Intestinal atresia (from Greek meaning “non-perforated”) denotes a complete obliteration of the intestinal lumen and is commonly used to describe congenital conditions. Intestinal webs, which are thin intraluminal diaphragms that are lined with mucosa, are a form of atresia. Webs may be stretched out to give the appearance of a windsock. Stenosis is a narrowing of the intestinal lumen. Intestinal atresias and webs may be subclassified based on anatomical location. They may occur in the esophagus, stomach, duodenum, jejunum, ileum, colon, or anus.1

The underlying pathophysiology in all children with atresias and webs is obstruction to the flow of intestinal contents. The mode of presentation can be acute, with obvious features of regurgitation, vomiting, abdominal pain, and abdominal distension. Neglected cases may present with systemic decompensation and shock. Presentation can also be subtle especially when the obstruction is incomplete as may be seen with intestinal stenosis. Patients may have chronic intermittent abdominal pain, intermittent vomiting, and distension. They may have long-standing nutritional compromise or weight loss; however, some children will present with normal weight as they adjust their diet to minimize symptoms. Early diagnosis can be prompted by careful evaluation of clinical findings as well as antenatal history, and subsequent accurate interpretation of radiographic findings. Initial care should include appropriate resuscitation and identification of associated anomalies in preparation of the child for definitive therapy. It is critical that early in the course of the work-up, conditions that threaten the child’s life or lead to loss of intestinal length, such as heart disease, malrotation, or intestinal perforation, are identified and treated. Secondary investigation could then be performed safely. Treatment of intestinal atresia is surgical. The goal of the surgical treatment is relief of intestinal obstruction while preserving intestinal length and function. Prior to the advent of safe pediatric anesthesia and intensive care, as many as 50% of the children did not survive treatment.1–3 Mortality declined sharply starting in the 1950s, and currently acute mortality is less than 4–8%. Most patients can expect a good quality of life after surgical correction but a significant burden of disease is borne by those with inadequate intestinal length.

Congenital Esophageal Atresia

Definitions and Epidemiology

Esophageal atresia (EA) is a congenital malformation in which the esophagus is interrupted. Congenital EA occurs approximately in 1 in 3000 live births.4 The embryological basis for esophageal anomalies is still poorly understood. The esophagus and trachea separate 28–37 days following fertilization. Failure of the tracheal bud to separate from the primordial foregut is thought to result in EA. EA is often associated with other congenital anomalies, most commonly cardiac, and can be a component of vertebral, anorectal, cardiac, tracheoesophageal, renal, and limb anomalies (VACTERL) complex of anomalies (Table 15–1).

The primary finding in EA is an interrupted esophagus that ends in a blind pouch proximally, usually at the level of the thoracic outlet.5 In addition, a tracheoesophageal fistula (TEF) is associated with EA in greater than 85% of babies (Figure 15–1). In these children, the distal esophagus has a fistulous connection to the posterior trachea at or above the carina. Air entering the airway can pass through the fistula into the intestinal tract. Gastric contents can also reflux into the trachea through the fistula. A pure atresia with a short distal esophagus without communication to the trachea accounts for 5–7% of esophageal anomalies. Other subtypes including the H-type, where the esophagus has normal patency but communicates to the trachea via a TEF, and the even more rare variant with a fistula between the proximal pouch and the trachea are occasionally seen.

Clinical Presentation

The diagnosis of EA may be suspected antenatally based on the presence of polyhydramnios and a small stomach, but often the diagnosis is not made until after the child is born. Newborn children often sputter and spit up or may experience cyanotic episodes due to aspiration of feeds. Babies characteristically drool because they are unable to swallow saliva. Since the esophagus is interrupted, a naso- or orogastric tube cannot be passed (Table 15–2).

