Atresia is a congenital condition where a body cavity or passage is deficient or abnormally closed. It is widespread because it can take many forms such as esophageal atresia, duodenal, biliary or aural atresia and others. The last one is probably the most common and it refers to the absence or incomplete formation of an external ear canal which means that both the external and middle ear may be malformed, but the inner ear and auditory nerve are usually normal. The external auditory canal and structures in the middle ear fail to develop completely and therefore, there might be varying degrees of severity of this condition. In its most severe form, there is no identifiable ear canal and the middle ear and ossicles may be absent or show significant underdevelopment.
Aural atresia most commonly effects just one ear but sometimes it can occur in both ears and it is often accompanied by microtia, which virtually represents the incomplete development of the auricle. Most of the time, the condition is isolated, but in some rare cases, it can be a symptom of a larger syndrome, such as Treacher Collins, Goldenhar, Crouzon's, Alpert's, Pfeiffer, Klippel-Feil, BOR (Branchio-Oto-Renal) also known as Melnick-Fraser, 18-q chromosome, as well as Hemifacial Microsomia.
The effect of atresia depends on whether one or both ears are affected. Obviously, if just one ear is affected, the hearing in the other ear is quite normal, thus the person concerned is able to develop a normal speech. Yet, it is important to evaluate unilateral atresia early and treat it accordingly in order to prevent unilateral hearing loss. When it comes to bilateral aural atresia, thins are more complicated because the effect usually consists in moderately severe conductive hearing loss- aproximately 50-60dB. When a child is born with atresia, he should be fitted with a bone conduction hearing aid as soon as possible.
Aural atresia and microtia represent surgical reconstructive challenge which involve a deep understanding of the evaluation and management of the patients with CAA steams with significant advancements. When it comes to these congenital conditions, there are two main options: auricular reconstruction to restore the visual appearance and form of the outer ear and repair of atresia or application of a Bone Conduction Hearing Solution (BAHA) to restore hearing. The goal of this kind of surgery is to create a normal sized ear canal or a stenotic canal. It is very important to have an efficient communication between the otologist and the facial plastic surgeon, based on a comprehensive understanding of child's needs, in order to establish not only the adequate treatment, but also the right timing of the treatment.
Nowadays, doctors skilled in this area of reconstructive surgery usually use skin grafts and cartilage or bone from other parts of the body to effectively build a natural-looking, correctly-sized ear for both children and adults living with microtia. Usually doctors do not perform such surgeries if the child is under the age of 6 because the reconstruction is a complicated surgery that takes careful planning and may require several surgeries before a final result is achieved. Although a reconstruction is considered to be the optimal and most natural-looking solution, there are other options available which include prosthetic ones that can be glued or snapped on, or artificial implants, which unfortunately, come with the risk of rejection of the artificial part. However, the most important aspect is that nowadays, due to the numerous advancements, patients with aural atresia have the chance of hearing restoration, long-term stability of hearing and a natural-looking ears.