Evaluation and Management of the Pediatric Airway




Key Points





  • Initial evaluation of a child with noisy breathing involves assessment of phase and character of noisy breathing; distress in relation to states of sleep, wakefulness, and feeding; overall color and oxygen saturation; growth and weight gain; and awake fiberoptic laryngoscopy.



  • The most common cause of stridor in infants is laryngomalacia, but not all stridor can be assumed to be due to laryngomalacia.



  • Laryngomalacia improves spontaneously with increasing age in most children, but when surgery is needed, aryepiglottoplasty (supraglottoplasty) is highly successful to resolve the symptoms.



  • Noniatrogenic neonatal unilateral and bilateral vocal cord paralysis will resolve spontaneously in more than 50% of patients.



  • All children with congenital anterior laryngeal webs should undergo genetic testing for abnormalities of chromosome 22q11.



  • Patients with subglottic hemangiomas often present with a history of “recurrent croup,” because the lesion mimics the subglottic swelling of croup, and the symptoms improve with steroid treatment.



  • Laryngeal cysts—including vallecular thyroglossal duct cysts, saccular cysts, and subglottic cysts—are a source of potentially severe airway obstruction.



  • In the patient with feeding problems, recurrent aspiration, and stridor, the otolaryngologist must maintain a high index of suspicion that a laryngeal cleft may be present and must maintain a low threshold to perform direct laryngoscopy in the operating room to rule out potential clefts.





Assessment of a Child with Noisy Breathing


Characterization of Noisy Breathing


Noisy breathing in a neonate (birth to 1 month age), infant (1 to 12 months), and child (1 to 12 years) can be characterized in several ways and is a reflection of turbulent airflow at some level of the airway. The word stertor is derived from the Latin word stertere , which means “to snore.” The term stertor can be used to describe noisy breathing from the vibration of tissues above the level of the larynx. In contrast, stridor is the hallmark of any laryngeal obstruction and can be described as a high pitched, musical, or harsh sound often mistaken for “wheezing.” Stridor and stertor can be heard on exam without auscultation and can be correlated with phase of breathing, wakefulness, sleep, and feeding. On auscultation, noisy breathing can be an indication of tracheal sources of turbulent airflow.


Much can be learned about the nature of the airway obstruction by closely observing the infant and listening to the noise produced as air passes through the obstruction. Stertor can result from obstruction at the level of the nose, nasopharynx, oropharynx, hypopharynx, and/or supraglottis. Stridor that results from glottic obstruction is typically present on inspiration, whereas biphasic stridor originates from obstruction at or below the level of the glottis, in the subglottis and upper trachea; expiratory stridor is the result of lesions in the distal trachea or mainstem bronchi. The differential diagnosis of airway pathology in a child can be divided by characteristics that reflect the level of the airway affected, either above or below the larynx ( Tables 23-1 through 23-3 ).



TABLE 23-1

Causes of Pediatric Airway Obstruction Above the Level of the Larynx




































































Airway Pathology Age of Presentation Level of Airway Obstruction Characteristic Noisy Breathing Classic Signs/Symptoms Associated Sequences/ Syndromes/Findings Treatment
Piriform aperture stenosis Birth, first months of infancy Anterior nose Stertor, noisy mouth/nose breathing Nasal flaring, cyclical cyanosis, mouth breathing, difficulty sleeping or feeding Holoprosencephaly, single central incisor Nasal saline and suctioning, topical decongestant drops, McGovern nipple, surgical repair
Nasolacrimal duct cyst Birth, first months of infancy Anterior nose Stertor, noisy mouth/nose breathing Nasal flaring, cyclical cyanosis, mouth breathing, difficulty sleeping or feeding; symptoms are more severe if bilateral Dacrocystocele Warm compresses and massage of associated dacrocystocele, nasal saline and suctioning, topical decongestant drops, McGovern nipple, marsupialization with lacrimal duct dilation
Choanal atresia Birth (bilateral), birth through childhood (unilateral) Choanae Stertor, noisy mouth/nose breathing Nasal flaring, cyclical cyanosis, mouth breathing, difficulty sleeping or feeding; symptoms are more severe if bilateral CHARGE syndrome, craniosynostosis syndromes (Crouzon, Treacher Collins) Oral intubation, McGovern nipple, surgical repair
Nasal glioma, encephalocele Birth, infancy Nasal cavity Stertor, noisy mouth/nose breathing Nasal flaring, cyclical cyanosis, mouth breathing, difficulty sleeping or feeding Nasal pit with single hair, nasal dorsal mass, possible intracranial extension Endoscopic/open resection
Midface hypoplasia Birth, infancy Nasal cavity, choanae Stertor, noisy mouth/nose breathing Nasal flaring, cyclical cyanosis, mouth breathing, difficulty sleeping or feeding Craniosynostosis syndromes Nasal saline and suctioning, topical decongestant drops, midface advancement
Retrognathia, micrognathia, glossoptosis Birth, infancy Base of tongue Stertor, noisy mouth breathing Difficulty breathing, sleeping or feeding, retractions, cyanosis Pierre Robin sequence, craniosynostosis syndromes (Treacher Collins), laryngomalacia Prone positioning, nasal trumpet, tongue-lip adhesion, mandibular distraction, tracheostomy
Macroglossia Birth, childhood Posterior oropharynx/base of tongue Stertor, noisy mouth breathing Protruding tongue with oral incompetence; difficulty breathing, sleeping, or feeding Beckwith-Weidemann syndrome, vascular malformation Nasogastric tube feeding, oxygen supplementation, tracheostomy, tongue reduction


