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Congenital Anomalies of the Tracheobronchial Tree and of the Esophagus: Diagnosis and Treatment
{;ONGENITAL ANOMALIES OF THE TRA{;HEOBRON{;mAL TREE AND OF TIlE ESOPHAGUS
Diagnosis and Treatment PAUL H. HOLINGER, M.D.
KENNETH C. JOHNSTON, M.D.
JOYCE A. SCHILD, M.D.
Acute respiratory emergencies and severe swallowing problems in newborns frequently necessitate rapid, irrevocable decisions for their solution. A knowledge of the congenital anomalies that involve the air and food passages serves as the basis for establishing a program of procedure that will lead to the diagnosis and indicate appropriate treatment. EMBRYOLOGIC BACKGROUND
Congenital malformations of the tracheobronchial tree and the esophagus occur often in the general population. This is not surprising in view of the complexity and interrelationship of their development. Both arise from the caudal portion of the embryonic pharynx, the bronchopulmonary system budding off the digestive tract and enlarging and branching until it forms the entire tree. The original respiratory budding starts in the fourth week, elongates rapidly and bifurcates early into right and left masses which eventually become the tracheobronchial mucosa. All the major divisions are obvious by the thirtysecond day and the segmental bronchi by the thirty-sixth day. Supporting structures at the same time form from surrounding mesenchyme. The larynx at the entrance of the tracheal bud for a short time is not patent; later it opens and develops from the simple epiglottic and
1114
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
arytenoid swellings into the complex organ seen at birth. The esophagus, too, is an almost solid, rodlike structure in its earliest developmental phase. Multiple spaces appear and coalesce by the sixth week to form a continuous lumen throughout its length. Alteration in any of these sequential steps can lead to malformations of varying severity, pressures of developing structures determining the ultimate configuration of each organ. If one is absent or lagging in development, adjacent structures usurp the space as they grow. ANOMALIES OF THE TRACHEOBRONCHIAL TREE
Anomalies of the trachea and bronchi vary from a slight softening to severe forms of stenosis or partial or total absence. Tracheomalacia and bronchomalacia are characterized by collapse of the walls on expiration so that the lumen is partially or completely occluded in full expiration (Fig. 35). As a result, noisy respiration-in the expiratory phase-is present and in severe cases can cause the damming back of secretion
Fig. 35. Extreme tracheal and bronchial compression due to absence of cartilages.
with ronchi throughout the chest and inability of the child to expel the mucus, causing respiratory distress. The process can be present throughout the tracheobronchial tree or be found in localized areas affecting only portions of the distal lung. Lesser involvement is handled by the infant without too much difficulty except in the presence of a respiratory infection, when edema of the mucosa further aggravates the problem. Medical management with expectorants and high humidity atmosphere helps to keep the secretions liquid and easier to expel. In some instances bronchoscopic aspiration is necessary to remove the excess secretion and thus improve the child's breathing. Bronchodilators are usually of little help, since muscle spasm plays only a minor role compared to that of the diminished rigidity of cartilage. Growth potential
P. H. HOLINGER, K. C. JOHNSTON AND J. A. SCHILD
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is important, for as the infant increases in size, so does its tracheobronchial tree; the cartilages become better developed, and the lumen is less likely to collapse completely during expiration. Congenital webs are seen in the trachea and bronchi as well as in the larynx. These are usually merely thin membranes, but can be much thicker and quite tough. They give rise to wheezing or slight whistling sounds and may also cause retention of bronchial secretions with the ever-present possibility of infection. Very thin webs may be ruptured easily by advancement of the bronchoscope through the lumen. Firmer webs may need slower, progressive dilation with dilators of gradually increasing diameter, done during several bronchoscopic sessions at which time any retained secretions can be aspirated. Tracheal or bronchial stenosis is a much more serious problem. The narrowing not only extends along a greater length, but also usually involves a greater depth of the wall. X-ray films may show the stenosis if it is in the trachea or main bronchi; bronchography demonstrates tracheal or distal narrowings, but to avoid compromising an already precarious ventilation, only a thin medium may be used, and even this should be thoroughly aspirated immediately after it has served its purpose and appropriate films have been obtained. Bronchoscopy is helpful not only in diagnosis, but also in treatment by dilation of the stenosis. If the stenosis is high in the trachea, a tracheotomy can bypass the involvement; stenosis in midtrachea or below occasiomilly can be dilated and patency even maintained with a tracheotomy tube through the stenotic area. Prognosis for these infants is poor, however, and some die in early infancy because of ulceration, granulations and edema that occur around the end of the tube if the tube has to descend to the carina. Agenesis of a lobe or an entire lung is not uncommon and may not be discovered until adulthood. More often in this time of frequent chest films, the diagnosis is established early in life. Newborn infants with some respiratory difficulty are found to have complete opacity of one side of the chest (Fig. 36); older infants or young children with persistent respiratory complaints varying from frequent colds to episodes of cyanosis are x-rayed, and the films reveal a unilateral opacity and mediastinal shift of all structures into the involved hemithorax. Differentiation from a diaphragmatic defect with the abdominal contents herniated into the chest can be made tentatively on the basis of the presence or absence of bowel sounds in the chest; on x-ray film visible loops of bowel in the chest if gas is present must be differentiated from multiple pulmonary or pleural abscesses. Final confirmation is made by barium studies of the gastrointestinal tract. Bronchoscopy and bronchography in the infant with agenesis show only one bronchus with perhaps a small, rudimentary stump extending into the opacity on the involved side. The decreased respiratory reserve and often coexisting anomalies make good health rather precarious. Less severe forms of agenesis consist of lobes or segments missing or underdeveloped. They
1116
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
are usually asymptomatic and are incidental findings on bronchography done for other purposes. Bronchial duplication, at the opposite end of the development scale, consists of "extra" lobes formed by anomalous, overdeveloped septa or altered lobulation that arises early in formation. True accessory lobes are aerated by accessory bronchi. Superior right upper accessory lobes are commonest and may cause no symptoms except occasionally when localized disease processes are accentuated by the anomaly. Broncho· genic cysts consisting of pinched-off bronchial buds of either normal or accessory lobes or segments may also produce respiratory obstruction through direct compression of the adjacent trachea or bronchus (Fig. 37). After identification by bronchoscopy, bronchography and esophagograms, surgical resection is mandatory.
