Microtia

Synopsis

Microtia literally means “small ear” but is used in reference to a spectrum of auricular deformities that almost always occur in association with aural atresia (absence of an external auditory canal). From a practical point of view, any congenital deformity of the auricle that requires insertion of a complete or near-complete framework is an example of microtia. Microtia has been classified in various ways, but the most useful is the classification of Nagata: lobular microtia, small concha microtia, and large concha microtia. Complete anotia is almost never seen. Because microtia usually occurs with aural atresia, the patients have a total conductive hearing loss on the affected side. 10% of microtia is bilateral, and those patients are functionally deaf and require a bone conduction aid to have sufficient hearing to develop normal speech. Auricular reconstruction in patients with microtia can be performed in one of three ways: rib cartilage framework with cutaneous coverage (all autogenous), an alloplastic framework with cutaneous and fascial/skin graft coverage (partially alloplastic and partially autogenous), or a prosthesis (totally artificial). This chapter will deal primarily with autogenous reconstruction but will make reference to the other methods. Auricular reconstruction using autogenous tissues can be applied to post-traumatic and post-ablative deformities as well. The procedure usually is performed in two stages: placement of a rib cartilage framework and, after a period of approximately 6 months, elevation of the framework and construction of a retroauricular sulcus. The most significant complications of auricular reconstruction for microtia are related to: 1. Errors in judgment regarding size, position, orientation, or incisions; 2. Poor framework design; and 3. Necrosis of cutaneous coverage with exposure of the underlying cartilage framework.

Clinical Problem