What is microtia?
Microtia is a birth deformity of the ear that occurs about one in 5,000-7,000 births, depending on varying statistics in different countries and in different ethnic races. When broken down in Latin, the term “microtia” is easy to understand. Micro = small; otia = ear. In 90 percent of microtia, only one side is involved. There are twice as many right-sided microtias than left; microtia involves boys 65 percent of the time and girls 35 percent.
What is atresia?
Atresia is absence or underdevelopment of the ear canal and middle ear structures. Microtia is almost always accompanied by atresia because the outer ear and the middle ear develop from one common block of tissue at the same time of development in the womb. About 15 percent of microtia patients have what appears at first look to be a normal canal, but many of them have only a “blind alley.”
What causes microtia, and did the parents do anything to cause microtia in their child?
The exact cause (etiology) of microtia is somewhat obscure, but one sure thing is that the parents did not cause it and should not feel guilty. Although feelings of guilt are common amongst parents with a child having a congenital deformity, they certainly had nothing to do with the occurrence of the microtia, which is merely a “roll of the dice.” Children with microtia are great little kids who will lead normal productive lives with the support of their parents, family, physicians and friends.
What is the risk of recurrence of microtia within the family and what are the chances that a microtia patient could also have children with microtia?
When two people first conceive a child, the risk of that child’s having microtia is basically the same as any child born. Families with hereditary forms of microtia are rare.
What other medical problems are associated with microtia?
The majority of patients with microtia have no other problems aside from the ear. Approximately one-third have underdeveloped bony and soft tissues on the involved side of the face (hemifacial microsomia) and 15 percent have facial nerve weakness. As part of a syndrome other abnormalities such as cleft lip, cardiac, or urological problems are encountered but these are less frequent.
When does a child with microtia become aware of it?
Children with microtia become aware of their differences at approximately 3 – 3½ years of age. Typically, they start comparing sides in a mirror and begin referring to their microtia as their “little ear.”
What should the parents tell their child with microtia when they discover that they are “different”?
When the child discovers that he/she has a small ear, parents should tell the child that he/she was born with a small ear, and that the doctor is going to make it larger when the child is older—then treat the child as absolutely normal and not make a “big deal” about it. The only children ever seen bothered about their microtia before the age of 7 or 8 are those whose family is very worked up over it and transmits family anxieties to the child.
Quoted from the website of Dr.Burt Brent: www.microtia.us.com
Autogenous ear reconstruction
Autogenous reconstruction is worthwhile only if great attention is paid to fine detail. In addition to providing a realistic shape, it is important to leave the ear canal unaffected, to provide support for spectacles and a lobe for earrings. The ear must be positioned at the correct level and with a slight posterior slope to match the opposite normal ear. Some patients may need reconstruction of both ears.
If the missing area is small, then a conchal cartilage graft (a graft from the cartilage of the other ear) may suffice. However, for major defects, a detailed framework, which mimics the folds of a normal ear, is necessary. There are two essential elements for a good ear reconstruction – an accurate framework and loose and pliable skin of good quality to cover it. Scarred skin is not pliable, but usually thick and inelastic and it can mask the details of the framework and spoil the result, so a more complex ear reconstruction technique is required.
Frameworks made from artificial materials, such as preformed silicone or Medpor©, can often provide a realistic result but there is a risk of late extrusion of the framework when minor trauma has led to infection. As a result, a limited number of experienced surgeons choose this route. Those who do quite rightly point out that there is no additional scar or discomfort caused by the donor site on the chest. Those who use costal cartilage point out that the donor site scar is minimal, and the discomfort temporary.
Simple autogenous reconstruction
If the tissues have not been damaged by previous trauma or surgery, it is possible to fashion a completely new ear in two operations six months apart. In some circumstances, the two stages can be rolled into one, with a minor procedure later.
The first stage of a simple autogenous ear reconstruction takes several hours under general anesthetic. The first step is to map the shape of the normal opposite ear. When both ears are lost, such as in burned patients, an ear shape can be copied from a willing relative. The shape is drawn on a see-through plastic sheet, then cut out to leave a template which can be sterilized for use throughout surgery.
