title: Congenital high airway obstruction syndrome: natural history and management.
abstract: BACKGROUND
  Congenital high airway obstruction syndrome (CHAOS) is a life-threatening condition with a poorly understood natural history.
  
  
  METHODS
  A retrospective review of five patients with CHAOS between 1997 and 2002 was performed.
  
  
  RESULTS
  All fetuses had large echogenic lungs, dilated airways, inverted diaphragms, and massive ascites. One fetus with a laryngeal cyst was terminated at 22 weeks. A twin fetus with findings suggestive of a tracheal web had progressive hydrops, which led to fetal demise. The remaining 3 patients delivered via the ex utero intrapartum treatment (EXIT) procedure survived. The first patient tolerated progressive hydrops for 12 weeks in utero. He had tracheal atresia but underwent laryngotracheoplasty successfully. He is the first long-term CHAOS survivor and is speaking at 5 years of age. The 2 patients with relatively stable lung volumes prenatally have laryngeal atresia with a pinpoint posterior laryngeal fistula. Their postnatal clinical courses were much more benign than the first survivor.
  
  
  CONCLUSIONS
  The prenatal natural history and postnatal course of CHAOS depends on whether the airway obstruction is complete. The EXIT procedure offers the potential for salvage of this otherwise lethal condition. Hydrops may be well tolerated prenatally for weeks with potential resolution if airway fistulization is present.
authors.affiliation: Center for Fetal Diagnosis and Treatment, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
authors.forename: Foong-Yen
authors.initials: FY
authors.lastname: Lim
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Crombleholme
authors.forename: Holly L
authors.initials: HL
authors.lastname: Hedrick
authors.forename: Alan W
authors.initials: AW
authors.lastname: Flake
authors.forename: Mark P
authors.initials: MP
authors.lastname: Johnson
authors.forename: Lori J
authors.initials: LJ
authors.lastname: Howell
authors.forename: N Scott
authors.initials: NS
authors.lastname: Adzick
mesh_terms: D000025:Abortion, Eugenic / Q000379:methods; D000402:Airway Obstruction / Q000151:congenital* / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D003560:Cysts / Q000151:congenital / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery; D004933:Esophageal Atresia / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery; D005260:Female; D005865:Gestational Age; D006801:Humans; D015160:Hydrops Fetalis / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery; D007231:Infant, Newborn; D007818:Laryngeal Diseases / Q000151:congenital / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery; D008297:Male; D011296:Prenatal Diagnosis / Q000379:methods; D019651:Plastic Surgery Procedures / Q000379:methods; D012189:Retrospective Studies; D013577:Syndrome; D016896:Treatment Outcome; D016216:Ultrasonography, Prenatal