Учебники / Otolaryngology - Basic Science and Clinical Review

defects, which contain epidermoid elements only, are lesions that usually present as duplications of the external auditory canal and thus are usually found close to that structure.There may be an opening in the skin above the hyoid bone, which signifies a sinus tract that runs in close association with the parotid gland as well as the branches of the facial nerve. The sinus tract frequently terminates deep in the external auditory canal or even in the middle ear space.

Type II anomalies are seen more frequently. These contain both ectodermal and mesodermal elements. An external opening may be present leading to a cyst or sinus tract that courses through the parotid gland, usually passing closer to the facial nerve than type I anomalies. The tract frequently terminates at the junction of the bony and cartilaginous portions of the external auditory canal. Patients frequently present with aural discharge that is unresponsive to traditional treatment.

Lesions of the second branchial apparatus are the most common. These can present as a cyst, sinus tract, or fistula. Second branchial cysts usually present anterior to the sternocleidomastoid muscle and have an associated tract that passes deep to the external carotid artery and lateral to the glossopharyngeal and hypoglossal nerves (Fig. 17-1). The tract from this lesion frequently ends in the tonsillar fossa. These lesions present as painless masses below the angle of the mandible and anterior to

Figure 17-1 Relationship of second and third branchial cleft anomalies to the carotid artery and cranial nerves.

Figure 17-2 Classic second branchial cleft fistula.

the anterior border of the sternocleidomastoid muscle (Fig. 17-2).

Abnormalities of the third branchial apparatus are uncommon (Fig. 17-3). Cysts associated with this anomaly are usually low in the neck and anterior to the sternocleidomastoid muscle. There is frequently an external opening. The fistula associated with this defect runs deep to the carotid artery, lateral to the hypoglossal

Figure 17-3 External opening of third branchial cleft sinus.

nerve, but superficial to the vagus nerve, which is a fourth arch derivative. The fistula usually enters the pharynx at the level of the pyriform sinus (Fig. 17-1).

Defects of the fourth branchial apparatus are extremely rare, if they exist at all. Theoretically, these anomalies should present with a cystic structure actually located in the chest. There may be an external opening along the lower, anterior border of the sternocleidomastoid muscle.The fistula associated with this lesion should pass under the arch of the aorta on the left side or the subclavian artery on the right. These structures are fourth branchial derivatives.The fistula would then theoretically ascend in the neck and have an internal opening in the esophagus, a fourth branchial derivative.

DEFINITIVE TREATMENT

The definitive treatment for all of these lesions is surgical excision. These lesions may be quite troublesome for patients, especially if there is an external opening to the skin. There are usually persistent secretions of mucus, and once infection has occurred, there is a high tendency for recurrence. Carcinomatous degeneration of branchial cysts has been reported to occur on extremely rare occasions in the adult population.

OTHER CONGENITAL MASSES

Other congenital masses may occur in the head and neck region of children. Perhaps the most common, after branchial cleft anomalies, is the thyroglossal duct cyst. Embryologically, the primitive thyroid begins its development in the pharynx in the area of the foramen caecum of the tongue base. The duct descends through the anterior neck, reaching the level of the larynx. During this descent, the duct passes close to or in fact through the central portion of the hyoid. This duct usually disappears before birth, but in a small number of individuals, the duct persists potentially anywhere along its path (Fig. 17-4).

These lesions may become infected on a repeated basis, thus prompting surgical excision, which is the definitive treatment. Although rare, carcinomatous degeneration of these lesions occurs, which is also a valid reason for removal.

Before removal, the presence of normal thyroid tissue should be documented by the use of ultrasound or thyroid scan. In extremely rare situations, the patient’s only functioning thyroid may be located within the cyst itself. These diagnostic studies will make this determination prior to surgery.

Dermoids usually occur in the midline of the neck in a similar location to the thyroglossal duct cyst.These lesions

Figure 17-4 Classic anterior thyroglossal duct cyst.

are frequently located in the submental region and are well encapsulated, with no accompanying sinus tract.

Cervical thymic cysts may present in the midline or lateral cervical region. These lesions arise in the third branchial pouch as a result of the migration of the thymus from the upper neck to its final location below the clavicles.Thymic remnants may persist as cords or cysts along this pathway.

