This patient has EA with a TEF. This occurs in 1 per 3,000 live births. The diagnosis is suspected prenatally by the presence of polyhydramnios, which is caused by the failure of the fetus to swallow amniotic fluid (secondary to EA). Polyhydramnios is a nonspecific prenatal finding that can also be caused by other defects, including duodenal atresia, anencephaly, congenital diaphragmatic hernia, and trisomy 18. Only 10% to 20% of fetuses with polyhydramnios will have other anomalies. There will be an absence of a fluid-filled stomach bubble on prenatal ultrasound. After birth, the neonate will have copious drooling. Attempts to feed the baby will result in coughing and cyanosis. An orogastric tube (OGT) will coil up in the upper esophageal pouch rather than pass into the stomach.

In this abnormality, there are two distinct problems: TEF and EA. In TEF, the trachea is connected to the esophagus through a fistula. This causes two problems. First, inhaled air can bypass the lungs through the fistula into the stomach and cause hypoventilation and gastric distension. If the lungs are especially noncompliant or the fistula is large, attempts to institute positive pressure ventilation (PPV) can lead to severely compromised ventilation due to gastric expansion or even rupture. Second, there is the continual risk of acidic stomach contents refluxing via the fistula back into the trachea causing aspiration pneumonitis. With EA, the esophagus is divided into a proximal and distal portion. The proximal portion ends in a blind pouch. Secretions from the hypopharynx pool here and cause drooling, coughing, and choking with feeds. The child is unable to feed orally.

The lung bud emerges from the embryonic foregut beginning at the fourth week of gestation. This bud gives rise to the trachea and lung tissue. There are two competing theories about how this happens. The first possibility is that the trachea simply grows rapidly out of the lung bud longitudinally. The second possibility, currently more favored, is a septation model in which the lateral sides of the foregut converge and pinch off two separate compartments that will become the trachea and esophagus; this septation process begins at the lung bud and proceeds cranially. Abnormal separation of the trachea from the foregut results in a residual fistula between the esophagus and trachea.

There are multiple genes involved in the separation of trachea from foregut (future esophagus) making it unlikely that a single genetic error accounts for all cases of TEF/EA. Rats exposed to Adriamycin during development develop TEF/EA of the type most common in humans as well as associated defects in the cardiovascular, skeletal, and gastrointestinal systems that are also seen in humans afflicted with TEF/EA. (These associated defects are described in the following sections.) Aberrant patterns of gene expression gradients from dorsal to ventral in the primitive foregut may be involved. Involved genes include sonic hedgehog
and FOX. Studying rats prenatally exposed to Adriamycin has led to a greater understanding of the process of compartmentalization of the foregut, which is incompletely understood in humans, and hopefully, this knowledge will shed light on the human variety of TEF/EA.

TEF/EA is believed to be multifactorial in etiology and sporadic. Rarely, it is associated with a specific genetic mutation or syndrome. These include trisomy 18, CHARGE syndrome, anophthalmia-esophageal-genital (AEG) syndrome, Feingold syndrome, and 16q24.1 deletion syndrome. Most of the cases, however, are non-familial. There is a 1% chance of recurrence in each sibling of someone with EA. EA is twice as common in twins.

There are five types of TEF according to the classic Gross’s classification (Fig. 36.1). Type A is pure EA with no involvement of the respiratory tree; this occurs in 8% of cases. Gross type B has EA and a fistula connecting the proximal esophageal pouch to the trachea; this occurs in less than 1%. The most common is type C, with EA and fistula linking the distal esophagus to the trachea; this occurs in 75% to 80% of cases. Rarely, type D occurs with two fistula connecting both proximal and distal esophagus to the trachea (2%). Type E, known as an H-type fistula, has no atresia. Instead, an intact esophagus has a linkage with trachea through a fistula, and it occurs in 4%.

Unfortunately, TEF often does not occur in isolation. Fifty percent of children with EA/TEF will have additional anomalies. Most often, they occur in the spectrum known as VACTERL (formerly known as VATER):

V = vertebral anomalies (10%)

A = anal canal defect (anal atresia) (14%)

C = cardiac malformations (29%), including ventricular septal defect, atrial septal defect, tetralogy of Fallot, right-sided arch, patent ductus arteriosus

TE = tracheoesophageal fistula

R = renal dysplasia

L = limb defect (radial aplasia)

A patient is considered to have VACTERL association with the presence of three or more of these lesions. Nearly one-third of TEF patients will have an additional VACTERL lesion, and an additional one-fifth will have two VACTERL problems. Other possible gastrointestinal problems include malrotation of the midgut and duodenal atresia. Renal problems can include malposition, hydronephrosis, and ureteral abnormalities.

Because the existence of these associated defects may alter the surgical or anesthetic plan, and because the TEF is an urgent but not emergent procedure, these other possible defects should be assessed prior to TEF repair.

The survival of TEF babies has improved over the years because of improvements in intensive care unit care, anesthesia, and surgical technique. Waterston developed the first classification of prognosis of TEF in 1962 as follows:

With improvements in neonatal care, the survival in Waterston groups A and B both approached 100%. So Spitz developed a new classification system in the 1990s to better stratify the surgical risk incorporating the realization that cardiac disease is a leading cause of mortality in the TEF group: