**2. Foregut disorders**

### **2.1 Esophageal atresia (EA) +/− tracheal fistula (TEF)**

#### *2.1.1 Embryology*

During the fourth week of gestation, the embryonic ventral foregut differentiates into the esophagus and trachea. Muscular and neurovascular development of the esophagus is complete by the end of ninth week of gestation. It is likely that esophageal malformations result from errors during this developmental time period.

#### *2.1.2 Clinical presentation*

EA/TEF is categorized into five types and clinical presentation varies depending on the type of pathology (**Figure 1**). Type A is the most common (90% cases) and consists of proximal EA with a distal TEF. Type B consists solely of proximal EA (no fistula) whereas type C only has a TEF (no atresia). Type D has both a proximal and distal TEF in the setting of atresia. Type E consists of proximal EA with TEF and a distal esophageal pouch. Types D and E are exceedingly rare.

The infant will exhibit drooling and attempts at feeding will result in coughing, choking and regurgitation. Since types B and E have a proximal obstruction without distal fistulization, the infant will have a scaphoid abdomen and gas will not be seen in the bowel distally on radiograph. Type C may present with recurrent aspiration pneumonia and may not be diagnosed until later in life.

#### *2.1.3 Diagnosis*

Prenatal ultrasound will demonstrate polyhydramnios and the blind end of the esophageal pouch may be visualized. After birth, unsuccessful attempt at passage

**87**

**Figure 1.**

esophageal pouch on radiography.

*Types of tracheoesophageal fistulae depicted as figures A-E.*

*2.1.4 Surgical management*

*Congenital Anomalies of the Gastrointestinal Tract DOI: http://dx.doi.org/10.5772/intechopen.92588*

of an oro- or nasogastric tube is diagnostic. The tip of the tube will be seen in the

Because of the VACTERL phenomenon (vertebral, anal, cardiac, tracheoesophageal, renal and limb deformities), renal and cardiac ultrasounds as well as plains films of the spine and limbs must be obtained to determine the presence of any other anomalies. An echocardiogram is particularly essential to ensure that the aortic arch is in its normal left-sided anatomic location because this impacts operative planning. Ventricular septal defect is the most common anomaly associated with EA/TEF.

Ideally, EA/TEF is corrected in a single procedure. Staged procedure, beginning with decompressive gastrostomy and fistula takedown, followed by esophageal

*Congenital Anomalies in Newborn Infants - Clinical and Etiopathological Perspectives*

Proximal to ligament of Treitz

Treitz

Distal to ligament of

**Anatomic relation Embryonic** 

**source**

Foregut Celiac

**Blood supply**

axis

Midgut SMA Jejunum

Hindgut IMA Distal 1/3 transverse

**Viscera**

Esophagus Stomach Duodenum Biliary ducts Liver Pancreas

Ileum Cecum Ascending colon Proximal 2/3 transverse colon

colon

Descending colon Sigmoid colon Rectum Anal canal

**86**

*2.1.3 Diagnosis*

**2. Foregut disorders**

Upper gastrointestinal

Lower gastrointestinal

tract

tract

*2.1.2 Clinical presentation*

*2.1.1 Embryology*

period.

**Table 1.**

**2.1 Esophageal atresia (EA) +/− tracheal fistula (TEF)**

*SMA: superior mesenteric artery; IMA: inferior mesenteric artery.*

*Embryologic derivates of the gastrointestinal tract.*

During the fourth week of gestation, the embryonic ventral foregut differentiates into the esophagus and trachea. Muscular and neurovascular development of the esophagus is complete by the end of ninth week of gestation. It is likely that esophageal malformations result from errors during this developmental time

EA/TEF is categorized into five types and clinical presentation varies depending on the type of pathology (**Figure 1**). Type A is the most common (90% cases) and consists of proximal EA with a distal TEF. Type B consists solely of proximal EA (no fistula) whereas type C only has a TEF (no atresia). Type D has both a proximal and distal TEF in the setting of atresia. Type E consists of proximal EA with TEF

The infant will exhibit drooling and attempts at feeding will result in coughing, choking and regurgitation. Since types B and E have a proximal obstruction without distal fistulization, the infant will have a scaphoid abdomen and gas will not be seen in the bowel distally on radiograph. Type C may present with recurrent aspiration

Prenatal ultrasound will demonstrate polyhydramnios and the blind end of the esophageal pouch may be visualized. After birth, unsuccessful attempt at passage

and a distal esophageal pouch. Types D and E are exceedingly rare.

pneumonia and may not be diagnosed until later in life.

**Figure 1.** *Types of tracheoesophageal fistulae depicted as figures A-E.*

of an oro- or nasogastric tube is diagnostic. The tip of the tube will be seen in the esophageal pouch on radiography.

Because of the VACTERL phenomenon (vertebral, anal, cardiac, tracheoesophageal, renal and limb deformities), renal and cardiac ultrasounds as well as plains films of the spine and limbs must be obtained to determine the presence of any other anomalies. An echocardiogram is particularly essential to ensure that the aortic arch is in its normal left-sided anatomic location because this impacts operative planning. Ventricular septal defect is the most common anomaly associated with EA/TEF.
