Approach Considerations
Most patients with gastrointestinal (GI) foreign bodies do not require any laboratory studies. Exceptions are patients who present with signs and symptoms consistent with infection or complications, in which case a complete blood cell count may be indicated, and patients who require preoperative studies.
In general, radiography and computed tomography (CT) scanning are the main imaging modalities used to evaluate GI foreign bodies. [23] However, ultrasonography may be useful in detecting ingested drug packets [24] ; endoscopic ultrasonography can help identify foreign bodies of the colon and rectum. [18] CT scanning is more accurate if the patient is stable. In the case of an unstable patient, bedside ultrasonography (or portable radiography) may be the only imaging option.
Radiography
Plain radiographs are indicated for every patient with a known or suspected radiopaque foreign body in the oropharynx, esophagus, stomach, or small intestine. Plain radiographs are also mandated for children in whom any ingestion of a radiopaque foreign body is suspected. Keep in mind, however, that in cases of nonradiopaque foreign bodies, imaging studies rarely have any influence on management, except in delaying endoscopy or computed tomography (CT) scanning.
In small children, a mouth-to-anus radiograph can be obtained. In older children and adults, posteroanterior (PA) and lateral chest radiographs provide better localization.
Radiopaque objects are easily seen and localized on the radiograph.
Plain radiographs typically have been used in patients who have swallowed bones, although the yield is low, with only 20-50% of endoscopically proven bones visible on plain radiographs. Xeroradiography does not increase this yield.
Coins are usually seen in a coronal alignment on anteroposterior (AP), or frontal, radiographs (examples of a lodged coin are shown in the radiographs below).
Button batteries can usually be differentiated from coins on plain films. [25] However, if any question exists as to whether the object is a button battery, urgent intervention is indicated because of the rapidity of esophageal necrosis that can be seen in button battery ingestion. [17]
If the foreign body is in the trachea, it presents in a sagittal orientation because the tracheal rings are incomplete in the posterior aspect.
In adults with food impactions, a plain radiograph may be indicated to search for imbedded bony fragments if techniques, such as LES-relaxing agents or bougienage, are being considered. If endoscopy is used to treat the patient, plain radiographs are not indicated.
Drug packets typically have a characteristic appearance on plain films. [26]
Barium or Gastrografin Swallow
Barium swallow may be indicated in cases of ingestion of nonopaque foreign bodies, such as toothpicks or aluminum soda can tabs, although CT scanning is a much better imaging modality and should be used as the first choice when available.
A barium or Gastrografin swallow, without cotton balls, can sometimes outline the foreign body, but, again, the yield is very low.
Barium swallow can be used for food impactions; however, most authorities believe that it adds nothing to the evaluation and delays definitive treatment.
Contrast studies are not useful in detecting foreign bodies in the stomach or small intestine.
Barium is contraindicated in cases in which esophageal perforation is suspected. Gastrografin may be used if a study is needed.
Computed Tomography Scanning
In one study, computed tomography (CT) scanning was superior to plain radiographs for localization and identification of foreign bodies in 83-100% of cases. CT scanning is highly reliable in localizing foreign bodies in the esophagus. [27, 28]
CT scanning is the modality of choice for the diagnosis of perforation of gastrointestinal (GI) tract by ingested bone fragments, toothpicks, and dentures. Ultrasound is of limited value in depicting a foreign body, but can often reveal secondary signs of perforation. [29]
CT scanning is considered the imaging modality of choice to locate nonradiopaque foreign objects in the oropharynx or esophagus. However, the application is probably unwarranted in every case of acute bone dysphagia, as only a minority (17-25%) of patients who sense a foreign body after eating chicken or fish has a bone present.
CT scanning is also the imaging modality of choice in cases of suspected perforation or abscess. This should be performed with IV contrast if the patient does not have any contraindications to the use of contrast material such as allergy or renal insufficiency.
Metal detectors
Handheld metal detectors have been shown to be accurate in determining if a coin has been swallowed and may be a useful noninvasive screening tool in children with a suspected coin ingestion. However, the specificity of localization is poor, especially in differentiating LES impaction from coins in the stomach. [30]
Endoscopy
Emergent endoscopy is indicated for patients whose airway is compromised or who show signs of complications. Urgent endoscopy is indicated for patients who have swallowed aluminum soda can tabs or toothpicks, since these objects are not visible on plain radiographs and both have a relatively high incidence of complications. If the history is clear, proceed to endoscopy; if unclear, computed tomography (CT) scanning may be used to confirm the presence of the foreign body before endoscopy.
Endoscopy is absolutely indicated for foreign bodies that are sharp, nonradiopaque, or elongated; for multiple foreign bodies; or for possible esophageal injuries. Thus, it is indicated for multiple (>1) small magnets in the esophagus or stomach and may be indicated for single magnets, owing to their potential complications.
This procedure is the most commonly used technique for active management of impacted esophageal foreign bodies. Endoscopy has been traditionally used for the visualization of the esophagus and the removal of foreign bodies. [31]
Endoscopy is indicated for patients with foreign bodies in the stomach or proximal duodenum if the foreign bodies are larger than 2 cm in diameter or longer than 5-7 cm or for oddly shaped foreign bodies such as open safety pins.
Endoscopy is safe and effective but relatively expensive. [5, 32, 33] Advantages of the endoscopic approach to managing ingested foreign bodies and food impaction include high success rates, lower incidence of minor complications, decreased need for surgery, and shortened hospitalizations. [34]
If endoscopy is not successful for removing magnetic foreign bodies, timely surgical intervention may help avoid serious complications such as gastrointestinal perforation and intestinal obstruction, as well as local bowel wall tissue ischemia necrosis and perforation and fistula-related complications. [35]
Delayed flexible endoscopy in patients, especially elderly patients, with sharp esophageal foreign body impactions results in worse endoscopic outcomes. [36] Therapeutic results with the use of general anesthesia versus topical pharyngeal anesthesia does not appear improve the success rate or reduce the complication rate. [36]
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Coin (quarter) lodged at the level of the cricopharyngeus muscle.
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Coin lodged at the level of the aortic crossover.
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Coin lodged at the lower esophageal sphincter.
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A screw in the stomach; peristaltic action will carry the screw through the GI tract with the blunt end (head) leading and the sharp end trailing.
