Tracheo/Laryngomalacia

Donna M. Santer, M.D., Michael P. D'Alessandro, M.D.
Peer Review Status: Externally Peer Reviewed by Lauren D Holinger, MD, Robert J. Winter, MD and the AMA

Tracheomalacia
Tracheomalacia may result from a congenital abnormality such that the entire cartilaginous structure of the upper airway is diffusely involved, or a localized area of decreased rigidity may be seen secondary to abnormal development of the foregut and vasculature in embryonic life. For example, abnormal development of the vasculature around the trachea may create a vascular ring that impinges on the trachea. The ring does not allow normal development in that area of the trachea, and malacia is seen only in the area of the impingement.

Diffuse malacia of the airway may be congenital and associated with no other anomalies. As the child grows, structural integrity is gradually restored with resolution of the process.

These children generally present in the neonatal period, but occasionally they may not present until 2-3 months of age. They have noisy respirations, and expiratory stridor is usually present from birth. Some more affected children will have hoarseness, aphonia, and inspiratory retractions that are severe enough to cause chest wall deformity. These infants obviously have a difficult time coordinating breathing and feeding. Thus they have poor weight gain. Rhonchi can also be heard on auscultation, (SOUND) and hyperinflation of the chest can be seen.

Tracheomalacia is caused by a diffuse process as already noted or by vascular anomalies such as an anomalous innominate artery or vascular ring , esophageal atresia and tracheoesophageal fistula, and internal compression by an endotracheal tube or tracheostomy tube.

Its clinical presentation is as previously discussed, but those children who have received a repair for an esophageal atresia or fistula may also develop "dying spells" or reflex apnea. During these episodes, the child develops marked apnea, cyanosis, and bradycardia usually associated with feeding. These dying spells are believed to be caused by severe hypoxia. These spells are treated by providing oxygen and oxygen monitoring, repositioning during feedings, and other supportive measures until the child grows.

Diagnosis is presumptively made by the history and physical examination, but further evaluation is needed to determine if there is an underlying cause. Vascular anomalies, such as right sided aortic arch or double aortic arch may be easily seen on a standard anteroposterior chest x-ray. Other ascular anomalies may be more difficult to see and originally were evaluated by angiography. Today, echocardiography and computed tomograph scanning (CT) can usually provide the necessary information for evaluation and planning of treatment.

Esophageal atresia can be diagnosed by a history of feeding difficulties and cinefluoroscopy showing proximal dilatation of the esophagus. Cinefluoroscopy can also show the dynamic motility of the esophagus. A deformation of the esophageal contour as well as the tracheal contour during cinefluoroscopy may indicate a vascular anomaly also. Cine CT can show the dynamic motility of the airway.

Bronchoscopy reveals compression of the trachealumen to various extent in the affected area. Depending on the severity the trachea may be elliptical in appearance or even slitlike (SUMMARY).

Treatment consists of initially treating the underlying cause. For example, patients with vascular rings should have the constricting vessels surgically divided and affixed to other structures to eliminate the impingement on the trachea. Other available treatment includes stenting the trachea open. This can be done both internally and externally. Tracheoplasty, with removal of the area of collapse and insertion of a rigid piece of cartilage in its place, also relieves the patient's symptoms. Intercurrent respiratory illnesses exacerbate tracheomalacia and children should be properly monitored and evaluated as indicated. As with subglottic stenosis, children's symptoms improve as they grow.

The differential diagnosis of tracheomalacia includes laryngomalacia, subglottic stenosis, congenital cysts, vocal cord paralysis, and hypocalcemic tetany. Complications include problems with acute airway obstruction and perioperative morbidity and mortality.

Laryngomalacia
Laryngomalacia is a collapse of the supraglottic laryngeal structures. This produces symptoms on inspiration since these floppy structures, such as the epiglottis and aryepiglottic folds, may be pulled into the airway during inspiration.

The presumptive diagnosis is made based on history and physical examination, but further evaluation is needed. Endolateral neck x-rays may - but rarely - show fullness of the laryngeal structures. Definitive diagnosis is based on bronchoscopy findings showing the floppiness of the laryngeal structures during the respiratory cycle.

Treatment is usually conservative by changing feeding postures and feeding the infant slowly. Laryngoplasty, either via laser surgery or traditional means, can also relieve symptoms in select cases.

Rarely do children need tracheotomy. These children also have exacerbations with intercurrent respiratory illnesses and therefore need good parental monitoring. The long-term prognosis is good as these children outgrow their problem.

Differential diagnosis includes malformation of the laryngeal cartilages or vocal cords including congenital vocal cord paralysis , laryngeal webs, mucus retention cysts, hemangioma, lymphangioma, goiters, thyroglossal duct remnants, branchial cleft cysts, tetany, and laryngeal edema secondary to trauma or aspiration at birth. Complications are due to acute airway obstruction and perioperative problems.

Conclusion
Tracheomalacia and laryngomalacia are congenital problems that commonly lead to respiratory distress in children (TABLE). The key points are:

1. Malacia, or softening, of the airway structures is the underlying structural problem.
2. Underlying causes of tracheomalacia must be sought and treated.
3. Masqueraders of laryngomalacia must also be sought and treated.
4. In the long term, children do well as they outgrow this disorder.

Questions about tracheo/laryngomalacia

1. What does malacia mean? (ANSWER)
2. What is localized tracheomalacia due to? (ANSWER)
3. Another name for "dying spells" is _____? What symptoms does the child have? (ANSWER)
4. Cinefluoroscopy may be used to diagnose what types of anomalies? How? (ANSWER)
5. Describe the findings on bronchoscopy for a child with tracheomalacia? (ANSWER)
6. List three disease processes that may mimic tracheomalacia. (ANSWER)
7. Laryngomalacia, in contrast to tracheomalacia, produces stridor during the _____ phase of the respiratory cycle. (ANSWER)
8. What simple interventions can be instituted for a child with tracheomalacia or laryngomalacia before a surgical procedure is done? (ANSWER)

References for tracheo/laryngomalacia

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