Fig. 36. A, Apparent atelectasis of the left lung. B, Bronchogram demonstrating rudimentary left bronchus in total agenesis of the left lung.
Most rare is the functionless accessory lobe originating from the esophagus, stomach or trachea and classified as extralobar sequestration. These may have their own isolated pleural coverings. Interlobar sequestrations do have a common pleural investment, but no normal connection with the tracheobronchial tree. They have a completely separate blood supply that can sometimes be demonstrated by arteriography, occasionally originating from below the diaphragm. They are usually seen in the right and left lower lobes and are often infected, causing fever, cough, physical signs of consolidation and an x-ray picture similar to that in lobar pneumonia or atelectasis. Bronchoscopy and bronchography show the absence of communication with the tracheobronchial tree. Treatment of such a lesion is by thoracotomy and lobectomy of the offending lobe. Bronchial obstruction due to a congenital anomaly may manifest itself by obstructive emphysema in the newborn. This leads to respiratory symptoms just as severe as those of atelectasis. The partial obstruction may be caused by intrabronchial, endobronchial or extrabronchial fac
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Fig. 37. Bronchogenic cyst (bud) compressing trachea and left bronchus to produce emphysema of left lung. The esophagus deviates to the right.
Fig. 38. Idiopathic emphysema of the left upper lobe.
tors, such as a mucous plug, inflammatory bronchial mucosa or a vascular anomaly, respectively. "Idiopathic emphysema" of a lobe (Fig. 38) has been forlrid to be caused by a lack of pillmonary ela~tic tissues and is differentiaied clinically by an absence of demonstrable bronchial obstruction on bronchoscopy. More commonly, however, obstructive emphysema in infants is found to be caused by extrabronchial pressure
1118
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
due to vascular anomalies, mediastinal pathology or hilar node enlargement; or to intrabronchial lesions such as a web, inspissated mucus or a foreign body. The effect of the obstruction is demonstrated by comparing inspiration and expiration chest films, and the cause of the obstruction must be determined by bronchoscopic examination. ANOMALIES OF THE ESOPHAGUS
Esophageal anomalies, similar to bronchial tree anomalies, vary from no lumen at all to duplication of structure. Isolated esophageal webs are found occasionally (Fig. 39). They cause dysphagia in infants and chil-
Fig. 39. Congenital esophageal web.
dren, but often are not manifest until after solid food has been introduced into the diet. The symptoms may be interpreted only as a "feeding problem" or that the child is a "slow eater" unless the stenosis is so severe as to approach complete atresia. Repeated bouts of total obstruction during eating occur as food becomes impacted in the stenosis. X-ray studies with contrast material will show a smooth narrowing of the esophagus, and occasionally there may be more than one stenotic area. Esophagoscopy confirms the x-ray findings and at the same time may be therapeutic, serving to dilate the narrowed segment. Passage of the esophagoscope or of mercury-filled bougies of gradually increasing diameters will usually be effective treatment. There are few patients who need surgical intervention.
