Tracheoesophageal fistula (TEF) is a common congenital anomaly of the respiratory tract, with an incidence of approximately 1 in 3500 to 1 in 4500 live births.
Classification, epidemiology, and pathogenesis — TEF typically occurs with esophageal atresia (EA). EA and TEF are classified according to their anatomic configuration. Type C, which consists of a proximal esophageal pouch and a distal TEF, accounts for 84 percent of cases. TEF occurs without EA (H-type fistula) in only 4 percent. Other rare variations have been reported.
TEF and EA are caused by a defect in the lateral septation of the foregut into the esophagus and trachea. The fistula tract is thought to derive from a branch of the embryonic lung bud that fails to undergo branching because of defective epithelial-mesenchymal interactions. There are associated anomalies in approximately one-half of the cases of TEF and EA, often as part of the VACTERL association(vertebral defects, anal atresia, cardiac defects, TEF, renal anomalies, and limb abnormalities) or CHARGE syndrome (coloboma, heart defects, atresia choanae, growth retardation, genital abnormalities, and ear abnormalities), and especially with congenital heart or genitourinary defects.
Clinical features — The clinical presentation of TEF depends upon the presence or absence of EA. In cases with EA (95 percent), polyhydramnios occurs in approximately two-thirds of pregnancies. However, many cases are not detected prenatally. Additional clinical features relate to the presence of the VACTERL association (a constellation of malformations including vertebral, anal, cardiac, TEF, renal, and limb defects).
Infants with EA become symptomatic immediately after birth, with excessive secretions that cause drooling, choking, respiratory distress, and the inability to feed. A fistula between the trachea and distal esophagus leads to gastric distension. Reflux of gastric contents through the TEF results in aspiration pneumonia and contributes to morbidity.
Patients with H-type TEFs may present early if the defect is large, with coughing and choking associated with feeding as the milk is aspirated through the fistula. However, smaller defects of this type may not be symptomatic in the newborn period. In one series, the delay in diagnosis ranged from 26 days to four years. These patients typically have a prolonged history of mild respiratory distress associated with feeding or recurrent episodes of pneumonia. On occasion, the diagnosis may be delayed for longer periods and even into adulthood.
Diagnosis — The diagnosis of EA can be made by attempting to pass a catheter into the stomach. In affected infants, the catheter cannot be passed farther than approximately 10 to 15 cm. This finding can be confirmed with an anterior-posterior chest radiograph that demonstrates the catheter curled in the upper esophageal pouch. A distal TEF may be suspected based on chest radiographs; both anterior-posterior and lateral views will reveal a gas-filled gastrointestinal tract. When the diagnosis is uncertain or a proximal TEF is suspected, a small amount of water-soluble contrast material placed in the esophageal pouch under fluoroscopic guidance will confirm the presence of EA. Barium should not be used as the contrast agent, because it causes pneumonitis if aspirated into the lungs. The contrast material must be removed immediately to avoid regurgitation and aspiration.
Diagnosis of H-type (ie, without EA) TEF is more challenging. Demonstration of the fistula should be attempted with an upper gastrointestinal series using thickened water-soluble contrast material. The traditional method requires a pull-back technique in which the distal esophagus is filled first and then the catheter is pulled in a cephalad direction. Subsequent studies have suggested equal or better diagnostic sensitivity with contrast swallow radiography. However, the fistulous tract may be missed in these studies. In that case, esophageal endoscopy and bronchoscopy may be used to detect the TEF. Demonstration of the fistula may be accomplished by the appearance in the esophagus of a small amount of methylene blue that is injected into the trachea. Improved computed tomography (CT) technology has led to increasing use of three-dimensional CT scanning, with airway reconstruction as an additional modality for the diagnosis of TEF. However, CT scanning is not necessary if the TEF has been adequately identified on contrast radiography.
Because TEF/EA is often part of a constellation of other abnormalities (CHARGE syndrome or VACTERL association), evaluation for other anomalies is appropriate. Echocardiography and renal ultrasonography should be performed in all infants in whom TEF has been identified. Consideration may be given to additional evaluations (eg, contrast enema, limb radiographs) if clinically indicated.
Initial management — Treatment of TEF consists of surgical separation of the trachea and esophagus by ligation of the fistula. With H-type TEF, a cervical approach can be used in most cases. In cases with EA, primary anastomosis of the esophageal segments with simultaneous fistula ligation is preferred and typically is performed as soon as possible. Preoperatively, the esophageal remnant is evacuated by continuous suction to avoid pooling of secretions and soiling of the respiratory tract. Advances in the medical management of these infants combined with newer surgical techniques have improved outcomes. Primary repair may not be possible if the distance between esophageal segments is large. In that case, the first-line option is to delay the repair for two to nine months to allow for esophageal growth, which often permits primary repair. If this is not successful, alternatives include elongation of the esophagus, interposition of the jejunum or colon, and gastric transposition. Historically, surgical intervention (ligation and anastomosis) in the first few days of life has been associated with increased morbidity among preterm infants. For this reason, in very low birth weight infants (<1500 grams), a staged approach with early TEF separation and subsequent EA anastomosis has been advocated. This approach is associated with improved outcomes.