TABLE 23-2

Causes of Pediatric Airway Obstruction at the Level of the Larynx




















































































































Airway Pathology Age of Presentation Level of Airway Obstruction Characteristic Noisy Breathing Classic Signs/Symptoms Associated Sequences/ Syndromes/Findings Treatment
Laryngomalacia Birth, infancy Supraglottis Stertor, stridor, “congestion,” transmission of sound out of nasal cavity Retractions, difficulty sleeping/feeding, failure to thrive Micrognathia, retrognathia Antireflux medications and precautions, supraglottoplasty
Laryngeal agenesis Birth Larynx Cyanosis Prenatally diagnosed on ultrasound with fetal echogenic lungs, hydrops, ascites EXIT procedure, tracheostomy
Laryngeal web Birth, infancy Larynx Stridor, aphonia, hoarseness Retractions, difficulty feeding Velocardiofacial syndrome Surgical repair
Vocal fold paralysis Birth, childhood Larynx Stridor, aphonia, hoarseness Retractions, difficulty feeding/sleeping, aspiration Bilateral: central nervous system pathology (Arnold-Chiari malformation), birth trauma, postsurgical (cardiac surgery), mediastinal mass Nasogastric tube feedings, oxygen supplementation, tracheostomy, posterior cricoid graft (bilateral); vocal fold injection (unilateral)
Paradoxic vocal fold motion Birth, childhood Larynx Inspiratory stridor Episodic inspiratory stridor with crying, agitation, during feeding (infant), or with anxiety or exercise (child) Gastroesophageal reflux, allergic rhinitis with postnasal drip, anxiety Reflux treatment, treatment of nasal allergies, soothing/calming measures, speech therapy
Gastropharyngeal reflux Birth, infancy Larynx Stertor, stridor “congestion”; transmission of sound out of nasal cavity Noisy breathing after feeding Prematurity Antireflux medications, Nissen fundoplication
Posterior glottic stenosis Birth, childhood Larynx Stridor, hoarseness Retractions, difficulty sleeping/feeding History or intubation Reflux treatment, lysis of scar, tracheostomy, posterior cricoid graft
Laryngeal cleft Birth, childhood Larynx, trachea Stertor, stridor Feeding difficulties, recurrent pneumonia Tracheoesophageal fistula, esophageal atresia, congenital heart disease, cleft lip and palate, micrognathia, glossoptosis, laryngomalacia, and Opitz-Frias syndrome Endoscopic or open repair
Papillomatosis Infancy, childhood Supraglottis, larynx, trachea Stridor, hoarseness, aphonia Retractions, hoarseness progressing to aphonia Pulmonary seeding as the disease progresses Surgical debridement, cidofovir intralesional injection
Laryngeal cysts Birth, childhood Larynx Stertor, stridor, hoarseness Retractions, difficulty sleeping, feeding Laryngocele or saccular cyst Endoscopic or open repair
Subglottic hemangioma Infancy Subglottis Stridor Retractions, difficulty sleeping/feeding Infantile hemangioma in the beard distribution, PHACES syndrome Oral steroids, surgical removal, oral propranolol
Subglottic cyst Birth, childhood Subglottis Stridor Retractions, difficulty sleeping/feeding History of intubation Surgical removal
Subglottic stenosis Birth, childhood Subglottis Stridor Retractions, difficulty sleeping/ feeding History of intubation, congenital stenosis Endoscopic dilation or laser treatment, tracheostomy, laryngotracheal reconstruction

EXIT, ex utero intrapartum treatment procedure; PHACES, posterior fossa intracranial abnormalities, hemangiomas, arterial abnormalities, cardiac defects and coarctation of the aorta, eye abnormalities, and sternal clefting.


