The human ear is a beautifully-sculpted structure consisting of a three-dimensional cartilage framework draped with a network of fine blood vessels and covered with a delicate skin. Microtia (small ear) is a congenital condition in which the external ear is abnormal in shape or size. Microtia presents in a varying spectrum of severity. The most severe form (type III) involves a missing ear canal and a near-complete or total absence of the external ear. Reconstruction of a missing ear should strive to replace the individual components in as natural a manner as possible.
The embryologic defect underlying microtia is not completely understood. However it is known that cells having the capacity to form ear cartilage originate just above the developing brain and subsequently migrate into the face. These neural crest cells receive “instructions” from the skin overlying the site of the future ear. Defective production of the local skin “program” can lead to failure to produce appropriate cartilage structures. An interesting finding supporting this idea is the lowered hairline seen in microtia patients. The absence of skin containing the cartilage program causes hair-bearing skin to be displaced downward. The low-lying hairline seen in such children has important surgical implications (see below).
The technique most widely used for ear reconstruction has changed little over the past 60 years. Repair is carried out between the ages of six and twelve using a cartilage framework fashioned from the child’s own rib cartilage. The framework must be sturdy enough to resist warping over time; hence it must be quite thick. Reconstruction requires three or four separate procedures to complete. The cartilage is first buried beneath a skin envelope that is congenitally inadequate. Later, the framework is elevated and a skin graft placed behind it. Unfortunately, the low-lying hairline frequently results in an external ear covered with scalp hair. Results of this procedure are variable and depend greatly on the expertise and experience of the individual surgeon. Because the technique depends upon rib cartilage, early reconstruction is not possible because the child’s rib cage has not yet achieved sufficient size.
At St. Louis University School of Medicine and SSM Cardinal Glennon Children’s Hospital, we use a new technique that replaces the child’s own rib cartilage with a synthetic material. The material is placed under a covering of fine blood vessels and covered with the child’s own skin. This technique resolves the embryologic skin deficit and avoids pulling hair-bearing skin over the framework. The biggest advantage to this technique is that ear reconstruction can be performed in early childhood, usually at age three years. Avoidance of a painful and disfiguring scar on the chest is beneficial. Fewer procedures are required. The surgical sequence can frequently be performed on an outpatient basis.
Ear reconstruction can contribute to a child’s quality of life in a very significant way. It is recommended that you discuss the best option for your child with a qualified pediatric plastic surgeon familiar with both techniques.
If you have questions or wish additional information, please email Debbie, our nurse coordinator - firstname.lastname@example.org.