1. Laryngomalacia
Definition
Laryngomalacia 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.
Etiology
1. Anatomical problem: is caused by a physical defect in the
cartilage and tissue around the larynx.
o Laryngomalacia may affect the epiglottis, the arytenoid
cartilages, or both.
o When the epiglottis is involved, it is often elongated, and
the walls fold in on themselves.
o The epiglottis in cross section resembles an omega, and
the lesion has been referred to as an omega-shaped
epiglottis.
o 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.
2. Another theory is that of immature neuromuscular
development causing supraglottic compromise.
3. Gastroesophageal reflux (GERD).
o It result of the more negative intrathoracic pressures
necessary to overcome the inspiratory obstruction.
o 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.
2. Types of laryngomalacia:
Type I: Inward collapse of aryepiglottic folds
Type II: Long tubular epiglottis infolding on itself (Omega shaped)
Type III: Anterior and medial collapse of corniculate and cuneiform
cartilages
Type IV: Posterior displacement of epiglottis against posterior pharyngeal
wall or inferior collapse towards vocal folds
Type V: Short aryepiglottic folds
Epidemiology
Commonest cause of congenital anomaly of the larynx (60%).
Can be associated with other air lesions in 12-45%.
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
Sex
More common in Male infants (2:1=Males :Females).
3. Age
o 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.
o Symptoms typically peak at age 6-8 months and remit by age 2 years.
o Late-onset laryngomalacia may be a distinct entity, which can present
after age 2 years.
Clinical Presentation
The infant presents with intermittent respiratory , positional
stridor that starts to appear few weeks after birth .
Usually mild at the beginning then react its peak after few
months and resolve spontaneously between 18-24 months of
age.
Inspiratory stridor increase in supine position , sleep, feedng
, or crying .
Inspiratory stridor decrease in prone position or neck
extension.
Voice and feeding are normal
Weight gain and mile stone is usually normal except in
advanced conditions
Cyanosis is very unusual and should indicate another
associated pathology.
4. Dignosis
o It is important for a clinician to differentiate laryngomalacia from
other conditions that cause noisy breathing.
o All too often the diagnosis of tracheomalacia, asthma,
bronchiolitis, and reactive airway disease may precede the correct
diagnosis of laryngomalacia.
History
In noisy breathing & Sound specially on crying : Stridor .
Clinical Presentation (discussed above).
Imaging Studies
Fluoroscopy
Fluoroscopy of the airway may be performed by a pediatric
radiologist.
The cartilages may be observed collapsing on inspiration on a
lateral view of the airway
Laryngoscopy and bronchoscopy
These studies are the best studies used to confirm the diagnosis.
A flexible fiberoptic laryngoscopy is typically performed. During
this procedure, a small flexible tube is passed through the nose to
examine the upper airway.. This is a brief and mildly
uncomfortable procedure for the baby and does not require
anesthesia
Direct visualization of the airway reveals an omega-shaped
epiglottis that prolapses over the larynx during inspiration.
Enlarged arytenoid cartilages that prolapse over the larynx during
inspiration may also be present.
Endoscopic Findings :
Omega-shaped Epiglottis.
Inward collapse.
Short aryepiglottic fold.
Redundant bulky arytenoid mucosa
Discoordinate pharyngolaryngeal movements.
5. Complications
o Difficulty with gaining weight
o Difficulty with feeding
o Oxygen desaturations (apparent life-threatening events)
o GERD (acid reflux)
o Apnea
o Pulmonary hypertension.
Treatment
o No treatment is usually required. The stridor usually disappears
gradually by the end of the first year.
o In mild to moderate cases anti reflux treatment is very effective.
o Failure to gain weight or sever stridor will need surgical
correction, only in 10% of cases.
Surgical Care
Approximately 10% of patients with severe congenital
laryngomalacia require surgical intervention
o Absolute Indications
failure to thrive,
Elevated carbon dioxide or hypoxemia,
severe obstructive sleep apnea,
pulmonary hypertension, or cor pulmonale.
Stridor with respiratory compromise or with significant retraction.
o Relative Indications
Aspiration.
Difficult to feed child
Weight loss
Operations include
Tracheostomy was performed in order to alleviate symptoms.
It serves to bypass the supraglottic obstruction until spontaneous
resolution occurs with growth .
tracheostomy-related mortality rate of about 2%
6. Currently Supraglottoplasty is the treatment of choice. The major
advantage of this procedure is that it addresses the area of
obstruction directly.
This procedure to modify the supraglottis to relieve obstruction has an
excellent success rate, with reports of 79% to 98% of cases having a good
outcome.
Complications occur in less than 8% of cases, and are related to
the extent of surgery, amount of tissue excised, and mode of
excision.
o Complications include granulomas, synechiae, aspiration, and
supraglottic stenosis. Supraglottic stenosis occurs in 2% to 4% of
cases and is difficult to treat.
Co-existing GORD should be assessed and treated appropriately
in all patients, with either changes to feeding techniques,
medication, or, in severe cases, surgical intervention.
Further Outpatient Care
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.
Prognosis
Prognosis is excellent. Most babies outgrow the condition by their
second birthday, many by the first.
Refrences :
John Hopkins Hospital Handout of Laryngomalacia.
Medscape.
BMJ Journal.
