Craig S. Derkay and Michael J. Cunningham
CONGENITAL ANOMALIES OF THE HEAD AND NECK
The critical period of cervicofacial growth and differentiation occurs between weeks 4 through 8 of embryologic development.1 The beginning of this stage is characterized by the appearance of the frontonasal process—the precursor of the forebrain and upper face—with development soon thereafter of the optic and otic vesicles; the nasal placodes; the primitive mouth, or stomodeum; and five ridges on the ventrolateral surface of the embryonic head, which is known as the branchial system. Many of the symmetrically paired skeletal and neuromuscular structures of the head and neck arise from the first (mandibular), second (hyoid), third (pharyngeal), and fourth (laryngeal) arches of this fetal branchial system (Table 372-1). The skull, facial, and neck bones have begun to ossify by the end of the eighth fetal week, which coincides with a recognizable human embryonic face with easily discernible ears, eyelids, cheeks, nose, and upper and lower lips.
Table 372-1. Derivatives of the Pharyngeal Arches and Their Innervation
Most of the congenital anomalies of the face and neck are believed to arise from altered or arrested growth during this critical developmental stage. Such anomalies may initially manifest at birth as an asymptomatic palpable mass or a sinus or fistula opening; they alternatively may remain unnoticed until secondary infection causes acute presentation later in childhood.2 The anatomic location of such lesions often suggests their embryologic origin3 (Table 372-2).
BRANCHIAL ANOMALIES
Lesions of the anterolateral neck are often of branchial system origin. Each of the four mesodermal branchial arches were separated from one another by an external cleft of ectodermal origin and by an internal pouch of endodermal origin with a thin epithelial plate separating cleft and pouch. Branchial cleft anomalies are classified by the likely arch of origin, with second branchial anomalies being most common.4 They form either sinuses, fistulas, or cysts. A sinus tract with either an external or internal opening represents a vestigial cleft or pouch. Branchial cleft sinuses with external openings to the skin are typically associated with the first and second arches. Second branchial anomalies can present as enlarging neck masses or as small draining sinuses in the lateral neck at the border of the sternomastoid muscle (eFigs. 372.1 and 372.2 ). Third and fourth arch anomalies, sometimes referred to as piriform fistulas, are quite rare. They usually present as recurrent neck abscesses or suppurative thyroiditis, almost exclusively on the left side.5 While excision of these piriform fistulas and the associated mass/tract is curative, recent reports have indicated at least short-term benefits from cautery of endoscopically demonstrated fistula tracts in the piriform sinus.6 Recurrence of branchial anomalies after surgical excision is more common after multiple infections, so early removal of these lesions is usually recommended.7 Treatment is complete excision of the cyst and/or sinus tract. First branchial anomalies are less common, with tracts that involve the ear canal or the facial nerve. First branchial anomalies can present as sinus tracts or masses near the ear or parotid gland. Excision of these anomalies usually requires dissection of the facial nerve to prevent injury (Fig. 372-1).8 Third and fourth arch anomalies, sometimes referred to as piriform fistulas, are quite rare. They usually present as recurrent neck abscesses or suppurative thyroiditis, almost exclusively on the left side.5 While excision of these piriform fistulas and the associated mass/tract is curative, recent reports have indicated at least short-term benefits from cautery of endoscopically demonstrated fistula tracts in the piriform sinus.6
Table 372-2. Congenital Malformations of the Neck
The external opening of a congenital sinus or fistula tract is often detectable at birth; noninfected tracts may secrete a mucuslike material. In contrast, branchial cysts may enlarge slowly and may not be evident until the second or third decade of life. Cyst presentation early in childhood is often due to acute, painful enlargement associated with an upper respiratory tract infection. Recurrent neck abscesses, particularly in the left thyroid region, should raise concern that a vestigial branchial pouch is maintaining an internal opening into the oropharynx or hypopharynx.
Although branchial anomalies typically occur as isolated entities, anomalous branchial system development does occur in association with some craniofacial and multiorgan syndromes, such as oculo-auriculo-vertebral spectrum (hemifacial microsomia or Goldenhar syndrome) and branchio-oto-renal (BOR) syndrome.
THYROID ANOMALIES
Midline neck masses raise suspicion of alternative developmental anomalies, most commonly of thyroid origin. Such thyroid anomalies include thyroglossal duct cysts and comparatively rare ectopic cervical thyroids. The thyroid gland originates as a diverticulum from the floor of the mouth. During embryologic descent into the inferior neck, the thyroid gland remains connected to the pharynx by an embryonic duct that eventually involutes. The persistence of a portion of this duct causes the thyroglossal duct cyst, whereas arrest in the normal descent of the gland results in an ectopic thyroid. The majority of thyroglossal duct cysts present in children and adolescents as asymptomatic or inflamed neck masses at or below the level of the hyoid bone (Fig. 372-2). These cysts comprise up to 13% of excised neck masses in children in one series and over 50% of surgically treated congenital neck cysts in another series.9,10 They arise from expansion of persistent remnants of the thyroglossal duct tract, which usually disappears between the 5th and 10th embryonic weeks. While most of these cysts occur close to the thyroid notch or the hyoid bone, they can occur anywhere from the tongue base to the thyroid isthmus. Thyroglossal duct cysts present most commonly as asymptomatic masses, but they can become infected with enlargement and overlying skin erythema. Preoperative evaluation should include imaging to exclude the diagnosis of ec-topic solitary thyroid tissue by confirming the presence of a normal thyroid gland. The operation described by Sistrunk—excising the cyst, the thyroglossal duct tract, a portion of the central hyoid, and a core of tongue base tissue—remains the standard of care with low rates of recurrence (eFig. 372.3 ).11,12
Figure 372-1. Inflammation around the orifice of an infected first branchial sinus in a 3-year-old child. (Source: Photo courtesy of David E. Tunkel and Johnathan A. Perkins.)
