What is the comparative value of contrast esophagram, computed tomography and fibroscopy in patients with suspected esophageal perforation?
F.H. Miller (Chicago), G.G. Ghahremani, R.M. Gore (Evanston)
Esophageal perforations
Esophageal injuries may result from diagnostic or therapeutic instrumentation, blunt or penetrating injuries, swallowed foreign bodies, operative injuries, or sudden increased intraesophageal pressures. The incidence of perforations is increasing and most commonly is due to diagnostic and therapeutic instrumentation of the esophagus [1, 2]. The types of esophageal injuries may vary from mucosal laceration, intramural dissection, to full thickness tears. Early diagnosis may be difficult and the symptoms are often non specific. While the injury may be limited and not require treatment, some injuries may be major and potentially life-threatening. Contrast studies, CT examinations, and/or endoscopy may help diagnose the perforation as the morbidity and mortality is related to the time between the perforation and starting therapy [3]. This paper will briefly discuss the types of esophageal injuries and the use of these modalities in diagnosis.
Transmural perforation
Esophageal transmural perforation is the most severe and potentially fatal injury of the gastrointestinal tract. It is the most common type of esophageal perforation. When not treated, the mortality is high due to a fulminant mediastinitis that develops. A high index of suspicion is required as the diagnosis may not be suspected and the symptoms may be non specific.
The hypopharynx and cervical esophagus are the most common sites of perforation due to ingested foreign bodies, intubation, and endoscopy [4, 5] (Figure 1). A cervical location is less severe than thoracic location for perforations. Less frequent causes are postemetic and postoperative tears, penetrating knife or bullet wounds, and blunt trauma from automobile accidents [6].
Boerhaave's syndrome or spontaneous esophageal perforation is a result of violent emesis due to increased intraesophageal pressure and most commonly seen after significant alcohol drinking. It is a result of a full-thickness tear of the esophagus. A 2-4 cm transmural tear is generally seen in the posterolateral wall of the distal esophagus. Chest radiographs and CT scans generally demonstrate pneumomediastinum, subcutaneous emphysema in the neck, and a left sided pneumothorax. The presence of pneumothorax and pneumomediastinum on CT examination is suggestive of esophageal perforation but can also be seen with tracheal or bronchial injuries as well. An esophagram is more reliable to demonstrate the site of perforation (Figure 2).
Figure 1. Cervical perforation. Patient with traumatic intubation prior to surgery. Esophagram demonstrates perforation extending from right pyriform sinus (arrow).
Figure 2. Boerhaave's syndrome. 55 year old male in town for convention who after drinking presented with vomiting and severe chest pain. The emergency room suspected an aortic dissection and consequently a CT scan was initially performed. CT scan demonstrates significant soft tissue density in the posterior mediastinum and left pleural effusion from esophageal tear without demonstrating exact site. B. Subcutaneous emphysema (white arrow) and pneumomediastinum (white open arrow) were demonstrated on more cephalad images. C. Subsequent esophagram with gastrografin confirms extravasation of contrast from esophageal tear in left posterolateral distal esophagus extending laterally (arrow). Large barium collection more inferiorly is within the stomach.
A
B
C
Plain film findings of perforations vary based on the location and cause of the perforation and time elapsed between the perforation and radiographic examination [7]. Chest radiographs are non specific with esophageal perforation. Plain film findings that may be seen include pleural effusions, pneumothorax, pneumomediastinum, soft tissue emphysema, consolidation and/or atelectasis. Chest radiographs will be normal when the perforation is intramural and does not dissect through the wall or if the perforation is small or rapidly closes. CT examination is more sensitive for extraluminal air but often extraluminal air may not be present. The CT findings suggestive of perforation include esophageal wall thickening, pleural effusions, and extraluminal air and fluid [8, 9]. These findings are not pathognomonic but suggestive of the diagnosis and should be followed with a contrast study [8, 10]. The site of perforation is extremely difficult to identify with CT scans. Other disorders that can cause pneumomediastinum include penetrating injury and tracheal and bronchial tears. The most reliable method to detect the presence and site of perforation is contrast esophagram. Initially water-soluble iodinated contrast agents such as diatrizoate meglumine (Gastrografin, Squibb and Sons, Inc., Princeton, NJ) should be administered followed by barium if the site of perforation is not demonstrated [11]. The water-soluble agents have a lower radiographic density and may not demonstrate the perforation as well as barium sulfate. Barium has been reported to cause mediastinitis and as a result is generally not initially used. The earlier diagnosis and treatment of esophageal tears, a potentially fatal condition, more than compensates for the harmful effects of barium [12]. Gastrografin however should not be administered in patients prone to aspiration or with tracheoesophageal fistulas, as there is the potential for causing pulmonary edema [13].
