Hindawi Publishing CorporationInternational Journal of PediatricsVolume 2012, Article ID 753526, 6 pagesdoi:10.1155/2012/753526
Laryngomalacia: Disease Presentation,Spectrum, and Management
April M. Landry1 and Dana M. Thompson2
1Department of Otolaryngology, Head and Neck Surgery, Mayo Clinic Arizona, Phoenix, AZ 85054, USA2Division of Pediatric Otolaryngology, Department of Otorhinolaryngology, Head and Neck Surgery, Mayo Clinic Childrens Centerand Mayo Eugenio Litta Childrens Hospital, Mayo Clinic Rochester, 200 First Street SW, Gonda 12, Rochester, MN 55905, USA
Correspondence should be addressed to Dana M. Thompson, firstname.lastname@example.org
Received 10 August 2011; Accepted 23 November 2011
Academic Editor: Jerey A. Koempel
Copyright 2012 A. M. Landry and D. M. Thompson. This is an open access article distributed under the Creative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work isproperly cited.
Laryngomalacia is the most common cause of stridor in newborns, aecting 4575% of all infants with congenital stridor. Thespectrum of disease presentation, progression, and outcomes is varied. Identifying symptoms and patient factors that influencedisease severity helps predict outcomes. Findings. Infants with stridor who do not have significant feeding-related symptoms canbe managed expectantly without intervention. Infants with stridor and feeding-related symptoms benefit from acid suppressiontreatment. Those with additional symptoms of aspiration, failure to thrive, and consequences of airway obstruction and hypoxiarequire surgical intervention. The presence of an additional level of airway obstruction worsens symptoms and has a 4.5x riskof requiring surgical intervention, usually supraglottoplasty. The presence of medical comorbidities predicts worse symptoms.Summary. Most with laryngomalacia will have mild-to-moderate symptoms and not require surgical intervention. Those withgastroesophageal reflux and/or laryngopharyngeal reflux have symptom improvement from acid suppression therapy. Those withsevere enough disease to require supraglottoplasty will have minimal complications and good outcomes if multiple medicalcomorbidities are not present. Identifying patient factors that influence disease severity is an important aspect of care provided toinfants with laryngomalacia.
Laryngomalacia is the most common cause of stridor innewborns, aecting 4575% of all infants with congenitalstridor . The stridor can be overwhelming to parents andcaregivers. The high-pitched noise of stridor is created byairflow through an area of obstruction. In laryngomalaciathe supraglottic structures collapse into the airway during theinspiratory phase of respiration which produces inspiratorystridor. Most infants with laryngomalacia will have mildsymptoms and a benign disease course that resolves by theage of 12 to 24 months; however, it is important to recognizethat not all cases of laryngomalacia have a benign course. Once the condition is diagnosed and dierentiated fromother causes of stridor, most mild cases can be followedexpectantly by their pediatrician and referred back to an oto-laryngology if symptoms worsen. The purpose of this paper
is to review the disease presentation spectrum, highlightingsymptoms and patient factors that predict which infantsmay worsen and require intervention or comanagement withan otolaryngologist. Supraglottoplasty is the mainstay sur-gical management. Tracheotomy to bypass the obstructionis rarely performed and reserved for surgical failures orchildren with multiple medical comorbidities.
Laryngomalacia presents with inspiratory stridor that typi-cally worsens with feeding, crying, supine positioning, andagitation. The symptoms begin at birth or within the firstfew weeks of life, peak at 6 to 8 months, and typicallyresolve by 12 to 24 months . Laryngomalacia is usuallydiagnosed within the first 4 months of life . Although
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inspiratory stridor is the classic symptom of laryngomalacia,there are a number of associated symptoms. The mostcommon associated symptoms are related to feeding whichinclude regurgitation, emesis, cough, choking, and slowfeedings. Infants with laryngomalacia may have a diculttime coordinating the suck swallow breath sequence neededfor feeding as a result of their airway obstruction . Theincreased metabolic demand of coordinating eating andbreathing against the obstruction can be so severe thatit results in weight loss and failure to thrive. Other lesscommon but concerning associated symptoms are tachyp-nea, suprasternal and substernal retractions, cyanosis, pectusexcavatum, and obstructive sleep apnea. Chronic hypoxiafrom airway obstruction can lead to pulmonary hypertensionif not recognized and managed.
