You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > CONGENITAL MALFORMATIONS OF THE HEAD AND NECK Congenital Malformations, TracheaArticle Last Updated: Nov 13, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: David J Kay, MD, Consulting Staff, Department of Otolaryngology, Center for Pediatric ENT-Head and Neck Surgery David J Kay is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Medical Association Coauthor(s): Ari J Goldsmith, MD, Program Director, Associate Professor, Department of Otolaryngology, Division of Pediatric Otolaryngology, State University of New York Downstate Medical Center Editors: Ari J Goldsmith, MD, Program Director, Associate Professor, Department of Otolaryngology, Division of Pediatric Otolaryngology, State University of New York Downstate Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Gregory C Allen, MD, Assistant Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine; Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders; Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine Author and Editor Disclosure Synonyms and related keywords: congenital tracheal malformations, tracheal agenesis, tracheal atresia, tracheal webs, tracheal stenosis, tracheoesophageal fistulas, TEFs, tracheomalacia, tracheal rings, vascular anomalies, tracheal cysts, neck hyperextension INTRODUCTIONSection 2 of 10
  Congenital tracheal malformations may be either disorders intrinsic to the trachea itself or may represent external forces compressing the airway. While congenital tracheal malformations are by definition present at birth, at times they may not cause symptoms until far later in life. The primary presenting symptom is most commonly biphasic stridor, with a considerably prolonged expiratory phase. Nevertheless, other airway-related symptoms (eg, wheezing, cough, pneumonia, croup) may be present as well. A history of frequent neck hyperextension is common as the child tries to maximally open the airway. Many tests are available to assist in the workup of congenital tracheal malformations. The initial otolaryngologic evaluation should include a fiberoptic nasopharyngolaryngoscopy to rule out any supraglottic or glottic abnormalities. Radiographic imaging is helpful, with many available modalities to consider. Neck radiography should consist of posteroanterior (PA) and lateral view high kiloelectron volt (keV) airway radiographs rather than soft tissue images. Similarly, the chest radiographs should include PA and lateral views. The yield from these studies, however, is rather low. Barium swallow studies may reveal extrinsic esophageal compression. In a child with dysphagia, a dynamic fluoroscopic study may be considered. CT scanning of the neck and chest provides additional data, while MRI together with magnetic resonance angiography (MRA) can provide detailed vascular information and may obviate the need for conventional contrast angiography. However, the criterion standard diagnostic modality is still direct laryngoscopy with rigid bronchoscopy and possible rigid esophagoscopy. TRACHEAL AGENESIS AND ATRESIASection 3 of 10
Tracheal agenesis and atresia are almost uniformly fatal and are fortunately quite rare. The trachea may be completely absent (agenesis), or it may be partially in place but considerably underformed (atresia). In either case, communication between the larynx proximally and the alveoli of the lungs distally is lacking. Because of the lack of a normal continuous airway, affected newborns survive only if an alternate pathway for ventilation (eg, a patent bronchoesophageal fistula) exists. Although operative techniques are available to correct the underlying abnormality, surgical attempts have yielded poor results, essentially making this a noncorrectable malformation. TRACHEAL WEBS AND STENOSIS (FIBROUS CONSTRICTIONS)Section 4 of 10
A tracheal web consists of a thin layer of tissue draped across the tracheal lumen. While the thickness of the web may vary, no deformity or abnormality of the underlying cartilage framework exists (in contrast to tracheal stenosis). The web is not complete; the degree of ventilatory symptoms present is directly related to the size of the remaining tracheal lumen. Treatment consists of rupturing the web. This may be accomplished via rigid dilatation through use of a laser or other ablative or cutting instruments. Only the most thickened webs require a more invasive open surgical approach; local resection is the treatment of choice. In tracheal stenosis, a rather rare condition, pathological involvement continues to a much greater underlying tissue depth when compared to a web. A single tracheal ring, multiple rings, or even the entire length of the trachea may be involved. While affected patients may be symptomatic at birth, symptoms may be delayed several months until the airway lumen is compromised further by exacerbation of an upper respiratory tract infection. Symptoms include dyspnea, as well as a biphasic stridor with a prolonged expiratory component. If an affected patient requires intubation, efforts should be made to extubate early to prevent development of further edema and acute