TABLE 23-3

Causes of Pediatric Airway Obstruction Below the Level of the Larynx




















































Airway Pathology Age of Presentation Level of Airway Obstruction Characteristic Noisy Breathing Classic Signs/Symptoms Associated Sequences/ Syndromes/Findings Treatment
Vascular ring/extrinsic tracheal compression Birth, childhood Trachea Stridor, biphasic “washing machine” or “rattling” noise, coarse upper airway sounds on auscultation Retractions, exacerbated with exertion or excitement, recurrent pneumonia, difficulty swallowing Down syndrome, velocardiofacial syndrome, CHARGE syndrome, TEF Cardiothoracic surgical repair
Tracheal stenosis, complete tracheal rings Birth, childhood Trachea Stridor, biphasic “washing machine” or “rattling” noise, coarse upper airway sounds on auscultation Retractions, exacerbated with exertion or excitement, recurrent pneumonia Down syndrome, pulmonary and cardiac anomalies Tracheoplasty
Tracheomalacia Infancy, childhood Trachea Stridor, biphasic “washing machine” or “rattling” noise, coarse upper airway sounds on auscultation, expiratory wheeze Retractions, exacerbated with exertion or excitement, persistent cough Laryngomalacia, external compression, chronic tracheal inflammation after TEF repair CPAP, tracheostomy for severe cases
Laryngotracheoesophageal clefts, tracheoesophageal fistula Infancy, childhood Larynx, trachea Stridor, biphasic “washing machine” or “rattling” noise, coarse upper airway sounds on auscultation Retractions, persistent cough, recurrent pneumonia Opitz-Frias syndrome, Townes-Brock syndrome, chromosome 1q43 deletion, and Down syndrome, VACTERL Surgical repair
Foreign body aspiration Infancy, childhood Larynx, trachea, bronchus Stridor, recurrent cough, unilateral wheezing/rattling on auscultation Retractions, persistent cough, unilateral pneumonia Hyperinflation, lung collapse, mediastinal shift, and/or radiopaque FB on CXR Bronchoscopy and removal of foreign body

CHARGE, coloboma, heart defect, choanal atresia, retarded growth and development, genital abnormality, and ear abnomality; CXR, chest radiography; FB, foreign body; TEF, tracheoesophageal fistula; VACTERL, vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal abnormalities, and limb abnormalities.


Noisy breathing is the hallmark symptom that leads to an airway evaluation. Severity of the airway process and need for intervention can be determined by level of distress, cyanosis, hypercapnea, poor weight gain or failure to thrive, difficulty feeding, difficulty sleeping, and obstructive sleep apnea.


History


Obtaining a history that elicits whether the noisy breathing is positional or related to states of wakefulness, sleep, or feeding is helpful in determining a differential diagnosis. Important features also include age of onset, exacerbating and ameliorating features, presence of progression, and occurrence of cyanosis. History of illness or recurrent pneumonia and comorbidities such as Down syndrome are useful in identifying associated factors. A history of intubation, prematurity status, and history of cardiac surgery increase suspicion for glottic or subglottic processes. History of a choking episode raises the suspicion of foreign body aspiration.


Physical Exam


The exam of the child begins with an overall assessment of size relative to age, level of distress, retractions, posturing, irritability, level of fatigue, and skin color. Evidence of syndromic features should be noted. Severe obstruction may be inferred by the type and anatomic level of retractions, including nasal flaring, suprasternal retractions, subcostal retractions, and intercostal retractions; the latter reflects recruitment of additional chest muscles for respiration. Altered voice quality may lead to a higher suspicion for a laryngeal process, especially if the child is aphonic, has a muffled voice, or does not generate a cough. Phase of stridor with inspiration or expiration is timed with chest motion. A complete head and neck exam and auscultation of the chest should be performed. Nasal and nasopharyngeal patency can be inferred when fog is seen under each nostril with a mirror.