It is important for a clinician to dierentiate laryngo-malacia from other conditions that cause noisy breathing.All too often the diagnosis of tracheomalacia, asthma,bronchiolitis, and reactive airway disease may precede thecorrect diagnosis of laryngomalacia. Because infants areoften misdiagnosed with these conditions, understandingpatterns and characteristics of breathing will aid the clinicianin dierentiating the noisy breathing of laryngomalacia fromothers. Identifying which phase of the respiratory cyclewill also help determine the level of obstruction. Wheez-ing, stertor, and stridor are the types of noisy breathing.Wheezing is typified as a coarse whistling sound heard onthe phase of expiration and is usually due to lung disease.Stertor is a grunting or a snoring sound and is loudestduring inspiration. In children it is typically caused byadenotonsillar disease. The high-pitched noise of stridor canoccur during the respiratory phase of inspiration, expiration,or both (biphasic). Inspiratory stridor is caused by airwayobstruction at the vocal cords or higher. Biphasic stridoris caused by obstruction below the vocal cords. The mostcommon cause of biphasic stridor in children is viral croup.Expiratory stridor is caused by obstruction in the trachea.The most common cause of expiratory stridor in childrenis tracheomalacia. Infants and children who have chronicstridor should be referred to an otolaryngologist for accuratediagnosis.
The diagnosis of laryngomalacia is suspected by the typicalclinical history but is confirmed by flexible laryngoscopy inan awake infant. Flexible laryngoscopy is easily preformed inthe otolaryngology oce with the help of a caregiver. Theinfant is held in the caregivers lap in an upright or semire-clined position, and a flexible laryngoscope is passed throughthe nose, pharynx, and positioned above the larynx. Theotolaryngologist is able to examine the dynamic movementof the laryngeal structures during spontaneous respirationand dierentiate laryngomalacia from other cause of inspi-ratory stridor such as vocal cord paralysis or a laryngealcyst. Supraglottic tissue collapse and obstruction duringinspiration is the hallmark of laryngomalacia. The epiglottis,false vocal cords, arytenoids, ventricle, and aryepiglottic folds
are the structures making up the supraglottis. As seen inFigures 1(a) and 1(b), the common findings seen on examare prolapse of the posteriorly positioned arytenoid cartilagesand mucosa into the airway during inspiration, shorteningof the distance between the arytenoid and epiglottis, and anomega-shaped or retroflexed epiglottis.
The exact etiology of laryngomalacia is unknown and con-tinues to be an area of great interest and research. Theories ofetiology include the anatomic, cartilaginous, and neurologictheories. The anatomic theory proposes that there is anabnormal placement of flaccid tissue resulting in stridor. Thechallenge with the anatomic theory is there are infants whohave the typical anatomic laryngeal findings of laryngoma-lacia who do not have symptoms of airway obstruction. Thecartilaginous theory proposes that the cartilages of the larynxare immature and abnormally pliable. This theory has beenrefuted by the finding of histologically normal cartilage ininfants with symptomatic laryngomalacia. The neurologictheory is the best supported by the literature and as a resultis the prevailing etiologic theory .
The neurologic theory recognizes that laryngomalaciamay be a consequence of an underdeveloped or abnormallyintegrated CNS system, particularly the peripheral nervesand brainstem nuclei responsible for breathing and airwaypatency. As the infant matures laryngomalacia likely resolvessecondary to the maturation of the CNS system. Thelaryngeal adductor reflex is a vagal nerve reflex responsiblefor laryngeal function and tone. The aerent activationof the reflex is mediated by the superior laryngeal nervewhich is located in the aryepiglottic fold . Sensoryinformation from this nerve is then transmitted to thebrainstem nuclei that regulate respiration and swallowing.A motor response to sensory stimulation is mediated bythe vagus nerve resulting in glottic closure, inhibition ofrespiration, and swallow. An alteration in this pathway hasa role in the etiology of laryngomalacia and the associatedfeeding symptoms. Laryngeal sensory testing in infants withlaryngomalacia has demonstrated that the sensory stimulusthreshold needed to elicit the typical motor response iselevated in those with moderate-to-severe disease versusthose with mild disease. This testing supports the notion ofan underdeveloped or abnormally integrated peripheral andcentral nervous systemmechanism of laryngeal function andtone .
5. Spectrum of Disease
Laryngomalacia has a disease spectrum that can be dividedinto mild, moderate, and severe categories . These cate-gories are not based