
The rib cartilage is harvested from 6th,7th,8th and 9th ribs and different portions of the cartilages are sculpted using precision instruments and joined together with the help of specially designed stainless steel wire sutures.
A small incision is given at the site of designated ear position which should match with the normal ear on the other side.
The deformed and redundant cartilage is excised carefully and with the help of specially designed scissors an ear pocket is created
The newly created framework is placed into the ear pocket. To help the skin conform to the newly implanted framework suction is applied through one drain. At the completion of the first stage operation all the features visible in a normal human ear should be identifiable in the reconstructed ear. The suction drain is removed after few days. During that time it helps in removing excess blood and secretions from the site of implanted framework.
This is usually done six months after the first stage. In this, ear framework is elevated by giving an incision in the scalp.
The piece of rib cartilage, which was put under the chest wall skin at the time of first stage operation is taken out, shaped and used as a support for the elevated ear framework by precisely suturing it behind the ear. It helps in maintaining the projection of the ear.
The upper part and back of the ear is then covered by taking a layer of tissue from the undersurface of the scalp (this is scientifically known as temporoparietal fascial flap). It has a rich blood supply and it helps in maintaining the nutrition of the cartilage thereby sustaining the proper shape and strength of the reconstructed ear over long term.
Once this is done the back side of ear is further covered with a piece of skin which is taken from the scalp itself, this is known as split thickness skin graft and it finally closes the surgical wound.
The skin graft is sutured in place and dressing is applied.
One drain tube is placed under the scalp skin for removing the excess blood and fluid, this tube is generally removed after two days.
Two days after surgery, dressings are done and continued every alternate day till satisfactory healing occurs.
The patient could be discharged from the hospital after stitch removal which takes place one week after surgery.
The dressing may need to be changed every alternate day for a week.
A special splint is provided to the patient at the end of second week. This helps in maintaining the elevation of the ear over long term and needs to be worn by the patient at all times other then bathing and cleaning for the duration of six to nine months.
If the patient wears spectacles and has difficulty in wearing the splint, the spectacle limbs could be modified to incorporate the splint thereby avoiding the problem.
In microtia, the inner ear is normal but because there is deformity of external and middle ear, the conduction of sound waves to the inner ear is impaired. As a result, there is significant hearing impairment.
One ear is normal. Children generally adjust to hearing by one ear and their speech develop normally. Usually hearing aids are not needed. Ear canal opening surgery is not needed in most of the patients with one-sided microtia. Still if the child finds it difficult to discriminate fine sounds and is unable to localize the sounds then great benefit could be achieved by fixing a bone conducting or bone anchored hearing aid.
Hearing impairment on both the sides make the children functionally deaf. If not corrected early this leads to speech impairment also. Therefore, the patient should be seen by an ENT specialist and fitted with bone conduction hearing aids as soon as possible. When the child is older he can be fitted with a bone anchored hearing aid based on a titanium abutment. In almost half of the patients suffering from bilateral microtia, reconstruction of the hearing apparatus could be done surgically and may reduce the dependence on hearing aids.
Ideally it should be done after microtia reconstruction, otherwise, the scar it produces may jeopardize the result of ear reconstruction.
The same principles and technique could also be utilized to achieve excellent results in previously operated cases having suboptimal outcomes.
Based on the requirement, the technique of microtia reconstruction could be adopted to reconstruct the ear loss after burns or trauma because the principles of reconstruction remain the same.
Microtia occurs in about 1 in 5000 to 6000 live births and is more common in males.
Although literature suggests 8-10 years of age as the ideal age to commence reconstruction, we have noted as well as published the fact that in Indians more stable results are achieved when reconstruction is done at around teen age (13- 19 years). By this time the young patient’s cartilage is mature enough to withstand the shearing stress it is subjected to in a newly created skin pocket.
The number of stages would depend on the technique chosen for reconstruction after examining the patient. Generally a two-stage reconstruction protocol works well for most of the patients.
On account of the unique cartilage harvesting technique , there would be no chest wall deformity.
The entire reconstructive regime would require about 6 months to conclude.
First and second stage surgery both require about one week of hospital stay.
After first stage - Normal activities could be resumed as soon as the chest and ear drains are removed, usually it takes around three days.
After the second stage – It takes around a week for the skin graft to settle after the ear framework elevation, there after the patient could resume normal activities.
Yes, this technique of ear reconstruction which is used for microtia could also be used for reconstructing ears after loss due to any other reason.
Yes, piercing of the ear is possible after autogenous reconstruction of the ear.
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