In general, most children with retrognathia have some degree of airway obstruction as part of their anomaly. In managing these children, physicians should attempt to minimize any airway obstruction present while promoting normal neurologic development and ensuring appropriate weight gain. Although positioning may be successful in some patients, alternative measures have been necessary in other children in order to enable retrognathic children to grow and develop normally. The literature is polarized over this issue, and clinical decisions seem to be based as much on emotion as on scientific data. This chapter is intended to help the clinician decide which retrognathic patients warrant operative intervention and those who should be managed conservatively.
Several potential etiologic factors in airway obstruction with retrognathia have been described, including (1) posterior displacement of a normal-size tongue; (2) loss of support of the genioglossus muscle; and (3) development of negative pressure within the upper aerodigestive tract during deglutition and inspiration resulting in glossoptosis. These events cause airway obstruction by means of four different mechanisms: (1) antero/posterior collapse secondary to posterior movement of the tongue against the posterior pharyngeal wall; (2) posterior/superior displacement of the tongue, prompting contact between the tongue, velum, and pharyngeal wall in the superior oropharynx; (3) pharyngeal obstruction secondary to prolapse of the medial walls of the pharynx; and (4) constriction of the pharynx in a circular manner with movement of the tongue as well as both lateral pharyngeal walls. In some children with retrognathia, brain stem immaturity may lead to apnea and hypoxia from vagal overactivity and esophageal motor abnormalities.1-3
The need for intervention in retrognathic children is driven by the potential consequences of unrecognized and inappropriately managed obstruction (i.e., hypoxia, cor pulmonale), failure to thrive, and embarrassment of central nervous system (CNS) activities. It is essential to remember that children with retrognathia may have significant hypoxia without apparent obstructive episodes.4 These may occur more frequently with advancing age as the child's metabolic demands increase associated with increasing physical activity. Similarly, the degree of obstruction and resultant hypoxia may worsen with superimposed upper respiratory infections. Thus, vigilant observation is mandatory in order to prevent the potentially devastating growth and neurologic sequelae of prolonged hypoxia.
Once a patient is recognized as being at risk of airway obstruction with retrognathia, an appropriate evaluation should be undertaken in order to optimize management. In addition to performing continuous pulse oximetry and serial polysomnography (as necessary),4 a full endoscopic evaluation of the upper aerodigestive system should be considered, to rule out other possible treatable causes of obstruction.1 An evaluation for gastroesophageal reflux disease (GERD) may be appropriate, as GERD may worsen known airway compromise. Children with retrognathia are at risk of GERD because of the increased negative intrathoracic pressure often found in this population of children. Both a pH probe and a gastric emptying scan should be obtained to quantify any potential problems.4
Although airway obstruction often improves with time as infants develop voluntary tongue control and progressive mandibular growth occurs, this may take months. It is clearly impractical to keep children hospitalized until these events occur, assuming they take place. Thus, as a result of economic issues and the desire to establish family integrity, it is necessary for physicians to develop a rational plan for airway management at home.5 Should a child be premature or have associated medical problems that mandate hospitalization, definitive intervention may be delayed until discharge planning begins.
In making a determination about whether a patient needs intervention, one should consider whether the patient has isolated retrognathia or retrognathia associated with a syndrome. A classic example is provided by examining children with Pierre Robin sequence (PRS), who have either isolated Robin sequence (IRS) or Robin sequence with a syndrome (RSS). Associated malformations have been reported in up to 82% of children with PRS. Categorization is important prog-nostically as one group found that there was a 22.8% mortality in RSS but only a 5.9% mortality in those with IRS.6 Another method of categorization places patients into groups with mild obstruction (airway obstruction resolves with posture alone; supine nursing possible), moderate obstruction (utilization of nasopharyngeal airway and prone positioning for feeding after removal of nasopharyngeal airway), and severe obstruction (long-term management with nasopharyngeal airway or tracheotomy).7 There are probably more children with mild obstruction than are recognized generally since most studies only involve hospitalized children. PRS patients in the general population may be managed conservatively at home in most circumstances and therefore would not be included in most studies. As a result, the percentage of children with PRS who require surgical intervention is overestimated in the literature. In one study of 125 hospitalized patients with PRS, 45% had mild obstruction, 32% had moderate obstruction, and 23% had major respiratory difficulties.6
Several different methods have been described for airway management in children with retrognathia and symptomatic airway obstruction. These include lateral and prone positioning, use of intraoral devices, use of a nasopharyngeal airway, intubation, glossopexy (including tongue-lip adhesion [TLA]), mandibular expansion by traction, and tracheotomy.8 Advantages and disadvantages are present in each of these techniques, and their relative merits will be compared and contrasted.
