You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > CONGENITAL MALFORMATIONS OF THE HEAD AND NECK Congenital Malformations, EsophagusArticle Last Updated: Apr 28, 2006AUTHOR AND EDITOR INFORMATIONAuthor: Ted L Tewfik, MD, FRCS(C), Professor, Department of Otolaryngology, Director of Continuing Medical Education of Otolaryngology, McGill University Medical School; Director, Director of Professional Affairs of Otolaryngology, Department of Otolaryngology, Montreal Children's Hospital; Senior Staff, Montreal General Hospital and Royal Victoria Hospital Ted L Tewfik is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons, American Society of Pediatric Otolaryngology, Canadian Medical Association, Canadian Society of Otolaryngology-Head & Neck Surgery, Quebec Medical Association, and Royal College of Physicians and Surgeons of Canada Coauthor(s): Naznin Karsan, MD, MSc, Staff Physician, Department of Otolaryngology, McGill University, Canada; Jean-Martin Laberge, MD, FRCSC, Director, Department of Surgery, Associate Professor, Montreal Children's Hospital, McGill University Editors: Russell A Faust, MD, PhD, Consulting Staff, Department of Otolaryngology, Columbus Children's Hospital; 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 malformations of the esophagus, esophageal atresia, tracheoesophageal fistula, laryngotracheoesophageal cleft, esophageal stenosis, esophageal webs, foregut duplications, congenital bronchopulmonary foregut malformations, diverticulum of esophagus, congenital short esophagus INTRODUCTIONCongenital anomalies of the esophagus comprise a diverse group of malformations. This chapter discusses embryology of the developing esophagus and esophageal anomalies secondary to its aberrant development. The chapter also reviews major esophageal malformations as follows:
EMBRYOLOGY OF THE ESOPHAGUSDevelopment of the esophagus occurs during embryonic and fetal periods. Embryonic Period The embryonic period extends from conception to the ninth week of gestation. During the latter half of the third week of development, the primitive foregut develops a ventral diverticulum that is cranial to the hepatic primordium and caudal to the fourth and fifth pharyngeal pouches. The diverticulum grows caudally and develops bronchopulmonary buds soon after appearance. The trachea develops from further caudal growth of the respiratory diverticulum. During the fourth and fifth weeks of development, the rapidly growing heart and liver stretch the esophagus. Because of the stretching, the esophagus narrows almost to obliteration at the level of the carina. Although vacuoles have been seen within the esophagus during this period, the lumen of the esophagus remains intact. In addition, the bronchial primordia curve in a dorsal direction, likely due to the growth of the pericardium anteriorly. The dorsal "embracement" of the esophagus results in close approximation of the tracheal bifurcation to the front wall of the esophagus, further narrowing its lumen. Between the sixth and eighth weeks of gestation, the epithelium becomes 2-5 cells thick and remains stratified columnar epithelium. The esophagus also is surrounded by a layer of undifferentiated mesenchyme and a circular layer of myoblasts. Longitudinal muscle fibers appear in the lower esophagus as the circular layer of muscle becomes well established. Cartilage also appears in the tracheobronchial tree. Fetal Period The fetal period encompasses the ninth week of gestation until birth. During the 10th week of development, stratified columnar epithelium becomes ciliated, and mesenchymal ridges result in longitudinal folds of mucosa. Muscular proliferation peaks during the 11th and 12th weeks, and epithelial and mesenchymal proliferation decrease from the 10th to 15th week. Ganglion cells also appear in the myenteric plexus, while the longitudinal muscle becomes well defined between the 10th and 12th week of gestation. In addition, the epithelium is completely ciliated, and proliferation occurs only in the basal layers at the 12th week. Striated muscle appears in the upper esophagus from the 12th to 15th week. Furthermore, the muscularis mucosa becomes well defined, and typical mucosal folds formed by longitudinal mesenchymal ridges can be appreciated. During the fourth and fifth months of gestation, stratified squamous epithelium replaces the ciliated columnar epithelium. Growth of the esophagus continues at a slower pace once morphological changes conclude. On a functional level, swallowing first appears at the 14th week and is well established by the end of the fourth month of gestation. ESOPHAGEAL ATRESIA AND TRACHEOESOPHAGEAL FISTULAIncidence The literature variably places incidence of esophageal atresia at 1 per 3000-4500 live births. Etiology has been attributed to genetic factors, infections, and teratogens, but in most instances, no cause is identifiable. Classification Esophageal atresia and/or tracheoesophageal (TE) fistula have been classified anatomically into 5 different types as follows:
