Age distribution of patients at the time of diagnosis. Note that 47% presented at 3 months or younger, and 67% presented at 6 months or younger.
Major comorbid medical abnormalities.
Symptoms and diagnoses of patients at presentation. "Other" includes cough, oxygen desaturation and/or bradycardia while being monitored, tachypnea, poor pulmonary toilet, weak cry, upper respiratory tract infection, asthma or wheezing, and restless sleep.
Altman KW, Wetmore RF, Marsh RR. Congenital Airway Abnormalities in Patients Requiring Hospitalization. Arch Otolaryngol Head Neck Surg. 1999;125(5):525-528. doi:10.1001/archotol.125.5.525
To determine the cause of congenital airway abnormalities in pediatric patients requiring hospitalization for their respiratory status.
Design and Setting
Case series in a tertiary care center.
A 5-year retrospective chart review was conducted at our institution. A total of 174 patients were identified who required hospitalization for their respiratory status as a result of a congenital airway abnormality.
Of the 174 patients, 114 (65.5%) were male and 60 (34.5%) were female. Eighty patients (47%) presented within the first 3 months of life. Forty-six patients (26%) were born prematurely, and 49 patients (28%) were diagnosed as having gastroesophageal reflux. The majority of patients (139 [80%]) had multiple presenting symptoms or signs. Stridor was the most common (129 [74%]), followed by accessory respiratory effort, cyanosis, apnea, and failure to thrive. Diagnosis was made at the time of surgical evaluation in 91% of the patients, with the remaining diagnoses made using radiological findings and/or clinical evaluation. Sixty-five patients (37%) had multiple sites of airway abnormalities; laryngeal abnormalities were noted almost 3 times as often as tracheal abnormalities (161 vs 62, respectively). Of the laryngeal abnormalities, laryngomalacia was the most common, followed by glottic web, subglottic stenosis, vocal-cord paralysis, and subglottic hemangioma. Tracheomalacia was the most common tracheal abnormality, followed by external compression and tracheal stenosis. Thirty-three patients (19%) required tracheotomy for management of recurrent respiratory decompensation.
While congenital airway abnormalities are usually self-limited, those patients requiring hospitalization represent a group with a more severe respiratory status who have a greater chance of requiring tracheotomy. The recognizable percentage of patients with gastroesophageal reflux and prematurity accounts for comorbid factors in the need for hospitalization for respiratory issues related to congenital airway abnormalities.
CONGENITAL AIRWAY abnormalities in the pediatric population are usually mild in severity, often presenting with stridor (noisy breathing from obstructed airflow) or stertor (snorting or gurgling from obstruction in the nose or pharynx). However, exacerbation of symptoms with compromise of respiratory status may become evident in patients with comorbid medical conditions, multiple sites of airway abnormalities (synchronous lesions), and during upper respiratory tract infections. The purpose of this study is to determine the cause of congenital airway abnormalities in pediatric patients requiring hospitalization for their respiratory status, with attention to prematurity, comorbid medical conditions, and outcome.
A retrospective chart review was conducted in all patients treated at the Children's Hospital of Philadelphia, Philadelphia, Pa, with congenital airway abnormalities requiring hospitalization between July 1, 1991, and June 30, 1996. Patients were selected if their diagnoses were categorized from the following International Classification of Diseases, Ninth Revision1 diagnostic codes: 748.2 (laryngeal web), 748.3 (congenital anomalies of the larynx, trachea, and bronchus), and 478.30 to 478.34 (vocal-cord or vocal-fold paralysis). Patients with the following anomalies that were presumed to be acquired were excluded: subglottic stenosis, tracheomalacia or bronchomalacia as a sole finding in patients who had received ventilation through an endotracheal tube for longer than 6 days, and vocal-fold paralysis in newborn patients without central nervous system findings. Medical records were reviewed for patient demographics, clinical presentation, comorbid medical conditions, diagnostic evaluation, treatment, and outcome. Patients whose medical records had incomplete documentation in these areas were also excluded.
A total of 174 patients were identified who required hospitalization for their respiratory status as a result of a congenital airway abnormality. One hundred fourteen patients (65.5%) were male, and 60 patients (34.5%), female. Seventy-three patients (42%) required endotracheal intubation prior to the time of diagnosis of a congenital airway abnormality, with a mean duration of 22 days and a median duration of 2 weeks. The age distribution at the time of diagnosis is shown in Figure 1, with a mean age of 7.6 months and a median age of 3.2 months. Of the 174 patients, 82 (47%) were diagnosed at 3 months or younger.
