Imaging Studies
Prenatal diagnosis of congenital tracheoesophageal fistulas (TEFs)
Prenatal ultrasonography may reveal polyhydramnios, absence of fluid-filled stomach, small abdomen, lower-than-expected fetal weight, and a distended esophageal pouch.
Postnatal diagnosis of congenital TEFs
Note the following:
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Plain chest radiographs may reveal tracheal compression and deviation. Absence of a gastric bubble indicates esophageal atresia without a TEF or esophageal atresia with a proximal TEF. Chest radiography leads to the diagnosis of TEF in most cases of congenital TEF, and other investigations are rarely required.
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Aspiration pneumonia in the posterior segments of the upper lobes may occur secondary to aspiration of the contents from the esophageal pouch or stomach. Recurrent or massive aspiration may lead to acute lung injury in some patients. (Infiltrates occur diffusely in these patients.)
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Insertion of a nasogastric tube may show coiling in the mediastinum of patients who have concomitant esophageal atresia. This finding is diagnostic of TEFs associated with esophageal atresia.
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Contrast studies are seldom required to confirm the diagnosis. These studies have the risk of aspiration pneumonitis and pulmonary injury, and they add minimal information to the diagnostic workup. If the contrast study is performed, 1-2 mL of barium is instilled through an 8F catheter placed into the esophagus. Chest radiographs are taken in the lateral decubitus position as well as the anteroposterior position to detect spilling of the contrast into the trachea.
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Use of multidetector-row CT scans have made 3-dimensional (3D) displays of many organs and structures a popular clinical examination tool, as the quality of images has markedly improved. Presence of TEF was correctly diagnosed with multidetector-row CT esophagography. Furthermore, the images provided crucial information for planning surgery, and, without contrast medium, it is a less invasive examination.
Diagnosis of acquired TEFs
Acquired TEFs can be diagnosed by instillation of contrast media into the esophagus or during direct visualization by flexible esophagoscopy or bronchoscopy. Either method can be useful, depending on the individual center's expertise and experience.
Some clinicians prefer to visualize the fistula and assess its exact location prior to surgery. The diagnosis of a TEF secondary to malignancy is confirmed by contrast radiography, esophagoscopy, bronchoscopy, and clinical testing (methylene blue).
Procedures
Flexible esophagoscopy or flexible bronchoscopy may be useful in the diagnosis of acquired tracheoesophageal fistulas (TEFs). Either or both of these procedures may be required to evaluate the anatomy of these structures and to exclude an unsuspecting mucosal lesion. The role of endoscopic procedures is especially important in localizing the acquired nonmalignant or malignant TEF.
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Tracheoesophageal fistula. During development of respiratory and digestive systems, a single primitive tube develops lung bud and tracheoesophageal septum forms by 4-6 weeks of gestational age. The septum separates the foregut and tracheobronchial tree by 6 weeks of gestational age.
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Tracheoesophageal fistula (TEF). The cuff of endobronchial causes circumferential ischemia and injury to the trachea; the erosion leads to formation of a TEF.
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Tracheoesophageal fistula. H-type of tracheoesophageal fistula.
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Tracheoesophageal fistula. Esophageal atresia with distal tracheoesophageal fistula.
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Tracheoesophageal fistula. Isolated esophageal atresia without tracheoesophageal fistula.
Tables
Anatomic Characteristics |
Percentage of Cases |
Esophageal atresia with distal TEF |
87 |
Isolated esophageal atresia without TEF* |
8 |
Isolated TEF |
4 |
Esophageal atresia with proximal TEF |
1 |
Esophageal atresia with proximal and distal TEF |
1 |
*Classified as TEF although there is no fistula. |
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