Congenital high airways obstruction syndrome

Congenital high airways obstruction syndrome (CHAOS) refers a rare, often lethal, congenital laryngotracheal condition and is primarily characterised by obstruction to the fetal upper airway.

CHAOS can be of three possible types 2:

Associations
Antenatal ultrasound

Ultrasound may show some of all of the following features 4,5

  • dilated trachea/bronchi: distal to the obstruction
  • enlarged and echogenic lungs
  • diaphragmatic inversion and/or flattening
  • presence of fetal ascites
  • the fetal heart may appear displaced to the midline and compressed
Ancillary sonographic features include
Fetal MRI

May confirm features detected on ultrasound as well as more accurately show the level of obstruction. Lung signal is increased 5

The prenatal natural history and postnatal course of CHAOS often depends on whether the airway obstruction is complete. An ex utero intrapartum treatment (EXIT) procedure may offer potential for salvage 1,3. Overall prognosis is considered considered generally poor 6.

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Article Information

rID: 13887
Section: Syndromes
Tag: cases
Synonyms or Alternate Spellings:
  • CHAOS
  • Congenital high airways obstruction syndrome (CHAOS)

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