Associated Anomalies Approximately half of babies with esophageal atresia have other associated congenital malformations (see Image 1). Cardiac malformations occur in up to 28% of patients. The most common cardiac anomalies are patent ductus arteriosus, ventricular septal defect, atrial septal defect, and right aortic arch. Other gastrointestinal malformations also can occur, with an imperforate anus most frequent (10%). Anomalies of the musculoskeletal system include hemivertebrae, rib malformations, and limb anomalies. Association with anomalies or malformations of the vertebral, anal, cardiac, tracheal, esophageal, renal, and limb organs (VACTERL) has been observed in 10% of patients with esophageal atresia. Other anomalies associated with esophageal atresia include pulmonary hypoplasia, pulmonary sequestration, congenital diaphragmatic hernia, tracheal atresia, and chromosomal anomalies. Diagnosis and Clinical Findings During gestation, a diagnosis of esophageal atresia usually can be made using fetal ultrasound. Almost all patients with esophageal atresia (and up to 60% of patients with atresia and TE fistula) have polyhydramnios. In the neonate, excessive drooling is often the first symptom. If feedings are attempted, the baby often chokes, regurgitates, and becomes cyanotic. Overflow of pharyngeal secretions into the trachea results in noisy breathing, and respiratory distress is progressive. If mechanical ventilation is necessary and lung compliance is poor, massive abdominal distention resulting in gastric rupture may occur due to free passage of air through the fistula into the stomach. Diagnosis of esophageal atresia is confirmed by inability to pass a firm oral or nasal tube into the stomach. Perform a radiograph to confirm the position of the tube. Also, perform a complete physical examination to assess cardiopulmonary status and to seek other congenital anomalies. Management The goal of treatment is to surgically restore esophageal continuity as soon as the baby can tolerate the procedure. If respiratory status is inadequate, or if further investigation is required to assess for other congenital anomalies, surgery may be delayed for a few days postpartum to avoid aspiration pneumonia. In premature infants with respiratory distress syndrome, a gastrostomy and fistula division can be performed. This decompresses the abdomen and allows adequate lung ventilation. Once the infant is stabilized and more mature, a definitive procedure to restore esophageal continuity can be undertaken. Primary repair is treatment of choice for esophageal atresia and TE fistula. The fistula is first divided and closed near the trachea to avoid formation of a tracheal diverticulum. The proximal end of the esophagus then is mobilized until the anastomosis can be performed with acceptable tension. This is performed with single-layer, interrupted, synthetic resorbable suture. Esophageal Atresia Without FistulaApproximately 5-8% of patients with esophageal anomalies have esophageal atresia without a fistulous connection to the trachea. Due to the long gap between upper and lower pouches, surgical correction of the deformity usually cannot be performed during the first few days of life. Diagnosis and Clinical Findings During intrauterine life, patients have polyhydramnios, and the diagnosis can be suspected with intrauterine ultrasound due to the absence of a stomach bubble. In the neonatal period, infants usually present with excessive drooling and a scaphoid abdomen. Radiologic findings pathognomonic of pure esophageal atresia include a dilated upper pouch and absence of air below the diaphragm. Treatment Continuous suction of the upper pouch and a feeding gastrostomy constitute initial treatment. The patient then is followed closely with contrast radiographs