Index
This condition is often associated with other congenital abnormalities, most commonly heart abnormalities such as ventricular septal defect, patent ductus arteriosus, or tetralogy of Fallot.
Esophageal atresia, with or without tracheoesophageal fistula, is a fairly common congenital disorder that family physicians should consider in the differential diagnosis of a neonate who develops feeding difficulties and respiratory distress in the first days of life.
Timely recognition, appropriate clinical management to avoid aspiration, and rapid referral to an appropriate tertiary care facility have resulted in significant improvement in morbidity and mortality rates in these children over the past 50 years.
Esophageal atresia with tracheoesophageal fistula occurs in one of 3,000 to 5,000 births. Family physicians caring for newborns should be aware of both the clinical presentation and treatment of newborns with this condition.
Before the first successful repair was made in 1939, this condition was fatal. Over the past 50 years, refinements in neonatal surgical technique, preoperative support, anesthesia, and neonatal intensive therapy have improved outcome.
It is also recognized that rapid diagnosis with appropriate clinical management and expedited referral to a tertiary care facility have had a dramatic impact on improving survival for these children.
Current estimates suggest that in the absence of other serious abnormalities, survival rates in these children are approaching 100 percent.
Illustrative case
It was administered to a neonate weighing 3,315 g (7 lb, 5 oz) after a 41-week, 5-day gestation by primary non-transverse cesarean section without complications.
This was the first pregnancy for the 26-year-old mother. Cesarean section was performed secondary to stopping dilation at 7 cm. The maternal history was notable for a positive Chlamydia screening result at 10 weeks’ gestation and mild anemia that was treated with iron, ascorbic acid, and prenatal vitamins.
The infection was treated with azithromycin, and the patient subsequently tested negative for Chlamydia. The rest of the prenatal screening laboratory tests were unremarkable. The total weight gain for the pregnancy was 23.6 kg (52 lb).
The height of the fundus was consistent with the dates throughout the pregnancy.
A routine post-test routine test one week before delivery was reactive. An abdominal ultrasonogram obtained at the same time revealed an amniotic fluid index of 21.5. At delivery, the baby was vigorous and had Apgar scores of 9 at 1 minute and 9 at 5 minutes.
The initial physical examination at one hour of life was notable only for a slight increase in white oral secretions, which cleared with suction.
The patient passed a meconium stool in the first six hours of life and reportedly tolerated her first feeding without difficulty.
At approximately 10 hours of age, the baby was observed to have some crackles on routine auscultation. The respiratory rate was normal.
The baby’s oral secretions also increased. Esophageal atresia was suspected and an attempt was made to pass a nasogastric tube. A nasogastric aspiration chest radiograph was obtained which revealed a copious white mucus-like aspirate.
A diagnosis of esophageal atresia with a probable tracheoesophageal fistula was made and the child was transferred to a tertiary care center with the capacity for pediatric surgery.
The patient underwent surgery on the second day of life. Bronchoscopy confirmed the tracheoesophageal fistula and a primary surgical repair was performed.
Causes
The esophagus and trachea are derived from the primitive foregut. During the fourth and fifth weeks of embryonic development, the trachea forms as a ventral diverticulum of the primitive pharynx (the caudal part of the foregut).
A tracheoesophageal septum develops at the site where the longitudinal tracheoesophageal folds fuse. This septum divides the foregut into a ventral portion, the laryngotracheal tube, and a dorsal portion (the esophagus).
Esophageal atresia occurs if the tracheoesophageal septum deviates posteriorly. This deviation causes incomplete separation of the esophagus from the laryngotracheal tube and results in a concurrent tracheoesophageal fistula.
Esophageal atresia as an isolated congenital anomaly can occur, rarely. In these cases, atresia is attributable to failure of esophageal recanalization during the eighth week of development and is not associated with tracheoesophageal fistula.
A recent experimental animal model, in which prenatal exposure to adriamycin leads to esophageal atresia and tracheoesophageal fistula, may increase our understanding of the embryogenesis of these malformations.
