What is laryngomalacia?
Laryngomalacia is a disorder that effects the larynx (voice box) of infants. Laryngomalacia most often presents as noisy breathing or stridor as early as 2 weeks of age. Infants with laryngomalacia will have stridor and may also have difficulty in breathing, feeding and gaining weight, failure to thrive and respiratory distress. This can lead to poor quality of life and anxiety in parents.
The larynx of a child with laryngomalacia will demonstrate one or all of the following:
- Excess tissue overlying the arytenoid cartilages (cartilage above the voice box) with evidence of arytenoid cartilages falling into the airway (arytenoid prolapse).
- Short aryepiglottic folds (AE folds).
- Omega-shaped epiglottis and prolapse of the epiglottis into the airway.
This prolapse of airway structures during inspiration is what leads to airway distress in children with laryngomalacia. The noisy breathing in these children is caused by increased resistance of air flowing though the larynx due the tissue blocking the airway.
The exact cause of laryngomalacia is not known. The underlying dysfunction is related to redundant mucosa, poor support of laryngeal cartilages and poor neurological tone. The most widely accepted theory describes laryngomalacia as a delay in neurological function and tone of the laryngeal structures above the vocal cords.
First line treatment for laryngomalacia includes positioning and treatment for gastric reflux. Typically, parents will be instructed to position their child on their stomach when they are having difficulty breathing. It is important never to leave a baby alone when they are on their stomach. Eating is typically easier for babies with laryngomalacia if they are sitting up. Babies with laryngomalacia will often be prescribed medication to decrease gastric reflux. If these conservative measures do not help or if the baby has severe laryngomalacia, surgery may be necessary.
Most of the time, laryngomalacia will resolve at 12 to 18 months of age without surgical intervention. Surgical intervention is warranted if a baby has severe laryngomalacia with recurrent apneic events, difficulty with feeding, failure to thrive and
recurrent cyanosis (bluish discoloration of the skin) and respiratory distress.
A supraglottoplasty is a surgical technique in which the structures of the larynx are altered in order to prevent collapse of the airway and improve breathing. While the baby is asleep, the surgeon will use a laryngoscope to look inside the mouth and
evaluate the larynx. The surgeon will then alter the airway to decrease obstruction caused by laryngomalacia. Short aryepiglottic folds are cut in order to lengthen them and provide a more open airway. Excess arytenoid tissue can be trimmed down so
it no longer prolapses into the airway. A third technique that is performed is called an epiglottopexy. This technique attaches the epiglottis to the base of tongue to prevent the epiglottis from falling into the airway.
What is tracheomalacia?
Tracheomalacia is a condition where the tracheal cartilage (windpipe) rings soften and partially collapse when a child is breathing. This collapse most often occurs during expiration. Tracheomalacia may be primary or secondary. Primary tracheomalacia is caused by anterior prolapse of the posterior tracheal wall, while secondary tracheomalacia (rare) is caused by external compression. This external compression is most often caused from a vascular anomaly where an artery compresses and weakens the tracheal cartilage leading to collapse. Examples of vascular malformations that can cause this problem include aberrant right subclavian artery, pulmonary artery sling and vascular rings and slings. In most cases, this is managed without surgical intervention.
What is bronchomalacia?
Bronchomalacia is very similar to tracheomalacia, however in bronchomalacia, the cartilage softening occurs in the bronchi of the lungs. Bronchi are branches from the trachea and have cartilage that can become soft and collapse. When this collapse occurs in the bronchi, it is called bronchomalacia. Bronchomalacia can also be primary or secondary.
How common is laryngomalacia, tracheomalacia and bronchialmalacia?
Laryngomalacia is very common. It is the most common cause of stridor in children and affects 35-75% of infants presenting with stridor. Tracheomalacia and bronchomalacia are less common. Estimated incidence of tracheobronchomalacia is around one in 2,100.
Frequently Asked Questions
In otherwise healthy babies, a single supraglottoplasty will usually improve the airway obstruction caused by laryngomalacia, and no further surgery will be needed. Supraglottoplasty has been shown to have over a 90% success rate in healthy children with laryngomalacia. There are times however, when a second surgery may be needed if your baby is still having symptoms of severe laryngomalacia such as recurrent apneic events, difficulty with feeding or failure to thrive. Studies have shown that this is more common in neurologically delayed children. Up to 70% of children with neurological delay and laryngomalacia may require a revision surpaglottoplasy.
