Esophageal atresia (EA) is a congenital defect in which the esophagus is partially (unusually narrow) or totally undeveloped i.e., the upper esophagus does not connect with the lower esophagus and stomach. This causes feeding problems of the infant that needs immediate medical intervention.
Polyhydramnios has been reported in 33% of mothers with Type C (EA/TEF) fetus and 100% of mothers with Type A (EA wihtout fistula) fetus. Clinical manifestations, such as abundant oral secretions, cyanosis, coughing, gagging, and vomiting, occur early in infants with congenital forms of EA/TEF. While breast-feeding, the infant may appear to choke and exhibit difficulty with maintaining an airway, which results in significant respiratory distress.
Physical examination may reveal concurrent anomalies such as vertebral defects, anorectal malformations, cardiovascular defects, tracheoesophageal defects, renal anomalies, and limb deformities (VACTERL)  . These must be dealt with promptly to prevent complications. The VACTERL syndrome occurs in 25% of EA patients, usually when three or more of the associated abnormalities are present as well. Anomalies associated with this syndrome include:
Other co-existing conditions include CHARGE syndrome. EA/TEF is not an important criteria for the diagnosis of CHARGE syndrome, which includes the following defects, i.e. coloboma of the eye, genital hypoplasia, heart anomaly, retardation of mental and somatic development, atresia of the choanae and ear abnormalities and/or hearing loss. However, EA/TEF is present in about 15-20% of neonates with CHARGE syndrome.
The sensitivity of prenatal ultrasonography is nearly 40%. Ultrasound imaging of the fetus in the uterus will reveal the occurrence of polyhydramnios, a small abdomen, absence of fluid-filled stomach, lower fetal weight, a distended esophageal pouch, and VACTERL anomalies.
MRI is likewise used to establish the diagnosis of EA/TEF. In the newborn, EA is confirmed when:
In the presence of clinical signs of cardiovascular disease, echocardiography is indicated in the diagnosis of EA in infants . EEG will show a right-sided aortic arch in the case of EA.
Radiography of the limbs is recommended for abnormal extremities. A spinal ultrasound examination can detect an associated tethered cord when done at less than 1 month of age.
The foremost consideration when the infant is feeding is to reduce the risk of aspiration pneumonia. This entails withdrawing oral feeds, installing a suction catheter to drain the secretions, and elevating the head side of the bed to prevent reflux. Meanwhile, intravenous fluids, glucose, and oxygen should be provided.
Remedial surgical procedure consists of closure of the TEF and anastomosis of the esophageal portions. Surgical treatment may be delayed in neonates with pneumonia, low birth weight, or other congenital defects. Parenteral nutrition should be facilitated with placement of a gastrostomy tube and upper pouch suctioning. A 10F Replogle double-lumen tube is installed through the mouth or nose to reach into the upper pouch in order to provide continual suction of collected secretions from the proximal portion of the atretic esophagus. The infant is placed in a 45° sitting position. Prophylaxis with broad-spectrum antibiotics such as gentamicin and ampicillin may be needed. Each case merits an individualized treatment plan at the discretion of the physician and to suit differences in pathologic anatomy of the patient .
Gastrostomy may be prescribed in the absence of distal TEF. Laparotomy may be required in case of a small stomach. Care must be taken to place the gastrostomy tube in proximity to the lesser curve so as to avoid damaging the greater curve of the stomach. Ligation is indicated for cases with a distal fistula that causes lung soiling. A right-sided thoracotomy is done through an extrapleural approach. The fistula may either be ligated or clipped.
The Foker technique employs serial dynamic lengthening of the infant's own esophagus instead of using extraneous materials   . The technique involves 2 thoracotomies. In the first instance, anchoring sutures are secured at the two ends of the atretic esophagus and brought back out diagonally to the chest wall. Over a period of a few days to weeks, the two ends are brought gradually closer through a series of daily lengthenings using traction over the exposed sutures. The gap closure is assessed and monitored radiologically with placement of radio-opaque markers at the atretic ends of the esophagus. A second thoracotomy is done to bring about a tension-free anastomosis.
Prognosis is at its worst with fetus in whom EA was not detected prenatally compared to those diagnosed prenatally. Mortality is 21% and 75%, respectively in these two groups . Infants who are treated early for EA and survive, succumb to morbidities related to the associated anomalies and their complications. Majority of the children who undergo successful repair of EA lead a relatively healthy life.
Early complications that may occur include an anastomotic leak , anastomotic stricture, and recurrent tracheoesophageal fistula (TEF). An anastomotic leak may occur within 3-4 days following surgery. This has been noted in about 15% of the cases. Pain, distress, and signs of sepsis may be present.
Recurring TEF may commence within a few days or after several weeks, as reported in 3-14% of cases. The initial signs are pneumonia, cough and dyspnea while feeding. Anastomotic stricture has been detected in approximately 50% of cases, severity depending on the extent of stricture. Complications may include esophageal dysmotility, gastroesophageal reflux, and tracheomalacia, some of which may appear early.