Symptoms
Esophageal atresia is characterized by incomplete formation of the esophagus. It is often associated with a fistula between the trachea and the esophagus.
Many anatomical variations of esophageal atresia with or without fistula have been described providing an overview of the incidence of these variations in multiple surgical centers around the world.
The most common variant of this abnormality is a blind esophageal pouch with a fistula between the trachea and the distal esophagus, which is estimated to occur 84 percent of the time. The fistula often enters the trachea near the carina.
The proximal esophageal bursa is often hypertrophied and dilated due to efforts by the fetus to swallow amniotic fluid.
The muscle bag can also compress the trachea, and this compression has been implicated in the development of tracheomalacia that is sometimes reported in these babies.
The second most common abnormality is pure atresia without a tracheoesophageal fistula. This condition is usually associated with an underdeveloped distal esophageal remnant, making surgical repair more cumbersome.
The third most common variation is type H fistula, which is a tracheoesophageal fistula without esophageal atresia. This aberration is more difficult to diagnose clinically. If the fistula is long and oblique, symptoms may be minimal and the condition may not be identified for many years.
Associated defects
Associated birth defects are discovered in about half of children with esophageal atresia.
Other midline defects are the most common abnormalities. Most babies have more than one malformation. Heart abnormalities are found in about a quarter of these babies and account for about a third of all identified abnormalities.
Ventricular septal defect, patent ductus arteriosus, and tetralogy of Fallot are the most common heart defects.
More complex cardiac malformations are often associated with multiple other anatomical defects and have been associated with a worse outcome.
Gastrointestinal abnormalities, including imperforate anus, duodenal atresia, and malrotation, constitute a quarter of the identified defects and occur in approximately 16 percent of children with esophageal atresia.
Musculoskeletal defects are common and include vertebral body abnormalities and defects of the ribs and limbs.
Urinary tract malformations such as ureteral abnormalities, hypospadias, horseshoe kidney, and renal agenesis can also occur.
About 10 percent of patients with esophageal atresia have an abnormality of the urinary tract or musculoskeletal system. Up to 10 percent of babies with esophageal atresia have VATER syndrome.
Isolated esophageal atresia is associated with a higher incidence of other malformations than esophageal atresia with tracheoesophageal fistula. Type H tracheoesophageal fistula has been associated with other abnormalities less frequently.
Clinical presentation and diagnosis
The first sign of esophageal atresia in the fetus may be polyhydramnios in the mother. Polyhydramnios, however, has a broad differential diagnosis, including intestinal atresia, hydrops fetalis, neural tube defects, diaphragmatic hernia, and intrathoracic lesions.
The inability to identify the fetal stomach bubble on a prenatal ultrasound in a mother with polyhydramnios makes the diagnosis of esophageal atresia more likely. Prematurity has also been associated with esophageal atresia.
Clinically, the diagnosis of esophageal atresia sometimes requires a high degree of suspicion. Classically, the newborn with esophageal atresia presents with abundant, fine, white, frothy mucus bubbles in the mouth and sometimes in the nose.
These secretions may disappear with aggressive suction, but eventually they return. The baby may have noisy breaths and episodes of coughing, choking, and cyanosis.
These episodes can be exaggerated during feeding. If there is a fistula between the esophagus and the trachea, abdominal distention develops as air collects in the stomach.
The abdomen will be scaphoid if there is no fistula. Other abnormalities, such as imperforate anus, skeletal abnormalities, or heart conditions, may be apparent on physical examination, but physical examination may not be relevant.
If esophageal atresia is suspected, an 8 French (premature infant) or 10 French (term infant) nasogastric or feeding tube should be passed through the nose into the stomach.
In patients with atresia, the tube usually stops at 10 to 12 cm. The normal distance to a baby’s gastric cardia is approximately 17 cm.
If a soft, flexible tube is used, it can curve into the upper pouch and give the doctor the false feeling that it has passed into the stomach.
In cases of suspected esophageal atresia, chest radiographs (posteroanterior and lateral views) should be obtained to confirm the position of the tube. The x-ray should include the entire abdomen.
