Etiology and Pathogenesis

The esophagus forms from a small ventral diverticulum of the embryonic foregut. This diverticulum separates into the esophagus and trachea around the fourth gestational week of fetal development. Anomalies can occur with abnormalities in any step in esophageal formation and development. One of the most common anomalies is TEF with or without atresia. This occurs when there is a disruption in the elongation and separation of the trachea from the esophagus. There are five types of TEF. The most common is type C in which there is atresia of the proximal esophagus with a fistula from the trachea to the distal esophagus (Figure 107-1). Other categories of TEF, in descending frequency, include isolated esophageal atresia without TEF, isolated TEF, esophageal atresia with proximal TEF, and esophageal atresia with proximal and distal TEF.

Figure 107-1 Tracheoesophageal fistula.

Congenital disorders of the esophagus are often associated with polyhydramnios as a result of the infant’s inability to swallow and absorb amniotic fluid and with prematurity. As many as 70% of children with esophageal abnormalities may have other congenital anomalies, including imperforate anus, vertebral anomalies, duodenal atresia, and annular pancreas. The VACTERL association is a combination of defects that are commonly found together: vertebral anomalies, anorectal atresia, cardiac anomalies, tracheoesophageal fistula, esophageal atresia, renal anomalies, and limb anomalies.

Clinical Presentation

A neonate with an esophageal congenital anomaly may present with episodes of respiratory distress worsened by feeding, regurgitation, a history of multiple episodes of pneumonia, or failure to thrive. Older children may present with dysphagia, regurgitation, halitosis, or respiratory symptoms. The severity of symptoms depends on the degree of esophageal compression or obstruction.

Evaluation and Management

Esophageal atresia or complete esophageal obstruction can be diagnosed by an inability to pass an orogastric or nasogastric tube into the stomach. TEF may be suggested on abdominal or chest radiograph; however, an isolated TEF (H-type) is best detected by esophagography with contrast. Barium swallow or endoscopy can be useful in diagnosing stenosis or incomplete obstruction from a web, ring, cyst, or diverticulum. Surgical correction is required to treat most congenital anomalies.

Etiology and Pathogenesis

Striated muscle makes up the upper esophageal sphincter along with the proximal one-third of the esophagus. Smooth muscle composes the remaining two-thirds. The lower esophageal sphincter (LES) is a physiologic sphincter. There is a rich nerve supply to the esophagus. Motility problems can arise from muscular disorders (polymyositis, dermatomyositis, muscular dystrophy, myasthenia gravis), neurologic disorders (stroke, multiple sclerosis, lead poisoning), systemic illness (lupus, scleroderma, sarcoidosis, thyroid disease, diabetes), or infection (tetanus, botulism, Trypanosoma cruzi infection).

Clinical Presentation

Evaluation

Achalasia

Chest radiograph may show widening of the mediastinum, loss of the gastric air bubble, or an esophageal air-fluid level. Barium swallow will show impaired contrast movement, abnormal peristalsis, and tapering of the distal esophagus known as the “bird’s beak” sign (Figure 107-2). Endoscopy should always be performed and often shows esophageal dilatation, erythema, and ulceration from stasis. Esophageal manometry assesses LES pressures and function in addition to esophageal contraction and motor pattern. In achalasia, manometry shows increased lower esophageal pressure, abnormal peristalsis, and elevated intraesophageal pressures.

Figure 107-2 Barium swallow findings seen with achalasia.

Management

Gastroesophageal Reflux

Gastroesophageal reflux (GER) is the intermittent movement of gastric contents into the esophagus. Infrequent GER is a normal process in all age groups. However, GER becomes pathologic when it causes clinical symptoms and is then labeled gastroesophageal reflux disease (GERD). GERD is the most common esophageal disorder in children of all ages. Emesis from GER occurs in 67% of all 4-month-old infants, and heartburn and epigastric pain from GERD occur in 1% to 8% of children. The incidence of GERD is increased in the population of children born prematurely and in those children with neurologic, pulmonary, and developmental disorders.

Etiology and Pathogenesis

Reflux of stomach contents into the esophagus is prevented by normal LES function and pressure in addition to normal transit of stomach contents into the intestine. GER occurs when the LES is not maintained at a pressure greater than 4 mm of Hg as a result of functional or mechanical defects or when peristalsis of the esophagus is inhibited.