additional airway narrowing. Various other abnormalities are associated with tracheal stenosis, including vascular slings, tracheoesophageal fistulas, pulmonary hypoplasia, and trisomy 21. The criterion standard for diagnosing tracheal stenosis is rigid bronchoscopy. Other adjunct tests include CT scanning and MRI. While contrast tracheobronchography is available, its use is reserved for cases of such tight stenoses that rigid bronchoscopy is not possible even with the smallest available telescopes. If stenosis is minimal, treatment may consist of only conservative management. Mild stenosis may require multiple dilatations, which may be performed either with tracheal dilators or with progressively larger rigid bronchoscopes. While the airway may be secured via a tracheotomy if the stenosis is high in the trachea, this option is not available for more distal obstructions. Short stenoses may be removed directly via a tracheal resection with primary end-to-end anastomosis. More severe lesions require tracheal reconstruction, or tracheoplasty, which generally involves placement of a graft harvested from the costal cartilage. TRACHEOMALACIASection 5 of 10
In tracheomalacia, the supporting structure of the trachea is too floppy, resulting from weakness of the tracheal walls. In addition, the posterior or membranous portion of the trachea, which does not add support to the trachea, may be wider than normal. Patients exhibit an expiratory stridor, which may resemble wheezing. During heavy breathing, the membranous posterior wall advances anteriorly, where it may approach or even touch the cartilaginous anterior tracheal wall, thus markedly reducing the airway lumen. Symptoms are more prominent in an older infant as the respiratory movement increases. Therefore, posterior tracheal wall migration increases as well. As a result, the affected infant may hyperextend his neck in order to adequately keep his airway open. Primary tracheomalacia is a congenital disorder of the tracheal rings and is relatively rare. On the other hand, secondary tracheomalacia is an acquired disorder in which cartilage weakness results from chronic wearing from some external pressure. Common causes of secondary tracheomalacia include vascular anomalies, such as innominate artery compression and tracheoesophageal fistula. Weakness may persist or even worsen immediately following vascular repair; because the external compressing/supporting structure has been removed/repaired, the area of tracheomalacia generally scleroses and firms with time, which may be months to years. Tracheomalacia may be diagnosed with airway fluorography. Perform rigid bronchoscopy with the patient spontaneously ventilating because positive pressure ventilation from the respirator may balloon the trachea, thus hiding its floppiness. Symptoms of tracheomalacia are generally self-limiting because adequate growth in the diameter of the trachea eliminates symptoms by the time the patient is aged 2 years. Treatment, therefore, is supportive and aimed at preventing atelectasis, which may require administration of mucolytics to decrease secretions. For severe cases, tracheotomy, continuous positive airway pressure (CPAP), or both may be necessary until the tracheomalacia is outgrown. VASCULAR ANOMALIESSection 6 of 10
In tracheal disorders of vascular etiology, the trachea is inherently normal. However, large vessels are extrinsically impinging upon it, and possibly upon the esophagus as well. The infant may hyperextend the neck in an effort to straighten the compressed airway, thereby stretching the trachea and pushing away the compressive extraluminal vessels. These anomalies are associated with reflex apnea and dying spells. In these conditions, respiration ceases, with resulting cyanosis. Fortunately, these episodes spontaneously resolve. The most common vascular anomaly is compression from the innominate artery. This is likely to occur especially in cases in which the take-off of the innominate from the aorta is more distal (ie, further left) than normal. Diagnosis consists of a rigid bronchoscopy, which reveals pulsatile anterior tracheal wall compression, and a rigid esophagoscopy, which does not show any compression at all. Because symptoms often resolve after several years, operative intervention is reserved for cases of severe symptoms only. Surgical correction involves suspending the innominate or the aorta anteriorly to the sternum (ie, inominopexy or aortopexy). The second most common vascular anomaly is the complete vascular ring, also known as the double aortic arch. This condition provides circumferential compression of both the trachea and esophagus. Additionally, a secondary tracheal cartilage deformity (tracheomalacia) may be present from the resulting pressure. Symptoms include both dysphagia and dyspnea, and stridor may be present as well. The barium swallow study reveals circumferential narrowing. Tracheal narrowing is observed on rigid bronchoscopy, while findings on rigid esophagoscopy are remarkable for posterior esophageal compression (vs no esophageal compression with innominate artery compression). Treatment