VASCULAR MALFORMATIONS

The most common lesions in this group are lymphatic malformations and hemangiomas. Lymphatic

Figure 17-5 Large hemangioma of the facial region in a young infant.

malformations are multiloculated, painless masses that usually present shortly after birth and are far less distinct than congenital cysts of the neck. These lesions may enlarge to become cosmetically disfiguring.Treatment is by surgical excision; however, these lesions do not grow along defined tissue planes and may envelop vital structures. This must be strongly considered when surgical planning is undertaken.

Hemangiomas are said to represent the most common neoplasms in children. They usually present in the facial area during the first few months of life and have their greatest growth rate during the first 12 months (Fig. 17-5). In most cases, spontaneous involution occurs. In rare cases where exceedingly large lesions are present, the cardiovascular system can be adversely stressed. In these cases, medical therapy in the form of steroids or interferon may be indicated. Surgical resection is rarely necessary.

SELF-TEST QUESTIONS

For each question select the correct answer from the lettered alternatives that follow.To check your answers, see Answers to Self-Tests on page 716.

1.The stapedius muscle is innervated by cranial nerve

A.V

B.VI

C.VII

D.IX

E.X

2.A patient is noted to have a draining sinus tract deep in the external canal. Surgical resection will include a dissection of

A.The jugular vein

B.The superficial temporal artery

C.The hyoid bone

SUMMARY

These disorders of embryological development represent important clinical entities. A clear understanding of these lesions is necessary for the clinician treating medical and surgical diseases of the head and neck in children and adults.

SUGGESTED READINGS

Albers GD. Branchial anomalies. JAMA 1963;183:399–409. Chandler JR, Mitchell B. Branchial cleft cysts, sinuses and fistulas.

Otolaryngolog Clin North Am 1981;14(1):175–186.

Gage JF, Lipman SP, Myers EN. Diagnosis and Management of Congenital Head and Neck Masses [self-instructional package].American Academy of Ophthalmology and Otolaryngology; 1976.

Proctor B, Proctor C. Congenital lesions of the head and neck. Otolaryngolog Clin North Am 1970;3(2):221–248.

WorkWP. Newer concepts of first branchial cleft defects. Laryngoscope 1972;82:1581–1593.

D.The stapes

E.The facial nerve

3.The central portion of the hyoid bone should be removed when removing a

A.Dermoid

B.Thyroglossal duct cyst

C.Thyroid nodule

D.Branchial cleft cyst

E.Thymic cyst

4.The removal of a second branchial cleft sinus tract may require removal of

A.The thyroid gland

B.The tonsil

C.The parotid gland

D.The hypoglossal nerve

E.The hyoid bone

The management of airway obstruction in children is considered a vitally important aspect of residency training and our practice of otolaryngology. Because of the often immediate consequences in pediatric airway disease, a clear understanding of the pathophysiology, diagnostic evaluation, and treatment options should be understood and practiced.The development of fiberoptic technology has greatly improved our diagnostic abilities, while maintaining a margin of safety in difficult airway conditions. Therefore, with a broad knowledge of the etiologies of pediatric airway disease and the application of fiberoptic evaluation, the diagnosis is often readily apparent prior to any operative intervention. This chapter will review the physiology of stridor and airway noise, the diagnostic evaluation, and the management options in patients with pediatric airway obstruction.

DEFINITION OF STRIDOR

AND AIRWAY NOISE

Stridor is a term that is often used to describe any abnormal airway noise.This broad definition, unfortunately, is

supported by many textbooks, which typically describe stridor as a high-pitched musical noise, often inspiratory in nature, which denotes laryngeal obstruction. Stridor may be high or low pitched, inspiratory, expiratory, or both, and may represent obstruction at nearly any part of the respiratory tract. The Latin word stridere means “to make a harsh noise,” although in practice the noise of airway obstruction may be soft or harsh in quality. The acoustic quality of stridulous noises is typically described as harmonious in frequency and pitch, greater than 200 msec in duration and best heard over the cervical region.

PHYSIOLOGY

The mechanism of stridor is that of a narrowing of the airway at some point between the oral or nasal cavity and the distal bronchi.The actual sound of stridor is the result of abnormal airflow patterns that develop from either anatomical or functional narrowing of the airway.To better understand this phenomenon, one must understand that gas moving through a partially obstructed tube is subject to certain principles of physics. As the lumen begins to

narrow, the net velocity of the air molecules must increase to allow the same volume of air to pass.According to the principles ofVenturi, the force vectors will shift 90 degrees forward, causing a decrease in the lateral wall pressure, thereby inducing airway collapse of the generally compliant airway in children.As airway obstruction proceeds to near-complete narrowing, turbulence of the typically laminar airflow commences.The narrowed airway begins to have rhythmic vibrations and produces an often musical sound, not dissimilar to the production of sound from the reed of a woodwind instrument. Because of its vibratory nature, stridor can often be felt as well as heard on examination.

The small size of the pediatric airway is an important factor in the development of airway obstruction, particularly in naturally narrow areas such as the glottis and subglottis. Because of its small size and complete encirclement by the cricoid cartilage, the subglottis is particularly susceptible to narrowing. Five millimeters is considered the normal-size subglottic airway in a newborn, with progressive enlargement with age (Table 18-1). Crosssectional area of the airway can be calculated by the equation area r2, where r radius. Because of the exponential relationship between the area of a circle and the radius, small changes in the radius can account for large changes in airway cross-sectional area. A 20% reduction in the radius of the airway; that is, 1 mm of narrowing in a normal neonate, would account for a 36% reduction in cross-sectional area.Two millimeters of narrowing (40% of the radius) would contribute to a 64% reduction in the airway area. Children, particularly neonates and infants, deserve vigilant attention to any airway complaints due to the narrow margin of safety their small airways afford.

Stridor is often incorrectly used to describe other pathological airway noises such as stertor, wheezing,

TABLE 18-1 NORMAL AIRWAY SIZE BY AGE

Normal

Subglottic

rhonchi, and rales. Location and the musical versus nonmusical quality of the sound usually delineate the proper diagnosis. Another musical noise that is similar to stridor is a wheeze. Although acoustically and pathophysiologically similar to stridor, wheezing is best heard over the chest, is often bilateral, and responds to bronchodilator medications. Stertor is a nonmusical noise described as an acoustically heterogeneous, lowpitched reverberation of the oropharyngeal tissues and better known as snoring. Rhonchi are similarly lowpitched noises of the large airways of the chest typically caused by secretions. Finally, rales (or “crackles”) are a fine, nonmusical, popping-like noise heard in the peripheral lung fields lasting less than 200 msec.The sound of rales represents the sudden opening of collapsed alveoli, usually indicative of the presence of fluid.

LOCALIZATION

Any child with airway obstruction should be carefully assessed from nasal cavity to distal lung to determine the cause of the airway noise.

During the examination, careful observation and auscultation of the patient can properly localize the point of airway obstruction prior to any endoscopic evaluation. As previously mentioned, nonstridulous noises can often be identified and properly diagnosed.The otolaryngologist is assisted by dividing the airway into acoustic zones: (1) nasoand oropharynx; (2) supraglottis;

(3) glottis, subglottis, and extrathoracic trachea; (4) intrathoracic trachea; and (5) distal pulmonary airways. Nasoand oropharyngeal obstruction typically produces stertorous noises and is generally not life-threatening. One exception is that of bilateral choanal stenosis in neonates due to their obligate nasal breathing requirement. Likewise, distal pulmonary airway noises such as wheezing and rales are easily determined on auscultation of the lung fields.

Significant and life-threatening airway obstruction can occur in the laryngeal and tracheal regions; therefore, a rapid and accurate assessment of the location of the airway lesion is imperative. Although factors such as the time course, severity, and presence of cyanosis are helpful to formulate the diagnostic and treatment plans, this information adds little to the localization of the lesion. Localization of the airway lesion can be accomplished by evaluating four factors: retractions, stridor, voice, and feeding [use the mnemonic “Real stridor is very frightening” (RSVF)] (Table 18-2).

The supraglottic airway zone is characterized by relatively loosely supporting structures, which, during inspiration, tend to collapse as a result of the Venturi

1The quality of the airway noise.