Clinical Presentation

GER and GERD manifest differently in infants and children. In infants, the most common symptoms of GER are regurgitation and emesis. When associated with additional symptoms of irritability, arching, respiratory distress, refusal of food, or failure to thrive, this may be considered GERD. Infantile GER and GERD usually begin to improve after 6 months of age and typically disappear by 2 years of age. In children, GERD most commonly manifests as abdominal pain or substernal heartburn after meals. Children with GERD may also experience cough, dysphagia, odynophagia, or nocturnal worsening of their asthma. GERD may be associated with sore throat, otalgia, oral cavity disease, wheezing, and hoarseness in some children. In infants with chronic vomiting, one must consider food allergies, anatomic abnormality (pyloric stenosis, malrotation, volvulus, rings, webs, and stenosis), infection, metabolic disorder, rumination, toxic ingestion, or increased intracranial pressure in the differential diagnosis.

Evaluation

The diagnosis of GERD can most often be made clinically with a thorough medical and dietary history and a physical examination. Diagnostic studies should be reserved for those with atypical or concerning symptoms (Box 107-1), symptoms unresponsive to therapy, or symptoms suggestive of anatomic abnormality or tissue damage (hematemesis, bloody stool, anemia). An upper GI study with barium swallow is used to demonstrate anatomic anomalies. Scintigraphy (also known as milk scan or gastric emptying study) can show delayed gastric emptying. Upper endoscopy assesses for mucosal injury, inflammation, or dysplasia and may distinguish GERD from eosinophilic esophagitis. Esophageal pH monitoring is helpful to evaluate the frequency of acid reflux events, and multichannel intraluminal impedance studies can demonstrate non–acid reflux events. These measurements are also correlated with symptoms to help establish or refute the relationship between clinical symptoms and GERD.

Management

The goals of treatment of GERD are to reduce symptoms; heal esophageal mucosal injury; and prevent complications, including esophagitis, Barrett’s esophagus (metaplasia of the lower esophagus), and stricture formation (Figure 107-3). In infants with GER who are not bothered by emesis and who are growing appropriately, no therapy is necessary. Initial therapy for symptomatic infants with GERD is lifestyle modification, including thickening of feeds, giving smaller volume frequent feeds, frequent burping, and maintaining upright position for longer duration after feeds. Pharmacologic therapy for GERD includes antacids to buffer existing acid and H2 receptor antagonists (e.g., ranitidine) or proton pump inhibitors (PPIs; e.g., omeprazole) to decrease secretion of acid from parietal cells. PPIs have been shown to be the most effective pharmacologic therapy for GERD. However, they are not always necessary and may be associated with adverse effects such as an increased risk of community-acquired pneumonia and acute gastroenteritis. Prokinetic use (e.g., metoclopramide) has declined because of unfavorable side effect profiles. Surgical fundoplication, a procedure in which the fundus is wrapped around the distal esophagus, is an option for children who are unresponsive to pharmacologic treatment and for those who develop respiratory compromise or stricture. Side effects of fundoplication are not inconsequential and include bloating, dysphagia, dumping syndrome, hernia, small bowel obstruction, and recurrence requiring a second fundoplication.

Figure 107-3 Complications of gastroesophageal reflux disease.

Esophagitis

Esophagitis (inflammation of the squamous epithelium of the esophagus) has a variety of causes in the pediatric population. Esophagitis may occur from chemical irritation, infection, immunologic response, trauma, or systemic disease or may be idiopathic in nature.

Etiology and Pathogenesis

Clinical Presentation

Esophagitis can present with irritability, dysphagia, odynophagia, food regurgitation, epigastric pain, chest pain, and food impaction. Children with infectious esophagitis may have a concurrent fever, skin lesions, oral ulcers, or thrush.

Evaluation

Endoscopy with biopsy is the main diagnostic modality for esophagitis. Macroscopic visualization of the esophagus may reveal erythema, erosions, or ulcerations; however, a normal macroscopic appearance of the esophagus does not exclude histologic esophagitis. Histology, electron microscopy, and immunohistochemistry can help distinguish the different causes of esophagitis (Table 107-1).

Table 107-1 Characteristic Histological Findings for Various Causes of Esophagitis

EoE, eosinophilic esophagitis; GER, gastroesophageal reflux; hpf, high-power field.

Management

Management of esophagitis depends on the etiology. The treatment of GERD has been discussed previously and involves behavioral modification, antacids, H2 blockers, and PPIs. Infectious esophagitis requires the appropriate antiviral, antifungal, or antibiotic therapy for the specific infection, especially in immunosuppressed hosts. However, eradication of Helicobacter pylori gastritis does not improve esophagitis. Treatment of EoE centers around removal of all offending dietary antigens. Often, it is difficult to identify the exact offending agents, so an elemental diet may need to be initiated until the esophagus heals with subsequent sequential reintroduction of foods.