Congenital Anomalies of the Larynx, Trachea, and Bronchi

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Chapter 378 Congenital Anomalies of the Larynx, Trachea, and Bronchi

Because the larynx functions as a breathing passage, a valve to protect the lungs, and the primary organ of communication, symptoms of laryngeal anomalies are those of airway obstruction, difficulty feeding, and abnormalities of phonation (Chapter 365). Obstruction of the pharyngeal airway (due to enlarged tonsils, adenoids, tongue, or syndromes with midface hypoplasia) typically produces worse obstruction during sleep than during waking. Obstruction that is worse when awake is typically laryngeal, tracheal, or bronchial and is exacerbated by exertion. Congenital anomalies of the trachea and bronchi can create serious respiratory difficulties from the first minutes of life. Intrathoracic lesions typically cause expiratory wheezing and stridor, often masquerading as asthma. The expiratory wheezing contrasts to the inspiratory stridor caused by the extrathoracic lesions of congenital laryngeal anomalies, specifically laryngomalacia and bilateral vocal cord paralysis.

With airway obstruction, the severity of the obstructing lesion, the work of breathing, determines the necessity for diagnostic procedures and surgical intervention. Obstructive symptoms vary from mild to severe stridor with episodes of apnea, cyanosis, suprasternal (tracheal tugging) and subcostal retractions, dyspnea, and tachypnea. Chronic obstruction can cause failure to thrive.

378.1 Laryngomalacia

Diagnosis

The diagnosis is confirmed by outpatient flexible laryngoscopy (Fig. 378-1). When the work of breathing is moderate to severe, airway films and chest radiographs are indicated. With associated dysphagia, a contrast swallow study and esophagram may be considered. Because 15-60% of infants with laryngomalacia have synchronous airway anomalies, complete bronchoscopy is undertaken for patients with moderate to severe obstruction.

378.4 Congenital Laryngeal Webs and Atresia

Lauren D. Holinger

Most congenital laryngeal webs are glottic with subglottic extension and associated subglottic stenosis. Airway obstruction is not always present and may be related to the subglottic stenosis. Thick webs may be suspected in lateral radiographs of the airway. Diagnosis is made by direct laryngoscopy (Fig. 378-2). Treatment might require only incision or dilation. Webs with associated subglottic stenosis are likely to require cartilage augmentation of the cricoid cartilage (laryngotracheal reconstruction). Laryngeal atresia occurs as a complete glottic web and commonly is associated with tracheal agenesis and tracheoesophageal fistula.

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Figure 378-2 Anterior glottic web. Most of the membranous true vocal cords are involved.

(From Milczuk HA, Smith JD, Evans EC: Congenital laryngeal webs: surgical management and clinical embryology, Int J Pediatr Otorhionlaryngol 52(1):1–9, 2000.)

378.8 Vascular and Cardiac Anomalies

The aberrant innominate artery is the most common cause of secondary tracheomalacia (Chapter 426). Expiratory wheezing and cough occur and, rarely, reflex apnea or “dying spells.” Surgical intervention is rarely necessary. Infants are treated expectantly because the problem is self-limited.

The term vascular ring is used to describe vascular anomalies that result from abnormal development of the aortic arch complex. The double aortic arch is the most common complete vascular ring, encircling both the trachea and esophagus, compressing both. With few exceptions, these patients are symptomatic by 3 mo of age. Respiratory symptoms predominate, but dysphagia may be present. The diagnosis is established by barium esophagram that shows a posterior indentation of the esophagus by the vascular ring (Fig. 426-2). CT scan with contrast or MRI with angiography provides the surgeon the information needed (Chapter 426).

Other vascular anomalies include the pulmonary artery sling, which also requires surgical correction. The most common open (incomplete) vascular ring is the aberrant right subclavian artery. Although common, it is usually asymptomatic and of academic interest only.

Congenital cardiac defects are likely to compress the left main bronchus or lower trachea. Any condition that produces significant pulmonary hypertension increases the size of the pulmonary arteries, which in turn cause compression of the left main bronchus. Surgical correction of the underlying pathology to relieve pulmonary hypertension relieves the airway compression.