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Short esophagus presents an entirely different picture roentgenologically and esophagoscopically from that of esophageal stenosis. The esophagus is too short to reach the level of the diaphragm, and the portion of stomach above the diaphragm remains there constantly. Cases of congenital shortening of the esophagus are almost invariably associated with a point of pronounced narrowing at the true cardia. It is at this point that foreign bodies become lodged; often the condition is first recognized after a foreign body has been removed and x-ray films disclose the nature of the obstruction. The area of narrowing is generally at the level of the seventh or eighth dorsal vertebra. Esophagoscopically, the congenitally short esophagus has a different appearance from that of congenital esophageal stenosis. The mucosa at the cardia, which now lies above the level of the diaphragm, is smooth and the stricture is firm. An esophagoscope can be passed through the cardia only with great difficulty, and response to dilation is not nearly as satisfactory as the response to dilation of a congenital esophageal stenosis. If the esophagoscope can be passed through the cardia of an infant with a short esophagus, gastric rugae are visualized immediately below it with the characteristic bright red, velvety appearance of gastric mucous membrane. The treatment consists of repeated dilation by any of the methods commonly used in benign esophageal strictures. The response to treatment is not as satisfactory as for most cases of congenital stenosis. Complete atresia with a trachea-esophageal fistula should be obvious in the newborn infant. First noted in the nursery to have excessive mucus and needing frequent mouth aspiration, these babies may havc great difficulties, if fed, because of immediate regurgitation and aspiration of the contents of the upper segment into the trachea. Because of this overflow, contrast studies may cause similar aspiration and confusion as to whether there is an associated high tracheo-esophageal fistula. Placing 0.5 cc. of Lipiodol into the mouth and obtaining films of the neck and chest with the infant in the upright position establish the diagnosis. Rarely is it necessary to put a small plastic catheter into the pouch to outline it to confirm the diagnosis, and esophagoscopy does not contribute additional information. In atresia associated with a tracheo-esophageal fistula the fistula may be present from the upper, lower or both segments to the trachea or bronchus and may be wide or tiny. Air wiH be present in the gastrointestinal tract if a communication exists from the respiratory tree to the lower segment of the esophagus, and contrast studies will outline the upper segment. In all cases the treatment consists in its surgical correction. Careful postoperative studies of the repaired atresias are essential to be sure there is no residual stenosis. Esophagograms should be made 10 days after operation, and if these show narrowing, esophageal dilations are started even if the child is asymptomatic, to maintain a full lumen consistent with the growth of the child. Bougienage started early in this manner is infinitely more effective in maintaining a lumen than is the
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ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
later dilatation by any means that may have to be done if the condition is recognized only after the stenosis has fully developed. Functionally, the results of early dilatation are much more satisfactory than dilatation or surgical reanastomosis that may become necessary later if the stricture at the point of anastomosis is allowed to become firm. Unfortunately, a stenosis may be unrecognized until the fourth or fifth month of life when semisolids are introduced into the diet and obstruction occurs. Occasional postsurgical esophagograms during the first months of life indicate a pattern of developing constriction, permitting bougienage before the stricture becomes rigid. Atresia without an esophagotracheal fistula is relatively rare. The upper and lower segments of the esophagus vary in length and may even be connected by a thin, fibrous strand of tissue. The symptoms are usually indistinguishable from those of an infant with an associated fistula, but on x-ray film no air is found below the diaphragm in the stomach or bowel. A small quantity of Lipiodol (0.5 cc.) again shows the upper sac with the typical meniscus of esophageal atresia. A gastrostomy and cervical esophagostomy complete the early therapy. Later a colon transplant, preferably intrathoracic, is used to connect the proximal and distal segments. Endoscopic problems arise because of obstruction at the sites of anastomosis. Dilatation over a thread may provide an improvement in swallowing function. Foreign body problems in these infants are numerous and require considerable ingenuity in their solution. Trachea-esophageal fistula without atresia is being recognized more frequently as cinefluoroscopy provides an improved method of study of the rapidly moving swallowing mechanism. Cough, frequent aspiration pneumonias and cyanosis with feedings suggest the presence of such fistulas. Some tracts are fairly long with the tracheal opening higher than the esophageal opening; in these, aspiration pneumonia follows a vomiting episode rather than occurring in association with normal swallowing. After demonstration of such a fistulous tract, surgical closure is immediately indicated. Cinefluoroscopy is also of great help in differentiating between aspiration of fluids because of the incoordination of the muscles of deglutition and a tiny fistula. Duplication of the various portions of the gastrointestinal tract can involve the esophagus as either elongated or rounded shadows. In either case esophageal symptoms of dysphagia, regurgitation or pain may lead to studies revealing the duplicated section of the tract. Pressure on the neighboring respiratory tract can cause cough, cyanosis and respiratory distress. The anomaly may occur in association with defects in the vertebrae and mediastinal displacement. Esophagograms reveal displacement or distortion of the column of contrast medium; occasionally, however, they fail to reveal the diagnosis. Final diagnosis and treatment of these embryonic duplications are by surgical excision. Cardiospasm is seen relatively rarely in infants and children, hut may give rise to dysphagia with regurgitation and aspiration of esophageal con-
T P. H. HOLINGER, K. C. JOHNSTON AND J. A. SCHll.D
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tents into the tracheobronchial tree. X-ray films of the chest often show infiltrates suggesting aspiration pneumonitis, and occasionally a broad mediastinal shadow, on barium or Lipiodol studies, is found to be a dilated esophagus above a narrowed cardia (Fig. 40). Esophagoscopy discloses a widened esophagus with ulcerated and exudate-covered walls. This esophagogastric junction is dilated easily with the advancing esophagoscope, giving considerable symptomatic relief. If there has been time for the development of an esophagitis from the retention of food, the cardia may be somewhat more rigid and dilate less easily. Mercury bougie bougienage at intervals sufficient to keep the patient comfortable is usually satisfactory. In older children, if they can tolerate it, pneumatic dilatation of the cardia under fluoroscopic control gives more lasting relief. Simple measures such as elevating the head of the
Fig. 40. Cardiospasm in an infant. A, Routine chest film. B, Esophagogram.