until primary esophagus repair can be performed, usually at an age of 2-3 months. If the gap between the proximal and distal segments of the esophagus is less than 2 vertebral bodies, the defect can be repaired with a tension-free primary anastomosis. If after an age of 3 months, the gap is still excessive, however, the esophagus can be reconstructed using a gastric or colonic graft. Another technique consists of creating a cervical esophagostomy with traction on the distal end. The upper esophagus is elongated gradually by repeatedly mobilizing it and placing the esophagostomy lower on the anterior chest wall until a primary anastomosis can be performed. TE Fistula Without AtresiaIncidence of TE fistula without atresia varies between 1-11% of esophageal malformations. Diagnosis and Clinical Findings Patients usually present in the neonatal period. Presentation symptoms can range from coughing and choking spells (precipitated by feeding), to abdominal distention due to passage of air from the fistula, to recurrent and severe pneumonias that often are unresponsive to antibiotics. Once the diagnosis is suspected, barium swallow with cineradiography is recommended, but bronchoscopy remains the investigation of choice to confirm diagnosis. Treatment Most H-type fistulas are above the clavicle and can be approached through a cervical incision. Intrathoracic fistulas require a thoracotomy for adequate access. Once identified, the fistula is divided and oversewn. Preplacement of a Fogarty catheter through the fistula (by tracheoscopy) facilitates intraoperative localization of the fistula and minimizes the risk of recurrent laryngeal nerve damage. Endoscopic obliteration of the fistula has been attempted with various techniques, such as tissue adhesives, electrocautery, and sclerosants. A recent study of 192 patients with tracheoesophageal fistulae concludes that fistulae that have not closed after 2 endoscopic attempts are not suitable for further endoscopic treatment; therefore, an external approach should be recommended. Follow-up Cimador et al studied the effect of postoperative morbidity during a long-term follow-up (6-12 y) in children with esophageal atresia who were treated at birth with primary anastomosis. Their results demonstrated that gastroesophageal reflux (GER) and esophageal dysmotility, which are reported as frequent findings in patients who underwent primary repair, do not cause any relevant impairment to the quality of their nutritional habit. LARYNGOTRACHEOESOPHAGEAL CLEFTA laryngotracheoesophageal cleft (LTEC) is a very rare anomaly with a midline defect of varying length between the posterior larynx and trachea and the anterior wall of the esophagus. Severe forms of the defect are lethal. Classification Evans, in 1985, classified LTEC into 3 categories as follow:
A modification of this classification was proposed by Benjamin and Inglis. In their classification, type I cleft is limited to the supraglottic lumen above the vocal folds. Type II is a partial cleft of the cricoid extending below the level of the vocal folds, and type III involves the whole cricoid cartilage and may extend to the cervical TE septum. Type IV involves a major part of the TE wall in the thorax (see Image 2). Associated Anomalies Moungthong and Holinger reported on their experience with LTEC in Chicago. Cardiovascular anomalies most frequently were seen (eg, pulmonary valvular stenosis, aberrant innominate artery, patent ductus arteriosus, aortic valvular stenosis, ventricular septal defect). Pulmonary agenesis, bronchoesophageal fistula, TE fistula, rudimentary uterus, and congenital blindness also were documented. Diagnosis and Clinical Findings Type I (Benjamin and Inglis classification) or the supraglottic type is the most difficult to diagnose. Clinicians may be alerted by feeding difficulties, husky cry, or aspiration pneumonia. Stridor, coughing, and cyanotic episodes precipitated by feeding are all symptoms that may vary in severity depending on cleft extent. The differential diagnosis should include TE fistula, esophageal atresia, and choanal atresia. Chest x-ray may demonstrate pneumonia, and the lateral view may show the anterior displacement of the nasogastric tube. Definite diagnosis is made endoscopically. Suspension microlaryngoscopy is necessary to avoid missing the subtle defect (see Image 3). Management Prevention of the gastroesophageal