Background
Laryngomalacia, shown in the image below, is a congenital abnormality of the laryngeal cartilage. It is thought to represent a delay of maturation of the supporting structures of the larynx. Laryngomalacia is the most common cause of congenital stridor and is the most common congenital lesion of the larynx.
Laryngomalacia: The epiglottis is small and curled on itself (omega-shaped). Approximation of the posterior edges of the epiglottis contributes to the inspiratory obstruction. (From B Benjamin, Atlas of Paediatric Endoscopy, Oxford University Press, NY, 1981, with permission.) Pathophysiology
Laryngomalacia may affect the epiglottis, the arytenoid cartilages, or both. When the epiglottis is involved, it is often elongated, and the walls fold in on themselves. The epiglottis in cross section resembles an omega, and the lesion has been referred to as an omega-shaped epiglottis. If the arytenoid cartilages are involved, they appear enlarged. In either case, the cartilage is floppy and is noted to prolapse over the larynx during inspiration. This inspiratory obstruction causes an inspiratory noise, which may be high-pitched sounds frequently heard in other causes of stridor, coarse sounds resembling nasal congestion, and low-pitched stertorous noises. More severe compromise may be associated with a lower ratio of the aryepiglottic fold length to the glottic length.
A classification system has been proposed. In type 1 laryngomalacia, the aryepiglottic folds are tightened or foreshortened. Type 2 is marked by redundant soft tissue in any area of the supraglottic region. Type 3 is associated with other disorders, such as neuromuscular disease and gastroesophageal reflux.
Laryngomalacia is the most common cause of chronic inspiratory noise in infants, no matter which type of noise is heard. Infants with laryngomalacia have a higher incidence of gastroesophageal reflux, presumably a result of the more negative intrathoracic pressures necessary to overcome the inspiratory obstruction. Conversely, children with significant reflux may have pathologic changes similar to laryngomalacia, especially enlargement and swelling of the arytenoid cartilages. Some of the swelling of the arytenoid cartilages and of the epiglottis may be secondary to reflux.
Occasional inflammatory changes are observed in the larynx, which is referred to as reflux laryngitis. When the epiglottis is involved, gravity makes the noise more prominent when the baby is supine.
The exaggerated inspiratory effort increases blood return to the pulmonary vascular bed. This could account for the increased likelihood of pulmonary artery hypertension in infants with hypoxemia.
Epidemiology
Frequency
United States
Frequency is unknown. Often, the diagnosis is presumed.
Mortality/Morbidity
Rarely, the lesion may cause enough hypoxemia or hypoventilation to interfere with normal growth and development. In severe cases, when laryngomalacia may be associated with gastroesophageal reflux, feeding problems such as choking or gagging may occur.
Race
No known race predilection has been reported.
Sex
Laryngomalacia has no sex predilection.
Age
Although this is a congenital lesion, airway sounds typically begin at age 4-6 weeks. Until that age, inspiratory flow rates may not be high enough to generate the sounds.
Dickson JM, Richter GT, Meinzen-Derr J, Rutter MJ, Thompson DM. Secondary airway lesions in infants with laryngomalacia. Ann Otol Rhinol Laryngol. Jan 2009;118(1):37-43. [Medline].
[Guideline] Institute for Clinical Systems Improvement (ICSI). Preventive services for children and adolescents. Oct 2008;[Full Text].
Unal E, Oran B, Baysal T, et al. Pulmonary arterial pressure in infants with laryngomalacia. Int J Pediatr Otorhinolaryngol. Dec 2006;70(12):2067-71. [Medline].
Richter GT, Thompson DM. The surgical management of laryngomalacia. Otolaryngol Clin North Am. Oct 2008;41(5):837-64, vii. [Medline].
Whymark AD, Clement WA, Kubba H, Geddes NK. Laser epiglottopexy for laryngomalacia: 10 years' experience in the west of Scotland. Arch Otolaryngol Head Neck Surg. Sep 2006;132(9):978-82. [Medline].
Bertrand P, Navarro H, Caussade S, et al. Airway anomalies in children with Down syndrome: endoscopic findings. Pediatr Pulmonol. Aug 2003;36(2):137-41. [Medline].
Cotton RT, Richardson MA. Congenital laryngeal anomalies. Otolaryngol Clin North Am. Feb 1981;14(1):203-18. [Medline].
Denoyelle F, Mondain M, Gresillon N, et al. Failures and complications of supraglottoplasty in children. Arch Otolaryngol Head Neck Surg. Oct 2003;129(10):1077-80; discussion 1080. [Medline].
Fauroux B, Pigeot J, Polkey MI, et al. Chronic stridor caused by laryngomalacia in children: work of breathing and effects of noninvasive ventilatory assistance. Am J Respir Crit Care Med. Nov 15 2001;164(10 Pt 1):1874-8. [Medline]. [Full Text].
Gessler EM, Simko EJ, Greinwald JH. Adult laryngomalacia: an uncommon clinical entity. Am J Otolaryngol. Nov-Dec 2002;23(6):386-9. [Medline].
Kay DJ, Goldsmith AJ. Laryngomalacia: a classification system and surgical treatment strategy. Ear Nose Throat J. May 2006;85(5):328-31, 336. [Medline].
Mancuso RF, Choi SS, Zalzal GH, Grundfast KM. Laryngomalacia. The search for the second lesion. Arch Otolaryngol Head Neck Surg. Mar 1996;122(3):302-6. [Medline].
Manning SC, Inglis AF, Mouzakes J, Carron J, Perkins JA. Laryngeal anatomic differences in pediatric patients with severe laryngomalacia. Arch Otolaryngol Head Neck Surg. Apr 2005;131(4):340-3. [Medline].
Midulla F, Guidi R, Tancredi G, et al. Microaspiration in infants with laryngomalacia. Laryngoscope. Sep 2004;114(9):1592-6. [Medline].
Sivan Y, Ben-Ari J, Soferman R, DeRowe A. Diagnosis of laryngomalacia by fiberoptic endoscopy: awake compared with anesthesia-aided technique. Chest. Nov 2006;130(5):1412-8. [Medline].
Smith JL, Sweeney DM, Smallman B, Mortelliti A. State-dependent laryngomalacia in sleeping children. Ann Otol Rhinol Laryngol. Feb 2005;114(2):111-4. [Medline].
Thompson DM. Abnormal sensorimotor integrative function of the larynx in congenital laryngomalacia: a new theory of etiology. Laryngoscope. Jun 2007;117(6 Pt 2 Suppl 114):1-33. [Medline].
Print