Endoscopy


Dynamic evaluation of the larynx by flexible laryngoscopy is best performed in the patient who is awake. Although at least a 2.5-mm diameter fiberoptic laryngoscope is recommended for optimal viewing, fiberoptic laryngoscopes with diameters as small as 1.9 mm allow the neonatal larynx to be viewed with a minimum of trauma to the young patient. Viewing the fiberoptic laryngoscopy from a monitor allows for a magnified view of the pediatric larynx. Technology that provides the ability to record and review the exam with slow motion views, frame by frame views, and stroboscopy may greatly aid in the evaluation of the dynamic pediatric larynx.


Direct laryngoscopy of the neonatal larynx with a telescope or microscope provides the best optics ( Fig. 23-1 ) and requires general anesthesia, often performed by a pediatric anesthetic team familiar with techniques to provide spontaneous respirations that allow for a full evaluation of the airway before intubation or airway manipulation is performed. Techniques of total intravenous anesthesia, using propofol-remifentanyl intravenously, and of sevoflurane volatile induction/maintenance anesthesia have been well described to allow for spontaneous respirations while permitting airway manipulation. The endoscopist should fully evaluate the larynx and note findings in the valleculae, piriform fossae, postcricoid region, arytenoids, interarytenoid area, aryepiglottic folds, epiglottis, false vocal cords, ventricles, true vocal cords, and the subglottis. A bronchoscopy can be completed with a telescope or Hopkins rod, and the trachea and mainstem bronchi can also be evaluated.




FIGURE 23-1


Normal infant larynx. Anatomic areas to be examined include epiglottis, vallecula, piriform sinuses, arytenoid cartilages, interarytenoid area, aryepiglottic folds, false vocal cords, ventricles, true vocal cords, anterior commissure, and subglottis.

(From Benjamin B. The pediatric airway, In Slide Lecture Series, American Academy of Otolaryngology–Head and Neck Surgery, 1992.)


Optional Diagnostic Exams


Other studies that may be helpful in the assessment of child with noisy breathing include oxygen saturation monitoring, capnography, arterial blood gas, lateral neck radiography, chest radiography, modified barium swallow, barium esophagogram, vocal fold ultrasound, vocal fold electromyography, pulmonary function testing, pH probe testing, and polysomnography (PSG). Associated imaging studies of the brain or chest may be needed to assess for associated findings such as Arnold-Chiari malformation or vascular rings.




Laryngomalacia


Without question, the most common cause of stridor in infants is laryngomalacia (LM), which has been thought to occur more frequently in term males with a normal birth weight, although recent evidence suggests that it is equally common in females. Premature Hispanic infants and black infants of all gestational ages are at higher risk for this laryngeal anomaly. The newborn with LM typically develops intermittent inspiratory stridor within the first 2 weeks of life, which resolves slowly over several months. For infants who are not managed operatively, the median time to spontaneous resolution of stridor is 7 to 9 months of age, and the vast majority will have no stridor by 18 months of age.


Many authors describe the stridor of LM as high-pitched, but compared with the stridor of vocal cord paralysis, it is relatively low in pitch and does not have a musical quality. The stridor nearly always worsens with feeding, and often the infant will need to take breaks while feeding in order to breathe. The stridor of mild LM often improves with crying, as tone in the pharynx is increased; conversely, in moderate to severe LM, the stridor typically will worsen with crying because of the increased airflow through the severely collapsed larynx. Infants with severe LM have been found to have shorter aryepiglottoic folds compared with infants without LM. Also, LM may be an isolated finding in the otherwise healthy infant, or it may be associated with other neurologic disorders such as cerebral palsy.