In patients with a high suspicion of perforation and normal contrast studies, CT examinations and endoscopy may be of value. CT scans may demonstrate findings suggestive of perforation including small collections of mediastinal air with small tears but these findings may be minimal or nonspecific. Endoscopy may demonstrate the actual site of leak but may be risky in some patients with perforation. In addition, endoscopy has limited application as it may show the mucosal extent but not the deeper extent and often is the cause of the perforation.
Mucosal injury with submucosal/intramural hematoma
Esophageal hematomas are a result of a mucosal laceration or tear generally of the distal esophagus near the gastroesophageal junction. Similar to Mallory-Weiss tears, they are generally a result of sudden increased intraesophageal pressure from violent vomiting. They may also be a result of iatrogenic trauma from esophageal instrumentation. The tears generally resolve following 1-2 weeks of conservative therapy of nasogastric suction, antibiotics, and intravenous hydration. Generally, they can be diagnosed with barium studies or endoscopy. For initial diagnosis, CT examination is less effective. Since the laceration extends into the submucosa and contrast will outline the abnormality, contrast studies are generally the most accurate. In addition, endoscopy may be the cause of the injury. With endoscopy, they may be seen as a large submucosal mass causing displacement of the lumen with dark-blue discoloration of the overlying mucosa [14]. Radiographically, most esophageal hematomas are outlined by contrast and appear as ovoid or elongated submucosal masses generally of the posterior or lateral wall of the distal esophagus [3]. When associated with a mucosal tear, contrast may dissect beneath the mucosa creating a "double-barrel" appearance (Figure 3). This appearance is similar to the angiographic appearance of an aortic dissection and is a result of barium within the true and false lumens. Chest radiographs are normal when the perforation is intramural and contained within the esophageal wall [15].
Mucosal perforation and laceration
Mucosal perforations and lacerations may be seen due to Mallory-Weiss tear as well as tears as a result of foreign bodies and sharp foods such as animal or fish bones and taco shells. Mallory-Weiss tear is a relatively common injury that results from a sudden, marked increase in intraesophageal pressure creating a linear mucosal tear at or near the gastric cardia. A Mallory-Weiss tear should be considered whenever a patient has an abrupt onset of hematemesis following violent vomiting especially after an alcoholic binge. Although patients may present with significant hematemesis, the tear generally is self-limited and heals spontaneously [16, 17]. Approximately 95% of Mallory-Weiss tears are diagnosed endoscopically which is the procedure of choice for the diagnosis and may help with treatment [18]. Because of the mucosal nature of the tears, endoscopy is ideal for evaluation. Barium studies play a very limited role and may uncommonly detect these tears while CT is not effective because of the mucosal nature of the tear. Double contrast esophagrams may occasionally demonstrate a linear longitudinal collection of barium in the esophagus near the gastroesophageal junction. When in the gastric fundus, Mallory-Weiss tears are not well-visualized because of being obscured by the prominent gastric folds [3].
Figure 3. Submucosal dissection of the esophagus in patient with endoscopy for ERCP and "difficulty passing scope." Gastrografin swallow demonstrates intramural dissection of the esophagus from submucosal passage of endoscope with appearance similar to aortic dissection and "true and false lumen." Arrows point to "false lumen" created by passage of endoscope.
In summary, patients with suspected transmural perforations should preferably have contrast esophagram and not endoscopy or CT examination for diagnosis. In patients with suspected esophageal submucosal hematomas, contrast esophagrams and less often endoscopy may be of value. Patients with suspected mucosal tears such as Mallory-Weiss tears should have endoscopy for the diagnosis and possible therapy.
References
3. Levine MS. Trauma. In: Radiology of the esophagus. Philadelphia: W.B. Saunders, 1989:209-229.
15. Ghahremani GG. Esophageal trauma. Semin Roentgenol 1994;24(4):387-400.
16. Ansari A. Mallory-Weiss syndrome: revisited. Am J Gastroenterol 1975;64:460-466.
