Upper Airway Lesions in the Neonate

Pyriform Aperture Stenosis

The pyriform aperture is defined as the bony inlet of the nose formed by the nasal bones superiorly, frontal process of the maxilla laterally, and the premaxilla and anterior nasal spine inferiorly. Pyriform aperture stenosis is hypothesized to occur from bony overgrowth of the medial process of the maxilla, causing unilateral or bilateral nasal airflow restriction. Clinical presentation may include tachypnea, difficulty passing a nasogastric tube, apneic events, or cyclic cyanosis improved with crying. While the etiology remains uncertain, there is correlation with holoprosencephaly, absent maxillary frenulum, pituitary dysfunction, and central maxillary megaincisor. The diagnosis of pyriform aperture stenosis can be confirmed with computed tomography (CT) scanning; while various radiographic criteria have been proposed, a pyriform aperture width of less than 11 mm in a full-term infant is commonly considered diagnostic. However, pyriform aperture dimensions do not correlate directly with symptoms, thus each infant should be evaluated based on specific symptoms and ability to compensate for the relative obstruction. In most patients, conservative therapy with judicious use of topical decongestants and topical steroids will reduce mucosal edema and provide symptomatic relief. A McGovern nipple or continuous positive airway pressure may also be helpful. The long-term prognosis of pyriform aperture stenosis is excellent, as the pyriform aperture will enlarge along with the craniofacial skeleton during normal development. However, in refractory cases, especially in infants with sleep apnea, growth restriction, and feeding difficulties, or failure to extubate, surgical intervention is indicated. Surgical techniques typically include a sublabial approach and drillout of the stenosis with or without nasal stenting.

Nasolacrimal Duct Cysts

Nasolacrimal duct cysts (dacryocystoceles) are congenital mucoceles of the nasolacrimal duct system, which include a proximal and distal obstruction. Clinical exam is notable for a cystic swelling of the lower medial canthus, associated epiphora and mucopurulent discharge, and a submucosal nasal cyst that appears as a smooth, mucosa-covered mass under the inferior turbinate. The diagnosis is confirmed with CT or MRI scanning. On CT, a cystic mass at the medial canthus and below the inferior turbinate is often noted ( Fig. 68.1 ). Conservative therapy includes topical decongestants and/or antibiotics, warm compresses, and local massage. However, in the event of local infection, mass effect, or respiratory compromise, surgical intervention is recommended, usually with a combined endoscopic approach as well as via dacryocystorhinostomy to marsupialize the cyst ( Fig. 68.2 ). While the external approach is more commonly performed, the endoscopic approach has gained popularity and has demonstrated similar rates of success in the pediatric population.

Choanal Atresia

Neonates are preferential nasal breathers for the first 4-6 weeks of life. The entire length of the neonate's tongue is in close proximity to the hard and soft palate, which creates a vacuum and resultant respiratory distress when nasal obstruction is present. The posterior choanae are the bony outlet of the nose, formed by the undersurface of the sphenoid bones, the medial pterygoid plates, the vomer, and the horizontal portion of the palatal bone. Bony overgrowth of any of these structures may cause choanal atresia, defined as closure of the posterior choanae of the nasal cavity, eliminating communication between the posterior nasal cavity and the nasopharynx. The estimated incidence is 1 in 5000-7000 live births, with up to two-thirds of cases being unilateral, affecting the right side, and occurring in females. Congenital anomalies are seen in about 50% of patients with choanal atresia, characteristically CHARGE syndrome. Other congenital anomalies include polydactyly, cleft palate, hypertelorism, laryngomalacia, and Treacher Collins and Crouzon syndromes. CHARGE syndrome is a clinical diagnosis that includes c oloboma or other ophthalmic anomalies, h eart defect, a tresia choanae, r estriction of growth and development, g enital hypoplasia, and e ar anomalies with hearing loss. Heterozygous mutations in the CHD7 gene (chromodomain helicase DNA-binding protein) located on chromosome 8q12 have been identified in 90%-95% of neonates meeting diagnostic criteria for CHARGE syndrome. Although there is phenotypic overlap between CHARGE and 22q11 deletion syndromes, including lymphopenia and hypocalcemia, no specific immune defects have been clearly linked with CHARGE syndrome. Children with CHARGE syndrome require intensive medical management and multidisciplinary care. A complete evaluation to rule out associated anomalies is, therefore, mandatory in all infants with bilateral choanal atresia.

Although bilateral obstruction always produces symptoms in the neonatal period, the degree of distress and cyanosis varies from severe asphyxia with a history of multiple failed extubations to choking during feeding. Typically, the infant has a history of distress when resting that is relieved with agitation and crying. In contrast, unilateral choanal atresia is typically diagnosed later in life and may present with chronic nasal obstruction, rhinorrhea, or sinusitis.

In a suspected case of choanal atresia, an attempt should be made to pass a 6-French catheter into the nasopharynx. Failure of the catheter to pass suggests choanal atresia. Flexible nasal endoscopy has also become invaluable in assessing the presence and character of the atresia ( Fig. 68.3 ). Definitive evaluation is obtained with a computed tomography scan to characterize the exact thickness and width of the atretic plate ( Fig. 68.4 ).