Postoperatively, feedings are reintroduced after surgical healing and then increased as tolerated. Gastrostomy is rarely needed if a primary anastomosis is successful.
Patients with TEF often have complicated gastroesophageal reflux (GER) because of impaired esophageal peristalsis. As a result, an expert panel has recommended that infants with repaired TEF be routinely treated with a proton pump inhibitor (PPI) for at least one year after TEF repair and longer for those with evidence of ongoing GER. This strategy is based upon expert opinion with limited evidence. Infants with TEF are at increased risk for feeding difficulties and may benefit from consultation with a feeding specialist to avoid a chronic feeding disorder.
Prognosis — The prognosis for H-type TEF (ie, without EA) is generally good. Outcomes of infants with EA and TEF are more guarded and depend upon associated abnormalities. In a report of 134 patients with EA or EA and TEF managed at a single institution between 1980 through 1997, 87 percent survived. Most of the early deaths (within 30 days after birth) in this series occurred in infants with cardiac and chromosomal anomalies. Mortality rates for EA and TEF were greater for infants with associated cardiac disease (42 versus 12 percent without). Low birth weight was not a significant risk factor. The gap length of the EA (the distance between the two esophageal pouches) also may determine the prognosis.
Complications after EA and TEF repair in a series of 227 cases included anastomotic leak (16 percent), esophageal stricture (35 percent), and recurrent fistulae (3 percent); esophageal stricture has been successfully managed with endoscopic balloon dilation. Residual tracheal diverticulum without complete fistula formation has also been reported. Tracheomalacia occurred in 15 percent of cases; 40 percent of these required surgical repair. Disturbed peristalsis and delayed gastric emptying are common and contribute to GER and aspiration. However, early routine upper gastrointestinal series in the absence of clinical findings did not predict the development of postoperative problems.
Gastrointestinal motility disorders and respiratory function abnormalities are common after EA and TEF repair and warrant monitoring. In many cases, these problems persist on long-term follow-up. A systematic review of long-term outcomes in adulthood after EA repair during infancy reported the following pooled estimated prevalences:
●Dysphagia – 50 percent
●Gastroesophageal reflux disease (GERD) with esophagitis – 40 percent
●GERD without esophagitis – 57 percent
●Respiratory tract infections – 24 percent
●Asthma (clinician-diagnosed) – 22 percent
●Wheeze – 35 percent
●Persistent cough – 15 percent
●Barrett esophagus – 6 percent
●Esophageal cancer (squamous cell) – 1 percent
The prevalence of Barrett esophagus in adulthood was four times that of the general population and is a recognized risk factor for esophageal cancer. The risk for esophageal cancer is approximately 50 times that in the general population over 40 years of age, and similar risk was found in a separate case series. The risk for Barrett esophagus is higher among patients with reflux symptoms and male patients over 35 years of age, but this lesion occasionally has been found in patients without these risk factors. The optimal approach to screening and surveillance has not been established.
Long-term management — Both pulmonary and gastrointestinal abnormalities may persist throughout adulthood. Long-term management focuses on early detection and aggressive management of these common complications, ideally guided by a multidisciplinary team with surgical specialists as well as specialists in pediatric pulmonology, gastroenterology, and otolaryngology. Specific recommendations have been made by an expert panel, primarily based on expert opinion with limited clinical evidence:
●All children and adults should be routinely monitored for symptoms of GERD, dysphagia, and aspiration. These pathologies have similar or overlapping symptoms, especially in young children.
●All patients should undergo at least three surveillance endoscopies during childhood to detect early esophagitis. Routine endoscopic surveillance should be continued in adulthood every 5 to 10 years.
●Patients with symptoms of GERD or dysphagia should be evaluated with an esophageal contrast study and endoscopy. Occasionally, patients may also have respiratory symptoms if the esophageal obstruction compresses the trachea. Esophagitis should be managed aggressively with PPIs and esophageal strictures with dilation and PPIs. Asymptomatic patients do not require routine screening or dilation for strictures.
●Patients with respiratory symptoms should be carefully evaluated for anatomic abnormalities, including anastomotic stricture, laryngeal cleft, vocal cord paralysis, congenital esophageal stenosis, recurrent fistula, or congenital vascular malformations. Acid suppression alone probably does not improve respiratory symptoms and may actually predispose to respiratory infection.
●Fundoplication has a limited role in patients with TEF because their underlying esophageal dysmotility predisposes to post-fundoplication complications (eg, esophageal stasis and possibly to aspiration). However, fundoplication may be considered in selected patients, such as those with poorly controlled GERD despite maximal PPI therapy, long-term dependency on transpyloric feeding, or cyanotic spells due to GERD. Eosinophilic esophagitis should be excluded before proceeding to fundoplication.
All patients and families should be educated about these health risks and the importance of clinical and endoscopic surveillance, and these issues should be incorporated into well-organized transition to care by an adult gastroenterologist.
From Up To Date: Congenital anomalies of the intrathoracic airways and tracheoesophageal fistula