The clinical course of babies with EA can be complicated by aspiration, pneumonia, and respiratory compromise. Aspiration pneumonitis can occur due to reflux of gastric contents through the TEF as well as from aspiration of excessive saliva from the upper pouch. Aspiration can lead to respiratory failure or pneumonia, necessitating mechanical ventilation. Specific complications can ensue in ventilated patients especially if the fistula is large or if high pressures are required for ventilation. Passage of air through the fistula can cause gastric and intestinal dilatation with diaphragmatic splinting, making ventilation inefficient. In cases where there is a distal intestinal obstruction (such as associated duodenal atresia), the stomach can distend enormously, leading to respiratory compromise and even gastric rupture, which presents with a very large pneumoperitoneum and acute clinical deterioration (Figure 15–2). Such patients will sometimes require life-saving emergent fistula interruption by either placement of a balloon catheter or surgery.

Differential Diagnosis

The differential for EA is short. Conditions to consider include laryngo-tracheoesophageal cleft, tracheal agenesis, esophageal stenosis, gastroesophageal reflux disease, and pharyngeal perforation. This latter iatrogenic condition typically occurs in premature very-low-birth-weight babies. The naso- or orogastric tube fails to pass because it perforates the pharynx and enters the mediastinum. The arrested passage of a tube in the mediastinum can give a false impression of EA.

Diagnosis

There are usually few findings on the physical exam that suggest the diagnosis of EA. However, the diagnosis needs to be strongly suspected if a naso- or orogastric tube cannot be advanced into the stomach in a newborn baby that experiences feeding difficulties, cyanosis with feeds, or excessive salivation. Chest auscultation may reveal signs of lobar atelectasis (especially on the right), or pneumonia. Few radiological studies are required to make the diagnosis of EA. A chest X-ray is usually sufficient, as it demonstrates the proximal esophagus filled with air contrasting against the soft tissues of the mediastinum, and the naso/orogastric tube stopping or curling in the upper esophageal pouch (Figure 15–3a). A chest X-ray is also valuable to assess the lung fields. An abdominal X-ray is mandatory to determine if there is air in the gastrointestinal tract, which suggests the presence of distal TEF. If the abdomen is gasless, a pure EA is likely (Figure 15–3b); if there is air in the stomach and duodenum but not beyond, duodenal atresia is likely to be present. Chest and abdominal films are also required as they reveal associated conditions such as vertebral and rib anomalies, which strongly support the diagnosis. In rare cases, if the diagnosis is in doubt, a contrast esophagram may be performed by an experienced practitioner (Figure 15–3c). As aspiration with severe pneumonitis is a significant risk, non-ionic contrast should be used judiciously. An alternative approach that can confirm the diagnosis and delineate the anatomy is bronchoscopy and esophagoscopy in the operating room.

The presence of other anomalies should be meticulously sought. Cardiac, renal, and chromosomal abnormalities have a great impact on the infant’s perioperative course, morbidity, and mortality. An echocardiogram is usually done to evaluate cardiac anomalies and to determine the location of the aortic arch. The patency of the anus should be established and duodenal atresia excluded and other features of the VACTERL association should be sought. To that end, ultrasound studies of the abdomen to evaluate renal anomalies, of the spine to rule out tethered cord, and of the head to assess for intracranial pathology are routinely performed. The studies need to be performed expeditiously but do not need to be performed emergently as long as the child is stable.

Treatment

The first step in treatment is resuscitation and cardiopulmonary support. To reduce the risk of aspiration of oral secretions, a Replogle-style orogastric suction tube (a double-lumen vented tube with suction openings near the tip) should be placed in the proximal esophageal pouch and connected to suction in order to evacuate saliva. The head of the bed needs to be elevated to minimize gastroesophageal reflux. Spontaneous ventilation without an endotracheal tube is preferred. If mechanical ventilation or airway control is required, strategies that minimize ventilator pressures should be used. Once the work-up is complete, surgical repair should be performed. The goal of surgery is two-fold: to divide and ligate the TEF in order to avoid pulmonary compromise from aspiration and abdominal distention, and to reconstruct the esophagus. Most children with EA and TEF can undergo successful surgical repair of the esophagus in the first few days of life. Babies that develop clinically significant abdominal distention or aspirate oral secretions may require emergent surgical intervention. Unstable babies that have severe pulmonary compromise or cyanotic heart disease, and babies whose esophagus cannot be reconstructed may benefit from delayed esophageal repair. Such babies may require gastrostomy tube placement to decompress the stomach and to provide access for enteral feeds. Non-cyanotic heart disease usually can be treated after repair of EA and TEF.