Tracheostomy is needed if your baby is still having symptoms of severe laryngomalacia after maximal supraglottic surgical intervention. This is rare in otherwise healthy children and is more common in babies who have neurological delay when a supraglottoplasty or revision supraglottoplasty does not work. In these situations, other airway factors often co-exist which make a tracheostomy needed.
Tracheobronchial malacia may be primary or secondary. Secondary tracheobronchial malacia is caused by extrinsic compression on the trachea or bronchus most often by vascular abnormalities. The cause of primary tracheobronchial malacia is not known but may be related to neurological immaturity or other airway abnormalities such as tracheoesophageal fistula or esophageal atresia.
Tracheobronchial malacia is most often treated conservatively with humidified air, chest physical therapy and slow, careful feedings. If babies with tracheobronchial malacia are in significant distress, positive pressure airways such as a CPAP may be helpful. There are surgical treatments for tracheobronchial malacia as well, though they are rarely needed except in extreme circumstances. Surgical treatment may involve placing a stent in the trachea or bronchi to keep it from collapsing during breathing. If tracheobronchial malacia is caused by vascular anomalies, surgery may be done to fix the artery that is causing obstruction. These surgeries are often done by pediatric cardiothoracic surgeons. Sometimes tracheostomy may be needed for severe tracheobronchial malacia to give time for the airway to develop and strengthen.
The natural course of laryngomalacia will present as early as 2 weeks of age and worsen progressively up to 4 to 8 months of age. Symptoms typically resolve without surgical intervention by 12 to 18 months of age. Laryngomalacia can be broken down into mild, moderate and severe cases. Mild laryngomalacia is associated with non-severe intermittent stridor and sporadic feeding difficulties. Moderate laryngomalacia is associated with dyspnea (difficulty breathing) and consistent feeding difficulties. Severe laryngomalacia is associated with recurrent cyanosis (bluish discoloration of the skin), apneic events and difficulty with feeding that is associated with aspiration and failure to thrive.
Patients with mild and moderate laryngomalacia can be treated with positioning and anti-reflux medications. Severe cases may need a surgical supraglottoplasty in order to decrease symptoms and allow the baby to breathe without difficulty and gain weight appropriately. For severe cases, most babies without neurological disease will do well with minimal complications.
Mild and moderate laryngomalacia can be treated with antacid medications and watchful waiting. The natural course of laryngomalacia will worsen until 4-8 months of age and then will begin to improve, resolving by 12 to 18 months of age.
While laryngomalacia itself is not hereditary, laryngomalacia is more common in infants with neurological disorders. Some neurological diseases may be hereditary. Infants with seizure disorders, hypotonia, developmental delay, cerebral palsy, microcephaly and Chiari malformation are at increased risk of having laryngomalacia. Laryngomalacia may also be seen in infants with CHARGE association and Pierre Robin sequence, as well as 22q11 microdeletion syndrome (DiGeorge syndrome).
There are not currently any prenatal tests to determine if a baby has laryngomalacia, tracheomalacia or bronchomalacia.
Studies have shown that babies with congenital tracheoesophageal fistula (TEF) and esophageal atresia do have an increased risk of other upper airway abnormalities. Tracheomalacia is the most common disorder seen with TEF and esophageal atresia, however laryngomalacia occurs as well. Babies with congenital TEF and esophageal atresia will often present with polyhydramnios, so there may be a link between polyhydramnios and laryngomalacia or tracheobronchial malacia.
There are not currently any studies linking laryngomalacia to the MTHFR gene. However, defects in the MTHFR gene are associated with neurological conditions such as anencephaly, homocystinuria and spina bifida. Babies with neurological conditions are at increased risk for laryngomalacia.
Laryngomalacia is almost always congenital. The natural progression of laryngomalacia will worsen over time until 4-8 months of age. Tracheomalacia may be primary or secondary. Secondary tracheomalacia is often due to extrinsic compression of the airway, often by vascular structures.
To date, there is no clear link between the risk of developing laryngomalacia in premature infants. It is theorized that some premature infants may have decreased neurological tone and thus, increased risk for laryngomalacia.