Common doubts and questions:
When a child is born with a congenital ear anomaly (microtia or atresia) the family has many doubts and questions about the child's hearing, what can be done about the ears appearance, did we do anything wrong during the pregnancy and/or will our other children have similar problems. For these reasons it is important that their initial visit to the physician specializing in congenital ear anomalies be as soon after birth as feasible.
- Congenital ear anomalies occur in approximately one in six thousand births with a higher incidence in Japanese and Navajo Indian populations.
- They occur more in males and are more frequent on the right side.
- Anomalies are unilateral in 90% of patients and bilateral in 10%.
- The anomaly can range from anotia (complete absence of the external ear), microtia (ranging from mild deformity of severe deformity) and more common mild anomalies such as lop ear deformity.
- Microtia may occur as an isolated deformity but frequently occurs in conjunction with other defects particularly in syndromic children. Therefore full evaluation including genetic consultation is important in children suspected of other anomalies. Microtia frequently occurs in children with hemifacial microsomia, Goldenhar and Treacher Collins syndromes. Most children with severely microtic ears also have atresia of the external ear canal.
- Atresia of the external ear canal may also occur in children with normal auricles. The overall incidence of atresia is approximately one in ten thousand births. Atresias may be unilateral or bilateral. Frequently there may be associated middle ear deformities but usually the inner ear anatomy is normal due to separate embryologic development.
- The cause of an ear anomaly is usually difficult to define. Ischemia in utero, environmental exposures or use of certain medications such as accutane have been implicated.
Early hearing and speech evaluation is critical.
Early evaluation of the child's hearing is imperative. All patients with bilateral microtia/atresia require early amplification with bone conduction hearing aids. Auditory brainstem response testing should be performed immediately with placement of the hearing aids in the initial few months of life. A CT scan of the temporal bones should be obtained. Some surgeons will wait until the time of reconstruction to obtain the CT scan to allow for the most accurate assessment of middle ear anatomy. Early speech evaluation and therapy is important to enhance speech and cognitive development.
Reconstruction of the external ear in severe microtia usually begins at age 5 in unilateral cases and age 4 in bilateral cases. It is important that the external reconstruction be performed prior to the atresia and middle ear surgery. Reconstruction of the external ear consists of 3 or 4 staged procedures over the course of nine months.
- The initial stage involves the harvest of autogenous rib cartilage and carving of an ear framework that is implanted under the skin of the scalp.
- At the second stage the lobule remnant is rotated to its normal position.
- The third stage involves separation of the reconstructed ear from the side of the head and skin grafting the posterior surface of the ear. The repair of the external ear canal atresia and the middle ear reconstruction may also be done during the third stage.
- The fourth stage is the construction of a tragus which can frequently be combined with the third stage in order to minimize the number of procedures performed.