2Unless associated with complete nasal obstruction in a neonate.

effect. This collapse can be made particularly worse during periods of air hunger. The inspiratory stridor of supraglottic obstruction is high pitched due to the vibratory ability of the loose supraglottic tissues. During expiration, the tissues open, and airflow is unimpeded. The loose tissues surrounding the supraglottic region are prone to retract during periods of airway obstruction because of its cervical (extrathoracic) location. Supraclavicular and thoracic retractions are common even with minimal stridor present. Due to the high compliance of the infant rib cage, retractions can be severe. The supraglottic region primarily contributes to the resonance of the voice; therefore, obstruction typically produces a muffled vocal quality. Because of its collocation with the pharynx, supraglottic obstruction is often associated with feeding problems. This may range from aspiration to the inability to swallow, with significant drooling.

The third zone consists of the glottis, subglottis, and extrathoracic trachea. These areas share a similar characteristic in that each is a relatively rigid and noncollapsible tube. The mucosa is tightly bound to the rigid supporting structures of the vocal ligament, cricoid cartilage, and upper tracheal rings. The airflow is less regulated by fluid dynamics, because there is little compliance of the airway tissues in this region, than by the absolute cross-sectional area. Critical airway narrowing is heralded by the onset of biphasic stridor, occurring in both inspiration and expiration. The stridor is often severe and associated with tremendous respiratory effort, with both supraclavicular and intercostal retractions. The less compliant vibratory tissue in this region also contributes to the intermediate pitch of the stridor, as compared with the high-pitched stridor of supraglottic obstruction. With glottic obstruction, the voice is obviously affected, and the patient may be hoarse or

completely aphonic. Subglottic obstruction often displays a normal voice because the free edge of the vocal cords is not involved, although a characteristic “doglike” barking cough is appreciated in patients with subglottic narrowing. In general, there are no direct feeding or swallowing problems, except those derived from being dyspneic. One exception to this rule is the possibility of aspiration with a vocal fold paralysis.

The intrathoracic trachea is dynamically quite unique. During inspiration, the negative intrathoracic pressure tends to maintain the integrity of the tracheobronchial lumen. It is during expiration that the relative positive intrathoracic pressure may contribute to dynamic airway collapse.This may be seen routinely during bronchoscopy because the posterior membranous wall tends to collapse during expiration. Of course, the lumen is maintained by the rigidity of the tracheal rings. Endobronchial lesions or foreign bodies only enhance the airway collapse during expiration. The expiratory stridor usually maintains its musical quality but is harsh, similar to a distal airway wheeze. Retractions are typically not present until airway collapse is imminent.Voice and feeding are typically normal, although, again, a characteristic “seal-like” barking cough may be present with tracheal obstruction.

DIAGNOSTIC APPROACH

TO STRIDOR

The clinician should inquire about the age of onset, initiating or relieving factors, and overall health of the child. Stridor at birth typically represents a fixed anatomical lesion, whereas dynamic conditions such as laryngomalacia usually present after several weeks of life. Progressive stridor often denotes either a growing tumor (subglottic hemangioma) or scar deposition (subglottic stenosis).

Positional changes to the stridor are characteristic of a functional supraglottic disorder, such as laryngomalacia (worsening stridor in the supine position and improvement in the prone position). Disorders of the cardiovascular, gastrointestinal, and neurological system may either mimic primary airway disorders or contribute to their severity. For instance, the diagnoses of cyanotic heart disease, vascular anomalies, gastroesophageal reflux, and central apnea should be carefully evaluated. For neonatal patients, perinatal historical facts including prematurity, difficult labor and delivery, and postnatal intubations should be carefully reviewed. A thorough assessment, using the previously mentioned RSVF mnemonic, will greatly assist in localizing the airway lesion. Pulse oximetry can be useful in the acute setting to document oxygen desaturations associated with airway compromise. A complete history and physical examination will often provide the clinician with enough information to make a presumptive diagnosis, but nothing should supplant the otolaryngologist from performing an endoscopic evaluation.

Endoscopic evaluation is the definitive manner to diagnose all airway disorders.The advances in fiberoptic technology have allowed the clinician easier access to and a clearer picture of the airway. Flexible fiberoptic laryngoscopy (FFL) is a mandatory part of the assessment in children with stridor. A kind bedside manner, gentle technique, and application of a topical anesthetic/ vasoconstrictor will usually allow visualization in most children over the age of 4 years. Gentle restraint will be required for younger children. A more detailed assessment of the cause of the stridor can be ascertained because this evaluation is dynamic and is not performed with general anesthesia. The two most common causes of stridor (laryngomalacia and vocal fold dysmotility disorders) can be easily diagnosed. Further benefit is gained by the use of a camera and monitor, together with video-recording and picture-taking ability to document the findings. If no abnormalities are found on flexible examination, the clinician should be concerned about a lower airway obstruction.