bed, avoiding food intake for several hours before bedtime and even postural drainage of the esophagus before lying down can keep the associated aspiration pneumonitis from recurring. CONSTRICTING VASCULAR ANOMALIES
Anomalies of the great vessels can affect both the respiratory tree and the esophagus. Alteration of the development pattern of the aortapulmonary artery complex of vessels from the dorsal and ventral arches of the embryo can result in a complete or incomplete ring of vessels surrounding and impinging on the trachea and esophagus. This is recognized now to be a relatively common cause of varying degrees of obstruction to both respiration and deglutition. The rings may be of several varieties of the anterior or posterior aortic arch with either a
1122
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
right or left descent of the aorta. The ligamentum arteriosum may complete the ring in some cases, or an anomalous take-off of such major vessels as the subclavian may do so. The patient may have stridor, cough and cyanosis with intermittent retractions. The symptoms increase with feeding or activity. Associated esophageal problems are dysphagia, regurgitation and slow feeding, all worse when solids are introduced into the diet; lodgment of solids often precipitates the need for the diagnostic studies. X-ray films may show tracheal narrowing (Fig. 41, A) and deformity of the barium column during esophageal studies (Fig. 41, B). Endoscopic examination confirms the findings of narrowing; however, if the obstruction is moderate or severe, esophageal examination will seriously increase the respiratory distress. Surgical release of the ring should be done as soon as possible to
Fig. 41. A, Lateral film of neck and chest demonstrating the entire airway to the tracheal bifurcation. The tracheal compression is caused by a vascular ring. B, Esophagograms of same infant.
relieve the difficulty, although the tracheal narrowing may not improve until further growth of the child provides a larger lumen. Tracheotomy bypass of the stenosis in an emergency is not always successful in those patients with obstruction near the bifurcation, since the tube may ride on the carina to cause granulations and further obstruction or actual erosion of the tracheal wall. DISCUSSION
In order to reach a diagnosis and thus to indicate treatment in the face of respiratory or deglutition problems in the newborn, a pattern of action should be established. Cardiac and central nervous system
, P. H. HOLINGER, K. C. JOHNSTON AND J. A. SCHILD
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lesions causing pharyngeal or laryngeal paralyses should first be considered and ruled out. The site and nature of the anomaly within the air and food passages must then be determined by physical examination, roentgen studies and endoscopic investigations. The nature of the cry is important; auscultation of the chest must be correlated with the x-ray findings; and regurgitation must be differentiated from vomiting. A comparison of inspiration and expiration chest x-rays reveals the presence of an obstructive emphysema. The lateral neck and chest film is of utmost importance and should be routinely requested. This film is taken with the infant's arms held down and back rather than up over the head, in which position they cover the all-important neck and laryngeal structures; this special lateral film reveals the entire airway from pharynx to carina, and with good technique one can identify all laryngeal structures (Fig. 41). Fluoroscopic studies of the infant esophagus, too, require care and special techniques to disclose anomalies of the swallowing function. The infant's feeding before the examination should be withheld to ensure the ingestion of adequate barium or Lipiodol to visualize the food passage. Cinefluoroscopy is of inestimable value in that it permits frame-by-frame analysis that may disclose a tiny fistula or a fleeting aspiration phenomenon. The function of the cardia can also be best observed in this manner, differentiating functional from organic strictures with greater accuracy. Bronchography, too, is best done under cinefluoroscapy with spot films available for recording filling patterns. In infants the bronchographic examination is most easily made by inserting a small polyethylene tube through the nose and guiding it into the trachea under laryngoscopic visualization. General anesthesia is unnecessary and undesirable. Lipiodol and Iodochloral are the most satisfactory media for bronchography in infants because the higher viscosity of other agents may lead to obstruction of the trachea or the major bronchi as they are instilled. The endoscopic examination in infants is made to augment the diagnostic studies and to initiate thera,Peutic procedures. No anesthesia is necessary for these examinations in infants, and general anesthesia is usually contraindicated by the nature of the lesion being investigated. Such therapeutic bronchoscopy or esophagoscopy as the aspiration of secretions and dilatation of strictures should be performed quickly, avoiding prolonged instrumentation with its associated laryngeal edema. Esophagoscopy requires the use of small esophagoscopes to avoid tracheal compression. The dilatation of strictures with bougies or the esophagoscope itself is the most common therapeutic indication for esophagoscopy. SUMMARY
Congenital tracheobronchial and esophageal anomalies are often responsible for dramatic, emergency problems of respiratory or swallowing obstruction. The diagnosis depends on the physical examination of
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ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
the chest as well as on x-ray studies of the neck, chest and swallowing function, the latter as outlined with barium or Lipiodol. Cinefluoroscopy is an invaluable aid in interpreting bronchograms and esophagograms in infants, permitting careful, repeated analysis of questionable or unusual observations. Bronchoscopic investigation of the cause of excessive secretions, of obstructive emphysema or of segmental, lobar or total unilateral atelectasis is rewarding both diagnostically and therapeutically. Such examinations in infants are best made without anesthesia, and oxygen may be administered through the oxygen post on the bronchoscope if the infant is in respiratory distress. A tracheotomy should be anticipated, not because of the procedure itself, but because of the anomaly or lesion found responsible for the symptoms. Tracheobronchial anomalies include webs, stenoses, the absence or duplication of bronchi and lobes or of their supporting structures. The esophagus, too, may be similarly affected with absence or duplication, the various parts occasionally connected through fistulous tracts with its developing partner, the trachea. The early recognition of the significance of regurgitation and fluid aspiration leads to the diagnosis of esophageal anomalies. The realization that "feeding problems" or "slow eaters" may have congenital esophageal disease permits early corrective esophagoscopic or surgical therapy. Of utmost importance is the early postsurgical study of the eophagus, with an adequate program of bougienage if an anastomotic stricture is demonstrated. The importance of the cardiovascular anomalies in regard to tracheobronchial and esophageal obstruction has been realized only relatively recently. All diagnostic measures should be used to determine their presence or absence in infants with airway and esophageal obstruction. If doubt still remains after careful study, exploratory surgery may be lifesaving as the obstructing ring is severed. 700 N. Michigan Ave. Chicago 11, Ill.