DERMOIDS
Dermoid cysts also frequently manifest in the cervicofacial region due to the predilection of such lesions to appear along the lines of embryologic fusion. Cervical dermoid cysts occurring in the lateral neck need to be distinguished from branchial cysts, while those occurring in the midline of the neck in the submental and ethyrohyoid regions can be difficult to differentiate from thyroglossal duct cysts.
Figure 372-2. Midline mass in an adolescent demonstrating a thyroglossal duct cyst. (Source: Tintinalli JE, Kelen GD, Stapczynski JS. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York: McGraw-Hill; 2004.)
THYMIC ANOMALIES
Thymic gland anomalies can also manifest in the anterolateral neck. The thymus arises bilaterally from the third and fourth branchial pouches and descends from the pharynx in a caudal and medial direction into the mediastinum. Ectopic solid thymus tissue results when one or both thymic lobes fail to descend. Failure of involution of the embryonic thymopharyngeal ducts with secondary cystic changes in their persistent remnants is the etiology of cervical thymic cysts.
MANAGEMENT
The principal treatment for each of the above congenital anomalies is surgical excision; this is because of their propensity for continued growth, potential impingement on vital aerodigestive tract structures, risk of secondary infection, cosmetic deformation, and rare reports of malignancy associated with untreated lesions. Recurrence of branchial anomalies after surgical excision is more common after multiple infections, so early removal of these lesions is usually recommended.7 The procedure utilized depends on the lesion, with the common goal being complete removal of both the presenting mass and its embryologic tract of origin.
HEAD AND NECK TRAUMA
Although facial and neck trauma occurs frequently during childhood, the small size, skeletal flexibility, and increased fatty tissue in a child’s face mainly results in soft-tissue injuries. Extensive soft-tissue laceration and fractures of the facial and neck skeleton are comparatively uncommon. Such serious injuries are not normally caused by childhood play but are usually the result of motor vehicle accidents, animal-related trauma, or iatrogenic injury.13
LACERATIONS
Cervicofacial lacerations are most commonly caused by animal, particularly dog, bites (see Chapter 116).14 The peak incidence occurs in children less than 10 years of age who may not anticipate an aggressive response and indeed may precipitate an attack through either irritating the animal or invading its personal space.15 The majority of such lacerations are usually closed by special suturing techniques under conscious sedation, though occasionally general anesthesia may be necessary if the defect is extensive.
NASAL TRAUMA
The nasal bones are the facial bones most frequently broken. The acute identification of a nasal bone fracture in a child may not be easy due to extensive facial swelling, which limits the examination. Additionally, plain radiographs can be difficult to interpret. The immediate evaluation should rule out gross disfigurement and the presence of a septal hematoma. If the patient is stable, reexamination in 2 to 7 days once the swelling has resolved can better determine nasal appearance and function. Concern in either respect should lead to otolaryngologic referral.
An obviously displaced nasal fracture with cosmetic deformity or functional compromise should be corrected as soon as possible, usually by closed reduction under general anesthesia. In more complicated fractures, or when fracture reduction has been delayed, a septorhinoplasty may need to be performed at a later date.
Subluxation of the nose may be as a complication of passage through the birth canal during delivery. This problem often corrects itself. If breathing problems are present or if the nose is markedly deformed, closed reduction in the neonatal period is recommended.
MANDIBULAR AND MAXILLARY TRAUMA
Because a child’s jaw is less ossified than an adult’s, mandibular fractures are infrequent. The majority of childhood mandibular fractures involve the condyle.16 Such “greenstick” fractures usually do not go through the growth plate. They usually heal rather well without surgery and with minimal immobilization. More extensive mandibular fractures require surgical reduction, with the approach depending on the patient’s age, the localization of the fracture relative to tooth eruption, and the child’s bite.
Because the maxilla in children is proportionately small, fractures here are also uncommon. Midface fractures often occur in a setting of significant trauma with associated orbital and/or nasal involvement. Such children are also more likely to have associated skull and cervical spine fractures.17
The preoperative evaluation of suspected mandibular and maxillary fractures often requires plain dental radiographs and bone algorithm computed tomography; magnetic resonance imaging may be necessary if there is an associated skull fracture or suspected closed head injury. Severe fractures may require securing the airway by endotracheal intubation or tracheotomy. Surgical reconstruction may be staged, with the ultimate goal of achieving good functional and cosmetic outcome.