Much controversy currently surrounds the necessity for formal direct laryngoscopy and bronchoscopy (DLB) conducted in the operating room for all patients with stridor. DLB allows the examination of the entire airway and both correctly identifies the diagnosis and rules out other airway lesions. In general, patients with stridor should have a DLB performed. This is particularly important for those patients who have cyanotic or “dying” spells [apparent life-threatening events (ALTEs)], require a surgical intervention to correct the stridor (no matter what the cause), have

multiple congenital anomalies, or have an uncertain diagnosis. One area that remains controversial is the necessity of DLB in patients with mild laryngomalacia (diagnosed by FFL) and who have none of the aforementioned criteria necessitating a DLB. As many as 10% of patients with laryngomalacia, in general, will demonstrate a second airway lesion. Many otolaryngologists feel that second lesions are uncommon in the subset of patients with mild laryngomalacia and that if a second lesion is present, it usually does not require therapy. One example of this would be mild tracheomalacia from innominate artery compression associated with laryngomalacia. Others believe that these possible second lesions located below the vocal cords (subglottic stenosis and tracheomalacia) are important to diagnose and recommend routine DLB for all patients with laryngomalacia. No matter which philosophy you subscribe to, careful monitoring and a thorough evaluation in all children with stridor is warranted.

The radiological evaluation for children with airway noise should include an anteroposterior (AP) and lateral radiograph of the chest and neck. These views are obtained during inspiration and expiration and should be of good quality. Expiratory views are often helpful to identify air trapping if a bronchial foreign body is suspected. Due to the redundancy of the soft tissue and the compliance of the cartilaginous structures in the upper airway of children, masses seen on expiratory views should be viewed with caution. Lateral views of the upper airway obtained during deep inspiration, with careful attention to the pharyngeal and tracheal air column, retropharyngeal soft tissue width, and epiglottis can provide valuable clues to the diagnosis of airway obstruction. High-voltage AP views best show the tracheal air column; particular attention should be paid to the region of the subglottis for evidence of narrowing of the air column.

Other types of radiographic evaluations that may be used on a case-specific basis include videofluoroscopy, bronchography, barium swallow study, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US). Videofluoroscopy alone has been used to detect lower airway foreign bodies, diaphragmatic immobility, and tracheomalacia. Videofluoroscopic exam during barium swallow (BaS) is very useful in detecting aspiration with or without pharyngeal dyscoordination and encroachment of the esophageal lumen by vascular anomalies. CT or MRI can confirm aberrant mediastinal vessels and tissue masses (i.e., lymphangiomas). Bronchography has limited usefulness in light of the superior evaluation now obtained

by rigid or flexible fiberoptic evaluation. US has been used to complement the endoscopic evaluation for vocal cord mobility disorders.

Gastroesophageal reflux disease (GERD), better termed pharyngoesophageal reflux, has recently been appreciated as an important underlying factor in some patients with stridor. Reflex laryngospasm, vocal fold dyskinesia, reactive airways disease, bronchitis, laryngomalacia, and subglottic stenosis have all been implicated in patients with GERD. Symptoms of overt regurgitation may be absent, so diagnostic studies such as BaS, milk scans, and pH probes (preferably a double-probe study) may be necessary. It should be noted, though, that normative data for pH probe results in young children are currently lacking, making interpretation difficult. More direct techniques of diagnosing the pathological changes of GERD may prove more useful. Bronchoalveolar lavage for analysis of lipid-laden macrophages is a very sensitive test of aspiration, and distal esophageal biopsies can easily show the inflammatory changes and basal cell hyperplasia associated with GERD. These latter two studies can be done in conjunction with the routine DLB, thereby not subjecting the patient to multiple diagnostic evaluations.

Other special diagnostic tests that may be used include polysomnography, pulmonary function tests, and acoustic analysis. The first can confirm the presence of an obstructive process or diagnose central apnea; the latter two studies have limited clinical usefulness.