Diagnosis and Treatment PAUL H. HOLINGER, M.D.
KENNETH C. JOHNSTON, M.D.
JOYCE A. SCHILD, M.D.
Acute respiratory emergencies and severe swallowing problems in newborns frequently necessitate rapid, irrevocable decisions for their solution. A knowledge of the congenital anomalies that involve the air and food passages serves as the basis for establishing a program of procedure that will lead to the diagnosis and indicate appropriate treatment. EMBRYOLOGIC BACKGROUND
Congenital malformations of the tracheobronchial tree and the esophagus occur often in the general population. This is not surprising in view of the complexity and interrelationship of their development. Both arise from the caudal portion of the embryonic pharynx, the bronchopulmonary system budding off the digestive tract and enlarging and branching until it forms the entire tree. The original respiratory budding starts in the fourth week, elongates rapidly and bifurcates early into right and left masses which eventually become the tracheobronchial mucosa. All the major divisions are obvious by the thirtysecond day and the segmental bronchi by the thirty-sixth day. Supporting structures at the same time form from surrounding mesenchyme. The larynx at the entrance of the tracheal bud for a short time is not patent; later it opens and develops from the simple epiglottic and
1114
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
arytenoid swellings into the complex organ seen at birth. The esophagus, too, is an almost solid, rodlike structure in its earliest developmental phase. Multiple spaces appear and coalesce by the sixth week to form a continuous lumen throughout its length. Alteration in any of these sequential steps can lead to malformations of varying severity, pressures of developing structures determining the ultimate configuration of each organ. If one is absent or lagging in development, adjacent structures usurp the space as they grow. ANOMALIES OF THE TRACHEOBRONCHIAL TREE
Anomalies of the trachea and bronchi vary from a slight softening to severe forms of stenosis or partial or total absence. Tracheomalacia and bronchomalacia are characterized by collapse of the walls on expiration so that the lumen is partially or completely occluded in full expiration (Fig. 35). As a result, noisy respiration-in the expiratory phase-is present and in severe cases can cause the damming back of secretion
Fig. 35. Extreme tracheal and bronchial compression due to absence of cartilages.
with ronchi throughout the chest and inability of the child to expel the mucus, causing respiratory distress. The process can be present throughout the tracheobronchial tree or be found in localized areas affecting only portions of the distal lung. Lesser involvement is handled by the infant without too much difficulty except in the presence of a respiratory infection, when edema of the mucosa further aggravates the problem. Medical management with expectorants and high humidity atmosphere helps to keep the secretions liquid and easier to expel. In some instances bronchoscopic aspiration is necessary to remove the excess secretion and thus improve the child's breathing. Bronchodilators are usually of little help, since muscle spasm plays only a minor role compared to that of the diminished rigidity of cartilage. Growth potential
P. H. HOLINGER, K. C. JOHNSTON AND J. A. SCHILD
1115
is important, for as the infant increases in size, so does its tracheobronchial tree; the cartilages become better developed, and the lumen is less likely to collapse completely during expiration. Congenital webs are seen in the trachea and bronchi as well as in the larynx. These are usually merely thin membranes, but can be much thicker and quite tough. They give rise to wheezing or slight whistling sounds and may also cause retention of bronchial secretions with the ever-present possibility of infection. Very thin webs may be ruptured easily by advancement of the bronchoscope through the lumen. Firmer webs may need slower, progressive dilation with dilators of gradually increasing diameter, done during several bronchoscopic sessions at which time any retained secretions can be aspirated. Tracheal or bronchial stenosis is a much more serious problem. The narrowing not only extends along a greater length, but also usually involves a greater depth of the wall. X-ray films may show the stenosis if it is in the trachea or main bronchi; bronchography demonstrates tracheal or distal narrowings, but to avoid compromising an already precarious ventilation, only a thin medium may be used, and even this should be thoroughly aspirated immediately after it has served its purpose and appropriate films have been obtained. Bronchoscopy is helpful not only in diagnosis, but also in treatment by dilation of the stenosis. If the stenosis is high in the trachea, a tracheotomy can bypass the involvement; stenosis in midtrachea or below occasiomilly can be dilated and patency even maintained with a tracheotomy tube through the stenotic area. Prognosis for these infants is poor, however, and some die in early infancy because of ulceration, granulations and edema that occur around the end of the tube if the tube has to descend to the carina. Agenesis of a lobe or an entire lung is not uncommon and may not be discovered until adulthood. More often in this time of frequent chest films, the diagnosis is established early in life. Newborn infants with some respiratory difficulty are found to have complete opacity of one side of the chest (Fig. 36); older infants or young children with persistent respiratory complaints varying from frequent colds to episodes of cyanosis are x-rayed, and the films reveal a unilateral opacity and mediastinal shift of all structures into the involved hemithorax. Differentiation from a diaphragmatic defect with the abdominal contents herniated into the chest can be made tentatively on the basis of the presence or absence of bowel sounds in the chest; on x-ray film visible loops of bowel in the chest if gas is present must be differentiated from multiple pulmonary or pleural abscesses. Final confirmation is made by barium studies of the gastrointestinal tract. Bronchoscopy and bronchography in the infant with agenesis show only one bronchus with perhaps a small, rudimentary stump extending into the opacity on the involved side. The decreased respiratory reserve and often coexisting anomalies make good health rather precarious. Less severe forms of agenesis consist of lobes or segments missing or underdeveloped. They
1116
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
are usually asymptomatic and are incidental findings on bronchography done for other purposes. Bronchial duplication, at the opposite end of the development scale, consists of "extra" lobes formed by anomalous, overdeveloped septa or altered lobulation that arises early in formation. True accessory lobes are aerated by accessory bronchi. Superior right upper accessory lobes are commonest and may cause no symptoms except occasionally when localized disease processes are accentuated by the anomaly. Broncho· genic cysts consisting of pinched-off bronchial buds of either normal or accessory lobes or segments may also produce respiratory obstruction through direct compression of the adjacent trachea or bronchus (Fig. 37). After identification by bronchoscopy, bronchography and esophagograms, surgical resection is mandatory.
