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A very rare developmental abnormality of the larynx.
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The exact incidence remains to
be determined. Approximately 50 cases with no sexual predilection have been
reported. Inheritance is most likely autosomal dominant with the responsible
gene located on chromosome 5.
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Laryngeal atresia is defined as a complete
absence of the laryngeal lumen and results from an arrest in the embryonic
development of the larynx at different stages. Depending on the localization
of the atresia, three types of laryngeal atresia can be distinguished:
atresia is both supraglottic and infraglottic in type I, infraglottic in
type II, and glottic in type III. Partial laryngeal atresia may result from
congenital webs, which may be localized between the cords, or from
supraglottic and/or infraglottic stenoses leading to a laryngeal lumen with
reduced size at birth. Clinical signs of complete atresia at birth may
include stridor, laryngeal obstruction or absent cry, and require tracheostomy
within minutes after birth. Partial atresia of the larynx may be revealed by
direct laryngoscopy. A common finding in complete laryngeal atresia (but not
in partial atresia) is pulmonary hyperplasia with dilatation of the
tracheobronchial tree. Approximately half of the patients described in the
literature also suffer from other anomalies, some of which are potentially
life-threatening. These anomalies may affect the central nervous system
(hydrocephalus), the heart (single ventricle, cardiac failure secondary to
venous obstruction), the respiratory and gastrointestinal tracts (tracheal
atresia, tracheoesophageal fistula, esophageal atresia, duodenal atresia),
the urogenital tract (aplastic/hypoplastic kidneys, hydroureter, urethral atresia, hypospadias), and the
musculoskeletal system (craniofacial anomalies, cervical vertebral anomalies, pes varus). Because complete
atresia requires immediate therapy (tracheostomy/tracheotomy) after birth, most
children born with this condition will die unless the condition is diagnosed
prenatally (minority of cases), which is possible only in complete, but not
in partial atresia (polyhydramnios, pulmonary hyperplasia, hydrops fetalis,
ascites). However, survival also depends on other concomitant anomalies.
Although survival in general is rare, the lifespan of a few patients with
immediate and successful therapy of isolated laryngeal atresia reportedly is
normal.
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These patients present immediately after
birth. As mentioned earlier, immediate action in the form of a
tracheo(s)tomy is required for complete laryngeal atresia. Preserve
spontaneous ventilation in partial atresia until the airway has been
secured. Anesthesia for this procedure must mainly rely on local anesthesia.
Ex utero intrapartum treatment (so-called EXIT procedure) has been used
successfully in a fetus at 35 weeks of gestation just prior to delivery via
cesarean section.
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Fraser Syndrome: A polymalformative condition characterized by the
association of cryptophthalmos with a wide range of abnormalities (orofacial
defects, syndactyly, decreased number of digits, urogenital and renal
malformations), easily recognized at birth by the evident absence of
eyelids.
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Cat Cry Syndrome: A syndrome clinically characterized by microcephaly,
round face, macrostomia and micrognathia,
scoliosis, muscular hypotonia, severe mental retardation and often congenital
heart defects. One of the
most important signs in the newborn is a high-pitched cat-like cry that ...