*4.3.2.1. Management*

De novo appearance of these auricular abnormalities associated with those on the face and neck may be related to the use of propylthiouracil in early pregnancy to treat maternal hyper-

When auricular fistulae and nodules are isolated, no further evaluation is required for these

Most cases with typical location of auricular and preauricular fistulas are asymptomatic and do not require surgery. They can retain epithelial and sebum debris, and can evolve to subcutaneous cysts or infection. This may in turn lead to cellulitis or abscess, and may require aspiration of the collection if the antibiotic therapy is not responding. In cases of recurrent cyst infection, surgical excision of the cyst and the fistula tract is indicated. A preauricular fistulae may vary in length, may have a sinuous tract or may be extensively branched. If there are auricular fistulas and subcutaneous cysts, they adhere to the auricular perichondritis. Thus, complete elimination of the fistula or cyst should also include a portion of the auricular perichondritis at the base of the lesion [26]. Auricular and preauricular nodules can be excised for esthetic reasons.

Microtia is a congenital anomaly characterized by the underdevelopment of the outer ear, while anotia is the complete absence of the ear. Because microtia and anotia have the same

Microtia can be unilateral or bilateral and its frequency is of approximately 1–3 to every 10,000 births [32]. In the case of unilateral microtia, the right ear is most frequently affected [31].

Etiologically, the administration of the teratogenic agent called isotretinoin (Accutane®) dur-

The pathogenesis of microtia is heterogeneous, and there have been indications of unique

Microtia has a broad spectrum of phenotypic aspects, from the uncomplicated hereditary one, (which is transmitted as a dominant feature, and it is most often harmless), to severe, complicated forms of hearing loss. From a clinical point of view, four grades of microtia have been described: • **Grade I:** A less than complete development of the external ear with identifiable structures

• **Grade II:** A partially developed ear (usually the top portion is underdeveloped) with a

• **Grade III**: the most common form of microtia: Absence of the external ear with a small peanut-like vestige structure and an absence of the external ear canal and ear drum.

Isolated microtia is relatively common, but it can be found in newborns in association with other facial dysmorphisms, such as hemifacial microsomia, Goldenhar syndrome or Treacher

ing pregnancy may lead to these congenital auricular abnormalities (anotia/microtia).

thyroidism [30].

516 Congenital Anomalies - From the Embryo to the Neonate

children [2].

*4.3.2. Microtia*

origin, they can be described as microtia-anotia [31].

genetic mutations or its presence as a family trait [33].

and a small but present external ear canal

• **Grade IV:** Absence of the total ear or anotia.

stenotic external ear canal producing a conductive hearing loss

A minor anomaly does not require surgical correction. When the auricle is very deformed or absent (grades III and IV), reconstruction is often required for esthetic reasons. Most reconstructive interventions are recommended after the age of 6–10 years old, when the ear pavilion has 80% of the size of an adult ear.

The management of a microtia case associated with an auditory meatus defect is performed by long term periodic audiological monitoring, especially if there is an atresia of the auditory meatus, with the possible placement of an amplification device, especially in the case of the bilateral forms [39].

The surgical procedure for restoring the pinna is complex and is performed in several stages, with esthetic results that vary greatly, as the outer ear structure is difficult to duplicate [40]. A plastic surgical alternative is the use of a synthetic prosthetic pinna or a pinna obtained via the three-dimensional printing technology, but the research is still underway [41].