Fig. 36. A, Apparent atelectasis of the left lung. B, Bronchogram demonstrating rudimentary left bronchus in total agenesis of the left lung.
Most rare is the functionless accessory lobe originating from the esophagus, stomach or trachea and classified as extralobar sequestration. These may have their own isolated pleural coverings. Interlobar sequestrations do have a common pleural investment, but no normal connection with the tracheobronchial tree. They have a completely separate blood supply that can sometimes be demonstrated by arteriography, occasionally originating from below the diaphragm. They are usually seen in the right and left lower lobes and are often infected, causing fever, cough, physical signs of consolidation and an x-ray picture similar to that in lobar pneumonia or atelectasis. Bronchoscopy and bronchography show the absence of communication with the tracheobronchial tree. Treatment of such a lesion is by thoracotomy and lobectomy of the offending lobe. Bronchial obstruction due to a congenital anomaly may manifest itself by obstructive emphysema in the newborn. This leads to respiratory symptoms just as severe as those of atelectasis. The partial obstruction may be caused by intrabronchial, endobronchial or extrabronchial fac
P. H. HOLINGER, K. C. JOHNSTON AND J. A. SCHILD
1117
Fig. 37. Bronchogenic cyst (bud) compressing trachea and left bronchus to produce emphysema of left lung. The esophagus deviates to the right.
Fig. 38. Idiopathic emphysema of the left upper lobe.
tors, such as a mucous plug, inflammatory bronchial mucosa or a vascular anomaly, respectively. "Idiopathic emphysema" of a lobe (Fig. 38) has been forlrid to be caused by a lack of pillmonary ela~tic tissues and is differentiaied clinically by an absence of demonstrable bronchial obstruction on bronchoscopy. More commonly, however, obstructive emphysema in infants is found to be caused by extrabronchial pressure
1118
ANOMALIES OF TRACHEOBRONCHIAL TREE AND ESOPHAGUS
due to vascular anomalies, mediastinal pathology or hilar node enlargement; or to intrabronchial lesions such as a web, inspissated mucus or a foreign body. The effect of the obstruction is demonstrated by comparing inspiration and expiration chest films, and the cause of the obstruction must be determined by bronchoscopic examination. ANOMALIES OF THE ESOPHAGUS
Esophageal anomalies, similar to bronchial tree anomalies, vary from no lumen at all to duplication of structure. Isolated esophageal webs are found occasionally (Fig. 39). They cause dysphagia in infants and chil-
Fig. 39. Congenital esophageal web.
dren, but often are not manifest until after solid food has been introduced into the diet. The symptoms may be interpreted only as a "feeding problem" or that the child is a "slow eater" unless the stenosis is so severe as to approach complete atresia. Repeated bouts of total obstruction during eating occur as food becomes impacted in the stenosis. X-ray studies with contrast material will show a smooth narrowing of the esophagus, and occasionally there may be more than one stenotic area. Esophagoscopy confirms the x-ray findings and at the same time may be therapeutic, serving to dilate the narrowed segment. Passage of the esophagoscope or of mercury-filled bougies of gradually increasing diameters will usually be effective treatment. There are few patients who need surgical intervention.