In patients with esophageal atresia, air in the stomach confirms the presence of a distal fistula, and the presence of intestinal gas rules out duodenal atresia.
The chest radiograph provides information on the cardiac silhouette, the location of the aortic arch, and the presence of vertebral and rib abnormalities, as well as the presence of pulmonary infiltrates.
Contrast studies are rarely necessary to confirm the diagnosis. Such studies increase the risk of aspiration pneumonitis and reactive pulmonary edema, and generally add little to simple film radiographs.
Management and treatment
Once the diagnosis of esophageal atresia is established, preparations should be made for surgical correction. Measures must be taken to reduce the risk of aspiration.
The oral pharynx should be cleared and an 8 French suction tube should be placed to allow continuous aspiration from the upper pouch. The baby’s head should be elevated.
Intravenous fluids (10 percent dextrose in water) should be started. Oxygen therapy is used as needed to maintain normal oxygen saturation. In infants with respiratory failure, endotracheal intubation should be performed.
Bag ventilation is not appropriate as it can cause acute gastric distention requiring emergency care.
If a lung infection or sepsis is suspected, broad-spectrum antibiotics (such as ampicillin plus gentamicin) should be given.
Some sources, however, recommend starting intravenous antibiotics empirically because of the increased risk of aspiration. The baby must also be transferred to a tertiary care facility with a neonatal intensive care unit.
Before surgical correction, the baby must be thoroughly evaluated for other congenital abnormalities.
Chest radiographs should be carefully evaluated for skeletal abnormalities, cardiovascular malformations, pneumonia, and a right aortic arch.
A series of abdominal radiographs will aid in the evaluation of skeletal abnormalities, intestinal obstruction, and malrotation.
Chest and abdominal radiographs are usually sufficient; An upper gastrointestinal series with contrast is generally not required for the evaluation of classic esophageal atresia. An echocardiogram and renal ultrasonogram may also be obtained.
Gastric decompression gastrostomy is reserved for use in patients with pneumonia or significant atelectasis, to prevent reflux of gastric contents through the fistula and into the trachea.
Healthy babies without lung complications or other major abnormalities can usually undergo primary repair in the first few days of life. Survival rates in this group of patients are close to 100 percent.
Surgical repair is delayed in babies with low birth weight, pneumonia, or other major abnormalities.
Low-birth-weight preterm infants and infants with major concomitant malformations are generally treated with parenteral nutrition, gastrostomy, and upper bag suction until they are appropriate surgical candidates.
The survival rate in this group is lower, but in the range of 80 to 95 percent. Heart abnormalities are often the cause of death in these more complicated cases.
Conclusions
Most neonates who undergo esophageal atresia and tracheoesophageal fistula repair have some degree of esophageal dysmotility.
The extent of repair determines the severity of subsequent complications. Stenoses at the site of the anastomosis are common and may require dilation later.
Serial esophagraphy should be performed at 2 months, 6 months, and 1 year of age, or whenever swallowing difficulties are present.
Recurrence of tracheoesophageal fistula has been reported; recurrence requires repeated surgical correction.
Recurrence is most common at the site of the primary anastomosis. Tissue damage to the poorly vascularized distal esophagus and surgical dissection performed very close to the trachea have been postulated as risk factors for fistula recurrence.
About half of patients with surgically corrected esophageal atresia develop gastroesophageal reflux disease (GERD).
Of those who develop GERD, about a half respond to routine medical therapy with prokinetic agents, histamine H 2 receptor blockers, or both, and a half require surgical intervention for correction.
Patients with prolonged GERD may develop changes in the esophageal mucosa such as esophagitis and gastric metaplasia (Barrett’s esophagus).
Adenocarcinoma of the esophagus resulting from gastric metaplasia was reported in a patient with esophageal atresia 20 years after neonatal anastomosis. Other cases of Barrett’s esophagus have been reported in patients with esophageal atresia.
For these reasons, some authors recommend long-term endoscopic follow-up in these patients.