Successful repair of the esophagus depends on the length of the gap between the proximal dilated esophageal pouch and the distal esophagus. In children with EA and TEF, the esophagus usually can be repaired primarily. Isolated or pure EAs may be associated with a very small stomach and very long gap between the proximal and the distal ends. Children with long-gap EA are usually managed by delayed repair performed usually at 2–3 months of age. Innovative methods of placing traction on the esophageal ends in order to encourage growth and allow for primary anastomosis have been reported; however, long-term success and general acceptance has been difficult to achieve. If primary anastomosis is not possible, esophageal reconnection by “pulling up” the stomach into the mediastinum may be achieved. Early esophageal reconstruction, in the first few months of life, even if it requires a gastric pull-up procedure, has been favored recently with the hope of avoiding feeding aversion.

Outcome

Mortality following esophageal repair depends on birth weight, and the presence of major congenital heart disease. Babies with major heart anomalies weighing less than 2000 g have approximately 40% survival rate (Table 15–3). Such high-risk babies may be considered for delayed esophageal repair. Repair of EA may be complicated by anastomotic leak, recurrent tracheoesophageal fistula, sepsis, and stenosis. Early complications may result from technical errors, long gap between the esophageal ends, tension at the anastomosis, and ischemia. Late stenosis may be the result of gastroesophageal reflux disease. Patients often complain of difficultly eating and food sticking in the esophagus. Anastomotic stenoses often respond to treatment that includes control of acid reflux and dilatations. Balloon dilatation under direct endoscopic or fluoroscopic control appears safest. Few babies may eventually require esophageal replacement using stomach, colon, or jejunum as a conduit. In addition to complications related to the esophageal surgery, children may suffer from airway compromise due to tracheomalacia.

Congenital Esophageal Stenosis

Presentation and Diagnosis

Embryologically, congenital esophageal stenosis is related to EA, and usually presents beyond the newborn period with difficulty swallowing solids and food sticking in the esophagus.5 Contrast studies demonstrate a short narrow segment in the mid or distal third of the esophagus. Computed tomography (CT) imaging usually demonstrates ectopic cartilaginous rings. The differential includes esophageal stenosis secondary to previous surgery, esophagitis resulting from gastroesophageal reflux disease, and eosinophilic esophagitis.

Treatment and Outcome

Congenital esophageal stenosis is treated with segmental esophageal resection and primary anastomosis. Resolution of symptoms is expected in most children.

Antral atresia and prepyloric web are rare congenital obstructions of the stomach, occurring in 1 in 20,000 live births.6 Patients present with feeding intolerance and non-bilious vomiting. Investigation demonstrates a single bubble sign on radiographs: an air-filled stomach with no air in the distal intestine. Gastric outlet obstruction may be diagnosed antenatally by ultrasound, in which case no further work-up is unnecessary. The treatment is surgical correction of the obstruction in the neonatal period and there are usually few long-term complications.

Junctional epidermolysis pyloric atresia syndrome is a specific rare entity transmitted in an autosomal recessive fashion and associated with a form of epidermolysis bullosa.6 Infants present with inability to feed due to gastric obstruction. Diagnosis is aided by genetic work-up. Surgical repair of the pyloric atresia can successfully relieve the obstruction; however, many patients continue to feed poorly, and suffer from malabsorption, failure to thrive, and sepsis eventually resulting in death in the first year of life. Because of poor prognosis, palliative care is usually offered to such children.

Duodenal Atresia and Stenosis

Definitions and Epidemiology

Congenital duodenal atresia and stenosis are the most common causes of duodenal obstruction in newborns and children. Duodenal atresia occurs in approximately 1 in 5000 live births.1,3,7 Unlike jejunal or ileal atresias, duodenal atresias are commonly associated with other anomalies, including cardiac malformations, malrotation, jejunoileal atresia, vertebral anomalies, TEF, renal anomalies, anorectal malformation, and VACTERL (Table 15–4). Up to 30% of babies have Down’s syndrome (trisomy 21) or other serious chromosomal anomalies.