The inspiratory stridor of LM results from collapse of the supraglottic larynx, which creates a narrow airway and turbulent airflow ( Fig. 23-2 ). The etiology of this collapse has been elusive, but it appears to be related to neuromuscular hypotonia. Sensorimotor integration of peripheral sensory afferent reflexes, brainstem function, and the motor efferent response are responsible for laryngeal function and tone. The laryngeal adductor reflex (LAR) is a vagal nerve-mediated reflex activated by sensory stimulation of the mechanoreceptors and chemoreceptors of the superior laryngeal nerve located in the region of the aryepiglottic fold. Dysfunction anywhere along the afferent, brainstem, or efferent pathway of the LAR can result in altered laryngeal tone and function. Infants with LM have been found to have elevated laryngopharyngeal sensory testing thresholds, which shows that the sensorimotor integrative function of the larynx is altered, likely leading to the weak laryngeal tones seen in infants with LM. In addition, pathologic specimens of surgically resected supraarytenoid tissue have been found to have nerve hypertrophy compared with controls, which supports the theory of neurologic dysfunction as the etiology of LM.




FIGURE 23-2


Laryngomalacia. Progressive airway obstruction on inspiration. Note the omega-shaped epiglottis.

(From Benjamin B. The pediatric airway, In Slide Lecture Series, American Academy of Otolaryngology–Head and Neck Surgery, 1992.)


The diagnosis of LM requires an endoscopic examination; however, the optimal type of endoscopic examination is somewhat controversial. If the patient is sedated and undergoes fiberoptic flexible laryngoscopy (FFL), the topical lidocaine typically used can cause increased collapse of the arytenoids and folding of the epiglottis during inspiration, which could possibly lead to overestimation of the severity of LM. These findings suggest that the optimal way to diagnose LM is with FFL in the awake patient. Conversely, the awake technique has been found to miss mild LM or lead to overdiagnosis in the patient with a normal airway. The advantages of awake FFL compared to FFL under general anesthesia include the ability to perform the examination expediently in the clinic setting with the parents present and avoidance of sedation, which reduces medical expense. The primary disadvantage of the awake FFL is that in nearly all cases, the infant is crying during the examination, which can alter the appearance of the supraglottic structures. Flexible nasolaryngoscopy has been found to be a consistently accurate method of diagnosis. An omega-shaped epiglottis is often associated with LM but can also be found in otherwise normal infants with no airway obstruction. Airway fluoroscopy has been proposed as a screening tool for the infant with stridor; however, although it has been found to have a relatively high specificity, it has a low sensitivity and is thus not recommended if FFL is available.


It is possible for infants with LM to have a second synchronous lesion that may lead to airway difficulties. The reported incidence of secondary lesions varies from 8% to 58%, with a higher incidence in children with more severe LM. The decision to perform a bronchoscopy in patients who present with typical LM is controversial. Some contend that bronchoscopy should be done only in select infants with LM who present with “apnea, failure to thrive, or features inconsistent with isolated LM.” Others have recommended a complete evaluation of the tracheobronchial tree in all symptomatic infants.


In several series, a high prevalence of gastroesophageal reflux disease (GERD) has been reported in patients with LM. Theoretically, when GERD is present, it can cause airway edema and thus contribute to the airway compromise. A recent systematic review of 27 studies representing 1295 neonates with LM showed an increased reflux prevalence of 59% in this group; however, reflux was not demonstrated to be more prevalent in infants with LM compared with matched children with other respiratory diagnoses. In this systematic review, an increased prevalence of reflux was seen in infants with severe LM compared with those with mild LM. The review points out that there currently are no controlled studies to correlate pH data to pathologic reflux findings in infants, and further trials of antireflux medication versus placebo are justified. Because no definitive evidence is currently available to suggest that mild LM will be improved with antireflux therapy, some have recommended that routine use of acid-suppressing medications be avoided. However, in children with moderate to severe LM, it is routine practice among pediatric otolaryngologists to consider antireflux therapy, often empirically, particularly when surgical intervention is being contemplated. Treatment of GERD may improve LM by preventing acid-induced irritation of the larynx and by improving laryngeal sensation and airway protection mechanisms. However, some evidence suggests that infants treated with acid-suppression therapy may have an increased incidence of lower respiratory tract infections. In the child with GERD related to airway obstruction, the GERD will often improve significantly after aryepiglottoplasty.


Laryngeal penetration and aspiration are also common in the child with severe LM. Functional endoscopic evaluation of swallowing (FEES) of children with severe LM has shown laryngeal penetration in 88% of infants and aspiration beyond the vocal folds in 72% of infants. Videofluoroscopic swallow studies are helpful preoperatively to assess the extent of aspiration. PSG may be indicated in the child with LM to assess the degree of sleep disturbance.


