Esophageal emergencies: another important cause of acute chest pain

In patients presenting with acute chest pain after a recent history of instrumentation such as simple endoscopy, esophageal stricture dilation, anterior cervical discectomy, or various cardiac procedures such as transesophageal echocardiography or radiofrequency catheter ablation, careful evaluation should be made for the diagnosis of EP [24, 25]. CT findings may be subtle and can include small locules of periesophageal and mediastinal air or fluid, left pleural effusion, or focal wall thickening (Fig. 2a, b). Similar findings can also be seen in spontaneous esophageal perforation such as Boerhaave syndrome, which is induced from a sudden increase in intraluminal pressure from acts such as forceful vomiting, cough, or Valsalva maneuver (Fig. 2c, d). Spontaneous perforation classically results in a longitudinal tear along the posterior wall of the abdominal esophagus, whereas the hypopharynx is the most commonly affected site in iatrogenic perforation [26, 27]. In a patient with suspected EP who is otherwise clinically stable, contrast esophagography with water-soluble contrast can be performed first to evaluate for extraluminal contrast material, but if negative, should be followed by barium esophagography due to the higher sensitivity of barium in the detection of EP [28]. In the authors’ experience, an EP is best visualized with the patient in the left posterior oblique position.

Due to its posterior and relatively protected location, direct injury to the esophagus is rare but results in great morbidity from associated synchronous airway, aortic, or spinal injuries [29, 30]. In the neck, however, the cervical esophagus and upper thoracic esophagus can be particularly susceptible to penetrating trauma [31]. Although fluoroscopy is the most sensitive study for EP, CT is often the first line of imaging in the emergent setting. Since the esophagus is usually collapsed, the role of CT is to assess for the secondary findings of EP including pneumomediastinum, posterior mediastinal hematoma, and pleural effusion (Fig. 2e). The presence of multiple of these supporting findings in conjunction with esophageal wall thickening, extraluminal contrast material, or focal wall defect should lead to a high index of suspicion for traumatic EP. A potential pitfall for misdiagnosis of EP in the setting of trauma is the Macklin effect, which also demonstrates pneumomediastinum, but develops secondary to increased intrathoracic pressure from alveolar rupture [32]. Air subsequently dissects along the peribronchovascular interstitial sheaths, interlobular septa, and into the mediastinum (Fig. 3). However, the Macklin effect is not associated with pleural effusion or the reactive changes associated with esophageal wall perforation.

Malignancy-related esophageal perforations can result from primary late-stage esophageal cancer, iatrogenic perforation from endoscopic treatment of esophageal cancer, or radiation induced esophageal injury leading to perforation [33]. Once EP occurs, morbidity and mortality significantly increase due to risk of infection such as mediastinal or lung abscess, or development of esophageal-tracheal fistula (Fig. 4) [34].

Transmural injury to the esophagus or prolonged inflammation of the mediastinum can have lasting effects, and due to the lack of serosa, the esophagus can be vulnerable to forming various fistulas with surrounding structures including the trachea or bronchus, pleura, pericardium, and rarely the aorta (Figs. 4 and 5) [35, 36]. The most common of these is development of a tracheoesophageal fistula (TEF), an abnormal connection typically between the anterior wall of the esophagus and posterior wall of the airway. Formation of a TEF can occur during the healing process after various insults such as mucosal injury of the esophageal and tracheal walls in blunt trauma, necrosis from tumor erosion, or focal ischemia as a result of an overinflated endotracheal cuff (Fig. 6). The classic clinical sign of TEF is paroxysmal cough and choking after swallowing liquids [37, 38]. When clinically suspected, esophagography is the study of choice with its ability to demonstrate tracheoesophageal communication of contrast. CT findings can include the presence of a fistulous tract extending from the esophagus to the bronchial tree, or extraluminal contrast. On CT, while water soluble oral contrast can more easily define smaller fistulous tracts, it is not always required. Associated findings such as inflammation and air tracking abnormally in a non-anatomic orientation can serve as diagnostic guides.

Fistulous tracts from the esophagus to additional adjacent structures are typically a result of prior surgery or endoscopic procedure, invasion of esophageal carcinoma, or sequala of prior radiation therapy. In the setting of esophagopleural fistulas, radiography can demonstrate a pleural effusion or hydropneumothorax. On CT, delineation of the fistula tract itself, or the presence of pleural air and fluid or oral contrast agent if administered are contributory findings to accurate diagnosis. In esophagopericardial fistulas, CT can identify pericardial air, indicating the anomalous tract. Aorto-esophageal fistulas are especially rare and typically form in the setting of prior thoracic aorta repair or eroding or ruptured thoracic aortic aneurysm [39, 40]. In stable patients in whom esophageal pathology is suspected, esophagography will demonstrate indentation or deviation of the esophagus secondary to the aneurysm and possible mucosal ulceration or spill of contrast posteriorly into the aorta. CT findings of oral contrast extravasation into the aorta, periaortic or intraluminal gas, and focal esophageal wall thickening are highly suggestive of the fistula. Spontaneous closure of esophageal fistulas is rare and management depends on etiology, size, anatomy, and additional patient comorbidities [41]. Esophageal stenting can serve as a palliating treatment in patients too ill for surgical repair, which is the preferred treatment option [42, 43].