In the retrognathic patient with acute obstruction, prone positioning may be effective if the airway obstruction is secondary to glossoptosis. This allows the effects of gravity to prevent the tongue from falling into the hypopharynx. In addition, this will minimize the effects of negative intrathoracic pressure during swallowing and inspiration, which cause the tongue to prolapse posteriorly due to its lack of voluntary muscular control.9 Although positioning may be effective on a short-term basis, it is not physiologic on a long-term basis. This will also prevent the normal parental-child physical contact needed for bonding to take place. In fact, at the Center for Craniofacial Disorders (CCFD) in the Bronx, New York, all patients who needed positioning or a nasopharyngeal airway greater than 30 days required surgical intervention. If feeding can be accomplished readily with the patient who requires prone positioning, this may be an appropriate solution for a relatively short time. However, if the feeding process becomes laborious, the joys of parenting may decrease significantly and make this an exhausting process. In that situation, an alternative method of airway control is necessary.3'10'11
The use of a nasopharyngeal airway is appropriate in some children with retrognathia who require airway support for a short period of time. However, at the CCFD any child who required support for more than 30 days needed a surgical procedure. It is interesting that in a review of several articles from the CCFD there are contradictory reports regarding timing of abandonment of management with a nasopharyn-geal airway. Specifically, different physicians from the same center have indicated that the decision to abandon use of a nasopharyngeal airway should be made at 7 to 10 days or at 8 weeks, even with the supporting data that any child requiring a nasopharyngeal airway for longer than 4 weeks required surgical intervention.
Use of a nasopharyngeal airway may be problematic because of placement of the tube at an inappropriate level. Accidental dislodgment of the tip of the tube from the correct position in the pharynx may precipitate gagging and vomiting if it slips inferiorly into the pharynx, while airway obstruction may be noted if it dislodges superiorly. Although some patients are discharged with a nasopharyngeal airway as a primary form of long-term therapy, some feel this is unstable for long-term management and is extremely risky.3,10,12
Similar to the CCFD experience, clinicians from San Diego have discharged patients successfully using a nasopharyngeal airway with a Tunstal connector to provide stability and minimize motion. This device is attached to the patient's forehead and connects to the nasal tube. These physicians use flexible laryngoscopy and bronchoscopy to rule out other causes of airway obstruction and define the level of obstruction before placing the tube under direct vision, ensuring that the top of the tube is distal to the site of obstruction. In general, polyvinyl chloride (PVC) tubes are used, as opposed to rubber tubes, because of their increased rigidity. The patients are discharged with pulse oximetry, a suction machine, oral airways, and extra nasopharyngeal tubes. The parents have been taught car-diopulmonary resuscitation skills, suctioning, oxygen saturation monitoring, and the method for placing oral and nasopharyn-geal airways. The parents will be familiar with gavage feeding if that is appropriate, and antimicrobial prophylaxis is often recommended to minimize inflammatory processes in the ears or sinuses. This group cautions that discharge of these patients may not be appropriate without cooperative, enthusiastic, and intelligent families.1
Another possible alternative for airway management is glossopexy, the type most frequently employed being a TLA. Although relatively simple in concept, the procedure has been known to fail in the hands of many experienced surgeons, often due to the button/suture cutting through the tongue. In addition, an anterior tongue mass can be created, which may block the airway itself. If the tongue is pulled too far anteriorly, it may tether the epiglottis and lead to possible aspiration. Other possible complications include wound infections, wound dehiscence, injuries to Wharton's ducts, and scar deformation of the lip, chin, and floor of mouth. Though feeding problems are not common with TLA, the procedure is not physiologic and it may lead to difficulties with oral intake.13 If not taken down before eruption of the teeth, significant dental abnormalities can occur, including retrodisplacement of the central and lateral mandibular incisors.