AIRWAY ANOMALIES

The otolaryngologist must consider a broad differential diagnosis when presented with a child with stridor and airway noise. Although laryngomalacia accounts for 60% of all cases of stridor in children, vocal fold dysmotility disorders, subglottic stenosis, tracheomalacia, and foreign bodies contribute another 30% of cases. The diagnosis in the remaining 10% of cases is from a large list of airway disorders (Table 18-3). As with identification of the source of the stridor by using the RSVF mnemonic, it is best to narrow the possible diagnoses of a child with an airway disorder by considering the differential diagnosis by anatomical site. Classifying the diagnosis in each anatomical site by each etiological category—congenital, inflammatory, neoplastic, iatrogenic, traumatic, and neurogenic— ensures a complete list of possible causes.The following section includes common and/or interesting etiologies of stridor and airway noise with which all otolaryngologists should be familiar.

NASAL/PHARYNGEAL

Choanal Stenosis/Atresia

Obliteration of the posterior choana is the result of a failure of the nasobuccal membrane to rupture during the fourth week of embryonic life.The resulting atretic plate may be only membranous, but in 90% of cases it has a bony component. Choanal atresia occurs in 1 in 5000 live births, and there is a female to male predominance of 2:1, with most lesions being unilateral and occurring on the right side. Up to 50% of cases are associated with other anomalies, predominantly with the CHARGE association.This includes colobomas of the eyes, a variety of cardiac (heart) defects, choanal atresia, retarded growth and development, genital anomalies in males, and external ear malformations with or without a mixed hearing loss. Bilateral choanal atresia occurs in 60% of cases associated with CHARGE.

Infants with any form of bilateral nasal obstruction will universally develop cyclical airway distress because neonates are obligate nasal breathers for the first 6 to 8 weeks of life. During crying spells, infants reflexively mouth breathe, and their airway obstruction improves. Once quiet, the respiratory distress and cyanosis will recur. Unilateral nasal obstruction often presents later in infancy or childhood as rhinorrhea and congestion that is unresponsive to medical therapy. Diagnosis is made by the inability to pass catheters through the nose or by nasal endoscopy (flexible or rigid), but a CT scan is always obtained to confirm the physical findings.

Immediate treatment in the neonatal period includes the placement of an oral airway, McGovern nipple, and possibly endotracheal intubation. If possible, surgical repair is delayed until the child is older than 2 years to allow better visualization during surgery. The most popular form of therapy is removal of the atretic plate under endoscopic or microscopic visualization. Powered instrumentation (microdebriders), lasers, otologic drills, and sinus instruments all assist in the resection. Soft silicone stents are typically placed for 2 weeks to 4 months, with most patients being stented for 4 to 6 weeks.

Oral Synechiae/Persistent

Buccopharyngeal Membrane

Similar to choanal atresia, the buccopharyngeal membrane that divides the oral cavity from the oropharynx can fail to divide in the fourth week of gestation, and abnormal attachments can remain. This condition is commonly associated with cleft palate and lip, microglossia, micrognathia, microstomia, synechial bands, temporomandibular joint ankylosis, and polyhydramnios.

Nasal/Pharyngeal

Congenital

Nasal aperture stenosis Choanal atresia/stenosis

Nasal masses (dermoid, teratoma, encephalocele) Oral synechiae/persistent buccopharyngeal membrane Oral masses (ranula, dermoid, thyroglossal duct cyst) Craniofacial anomalies (Pierre Robin syndrome,

micrognathia,Treacher Collins syndrome) Lymphangioma

Inflammatory

Adenotonsillar hypertrophy

Deep neck abscess (retropharyngeal, parapharyngeal) Ludwig’s angina

Nasal polyps Mononucleosis

Neoplastic

Rhabdomyosarcoma Teratoma

Juvenile nasopharyngeal angiofibroma

Trauma

Postoperative edema Penetrating objects

Supraglottic

Congenital

Laryngomalacia

Atresia

Web

Epiglottic cysts

Saccular cysts

Lymphangioma

Inflammatory

Epiglottitis

Abscess

Allergy

Neoplastic

Papillomatosis (RRP)

Chondroma

Neurofibroma

Trauma

Foreign bodies

Laryngeal fracture

Inhalation/caustic burns

Postoperative edema

Glottic/Subglottic

Congenital

Stenosis (malformations of the cricoid, i.e., elliptical

shape or trapped first tracheal ring)