ORBITAL FRACTURES
Evaluation of orbital injuries should always involve ophthalmologic consultation that assesses globe position, ocular motility, and vision. The location of an orbital fracture—the zygoma, above the eye, below the eye, or in the bones surrounding the eye socket—varies depending on the mechanism of facial injury. Potential complications of orbital fractures include enophthalmos, exophthalmos, excessive tearing (epiphora), double vision due to oculomotor muscle entrapment, and traumatic vision loss.18
TEMPORAL BONE INJURIES
Trauma to the temporal bone in children more commonly results in fractures than any other area of the skull.19 The primary cause is motor vehicle accidents, and the secondary causes are falls or blunt trauma.20 Fractures to the temporal bone may affect hearing, balance, and facial nerve function. Longitudinal temporal bone fractures that parallel the petrous ridge typically cause a conductive hearing loss as a result of hemotympanum, tympanic membrane perforation, or ossicular damage. Sensorineural hearing loss and vertigo are more common with transverse fractures that run perpendicular or oblique to the petrous pyramid due to disruption of the labyrinth or cochlea.21 Such transverse fractures are more likely to result in cerebrospinal fluid otorrhea.22 Localizing a temporal bone fracture is best accomplished with high-resolution computed tomography. Surgical intervention is infrequently necessary, as conductive hearing losses often spontaneously improve and sensorineural hearing losses are often not correctable.
ORAL AND PALATE INJURIES
Palatal injuries are common in children, often occurring when a child is running or playing with something in the mouth like a pencil, toothbrush, or stick. Lacerations on the hard and soft palate, tongue, and buccal mucosa usually heal spontaneously; larger lacerations may require suturing. Palatal and oropharyngeal lacerations that extend laterally pose potential injury to the great vessels, necessitating hospitalization for observation and MRI angio-graphic evaluation if worrisome neurological signs or symptoms develop (see also Chapters 371 and 375).23
EAR TRAUMA
Both auricular and external ear canal (EAC) lacerations are common. Potential complications include secondary infection in the short term and narrowing (stenosis) of the EAC in the long term. Tympanic membrane tears (perforations) can result from puncturing the eardrum with sharp or blunt objects such as bobby pins and Q-tips or from sudden pressure changes such as those experienced from injury during diving or water-skiing. Such perforations cause a conductive hearing loss. Spontaneous healing often occurs; if not, a tympanoplasty may be required (see also Chapter 269).
NECK AND LARYNGOTRACHEAL TRAUMA
Penetrating neck injuries may be intentional or unintentional. The objects causing these injuries can be divided into stabbing instruments and projectile instruments, each having specific characteristics that affect surgical findings. For example, stab wounds typically have a 10% higher rate of negative exploration than injuries from projectiles.24
The evaluation of a patient with penetrating neck trauma always should start with advanced trauma life support (ATLS), a paradigm that begins with a directed primary survey emphasizing airway, breathing, and circulation (ABC). Once stabilized, a secondary survey that includes a complete history and thorough physical examination should be performed. In few other regions of the body are so many vital structures located in so small an area. The sternocleidomastoid muscle delineates the posterior and anterior regions of the neck. Most of the vital structures are located in the anterior or lateral regions. Penetrating injuries are those that violate the platysma muscle. Such injuries and those that cross the midline have the greatest potential for damage.
Tracheobronchial and esophageal injuries resulting from penetrating trauma may have a mortality rate as high as 20%.25 Traumatic cervical esophageal injuries can result in devastating complications. Leakage of saliva and gastroesophageal fluid contents can produce early suppurative infection and an intense necrotizing inflammatory response in the neck and mediastinum. The overall mortality rate increases when esophageal injuries are not diagnosed within 12 hours.26 Diagnostic testing needed to ascertain the level and degree of injury includes direct hypopharyngoscopy and esophagoscopy, computed tomography, and contrast barium esophagraphy.
Laryngeal injury can occur from both anterior and posterior neck trauma. Airway compromise is the biggest immediate concern secondary to soft tissue swelling, vocal cord paralysis, and hematoma formation. Immediate treatment for traumatic laryngeal airway obstruction often requires a tracheotomy; endotracheal intubation is often not possible and may be contraindicated.
A long-term consequence of airway trauma may be narrowing (stenosis) of the airway, requiring future surgical reconstruction. The areas most prone to stenosis are the subglottis, the anterior and posterior commissure, and the tracheotomy site.27
While external causes of tracheal trauma in children have been associated with the escalating use of skateboards, minibikes, motorcycles, and motor vehicles, most injuries to the airway are the result of internal trauma.28 The primary culprit is endotracheal intubation with a tube that is too large and fits snugly. Many critically ill children are salvaged through prolonged respiratory support, only to develop laryngotracheal stenosis. In adults and older children, the glottic opening represents the smallest diameter of the airway,29 whereas in small children and infants, the cricoid ring is the narrowest section of the airway. Surgical reconstruction is often required (see also Chapter 371).