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Short esophagus presents an entirely different picture roentgenologically and esophagoscopically from that of esophageal stenosis. The esophagus is too short to reach the level of the diaphragm, and the portion of stomach above the diaphragm remains there constantly. Cases of congenital shortening of the esophagus are almost invariably associated with a point of pronounced narrowing at the true cardia. It is at this point that foreign bodies become lodged; often the condition is first recognized after a foreign body has been removed and x-ray films disclose the nature of the obstruction. The area of narrowing is generally at the level of the seventh or eighth dorsal vertebra. Esophagoscopically, the congenitally short esophagus has a different appearance from that of congenital esophageal stenosis. The mucosa at the cardia, which now lies above the level of the diaphragm, is smooth and the stricture is firm. An esophagoscope can be passed through the cardia only with great difficulty, and response to dilation is not nearly as satisfactory as the response to dilation of a congenital esophageal stenosis. If the esophagoscope can be passed through the cardia of an infant with a short esophagus, gastric rugae are visualized immediately below it with the characteristic bright red, velvety appearance of gastric mucous membrane. The treatment consists of repeated dilation by any of the methods commonly used in benign esophageal strictures. The response to treatment is not as satisfactory as for most cases of congenital stenosis. Complete atresia with a trachea-esophageal fistula should be obvious in the newborn infant. First noted in the nursery to have excessive mucus and needing frequent mouth aspiration, these babies may havc great difficulties, if fed, because of immediate regurgitation and aspiration of the contents of the upper segment into the trachea. Because of this overflow, contrast studies may cause similar aspiration and confusion as to whether there is an associated high tracheo-esophageal fistula. Placing 0.5 cc. of Lipiodol into the mouth and obtaining films of the neck and chest with the infant in the upright position establish the diagnosis. Rarely is it necessary to put a small plastic catheter into the pouch to outline it to confirm the diagnosis, and esophagoscopy does not contribute additional information. In atresia associated with a tracheo-esophageal fistula the fistula may be present from the upper, lower or both segments to the trachea or bronchus and may be wide or tiny. Air wiH be present in the gastrointestinal tract if a communication exists from the respiratory tree to the lower segment of the esophagus, and contrast studies will outline the upper segment. In all cases the treatment consists in its surgical correction. Careful postoperative studies of the repaired atresias are essential to be sure there is no residual stenosis. Esophagograms should be made 10 days after operation, and if these show narrowing, esophageal dilations are started even if the child is asymptomatic, to maintain a full lumen consistent with the growth of the child. Bougienage started early in this manner is infinitely more effective in maintaining a lumen than is the
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later dilatation by any means that may have to be done if the condition is recognized only after the stenosis has fully developed. Functionally, the results of early dilatation are much more satisfactory than dilatation or surgical reanastomosis that may become necessary later if the stricture at the point of anastomosis is allowed to become firm. Unfortunately, a stenosis may be unrecognized until the fourth or fifth month of life when semisolids are introduced into the diet and obstruction occurs. Occasional postsurgical esophagograms during the first months of life indicate a pattern of developing constriction, permitting bougienage before the stricture becomes rigid. Atresia without an esophagotracheal fistula is relatively rare. The upper and lower segments of the esophagus vary in length and may even be connected by a thin, fibrous strand of tissue. The symptoms are usually indistinguishable from those of an infant with an associated fistula, but on x-ray film no air is found below the diaphragm in the stomach or bowel. A small quantity of Lipiodol (0.5 cc.) again shows the upper sac with the typical meniscus of esophageal atresia. A gastrostomy and cervical esophagostomy complete the early therapy. Later a colon transplant, preferably intrathoracic, is used to connect the proximal and distal segments. Endoscopic problems arise because of obstruction at the sites of anastomosis. Dilatation over a thread may provide an improvement in swallowing function. Foreign body problems in these infants are numerous and require considerable ingenuity in their solution. Trachea-esophageal fistula without atresia is being recognized more frequently as cinefluoroscopy provides an improved method of study of the rapidly moving swallowing mechanism. Cough, frequent aspiration pneumonias and cyanosis with feedings suggest the presence of such fistulas. Some tracts are fairly long with the tracheal opening higher than the esophageal opening; in these, aspiration pneumonia follows a vomiting episode rather than occurring in association with normal swallowing. After demonstration of such a fistulous tract, surgical closure is immediately indicated. Cinefluoroscopy is also of great help in differentiating between aspiration of fluids because of the incoordination of the muscles of deglutition and a tiny fistula. Duplication of the various portions of the gastrointestinal tract can involve the esophagus as either elongated or rounded shadows. In either case esophageal symptoms of dysphagia, regurgitation or pain may lead to studies revealing the duplicated section of the tract. Pressure on the neighboring respiratory tract can cause cough, cyanosis and respiratory distress. The anomaly may occur in association with defects in the vertebrae and mediastinal displacement. Esophagograms reveal displacement or distortion of the column of contrast medium; occasionally, however, they fail to reveal the diagnosis. Final diagnosis and treatment of these embryonic duplications are by surgical excision. Cardiospasm is seen relatively rarely in infants and children, hut may give rise to dysphagia with regurgitation and aspiration of esophageal con-
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tents into the tracheobronchial tree. X-ray films of the chest often show infiltrates suggesting aspiration pneumonitis, and occasionally a broad mediastinal shadow, on barium or Lipiodol studies, is found to be a dilated esophagus above a narrowed cardia (Fig. 40). Esophagoscopy discloses a widened esophagus with ulcerated and exudate-covered walls. This esophagogastric junction is dilated easily with the advancing esophagoscope, giving considerable symptomatic relief. If there has been time for the development of an esophagitis from the retention of food, the cardia may be somewhat more rigid and dilate less easily. Mercury bougie bougienage at intervals sufficient to keep the patient comfortable is usually satisfactory. In older children, if they can tolerate it, pneumatic dilatation of the cardia under fluoroscopic control gives more lasting relief. Simple measures such as elevating the head of the
Fig. 40. Cardiospasm in an infant. A, Routine chest film. B, Esophagogram.