Prematurity (≤36 weeks' estimated gestational age at birth) was identified in 46 patients (26%). Major cardiovascular, neurologic, chromosomal abnormalities, and/or congenital syndromes were present in 34 patients (19.5%; Figure 2). Five patients had multiple major abnormalities. Cardiovascular abnormalities were present in 25 patients and included tetralogy of Fallot, abnormalities of the aortic arch, transposition of the great vessels, severe atrial or ventricular septal defect, and pulmonary artery and valvular deformity. Three patients had congenital syndromes, and 7 had chromosomal abnormalities including Down syndrome. Neurologic abnormalities were present in 4 patients and included spina bifida, microcephalus, communicating hydrocephalus, and cerebral palsy. Seventy-two patients (41%) had 1 or more of the above malformations and/or were born prematurely. Gastroesophageal reflux was identified in 49 patients (28%).
Stridor was the most common presenting symptom or sign, found in 128 patients (74%) as shown in Figure 3. This was followed by accessory respiratory effort in 71 patients (41%), cyanosis in 45 (26%), apnea in 43 (25%), failure to thrive in 39 (22%), and cough in 30 (17%). One hundred forty patients (80%) had multiple presenting symptoms or signs. Other presenting complaints included oxygen desaturation and/or bradycardia while being monitored, tachypnea, poor pulmonary toilet, weak cry, upper respiratory tract infection, asthma or wheezing, and restless sleep.
A diagnosis was made during surgery in 158 patients (91%). Direct laryngoscopy was performed in 111 (64%), flexible laryngobronchoscopy in 117 (67%), and rigid bronchoscopy in 54 (31%). The remaining patients were diagnosed clinically or via radiographic evaluation with airway fluoroscopy and/or barium swallow.
Sixty-five patients (37%) were found to have multiple sites of airway abnormalities. There were a total of 257 diagnostic findings, with laryngeal abnormalities noted almost 3 times as often as tracheal abnormalities (161 vs 62). Overall, 154 patients (86%) had laryngeal abnormalities, 60 patients (34%) had tracheal abnormalities, 18 patients (10%) had bronchial abnormalities (all bronchomalacia except 1 with bronchial stenosis), and 17 patients (10%) had upper airway obstruction (glossoptosis, pharyngeal collapse, micrognathia, and choanal atresia).
Laryngeal anomalies are listed below.
Tracheal anomalies are listed below.
Of the laryngeal abnormalities, laryngomalacia (congenital laryngeal stridor) was the most common, followed by glottic web, subglottic stenosis, and vocal-fold paralysis. Tracheomalacia was the most common tracheal abnormality, while other anomalies included tracheal compression, tracheal stenosis, tracheoesophageal fistula, and tracheal agenesis. Tracheal compression was due to vascular ring (2 patients), anomalous innominate artery (2), and tetralogy of Fallot (1), cardiomegaly secondary to pulmonic vein stenosis (1), severe atrial septal defect (1), cystic teratoma (1), supraglottic cystic hygroma (1), and soft tissue hemangioma of the neck (1). However, 18 patients with major cardiovascular abnormalities were not diagnosed as having tracheal compression as a surgical finding.
Eighty-one patients (47%) were followed up by the otolaryngology service or required additional hospitalization after the initial diagnosis, with a mean follow-up of 1.5 years and a median follow-up of 1 year. Thirty-three patients (19%) required tracheotomy for severe, unrelenting respiratory symptoms and/or prolonged ventilatory support following diagnosis. The prevalence of tracheotomy and endotracheal intubation prior to surgical diagnosis is listed in Table 1. Patients with diagnoses of external compression, subglottic stenosis, or tracheomalacia were significantly more likely to require tracheotomy than the sample as a whole (P<.01: exact binomial probability for n<20; z scores for others). There was a higher-than-average likelihood of intubation for subglottic stenosis, glottic web, and bronchomalacia or stenosis (P<.05). Thirteen patients underwent tracheotomy at the time of laryngobronchoscopy without prior intubation.
Of the 15 patients with laryngomalacia requiring tracheotomy, 12 patients (80%) had major medical comorbidity (including cardiovascular, congenital, neurologic, chromosomal, or syndromal abnormalities, or bronchopulmonary dysplasia requiring prolonged intubation prior to tracheotomy). Six patients (40%) had multiple airway abnormalities, 3 patients with 3 abnormalities each. Six patients (40%) were premature at birth (≤36 weeks estimated gestational age). Only 2 patients had no known comorbidity; they underwent carbon dioxide laser aryepiglottoplasty (along with 1 other patient with laryngomalacia) at or after the time of tracheotomy. All 3 patients who required laser aryepiglottoplasty underwent successful decannulation after tracheotomy.
There were 6 deaths (3.4%): cardiovascular collapse in 3 patients (2 after cardiac surgery or tracheoplasty and 1 while receiving extracorporal membrane oxygenation), and 1 each due to gastrointestinal hemorrhage, lymphoproliferative disease, and tracheal agenesis (the patient was unable to maintain an open airway at birth).