Various anatomic abnormalities that lead to supraglottic obstruction may cause laryngomalacia in infants. The most common findings are anterior prolapse of the mucosa overlying the arytenoid cartilages (57%), short aryepiglottic folds that tether the epiglottis posteriorly (15%), posterior collapse of the epiglottis (12%), or some combination of these findings (15%). Several classification systems have been proposed, with none being predominant at this time.


Infrequently, the LM is severe and results in feeding difficulties, microaspiration, failure to thrive, apnea, pectus excavatum, or cyanosis. In these cases, surgical intervention is recommended to prevent worsening failure to thrive, cor pulmonale, and cardiac failure. Approximately 10% to 31% of infants seen by a pediatric otolaryngologist require surgical intervention for their LM. The current standard treatment is supraglottoplasty (aryepiglottoplasty; Fig. 23-3 ). The surgical resection can be performed using the carbon-dioxide (CO 2 ) laser, laryngeal microscissors, sinus instruments, or microdébrider.




FIGURE 23-3


Laryngomalacia. Infant larynx before ( A ) and after ( B ) supraglottoplasty.


The simplest type of supraglottoplasty involves division of short aryepiglottic folds. Alternatively, various portions of the prolapsing supraglottis are removed: the tissue overlying the arytenoids, the aryepiglottic folds, or the posterior portion of the epiglottis. It is important to preserve the interarytenoid mucosa to avoid postoperative stenosis. For the child with a severely omega-shaped epiglottis, an epiglottopexy can be performed to unfurl the epiglottis and open up the airway. In this procedure, the mucosa of the lingual surface of the epiglottis and the corresponding mucosa of the base of the tongue are removed with the carbon-dioxide laser, followed by suturing of the epiglottis to the tongue base. Unilateral supraglottoplasty has been advocated by some to reduce the risk of postoperative supraglottic stenosis; however, most surgeons perform a bilateral procedure to obtain the maximum benefit.


The supraglottoplasty procedures are well tolerated by infants and typically require only a short hospital stay of 1 to 3 days. The success of the various forms of supraglottoplasty-epiglottopexy are high, and the vast majority of children obtain relief from their obstruction. Children with severe LM often have a lower-percentile weight on a standardized growth curve, and improvement in growth curve percentile is substantial after supraglottoplasty. Following supraglottoplasty, the incidence of aspiration also improves significantly. Some children have ongoing aspiration for months after surgery and require thickening of feedings or gastrostomy tube placement. Sleep mechanics also improve as evidenced in studies that have compared preoperative and postoperative PSG.


Those children who do not improve with supraglottoplasty often have underlying neurologic or syndromal abnormalities and may require a tracheotomy. Complications are rare, the most concerning of which is supraglottic stenosis, which may occur in up to 4% of cases. Children who do not improve significantly with the initial surgery may require revision supraglottaplasty, which is more commonly needed in children with comorbidities.


Although LM is typically thought of as occurring only in infants, it is occasionally observed in older children and adults and can be a cause of obstructive sleep apnea. Similar to neonates with LM, older children with sleep apnea and LM improve after supraglottoplasty. Neurologically impaired children (i.e., those with cerebral palsy) with poor pharyngeal tone are particularly prone to developing LM. Exercise-induced LM results when enough inspiratory force occurs during exercise to draw the aryepiglottic folds into the larynx and partially obstruct the glottis. In severe cases with redundant aryepiglottic folds, supraglottoplasty can be beneficial. Similarly, if the epiglottis is elongated and flaccid, a partial epiglottidectomy may be effective.




Vocal Fold Dysfunction


Vocal Fold Paralysis


Vocal fold paralysis (VFP) is another common cause of neonatal stridor. The stridor is inspiratory or biphasic with a high-pitched musical quality. VFP in a newborn may result from birth trauma, thoracic diseases or procedures, central or peripheral neurologic diseases, or from idiopathic causes. Birth trauma or forceps delivery results in a traction-type injury to the neck, associated with hematoma, soft tissue swelling, and/or compression injury to the vagus nerve as it descends in the neck. Traumatic intubation or aggressive suctioning may also result in direct laryngeal trauma and VFP.