bed, avoiding food intake for several hours before bedtime and even postural drainage of the esophagus before lying down can keep the associated aspiration pneumonitis from recurring. CONSTRICTING VASCULAR ANOMALIES
Anomalies of the great vessels can affect both the respiratory tree and the esophagus. Alteration of the development pattern of the aortapulmonary artery complex of vessels from the dorsal and ventral arches of the embryo can result in a complete or incomplete ring of vessels surrounding and impinging on the trachea and esophagus. This is recognized now to be a relatively common cause of varying degrees of obstruction to both respiration and deglutition. The rings may be of several varieties of the anterior or posterior aortic arch with either a
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right or left descent of the aorta. The ligamentum arteriosum may complete the ring in some cases, or an anomalous take-off of such major vessels as the subclavian may do so. The patient may have stridor, cough and cyanosis with intermittent retractions. The symptoms increase with feeding or activity. Associated esophageal problems are dysphagia, regurgitation and slow feeding, all worse when solids are introduced into the diet; lodgment of solids often precipitates the need for the diagnostic studies. X-ray films may show tracheal narrowing (Fig. 41, A) and deformity of the barium column during esophageal studies (Fig. 41, B). Endoscopic examination confirms the findings of narrowing; however, if the obstruction is moderate or severe, esophageal examination will seriously increase the respiratory distress. Surgical release of the ring should be done as soon as possible to
Fig. 41. A, Lateral film of neck and chest demonstrating the entire airway to the tracheal bifurcation. The tracheal compression is caused by a vascular ring. B, Esophagograms of same infant.
relieve the difficulty, although the tracheal narrowing may not improve until further growth of the child provides a larger lumen. Tracheotomy bypass of the stenosis in an emergency is not always successful in those patients with obstruction near the bifurcation, since the tube may ride on the carina to cause granulations and further obstruction or actual erosion of the tracheal wall. DISCUSSION
In order to reach a diagnosis and thus to indicate treatment in the face of respiratory or deglutition problems in the newborn, a pattern of action should be established. Cardiac and central nervous system
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lesions causing pharyngeal or laryngeal paralyses should first be considered and ruled out. The site and nature of the anomaly within the air and food passages must then be determined by physical examination, roentgen studies and endoscopic investigations. The nature of the cry is important; auscultation of the chest must be correlated with the x-ray findings; and regurgitation must be differentiated from vomiting. A comparison of inspiration and expiration chest x-rays reveals the presence of an obstructive emphysema. The lateral neck and chest film is of utmost importance and should be routinely requested. This film is taken with the infant's arms held down and back rather than up over the head, in which position they cover the all-important neck and laryngeal structures; this special lateral film reveals the entire airway from pharynx to carina, and with good technique one can identify all laryngeal structures (Fig. 41). Fluoroscopic studies of the infant esophagus, too, require care and special techniques to disclose anomalies of the swallowing function. The infant's feeding before the examination should be withheld to ensure the ingestion of adequate barium or Lipiodol to visualize the food passage. Cinefluoroscopy is of inestimable value in that it permits frame-by-frame analysis that may disclose a tiny fistula or a fleeting aspiration phenomenon. The function of the cardia can also be best observed in this manner, differentiating functional from organic strictures with greater accuracy. Bronchography, too, is best done under cinefluoroscapy with spot films available for recording filling patterns. In infants the bronchographic examination is most easily made by inserting a small polyethylene tube through the nose and guiding it into the trachea under laryngoscopic visualization. General anesthesia is unnecessary and undesirable. Lipiodol and Iodochloral are the most satisfactory media for bronchography in infants because the higher viscosity of other agents may lead to obstruction of the trachea or the major bronchi as they are instilled. The endoscopic examination in infants is made to augment the diagnostic studies and to initiate thera,Peutic procedures. No anesthesia is necessary for these examinations in infants, and general anesthesia is usually contraindicated by the nature of the lesion being investigated. Such therapeutic bronchoscopy or esophagoscopy as the aspiration of secretions and dilatation of strictures should be performed quickly, avoiding prolonged instrumentation with its associated laryngeal edema. Esophagoscopy requires the use of small esophagoscopes to avoid tracheal compression. The dilatation of strictures with bougies or the esophagoscope itself is the most common therapeutic indication for esophagoscopy. SUMMARY
Congenital tracheobronchial and esophageal anomalies are often responsible for dramatic, emergency problems of respiratory or swallowing obstruction. The diagnosis depends on the physical examination of
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the chest as well as on x-ray studies of the neck, chest and swallowing function, the latter as outlined with barium or Lipiodol. Cinefluoroscopy is an invaluable aid in interpreting bronchograms and esophagograms in infants, permitting careful, repeated analysis of questionable or unusual observations. Bronchoscopic investigation of the cause of excessive secretions, of obstructive emphysema or of segmental, lobar or total unilateral atelectasis is rewarding both diagnostically and therapeutically. Such examinations in infants are best made without anesthesia, and oxygen may be administered through the oxygen post on the bronchoscope if the infant is in respiratory distress. A tracheotomy should be anticipated, not because of the procedure itself, but because of the anomaly or lesion found responsible for the symptoms. Tracheobronchial anomalies include webs, stenoses, the absence or duplication of bronchi and lobes or of their supporting structures. The esophagus, too, may be similarly affected with absence or duplication, the various parts occasionally connected through fistulous tracts with its developing partner, the trachea. The early recognition of the significance of regurgitation and fluid aspiration leads to the diagnosis of esophageal anomalies. The realization that "feeding problems" or "slow eaters" may have congenital esophageal disease permits early corrective esophagoscopic or surgical therapy. Of utmost importance is the early postsurgical study of the eophagus, with an adequate program of bougienage if an anastomotic stricture is demonstrated. The importance of the cardiovascular anomalies in regard to tracheobronchial and esophageal obstruction has been realized only relatively recently. All diagnostic measures should be used to determine their presence or absence in infants with airway and esophageal obstruction. If doubt still remains after careful study, exploratory surgery may be lifesaving as the obstructing ring is severed. 700 N. Michigan Ave. Chicago 11, Ill.