Airway abnormalities of congenital origin represent more than 85% of those infants and children referred to the otolaryngologist for evaluation of chronic stridor and respiratory symptoms.2,3 The male preponderance of almost 2:1, of which there is no obvious explanation, is not unique to our study.2,4,5 Stridor is the most common presenting sign of congenital airway abnormalities, with exacerbations or severity producing accessory respiratory effort, cyanosis, and apnea.6
While a diagnosis based on the clinical history is sometimes sufficient for an isolated lesion, surgical diagnosis with flexible or rigid laryngobronchoscopy is often necessary for definitive evaluation. Synchronous lesions (multiple sites of airway abnormalities) were noted in 64 patients (37% compared with 12% in another study3 of patients with stridor), underscoring the need for direct visualization. Radiological evaluation of films of the lateral side of the neck, airway fluoroscopy, and barium esophagography are useful, but the results are not as definitive as those of laryngobronchoscopy.7
The prevalence of laryngomalacia in our study is consistent with other series of pediatric patients with chronic stridor in the United States2,3 and internationally.4,5 In a series of 191 patients with congenital stridor, Holinger2 found laryngeal abnormalities in 69%, tracheal abnormalities in 18%, and bronchial abnormalities in 6%. Laryngomalacia was the most common abnormality (41% of all congenital lesions), followed by congenital subglottic stenosis in 14% and vocal-fold paralysis in 9%. This distribution is consistent with the results of this study.
The origin of laryngomalacia is thought to include anatomical, histological, and neurologic features, although the current theory recognizes mild localized hypotonia of the musculature supporting supraglottic structures.8 Laryngomalacia tends to be self-limited with a natural history toward resolution by 18 months as the child grows and develops neuromuscular maturity.3 In a series9 of 985 patients with laryngomalacia, 12% required operative intervention (such as aryepiglottoplasty) and only 2 patients required tracheotomy.
Tracheomalacia was the second most common congenital airway abnormality in the present study. The pathophysiologic characteristic of congenital tracheobronchomalacia is an abnormal shape or consistency of the tracheobronchial rings leading to an inherent weakness.6,10 Both tracheomalacia and external compression of the trachea are sometimes associated with anomalous vascular structures compressing the trachea, resulting in respiratory symptoms in the majority of patients.11 In a study10 of 50 infants and children with tracheobronchomalacia, 48% were primary (congenital) and 52% were secondary (acquired). Overall, 62% required tracheotomy, but the rate was almost twice as high for patients who were born prematurely.
Laryngeal webs, atresia, and stenosis result from failure of the epithelial tissue over the laryngotracheal groove to resorb by 10 weeks of gestation.12 While patients with these abnormalities are relatively uncommon in our study, patients with glottic webs and congenital subglottic stenosis have about a 43% likelihood of requiring tracheotomy.13 Similarly, as many as 73% of patients with bilateral vocal-fold paralysis are also likely to require tracheotomy.14
We report a 19% tracheotomy rate in our series, comparable to the 10% to 14% rate previously reported.2,3 Of the patients requiring tracheotomy in our series, 58% had synchronous lesions. Based on the discussion herein, it is not surprising to find that 40% to 58% of our patients with congenital subglottic stenosis and glottic web required tracheotomy. Also, the diagnosis of tracheomalacia carried a 33% prevalence of tracheotomy in our series, consistent with previously reported findings.10,15 In our study, the risk of requiring tracheotomy or intubation (Table 1) is only statistically significant for those abnormalities with explanatory footnotes. This risk reflects our population of hospitalized patients with stated comorbidity and synchronous lesions and may not apply to strictly outpatient populations.
Gastroesophageal reflux was noted in 28% of our patients, similar to 23% to 53% found in studies of patients with laryngomalacia.8,16 It is possible that gastroesophageal reflux is a factor that aggravates respiratory symptoms; however, it also may represent a concomitant, yet unrelated finding. The relatively large percentage of patients with cardiovascular or other major malformations and prematurity accounts for comorbid factors in the need for intervention (hospitalization, intubation, and tracheotomy). The presence of synchronous lesions also portends a need for intervention.
This demographic study of patients with congenital airway abnormalities requiring hospitalization showed a 2:1 male preponderance of these lesions. Comorbid factors were present in 41% of the patients and included prematurity, cardiovascular malformations, and neurologic and congenital or chromosomal abnormalities. Synchronous lesions were found in 37% of the patients, contributing to the need for tracheotomy in 19% of the patients and endotracheal intubation in 42% prior to diagnosis. While laryngomalacia is the most common congenital airway abnormality, it is an uncommon reason for tracheotomy in the absence of comorbid factors.
Accepted for publication December 7, 1998.
Presented as a poster at the Annual Meeting of the American Society of Pediatric Otolaryngology, Scottsdale, Ariz, May 14-16, 1997.
Corresponding author: Ralph F. Wetmore, MD, Department of Otolaryngology, Children's Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104.