Iatrogenic left VFP is a known complication of thoracic surgery, particularly patent ductus arteriosus ligation or repair of an interrupted aortic arch, which may be associated with difficulty weaning the infant off ventilator support. The left recurrent laryngeal nerve is susceptible to injury at the point that it passes around the ductus arteriosus, unless a right aortic arch is present. The incidence of recurrent laryngeal nerve injury is estimated at 1% to 7.4% of patent ductus arteriosus ligation cases. Tracheoesophageal fistula repair, pediatric thyroidectomy, and transcervical resection of branchial anomalies have also been associated with VFP.


The diagnosis is best made by FFL in the awake patient so that the effect of anesthesia on vocal fold function is minimized. The combination of a small dynamic glottis and collapsing supraglottic tissues in infants can make the diagnosis of VFP difficult. VFP may be unilateral or bilateral; bilateral VFP of neurogenic origin cannot be differentiated from bilateral vocal fold fixation by FFL alone, direct laryngoscopy with palpation is necessary. Pediatric laryngeal electromyography has been found to be useful in the diagnosis and management of VFP ; when performed under a light plane of anesthesia, it is helpful to differentiate fixation from paralysis and assist with prognosis.


The presenting symptoms for infants with a unilateral VFP include a weak cry or stridor, aspiration, dysphagia, or feeding difficulties. The voice of most infants with a unilateral VFP is quiet but audible and gains strength with time. The patient with unilateral VFP is often able to compensate for purposes of feeding without medical intervention. Sometimes an infant will require nasogastric feeds on a short-term basis or a gastrostomy tube. An occupational or speech pathology feeding consult is helpful with these infants to rule out aspiration (as seen on modified barium swallow) and to counsel the parents on how to feed the patient. Most often, these infants should start with a slow-flow nipple and work up to a regular nipple.


Children with bilateral VFP often have severe airway obstruction, which requires a tracheotomy in up to 73% of children. Bilateral VFP is often the presenting symptom leading to diagnosis of many neuromuscular diseases, including fascioscapulohumeral myopathy, spinal muscular atrophy, and congenital myasthenia gravis. Meningomyelocele and Arnold-Chiari malformation may lead to herniating contents in the posterior fossa and/or hydrocephalus, which causes pressure injury on the vagus nerves as they exit the skull base. Neonatal subdural hemorrhage may also present with bilateral VFP.


Workup of patients with idiopathic bilateral VFP should include a magnetic resonance imaging (MRI) scan of the brain to rule out an Arnold-Chiari malformation or other intracranial cause of brainstem compression ; early decompression is recommended to obtain a better outcome. Genetics consultation to evaluate for chromosomal abnormalities is recommended for patients with idiopathic congenital bilateral VFP.


When unilateral VFP results in severe aspiration and dysphonia, injection of the vocal fold may be helpful. The most commonly injected materials include cadaveric dermis (Cymetra), calcium hydroxyapatite (Radiesse or Radiesse Voice Gel), hydrated porcine gelatin powder (Surgifoam), absorbable gelatin sponge (Gelfoam), or autologous fat. Alternatively, in the older child, a medialization laryngoplasty (thyroplasty) can be performed, taking into consideration that the vocal fold lies in an anatomically lower position in children compared with adults. However, not all children may be able to cooperate intraoperatively with vocal tuning. Vocal fold reinnervation has been described to restore vocal fold tone, thus providing neuromuscular medialization without the use of an implant. Ansa cervicalis to recurrent laryngeal nerve reinnervation has been described, which required 3 to 6 months for results, with improvement in vocal functioning reported.


Approximately 70% of noniatrogenic unilateral vocal fold paralyses will resolve spontaneously, most within the first 6 months of life. In one study of children evaluated by a pediatric otolaryngologist, 35% of those with unilateral vocal fold paralysis after cardiac surgery recovered vocal fold function; at least half of the patients had swallowing dysfunction, usually aspiration or laryngeal penetration evident on modified barium swallow. Although many of the patients with a unilateral vocal fold paralysis were able to feed orally, many initially required a gastrostomy tube.


The vocal folds spontaneously become mobile in up to 65% of patients with bilateral VFP. Prognosis is better if there are no associated anomalies. Most recovery of vocal fold function occurs within 24 to 36 months, although it has been reported in patients up to 11 years of age. If recovery occurs after 2 to 3 years, it is often incomplete because of laryngeal muscle atrophy, cricoarytenoid fixation, and/or synkinesis. The timing of possible surgical intervention is debated. Some authors recommend intervention at a young age, whereas others suggest waiting until adolescence when the patient is able to decide.