The current assumption is that EA is not genetically determined  and embryopathologic studies (possibly of human teratogens) have not been conclusive. Meanwhile, chromosome aberrations were found in 6-10% of EA/TEF patients. Observations of an association between EA and trisomy 13, 18, and 21, and an estimated 2% risk of recurrence in a family with an affected sibling suggest genetic involvement. Exposure to certain infections, drugs, and maternal diabetes mellitus are suspected potential risk factors for the development of EA/TEF during pregnancy.
The overall incidence of EA is 1 in 3000-4500 births. The problem does not end with EA per se. Epidemiologic studies indicate that EA/TEF in approximately 60% of patients is accompanied by concomitant anomalies in varying combinations - cardiovascular (35%), gastrointestinal (20%) and genitourinary (20%).
EA is classified into various types by anatomic criteria. One classification system was described by Gross , according to which the variants and estimated incidence are as follow:
With Type A, the fetus cannot swallow amniotic fluid, particularly in the absence of TEF . In Type C, a limited amount of amniotic fluid may pass through the fistula into the gut. This anomaly results in the accumulation of excess amniotic fluid (polyhydramnios) in the uterus in turn, triggering preterm labor. The fetus with EA is small for its gestational age.
The infant with EA cannot swallow saliva and drools a lot. As it attempts to feed, milk and saliva may seep into the trachea and cause aspiration pneumonia. In Type C neonates the lungs are exposed to gastric secretions. Air from the trachea may pass down through the distal fistula when the infant cries, strains, or breathes .
Normal development of the trachea is also impaired in EA. The membranous portion of the trachea, the pars membranacea, becomes dilated and assumes a cross-sectional D shape to the trachea, rather than the typical C shape. These alterations can result in secondary anteroposterior structural weakening of the trachea, a condition called tracheomalacia, leading to partial collapse of the intrathoracic portion of the trachea, with the infant emitting a sonorous cough, with forceful exhalation. It is difficult to clear off the secretions that accumulate and predispose to pneumonia. The trachea may partially collapse while feeding, after repair, or during gastroesophageal reflux episodes, leading to hypoxia and apnea.
Esophageal atresia (EA) is a developmental abnormality acquired in the uterus in which the esophagus is either underdeveloped (i.e., constricted) or totally absent so that there is no conduit for food to the stomach. In any case, the condition has to be treated as a medical emergency to enable the infant to survive.
In some cases, the lower esophagus is found connected to the trachea via an anomalous structure called tracheoesphageal fistula (TEF). EA/TEF is classified as isolated (occurring without other congenital defects), syndromic (associated with a specific genetically determined birth defect) or non-isolated (with non-specific genetic birth defect). Diagnosis of EA/TEF is based on clinical evaluation with or without genetic confirmation. EA can be detected in fetus and newborn via imaging studies. The precise etiology of EA remains unknown; however, chromosomal aberrations found in some patients point to a possible involvement of genetic factors.
EA interferes with fetal capacity to swallow amniotic fluid and with the neonate, to feed (tantamount to starvation). EA infants are debilitated and are predisposed to a shorter life span. Initially, the priority concern of postnatal intervention is preventing aspiration pneumonia and other potentially fatal complications. Treatment's aim is basically to correct or remedy the defect through surgery.
Esophageal atresia (EA) is a congenital defect in newborns in whom the esophagus is either underdeveloped (too narrow to function normally) or totally lacking in connection to the stomach. In any case, the infant is unable to feed properly, that is tantamount to starvation, and is at risk for aspiration pneumonia when food and saliva are diverted to the trachea. In extreme cases, the lower part of the esophagus attaches to the trachea forming an anomalous structure called tracheoesophageal fistula (TEF). The trachea may weaken and collapse causing breathing difficulties and deprivation of oxygen in the brain.These abnormalities are presumed to occur during the fourth week of gestation when the digestive tract is developing. EA has been detected in fetus in the uterus as well as in newborns by imaging techniques. The EA fetus is not able to swallow sufficient quantity of amniotic fluid resulting in excessive accumulation of this (polyhydramnios) and triggering preterm delivery. The precise cause of the disorder is not fully understood although genetic and extraneous factors may be involved.
EA may occur with or without TEF. However, other congenital anomalies may accompany EA, leading to complications and fatal sequelae. Hence, EA should be treated as a medical emergency provided that the neonate's status is stable enough to withstand surgery. One method entails installation of a gastrostomy tube proximal to the stomach. Foker technique involves gradual stretching or lengthening of the infant's own esophagus.
The corrective surgical procedure should be done as early as possible. Conditions such as the existence of other birth defects, prematurity, and aspiration pneumonia may cause the delay in surgery. The treatment involves surgery to fuse the two ends of the infant's esophagus to each other. Surgery to correct EA is generally successful, with survival rates of almost 100% in otherwise healthy infants.
Prevention should focus on minimizing the complications from co-existing anomalous conditions and risks from surgical intervention.