Laryngomalacia, shown in the image below, is a congenital abnormality of the laryngeal cartilage. It is a dynamic lesion resulting in collapse of the supraglottic structures during inspiration, leading to airway obstruction. 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....
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.
Frequency is unknown. Often, the diagnosis is presumed.
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.
No known race predilection has been reported.
Although previous reports in predominately white populations have reported a male predominance (58-76% of cases), a more recent study of a more ethnically diverse population demonstrated no significant difference between males and females.
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. Symptoms typically peak at age 6-8 months and remit by age 2 years.
Late-onset laryngomalacia may be a distinct entity, which can present after age 2 years.
The usual history in patients with laryngomalacia is of inspiratory noises that begin during the first 2 months of life. Sounds typically start at age 4-6 weeks, but they may begin in the nursery or as late as age 2-3 months.
Upon examination, the baby is usually happy and appropriately interactive.
A study found that because laryngomalacia may present primarily with snoring and/or sleep-disordered breathing and swallowing dysfunction in a significant proportion of children, the diagnosis must be considered in children, older than 3 months, presenting with these upper airway complaints.[3, 4]
Laryngomalacia is a congenital abnormality of the larynx. The pathology is unknown. In cases in which redundant or tight tissue has been removed, it is histologically indistinct from normal tissue.
No genetic pattern is known.
Oxygen saturation should be monitored in patients with laryngomalacia.
Laryngoscopy and bronchoscopy
In more than 90% of cases, the only treatment necessary for laryngomalacia is time. The lesion gradually improves, and noises disappear by age 2 years in virtually all infants. The noise steadily increases over the first 6 months, as inspiratory airflow increases with age. Following this increase, a plateau often occurs with a subsequent gradual disappearance of the noise. In some cases, the signs and symptoms dissipate, but the pathology may persist into childhood and adulthood. In those cases, symptoms or signs may recur with exercise or sometimes with viral infections.
Children with severe retractions, cyanotic spells, and apneas during sleep may have obstructive sleep apnea associated with laryngomalacia. These children should be evaluated with a sleep study. Supraglottoplasty may be of benefit in children with severe symptoms of laryngomalacia (see below). Thus, a detailed sleep history should be taken in all infants with symptoms of laryngomalacia.
If the baby has clinically significant hypoxemia (defined as a resting oxygen saturation < 90%), supplemental oxygen should be administered. Recent data suggest infants with laryngomalacia and hypoxemia may more readily develop pulmonary hypertension. Therefore, children with hypoxemia should periodically undergo evaluation for pulmonary hypertension.
If the baby has normal cry, normal weight gain, normal development, and purely inspiratory noise that developed within the first 2 months of life, then no further workup may be necessary. Parents may be told that laryngomalacia is the most likely diagnosis, and they can be assured of its natural history.
If the picture is not obvious or if the parents are not completely reassured, diagnostic procedures include fluoroscopy and flexible laryngoscopy or bronchoscopy. Flexible bronchoscopy with the child anesthetized is more specific and sensitive than flexible bronchoscopy in a child who is awake.
There is a distinct group of older children (aged >2 years) with late-onset laryngomalacia, or occult laryngomalacia, who do not present with the typical congenital symptoms of noisy breathing. Children manifest symptoms during feeding, exercise, or sleep. Many are identified with snoring or sleep-disordered breathing as initial symptoms and are diagnosed with laryngomalacia upon direct visualization of the airway. In late-onset laryngomalacia, supraglottoplasty may be beneficial for cases of moderate-to-severe obstructive sleep apnea associated with significant apnea-hypopnea index on sleep study.[8, 9] However, other causes for obstruction, such as adenotonsillar hypertrophy, should also be evaluated.
In severe cases in which the laryngomalacia interferes with ventilation enough to impair normal eating, growth, and development, a surgical approach is possible.
Approximately 10% of patients with severe congenital laryngomalacia require surgical intervention because of failure to thrive, significantly elevated carbon dioxide or hypoxemia, severe obstructive sleep apnea, pulmonary hypertension, or cor pulmonale. Operations include simple tracheotomy or supraglottoplasty in which support structures are tightened and excess tissue on the epiglottis is removed. Laser epiglottopexy has been successful.[11, 12]
A meta-analysis by Farhood et al found that the Apnea-Hypopnea Index (AHI) improved by a mean of 12.5 points after supraglottoplasty for laryngomalacia with obstructive sleep apnea, however, 88% (29 of 33 children) had residual disease.
If the parents require another opinion or if the lesion is clinically severe, consultation with a pediatric pulmonologist or pediatric otorhinolaryngologist may help.
No diet restrictions are necessary.
No activity restrictions are necessary.
Drug therapy is not currently a component of the standard of care for laryngomalacia. In more than 99% of cases, the only treatment necessary is time.
The lesion gradually improves, and noises disappear by age 2 years in virtually all cases. See Treatment.
Unless supplemental oxygen is required for oxygen saturation less than 90%, no home therapy is necessary.
The usual well-child visits should be performed.
Immunizations should not be delayed because of airway noise.
No inpatient care is necessary in patients with laryngomalacia unless the baby has clinically significant hypoxemia or apnea.
No medications are necessary.
Laryngomalacia is not a preventable lesion and does not appear to run in families.
Poor oxygenation that requires supplemental oxygen
Alveolar hypoventilation that requires surgery or positive pressure ventilation
Increased likelihood of gastroesophageal reflux
Prognosis is excellent. Most babies outgrow the condition by their second birthday, many by the first. In some cases, even though the signs and symptoms dissipate, the pathology persists. Such patients may have stridor with exercise later in life.
Laryngomalacia may be more common in children with Down syndrome, in whom it may persist beyond the second birthday.