Many surgical options are available to improve the airway of a patient with bilateral vocal cord paralysis, which implies that none is uniformly successful, particularly in the young patient. Endoscopically, a lateral cordotomy can be performed to increase the glottic area. Arytenoidectomy may be performed via an endoscopic or external cervical approach or the Woodman approach. Alternatively, an arytenoidopexy can be performed using a laterocervical approach. Triglia and colleagues performed an arytenoidopexy on 34 children with bilateral vocal cord paralysis (mean age, 20 months). Of the 15 children who had a tracheotomy or endotracheal tube before the procedure, 14 were successfully decannulated postoperatively. Another option is to expand the cricoid cartilage by placing a costal cartilage graft posteriorly, thereby separating the arytenoids and increasing the area between the vocal folds. This procedure can be performed with a laryngofissure or endoscopic approach. Finally, lateralization of the paralyzed cord has been described as a potentially reversible approach to vocal cord paralysis.


Hartnick and colleagues described 52 children who underwent surgery for bilateral VFP. The procedures most successful in realizing tracheotomy decannulation were those that included vocal cord lateralization procedures combined with a partial arytenoidectomy (71% decannulation rate). These procedures were more successful than CO 2 laser cordotomy or arytenoidectomy procedures (29% decannulation), isolated arytenoidopexy procedures (25% decannulation), or posterior costal cartilage graft procedures (60% decannulation). No prospective randomized studies have been performed to evaluate the outcomes of these different surgical options, although meta-analysis has suggested that external arytenoidopexy and external arytenoidectomy are more effective than carbon-dioxide ablation procedures.


Paradoxic Vocal Fold Motion


Paradoxic vocal fold motion may result in stridor in the neonate, infant, and child. The classic presentation is a patient with episodic stridor that is loud and high pitched, interspersed with periods of normal breathing. The history and presentation in a neonate vary greatly from that of an older child, although the exam findings are the same. The evaluation for stridor begins with an awake fiberoptic laryngoscopy. Vocal fold motion must be observed and timed with inspiration and expiration; the endoscopist will note that with inspiration, the vocal folds are adducted, especially the anterior vocal folds. Video recording of the endoscopy with slow motion and frame-by-frame views may aid in the diagnosis. Whereas a neonate may present with stridor at birth, the stridor may be more pronounced with crying episodes. This form of stridor in a neonate tends to be short lived and often resolves on its own within a few months of life, or it may be associated with significant gastroesophageal reflux. A child or adolescent may have stridor from paradoxic motion associated with stress, anxiety, or exercise, which is often confused with asthma. There have been reports of paradoxic vocal fold motion causing obstructive sleep apnea. The pathophysiology of paradoxic vocal fold dysfunction is unknown, but laryngeal hyperresponsiveness is suspected to play a role. Treating sources of laryngeal sensitivity such as postnasal drip, gastroesophageal reflux, laryngopharyngeal reflux, and/or psychological conditions may be of benefit. Speech therapy and breathing exercises have also been reported to be helpful.




Laryngeal Web/Atresia


Anterior congenital laryngeal webs are rare anomalies typically diagnosed in the neonatal period after an investigation for the source of aphonia or stridor ( Fig. 23-4 ). Occasionally a minor web will present as hoarseness in an older child. Most commonly, a web will cause partial obstruction of the anterior glottis and will extend into the subglottic area, causing congenital subglottic stenosis. Glottic webs are classified by the degree of glottic obstruction and the degree of extension into the subglottis ( Table 23-4 ).




FIGURE 23-4


Anterior glottic web. Patient presented with chronic hoarseness and mild stridor.

(Courtesy Peter Koltai, MD.)


TABLE 23-4

Glottic Web Classification by Cohen





























Severity Extent of Glottic Obstruction Subglottic Involvement Symptoms
Type 1 <35% None or little Mild hoarseness
Type 2 35%-50% Thin anterior web with little subglottic extension Hoarse, weak cry, stridor with exertion
Type 3 50%-75% Thin-thick web, extends to lower border of cricoid Severe hoarseness, moderate airway obstruction
Type 4 75%-90% Thick web, extends to lower cricoid Aphonic, severe airway obstruction, requires tracheotomy

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Jul 15, 2019 | Posted by in OTOLARYNGOLOGY | Comments Off on Evaluation and Management of the Pediatric Airway
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