An adjunct to the TLA is the use of mandibular traction. This technique uses a conformer from the trunk with support bars to maintain an elevated midline bar (outrigger bar). An elastic band connection between the mandible and the outrigger bar allows the newborn to move the head laterally, but it discourages hyperextension because this motion will increase tension and pain. Easter et al.13 believe that this device is necessary for up to 2 months during the healing phase of TLA. Frohberg and Lange8 describe the use of circumferential mandibular wiring as a means of mandibular expansion in their study. The wires are attached to weights for three weeks and their index case demonstrated improvement in oxygen saturation with a diminution in the apnea index. However, careful review of their case demonstrates that the child still had a significantly elevated apnea index (22/hour) when they removed the mandibular traction. Although this method of therapy does address specifically the causative anomaly, we would disagree with the authors who consider this method physiologic. In addition, Frohberg and Lange8 advocate waiting until 18 months of age to repair a cleft palate associated with retrog-nathia, allowing for more airway growth. Although there may not be subsequent airway problems when waiting this length of time to close the palate, there are other issues that must be considered in regard to facial growth. Another alternative for airway management in this population is hyomandibulopexy. However, once this is accomplished, the larynx is more anterior and more difficult to intubate should that be necessary following surgical repair. In addition, there may be interference with mandibular growth6 and even problems with difficulty closing the mouth.
Another method that has been described for airway management is the use of an adapted bed that employs a forehead rest and occipital splint. The patient is placed in the prone position with a headrest maintaining the head. Patients have been sent home with this arrangement understanding that failure may necessitate surgical intervention. Continuous positive airway pressure (CPAP) may be necessary in some of these patients. Caouette-Laberg et al.6 use a subperiosteal release of the floor of mouth musculature on the mandible when the adapted bed previously described does not work. Although they are unable to offer an explanation regarding the success of the procedure, the operation involves removal of the genioglossus insertion from its mandibular attachment. This results in decreased glossoptosis with improved laryngeal position and, subsequently, less airway obstruction.
Shprintzen and Singer2 and Sher3 offer alternatives for airway management depending on the site of obstruction. At the CCFD, the investigators feel that a procedure to keep the tongue forward, such as a TLA, is likely to be successful only if the obstruction is secondary to the tongue blocking the airway. At this center, when the tongue presses against the palate, long-term use of a nasopharyngeal airway may be appropriate while awaiting vertical growth of the craniofacial structures. If growth occurs during the first several months of life, this may allow the tube to be removed or a glossopexy then may be successful. When there is collapse of the pharyngeal walls, long-term use of a nasopharyngeal airway may be appropriate while awaiting maturation, characterized by improved muscle tone, weight gain, and improved neurologic function. When no improvement occurs, a tracheotomy is deemed appropriate. These same guidelines are utilized when there is sphincter closure of the airway. As mentioned previously, the decision to intervene surgically at the CCFD is made at 1 to 8 weeks of age.
The results of a survey of pediatric otolaryngology fellowship training programs in regard to their management of the airway in PRS patients mirrors the controversy seen in the literature.14 This study, conducted by the Department of
Otolaryngology at Children's Hospital Medical Center, Cincinnati, Ohio, found no unanimity among respondents in the decision-making process when positioning and observation are no longer sufficient to prevent apneic episodes and oxygen desaturation in the neonate or infant with PRS. However, a clear trend was seen toward the use of a tracheotomy for long-term airway management. In the collection of the data for this report, it became obvious that the responses often were based on emotions as much as on scientific data. In point of fact, no studies have been done in which the different forms of airway management in PRS have been subjected to comparative analysis, thus leading to the multitude of anecdotal reports and pronouncements. Unfortunately, the lack of a large number of cases at any one center prohibits individual comparative trials and makes multi-institutional investigations mandatory. With a topic that is marked by such prejudice, implementation of a cooperative study is virtually impossible.
The following algorithm summarizes the thought process that should be employed by the clinician in the management of a child with PRS. One should note that this algorithm is for the child with isolated retrognathia. If there is an associated syndrome, I am more inclined to do a tracheotomy because of the higher mortality rate (Fig. 73-1). In addition, one might consider use of a nasogastic feeding tube to break the seal created by the glossoptosis. In some cases, this may eliminate the need for further airway intervention. Similarly, feeding difficulties may be addressed with either a nasogastric tube or a gas-trostomy tube.
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