Treatment of choanal atresia depends on the severity of the obstruction and the clinical presentation of the infant. Unilateral atresia rarely requires surgical intervention during infancy and is usually corrected before the child begins school (4-5 years of age). Bilateral atresia is usually repaired within the first few days of life. Historically, this was performed via a transpalatal approach using a posteriorly based mucosal flap and drilling of the atretic plate. Today, transnasal endoscopic repair is the predominant technique employed by pediatric otolaryngologists ( Fig. 68.5 ). A 2.9 or 4.0 mm Hopkins rod is used while the atretic plate is opened with a urethral sound or microdrill, then progressively dilated, and a backbiter may then be used to remove the posterior vomer. Postoperative stenting remains a controversial topic and has not been shown to produce significant improvement in surgical outcomes while increasing rates of local infection, synechiae, and granulation tissue. Topical application of mitomycin C, an antineoplastic agent inhibiting fibroblast proliferation, has been described in multiple studies but has not shown a difference in the restenosis rate for choanal atresia repair. Regardless of the technique, recurrence rates following endoscopic techniques remain high, with risk factors including reflux, age less than 10 days, pure bony atresia, and associated malformations. Meanwhile CHARGE patients may require tracheostomy upfront due to multilevel airway obstruction or cardiopulmonary issues; surgical repair is also less likely to be successful in these patients because of more contracted anatomy and poor pharyngeal muscular control.

Congenital Nasal Masses

Nasal obstruction with airway distress can result from congenital midline masses such as dermoids, epidermoids, cerebral heterotopia, and encephaloceles. Any infant with a midline nasal mass should be fully evaluated, generally with both CT and magnetic resonance imaging (MRI) to assess for skull base involvement and intracranial extension before intervention is undertaken. Biopsy of an unsuspected nasal encephalocele can lead to cerebrospinal fluid leak, meningitis, and death.

Congenital midline nasal masses are theorized to arise from failed retraction of a dural diverticulum, and tissue extension through the fonticulus frontalis or foramen cecum may produce an extranasal or intranasal mass, respectively. Dermoids contain ectodermal and mesodermal tissue, while epidermoids contain only ectodermal tissue. These lesions are often grouped together due to their similar embryologic origin and may present as cystic or solid masses located anywhere between the columella and the glabella. Dermoids may also present with sinus tracts and pits secreting sebaceous material, classically with a dimple at the rhinion and protruding hair. Intracranial communication should be suspected in the case of recurrent meningitis, and imaging revealing an enlarged foramen cecum, bifid nasal septum, or bifid crista galli. Treatment consists of complete surgical excision, including associated tracts, and collaboration with neurosurgical teams as indicated.

Cerebral heterotopia (previously known as nasal glioma) represents sequestra of glial tissue following incomplete retraction of the dural diverticulum, and neonates may present with nasal obstruction and an intranasal mass. Up to 15% of lesions retain a dural connection, and 10%-30% retain a fibrous stalk. Failure to recognize the fibrous stalk can lead to incomplete resection and tumor recurrence. Encephaloceles maintain their intracranial communication with the subarachnoid space, with herniated brain tissue, dura, and cerebrospinal fluid constituting the tumor. These masses are pulsatile, transilluminate with light, and demonstrate a positive Furstenberg test (expansion following jugular vein compression). Early surgical resection with multidisciplinary coordination is generally recommended to alleviate the risk of meningitis that accompanies these tumors. In addition, progressive growth of the lesion can result in marked nasal deformity. Recently, transnasal endoscopic approaches have been described for the surgical resection of these lesions while shortening operative time and decreasing complication rates.

Nasopharyngeal Teratoma

Teratomas are benign tumors composed of all three germ layers with recognizable early organ differentiation. Females are disproportionately affected (6 : 1 ratio), and associated fetal conditions include hydrops and pulmonary hypoplasia. While these lesions are most commonly found in the sacrococygeal region, teratomas of the head and neck carry a notable risk of airway obstruction. In the nasopharynx, they may appear in the midline or lateral pharyngeal wall and appear heterogeneous on MRI with fat and bone. A persistently high alpha-fetoprotein (AFP) level may be suggestive of teratoma and may be used to monitor for disease progression or response to treatment. Prenatal diagnosis with ultrasound and MRI, along with multidisciplinary prenatal care, is critical to evaluate the degree and extent of airway obstruction, and an EXIT procedure may be indicated in severe cases.

Mucosal Obstruction

Neonatal rhinitis is a common cause of nasal obstruction that may present with stertor, difficulty feeding, and increased work of breathing. Generalized mucosal hypertrophy or edema can result in significant anterior nasal congestion and symptomatic obstruction in the neonate until oral breathing becomes reflexive. Treatment of these patients is generally conservative and includes humidification, saline drops, and judicious suctioning. Excessive attempts at suctioning can result in increased edema and exacerbation of the infant's symptoms. Gastroesophageal reflux may reach the level of the nasopharynx and can exacerbate nasal obstruction as well. Appropriate treatment of reflux may improve the nasal airway. Intranasal steroid drops might be helpful during periods of increased congestion such as that associated with viral rhinitis. Prolonged use of intranasal decongestants can lead to rhinitis medicamentosa (paradoxical mucosal swelling) and should be avoided.

Continuous Positive Airway Pressure Trauma

Care must be taken with the use of continuous positive airway pressure (CPAP) nasal prongs and masks in the neonate, because nasal trauma can occur. Cosmetic and functional sequelae of nasal injury from nasal CPAP have been described not only in neonates but also in adolescents and adults with a history of nasal CPAP administration as a neonate. Thus, if nasal injury is imminent and discontinuation of nasal CPAP is not possible, then changing to a different style of delivery (e.g., nasal mask) may be useful. Nasal cannulas cause significantly less nasal trauma than CPAP.