Vocal cord dyskinesia (paralysis, paradoxical motion)

Atresia

Web Lymphangioma

Inflammatory

Viral laryngotracheitis (croup) Bacterial laryngitis (diphtheria) Allergy

Sarcoid

Fungal (coccidiomycosis) Tuberculosis

Wegener’s granulomatosis

Neoplastic

Papillomatosis (RRP) Hemangioma

Granular cell myoblastoma Neurofibroma

Sarcoma (rhabdomyosarcoma, fibrosarcoma, chondrosarcoma)

Traumatic

Stenosis (fibrosis, i.e., post–prolonged intubation) Vocal fold paralysis (postintubation, postductus ligation) Laryngeal fracture

Neurogenic

Gastroesophageal induced laryngospasm

Vocal fold paralysis (Arnold-Chiari malformation, familial abductor paralysis)

Tetanus

Tetany secondary to hypocalcemia

Tracheal

Congenital

Stenosis Cartilaginous Tracheomalacia Primary

Secondary (vascular or cystic compression)

Complete tracheal rings (segmental, funnel, complete) Fibrous

Web

Associated with tracheoesophageal fistula Atresia

Inflammatory

Viral/bacterial tracheitis Tuberculosis

Fungal (histoplasmosis)

Neoplastic

Papillomatosis (RRP) Mucoepidermoid carcinoma Fibrous histiocytoma Leiomyoma

Traumatic

Foreign bodies Posttracheotomy

These infants may or may not present with airway distress at birth due to adequate nasal patency. Immediate otolaryngology consultation should be obtained because, in case of the potential airway distress, oral endotracheal intubation is typically impossible. Initial treatment for children with this condition includes airway stabilization with a tracheotomy, with anesthesia delivered through mask ventilation or fiberoptic endotracheal intubation. A gastrostomy tube is often required for long-term nutritional support.

Simple division via an intraoral approach can accomplish definitive correction of isolated synechial bands. A complete buccopharyngeal membrane will require a more complex intraoral resection with mucosal flaps and long-term stenting. Revision surgery is often required in patients with complete buccopharyngeal membranes. CT evaluation, particularly with three-dimensional reconstruction, is helpful to evaluate the craniofacial skeletal deformity. Mandibular advancement or distraction osteogenesis should be considered when treating mandibular hypoplasia. The timing of mandibular surgery is controversial, with most surgeons delaying definitive repair until at least 5 years of age.

SUPRAGLOTTIC

Laryngomalacia

Laryngomalacia is the most common cause of congenital stridor and accounts for 60% of all laryngeal causes of airway obstructions. Stridor typically begins after birth and worsens during the first several months of life. Classically, the stridor is inspiratory, worse in the supine position and with crying, and better with prone positioning. The pathophysiology of laryngomalacia is most likely multifactorial and includes redundant

laryngeal soft tissue, poor cartilaginous support, inadequate neurological control, and a narrow omegashaped epiglottis. An association with GERD has also been proposed.

The diagnosis of laryngomalacia is best made by FFL in an awake child. Common endoscopic findings include collapse of the supra-arytenoid tissue, arytenoepiglottic folds, and the epiglottis causing obstruction of the airway (Fig. 18-1).As previously discussed, strong consideration should be made for a formal DLB in all but the most routine and mild cases to rule out a concomitant airway lesion (10%). Most children (90%) require no therapy for isolated laryngomalacia and will have spontaneous resolution usually before age 1 year. Up to 10% will have signs of severe airway obstruction or failure to thrive and require surgical therapy. Supraglottoplasty, the most commonly performed procedure for this condition, is the removal of the offending redundant supraglottic tissue, which can vary between patients. This procedure can be performed either with a CO2 laser or with microlaryngeal instruments.

Acute Supraglottitis (Epiglottis)

Acute supraglottitis is a rare bacterial infection typically caused by Haemophilus influenzae type B (HIB). Other pathogens, such as Staphylococcus and Haemophilus parainfluenzae, have also been implicated in supraglottitis, particularly in older patients. The incidence of this potentially life-threatening disorder has dramatically decreased since 1987, when the first conjugate HIB vaccines were introduced.Today, most otolaryngology residents will never see a young child with supraglottitis in their training.