reflux is important in all types of clefts. Type I (Benjamin and Inglis classification) usually is corrected with growth. It requires nursing in the upright position and thickening of formula. Endoscopic repair may be needed to correct cases unresponsive to conservative measures. Types II and III can be corrected through cervical incision, while type IV requires lateral thoracotomy incision combined with cervical approach. Others require an anterior transtracheal repair. The pleura is used for interposition in the thoracic defect, and the sternocleidomastoid muscle is used for the cervical portion. Primary closure of small defects (those with redundant mucosa) and use of costal cartilage graft interposition (for type III) also have been described. Repair of a type IV with a cardiopulmonary bypass has been described. ESOPHAGEAL STENOSIS AND WEBSCongenital stenosis of the distal esophagus and esophageal diaphragms or webs has been reported. These anomalies have been classified histologically as follows:
Diagnosis and Clinical Findings Patients may present with aspiration and recurrent pneumonia, as with TE fistula. Once solid food is introduced, dysphagia and regurgitation become obvious. Endoscopy with biopsy and pH monitoring of the esophagus help to eliminate the possibility of a stricture secondary to gastroesophageal reflux. Barium swallow demonstrates narrowing of the distal esophagus. Treatment Pneumatic dilatation under fluoroscopy may be diagnostic and therapeutic; while it expands and cures a fibromuscular stenosis, a persistent "waist" in the balloon indicates a cartilaginous ring and the necessity for resection. Laser lysis of webs has been described and may be attempted in selected cases. FOREGUT DUPLICATIONSForegut duplications include esophageal cystic or tubular duplications and bronchogenic cysts. Due to foregut derivation of the duplications, they can be associated with an extralobar sequestration or a stenosis/atresia of the esophagus. Cysts usually are located in the right posterior mediastinum. Esophageal duplications may be separated from the esophagus or may share a common wall, but they are rarely in continuity with it. Duplications may contain gastric mucosa. Duplications of the esophagus also can be associated with vertebral anomalies and intraspinal cysts and often are associated with intra-abdominal intestinal duplications. Most authorities ascribe these anomalies to failure of the notochord to detach from the endoderm, with persistence of a neurenteric canal. Diagnosis and Clinical Findings Large duplications can result in cardiac or respiratory symptoms. Neurologic symptoms often predominate if there are associated vertebral anomalies. A chest x-ray may demonstrate a soft tissue mass with a mediastinal shift. Ultrasound can help distinguish a solid from a cystic mass, and barium contrast study can demonstrate extrinsic compression of the esophagus. CT scan delineates anatomy of the mass prior to surgical resection, and nuclear (technetium) scan may identify ectopic gastric mucosa. Treatment Definitive treatment involves surgical resection of the duplication. CONGENITAL BRONCHOPULMONARY FOREGUT MALFORMATIONSCongenital bronchopulmonary foregut malformations are very rare anomalies that result in a communication between the esophagus and a sequestered part of the lung. Symptoms include respiratory distress, cough during feeding, and recurrent pneumonias. Chest x-rays and ultrasound usually demonstrate the mass with a mediastinal shift. Barium contrast studies can demonstrate extrinsic compression of the esophagus. CT scan and/or MRI delineate pathology prior to surgical resection. Definitive treatment is surgical. OTHER RARER ANOMALIESCongenital Diverticulum of Esophagus Symptoms include emesis, regurgitation, and recurrent lung infections. Treatment is surgical excision of the diverticulum, fundoplication, and pyloroplasty. Congenital Short Esophagus This condition usually is associated with a hiatus hernia and an intrathoracic stomach. Infants usually present during the first month of life with failure to thrive. Surgical intervention involves an antireflux procedure, often combined with an esophageal-lengthening procedure (eg, Collis-Nissen fundoplication). MULTIMEDIA
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Congenital Malformations, Esophagus excerpt Article Last Updated: Apr 28, 2006 | |||||||||||||||||||||