Deformities of the external ear: causes, symptoms, diagnosis, treatment

Deformations of the outer ear include changes in the shape and size of the auricle and external auditory canal, which can be either congenital or acquired as a result of trauma or inflammatory-destructive diseases. Congenital defects of the outer ear are primarily developmental anomalies and are often combined with developmental anomalies of the auditory and vestibular apparatus, as well as with other developmental anomalies of the skull, such as Nager and Rainier's mandibular dysostosis, Crouzon's craniofacial dysostosis, congenital paralysis of the facial muscles, etc. According to J. Portman, these changes occur during the period of embryonic development of the branchial arches.

There is also an opinion that these disorders can occur as a result of intrauterine infection (rubella in the mother) or trauma.

Developmental defects of the auricle. The leading French specialist in the field of congenital defects of the head and maxillofacial region J. Robin (1923, 1929) divides all developmental defects of the auricle into congenital and acquired - partial and complete, as well as into anomalies of shape, position and number. Acquired deformations of the auricle are determined by the type of injury or disease and are described above.

Congenital anomalies of the development of the auricle are divided into the following types.

• Protruding auricle (one or both) with their normal size or in combination with macrotia. Protruding auricle can be of two types - total and partial. In the first case, the deformation also concerns the entrance to the external auditory canal, which can be covered by the bottom of the cavity of the auricle, in the second case, the forward bend of the auricle can only concern the area of the helix, which is caused by the reduction of the scaphoid fossa.
• Macrotia is characterized by a sharp increase in one or both auricles in their normal position.
• Microtia is characterized by a significant decrease in the size of the auricle, its atrophy and combination with shape defects.
• Poliotia is characterized by the presence of several skin formations in the pretragus region, containing within them the rudiments of cartilaginous tissue.
• Split earlobe (coloboma) can be congenital or acquired (in women) as a result of perforation of the earlobe or wearing heavy earrings.
• Gigantism of the lobe appears as a sharply enlarged lobe on one or both sides.
• Agenesis of the auricle is a total absence of the auricle of a congenital nature.
• Dystopia of the auricle, often combined with Robin syndrome; characterized by a downward and backward displacement of the UR, combined with aplasia of the lower jaw.

Developmental defects of the external auditory canal.

Pathological anatomy. P. Robin divides all developmental defects of the external auditory canal into congenital stenosis, membranous and bone atresia, and also into shape defects. Membranous atresia is localized on the border between the membranous-cartilaginous and bone sections of the external auditory canal, where a peculiar complete or partial diaphragm is preserved, covered on both sides by sheets of skin, between which a thin layer of mesenchymal tissue is preserved.

Congenital bone atresias can also be complete or partial and are often combined with developmental defects in the structures of the tympanic cavity.

Symptoms. Incomplete atresia of the external auditory canal does not manifest itself with any subjective signs, however, when the narrow opening is blocked by waste products of the dermis, a hearing impairment of the sound conduction type occurs. Complete atresias manifest themselves as severe hearing loss in one or both ears.

Diagnostics. When determining indications for surgical treatment, it is important to diagnose the form of atresia, for which it is necessary to exclude the bone form of this developmental disorder. In modern conditions, the most effective diagnostic method is computed tomography with the removal of the structures of the external auditory canal and tympanic cavity.

Treatment. The goal of treatment is to restore the lumen of the external auditory canal to ensure sound conduction and normalize hearing function. Treatment consists of surgical plastic surgery of the external auditory canal.

In the presence of membranous atresia, flap plastic surgery of the external auditory canal is performed using a behind-the-ear approach with excision of subcutaneous tissues and formation of the external auditory canal canal.

In the postoperative period, a dilator tube made of areactive synthetic material is inserted into the newly formed external auditory canal, which is removed only for a few minutes during the toilet of the external auditory canal. The newly formed external auditory canal has a pronounced tendency to scarring and stenosis due to the preserved connective tissue, so the dilator is kept in the external auditory canal for a long time (a month or more).

In bone atresia, surgical treatment is indicated only in the presence of normal structures of the tympanic cavity and inner ear (integrity of the auditory ossicle chain, normal development of the cochlea and vestibular organs), and there should also be normal hearing indicators for tissue sound conduction. Otherwise, surgical treatment is pointless.

[ 1 ], [ 2 ], [ 3 ], [ 4 ]