RT Book, Section A1 Bianchi, Diana W. A1 Crombleholme, Timothy M. A1 D'Alton, Mary E. A1 Malone, Fergal D. SR Print(0) ID 1106397224 T1 Congenital High Airway Obstruction Syndrome T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 978-0-07-144201-5 LK obgyn.mhmedical.com/content.aspx?aid=1106397224 RD 2024/10/14 AB Key PointsCongenital high airway obstruction syndrome (CHAOS) is characterized by bilaterally enlarged lungs, flat or inverted diaphragms, dilated tracheobronchial tree, and massive ascites due to complete airway obstruction.CHAOS is often mistaken for bilateral congenital pulmonary airway malformations.MRI is helpful in diagnosing CHAOS and excluding potential associated findings.CHAOS can be associated with syndromes such as Fraser syndrome.The natural history of CHAOS may be divided in thirds: 1/3 die in utero; in 1/3 the hydrops remains stable; and in 1/3 the hydrops resolves following spontaneous perforation.Fetoscopic treatment of the tracheal or laryngeal obstruction is possible in select cases.EXIT procedure is indicated to deliver all cases of CHAOS due to critical airway obstruction.