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Congenital High Airway Obstruction Syndrome (CHAOS) Cynthia Hayes PGY‐3 Genesys Regional Medical Center
Congenital High Airway Obstruction Syndrome (CHAOS)
Cynthia Hayes PGY‐3Genesys Regional Medical Center
Objectives• Define what is CHAOS.• Most common cause of CHAOS.• Diagnosis of CHAOS.• Treatment options of CHAOS.• Review two cases of patients with CHAOS.
CHAOS• First described by Dr. Rossi in 1826, but not named until 1994.
• Incidence equal in males to females. • Some reports of an autosomal dominance inheritance pattern, but reported in only four cases.
CHOAS• Intrauterine obstruction above the lungs that creates a closed system.
• Results in accumulation of fetal lung fluid leading to hyperinflation of the developing lungs with flattening of the diaphragm.
CHAOS• Laryngeal atresia (Most common cause)• Laryngeal stenosis• Subglottic stenosis• Tracheal aplasia and/or stenosis
CHOAS• Diagnosis
• Diagnosis can be possible as early as 15 weeks of gestation.
• Prenatal ultrasound (US)• Large echogenic lungs• Flattened or inverted diaphragms• Dilated distal airways• Fetal ascites or hydrops
• If fetus has a tracheoesophageal fistula the characteristic findings on US may be absent.
CHAOS
Image courtesy of Chaemsaithong 2012.
• Echogenic lungs
• Ascites
CHAOS
Image courtesy of Chaemsaithong 2012
• inverted diaphragm.
CHOAS• More detailed imaging recommended through magnetic resonance imaging (MRI) as up to 55.2% fetuses have additional anomalies.• Tetralogy of Fallot• Pulmonary atresia
CHAOS• Treatment
• Intrapartum intervention (Payam et al. 2012)• Decompress upper airway to allow more functional airway development.
• Passage of wire through obstruction.• All fetuses required further intervention.
CHAOS• Treatment continued.
• Ex utero intrapartum therapy (EXIT) procedure at the time of delivery to secure an airway through tracheostomy placement.
• Allows time to further delineate the anatomy and stabilize patient for reconstruction.
CHAOSTreatment‐EXIT
Image courtesy of Mychaliska 1997.
CHAOS• Reconstruction
• Twelve patients reconstruction at 17 months of age or older.
• Majority of the patients were tracheostomy dependent.
CHAOS• Case #1
• Prenatal US at 24 weeks of gestation• Enlarged echogenic lungs.• Flattening of diaphragm.• Mild ascites
• Amniocentesis revealed a normal karyotype.
CHAOS• Case #1 continued.
• Delivered by Cesarean section at 28 weeks with an EXIT procedure preformed to secure an airway.
• At one week of age a direct laryngoscopy and bronchoscopy was performed. • Blind pouch in subglottic region.
CHAOS• Case #1 continued.
• Reconstruction• Currently patient is 15 months old and still requiring ventilator support due to mild tracheobronchomalacia.
• Once weaned from the ventilator, laryngeal reconstruction will be performed.
CHAOS• Case #2
• Prenatal US at 20 weeks of gestation• Hyperinflated echogenic lungs.• Flattened diaphragm.• Dilated distal trachea.• Bilateral clubbed feet.
• Amniocentesis revealed a normal karyotype.
CHAOS• Case #2 continued.
• Delivered at 31 weeks via Cesarean section with an EXIT procedure at the University of Michigan.
• At two weeks of age a direct laryngoscopy and bronchoscopy was performed. • Laryngeal atresia.
CHAOS Case #2
Image courtesy of Dr. Green at the University of Michigan.
CHAOS• Case #2 continued.
• Reconstruction• At 3 months of age.• Arytenoids were divided using a CO2 laser.• Resection of anterior cricoid and rudimentary thyroid cartilage.
• Trachea was advanced superiorly to laryngeal notch.
• A 7mm Montgomery stent was placed and removed one week post operatively.
CHAOS• Case #2 continued.
• Post reconstruction follow‐up.• Direct laryngoscopy the CO2 laser was used for excision of granulation tissue.
• Spontaneous movement of right true vocal cord.
• At six months of age still requiring ventilator due to tracheobronchomalacia.
CHAOSCase #2
Image courtesy of Dr. Green at the University of Michigan.
CHAOS• Other things to consider
• Aspiration• Behavior modifications• Diet modifications
• Voice outcomes
References1. Saadai P, Jelin E, Nijagal A, Schecter S, Hirose S, Tippi M, Rand L, Goldstein R, Farrell J, Harrison M, Lee H. Long‐
term outcomes after fetal therapy for congenital high airway obstructive syndrome. Journal of Pediatric Surgery. 47(2012): 1095‐1100.
2. Foong‐Yen L, Crombleholme T, Hedrick H, Flake A, Johnson M, Howell L, Adzick N. Congenital high airway obstruction syndrome: Natural history and management. Journal of Pediatric Surgery. 38 (2003): 940‐945.
3. Okuyama H, Kubota A, Kawahara H, Oue T, Tazuke Y. Congential laryngeal atresia associated with esophageal atresia and tracheoesophageal: A case of long‐term survival. Journal of Pediatric Surgery. 41 (2006): 29‐32.
4. Kalache K, Chaoui R, Tennstedt C, Bollimann R. Prenatal diagnosis of laryngeal atresia in two cases of congenital high airway obstruction syndrome (CHAOS). Prenatal Diagnosis. 17:6 (1997): 577‐581.
5. Sandord E, Saadai P, Lee H, Slavotinek A. Congenital high airway obstruction sequence (CHAOS): A new case and a review of phenotypic features. American Journal of Medical Genetics. 158A (2012): 3126‐3136.
6. Chaemsaithong P, Chansoon T, Chanrachakul B, Worawichawong S, Wongwaisayawan S, Promsonthi P. Case report: Prenatal diagnosis and pathology of laryngeal atresia in congenital high airway obstruction syndrome. Case reports in Radiology. 616905 (2012).4 pages.
7. De Groot‐Van Der Mooren M, Haak M, Lakeman P, Cohen‐Overbeek T, Van Der Voorn P, Bretschneider J, Van Elburg R. Tracheal agenesis: Approach towards this severe diagnosis. Europe Journal of Pediatrics. 171 (2012): 425‐431.
8. Ergun S, Tewfik T, Daniel S. Tracheal agenesis: A rare but fatal congenital anomaly. McGill Journal of Medicine. 13 (2010). 10‐12.
9. Hoka S, Sato M, Yoshitake J, Kukita J. Management of a newborn infant with congenital laryngeal atresia. International Anesthesia Research Society. 69 (1989) 535‐536.
10. Zhang P, Herring D, Cook L, Mertz H. Fetal laryngeal stenosis/atresia and congenital high airway obstructive syndrome (CHAOS):A case report. Journal of Perinatology. 25 (2005):426‐428.
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Thank you.Any questions.