A small incision is made in the chest wall at the edge of the ribcage of the opposite side. Costal cartilage is removed from several ribs to use for the cartilage framework. At the end of the operation, a small drain is left in this wound so that pain-relieving medicine can be given directly into the area. A small piece of cartilage is usually stored here, to be used to jack out the ear at the second stage. In case of a one stage reconstruction this is not necessary.
The material used for the framework, known as costal cartilage, is usually fairly easy to carve. If an entire ear is missing, it is assembled from several carved components, one for the rim, one for the main part of the ear, and separate pieces to resemble the individual ridges and valleys that make a realistic ear shape. The finished framework is then inserted under the skin on the side of the head, blending with any ear elements which might be useful. The skin is draped over the framework to form an airtight seal and suction drains are used to draw the skin into its folds. By the end of the operation, a contoured framework in the shape of an ear sits in the right place on the side of the head, albeit almost flat against it. Suction is applied continually for up to five days so that the ear shape persists.
Release of the reconstructed ear
About six months after the first stage, the circulation to the zone of reconstruction has become established, and the second stage can proceed. The new ear is lifted from the side of the head, so that it projects normally, with a groove behind it. The block of costal cartilage stored beneath the scar in the chest wall is used to maintain projection, and the two raw surfaces, one behind the ear and one on the side of the head, are covered by skin grafts taken from the groin or the thigh.
Second stage surgery takes almost two hours, again under general anesthetic.
Complex autogenous reconstruction
For tissues which have been damaged, it is sometimes necessary to first increase the amount of skin cover by inserting a tissue expander before the first stage, or by raising a temporoparietal fascial flap at the time of the first stage surgery. If neither option is available, then a free flap or a bone anchored prosthesis is required.
Complex reconstructions are performed in case of ear loss due to bites, road traffic accidents, shootings, burns, failed surgery to set back prominent ears and infected piercings. Some patients are referred after failed attempts at reconstruction and these are especially challenging. In some of these, a bone anchored prosthesis is the only option. It is very important to resist attempts at surgery to improve the appearance of the ear or scalp area before definitive reconstruction, as the blood supply to the new ear can be irreparably damaged and the results compromised.
When there is an inadequate amount of pliable skin to cover the framework, an initial procedure to insert a tissue expander may be necessary. A large expander, which looks like a deflated balloon with a tube to inflate it, is introduced through a small incision some distance away from the site of the ear reconstruction. Expansion, using saline injections into a valve on the inflating tube, is begun the week after insertion and continues at weekly intervals for about eight weeks until the skin is stretched enough.
Quoted from the website of Dr.David Gault: www.earreconstruction.co.uk
Medpor© ear reconstruction
Medpor© stands for microporous high-density polyethylene implant. Although rib cartilage reconstruction is an established and effective treatment option, Medpor© is an alternative technique, which has become available in recent years. Using this technique, a new ear framework is created using biocompatible polyethylene. After placing this framework on the patient’s head, it is grafted with temporoparietal fascia and skin grafts from beneath the scalp, so that the new structure actually integrates with the surrounding skin and blood vessels. Ear reconstruction with Medpor© requires fewer surgeries and can be performed on patients as young as three years old.
As the ear reconstructed with Medpor© will not grow, it will be constructed to be the same size as an adult ear. Although it may look slightly large for several years, young patients can experience a natural appearance and increased self-confidence.
The key difference between Medpor© and rib cartilage ear is the material used to rebuild the ear. Where Medpor© uses a microporous high-density polyethylene implant, rib cartilage ear reconstruction uses the patient’s natural tissue as the framework. This procedure requires an initial surgery to collect cartilage from the rib cage.
With Medpor© ear reconstruction, microtia patients can be treated as young as three or four years old. For a rib ear reconstruction, one has to wait until about age eight to ten, for the child to have sufficient rib cartilage to create the framework.
These and other aspects of each procedure patients and parents must consider.
Quoted from the website of Dr.John Reinisch: www.drjohnreinisch.com