consists of surgically dividing the ring, generally by ligating the smaller of the 2 aortic arches. A pulmonary artery sling is also known as an aberrant left pulmonary artery. In these cases, the left pulmonary artery passes between the trachea and esophagus, resulting in distal tracheal and right bronchus compression. It is associated with the presence of complete tracheal rings. Barium swallow or rigid esophagoscopy study reveals anterior esophageal compression (in contrast to posterior esophageal compression with a double aortic arch). Treatment involves surgical rerouting of the aberrant vessel. Other vascular anomalies exist as well. For example, if a right aortic arch is present with a persistent ligamentum arteriosum, symptoms are similar to those of a double aortic arch. Also, an anomalous subclavian artery may compress the airway if it courses immediately anteriorly or posteriorly to the trachea. COMPLETE OR DEFORMED RINGSSection 7 of 10
When a complete tracheal ring exists, no posterior membranous portion of the trachea is present, leaving only a rigid ring around the airway. Symptoms include dyspnea and possibly stridor and are particularly exacerbated with upper respiratory tract infections. Diagnosis may be made based on CT scanning or rigid bronchoscopy findings, on which the complete ring may be observed to involve a single tracheal segment, multiple segments, or even the entire length of the trachea. Treatment consists of surgery. Single rings and short segments may be resected primarily with end-to-end anastomosis, while longer segments require a tracheal reconstruction or tracheoplasty with costal cartilage grafting. Absent or deformed tracheal cartilage rings can also occur, with resulting poor local structural support of the airway in the affected areas. Diagnosis is made by rigid bronchoscopy; flaccid segments may be observed and palpated. Management involves watchful waiting only, because symptoms resolve with tracheal growth as the diameter of the tracheal lumen increases. TRACHEOESOPHAGEAL FISTULAS AND TRACHEAL CYSTSSection 8 of 10
Various forms of tracheoesophageal fistulas (TEFs) exist, which may or may not have concurrent esophageal atresia. The most common form (85%) is proximal esophageal atresia with a distal TEF, while the next most common type (4%) is the H type TEF without esophageal atresia, in which the intact trachea and esophagus have a connecting tract between them (forming an H shape). Other types include proximal esophageal atresia with a proximal and distal (ie, double) TEF (2%) and proximal esophageal atresia with a proximal TEF (1%). The remaining 8% of cases are isolated esophageal atresia without a TEF. TEFs are associated with trisomy 18, trisomy 21, and the VATER (also known as VACTERL) constellation of anomalies—vertebral, anal, cardiac, TEF, esophageal atresia, renal, and limb abnormalities. Symptoms of a TEF include aspiration, dyspnea, and frank respiratory distress during feeding. Diagnosis may be suggested by failure to pass a nasogastric tube. A barium swallow study may reveal the fistula. A minimal amount of barium should be used because of the high risk of aspiration, and the barium should be inserted via a thin lumen tube placed past the cricopharyngeus to protect the larynx and minimize aspiration. During rigid bronchoscopy, the fistula entrance may be observed in the posterior tracheal wall; cannulation of the fistula may facilitate surgical repair. If the infant is stable from both cardiac and pulmonary perspectives, an early primary surgical repair should be performed. The unstable infant may undergo either delayed primary repair or a staged repair. Because tracheal cysts develop from evaginations of embryologic tracheal buds, they may develop anywhere along the trachea. The cysts may produce no symptoms at all or may become infected. If they are large enough, they may cause airway compression, resulting in dyspnea and possibly even stridor. Posteriorly located tracheal cysts may compress the esophagus as well, resulting in dysphagia. The diagnosis consists of the presence of a mediastinal cyst on imaging studies; rigid bronchoscopy shows a normal endotracheal lumen. Treatment involves surgical excision of the cyst. OTHER CONGENITAL TRACHEAL MALFORMATIONSSection 9 of 10
Trachiectasis refers to congenital tracheal enlargement. It is a rare condition, associated with organomegaly and with diseases of elastic fibers. A tracheal bronchus represents an abnormal tracheal bifurcation above the level of the carina. Incidence is estimated at 3%, with right side bronchus far outnumbering the left. While patients are generally asymptomatic, obstructive symptoms (eg, atelectasis, pneumonia) can result if the entrance to the airway lumen is unusually small. Other congenital tracheal malformations have also been described, including tracheal clefts and congenitally short tracheas. For excellent patient education resources, visit eMedicine's Procedures Center. Also, see eMedicine's patient education article Bronchoscopy. REFERENCESSection 10 of 10
Congenital Malformations, Trachea excerpt Article Last Updated: Nov 13, 2007 |
