Gastroenterology and Hepatology Board Review: Pearls of Wisdom, Third Edition
Section I GASTROENTEROLOGY
CHAPTER 4. Foreign Bodies and Caustic Injury
Rajeev Vasudeva, MD, FACG
Where in the gastrointestinal tract is the most common site of foreign body impaction?
The esophagus is the most common site, especially at the level of the hypopharynx. Other common places are areas of physiologic narrowing and include the pylorus, retroperitoneal duodenum, ileocecal valve, and the anus. The ileocecal region is the most frequent site of perforation beyond the esophagus.
Where in the esophagus are objects likely to become lodged?
Objects may become lodged at any of the areas of physiologic narrowing (cricopharyngeus, aortic arch, the left main stem bronchus, immediately above the esophagogastric junction) or any other area of structural abnormality (stricture).
True/False: Most foreign body ingestions occur in children between the ages of 5 and 8 years.
False. Most foreign body ingestions occur between the ages of 6 months to 3 years.
Which adults are at an increased risk for swallowing foreign bodies?
Adults at increased risk include those who wear dentures, those who are mentally retarded, those with psychiatric illnesses, and prisoners.
What is the most common symptom in patients presenting with an esophageal foreign body?
Dysphagia is the most common symptom followed by odynophagia, chest pain, choking, and drooling. The presence of respiratory distress and inability to swallow oral secretions suggests a need for urgent intervention.
What are the most common symptoms of complete esophageal obstruction due to a foreign body?
Ptyalism (drooling), regurgitation, and choking.
True/False: Most ingested foreign bodies that become lodged in the esophagus pass spontaneously.
True. Seventy percent of ingested foreign bodies pass spontaneously and <1% result in perforation.
What is the most common physical finding in patients presenting with an ingested foreign body?
Usually the physical examination is normal; however, signs of crepitation should always be sought.
A chest x-ray reveals an ingested foreign body aligning itself in the sagittal plane. Is the object more likely to be located in the esophagus or trachea?
Trachea. Tracheal foreign bodies align themselves sagittally and are best seen on lateral projections.
What is the best study for identifying a radiopaque foreign body in the esophagus?
Frontal view chest x-ray. Objects in the esophagus align themselves in an anteroposterior projection.
True/False: Contrast studies of the esophagus may be useful in determining the type and location of an ingested foreign body.
False. Contrast studies should be avoided due to their increased risk of aspiration and interference with subsequent endoscopic visualization.
What is the best imaging study to identify and localize a nonradiopaque foreign body in the esophagus?
CT scan can localize and identify the foreign body in >80% of cases.
How often do pointed sharp objects perforate the intestinal tract and how are they best removed?
Fortunately, up to 90% of objects pass spontaneously without complication and rarely perforate. Pointed objects should be removed with the pointed end trailing in order to avoid mucosal injury. Under these circumstances, an overtube or a hood attached to the tip of the endoscope should be used.
True/False: Enzyme preparations such as papain should be tried prior to endoscopy in all cases of meat impaction.
False. Besides being ineffective, it is important to avoid papain and other enzyme preparations because of an increased risk of perforation.
Prior to endoscopic removal of an ingested safety pin, what should be done by the endoscopist to increase the success rate?
Rehearsal of the retrieval process (dry run) should always be performed in order to facilitate removal of an object.
True/False: Blindly pushing a foreign body into the stomach followed by endoscopic retrieval is routinely advocated.
False. This technique should be avoided unless the lumen beyond the obstructing foreign body is adequately visualized and patent. In general, once the foreign body has passed into the stomach, it does not need to be retrieved as it will usually pass through the gastrointestinal tract without any problem.
A 72-year-old woman is brought to the emergency room 72 hours after swallowing a pointed object. What is the best management at this point?
Endoscopic removal should be attempted in this patient if it can be localized and is retrievable. Indications for prompt removal of ingested foreign bodies include the presence of complete esophageal obstruction and ingestion of sharp, pointed, or toxic objects (disc [button] batteries) lodged in the esophagus.
True/False: A 23-year-old man presents with fever, chills, neck pain, and obvious subcutaneous emphysema 2 hours after accidentally swallowing a fish bone. Endoscopic removal by an experienced gastroenterologist is the most appropriate management for this patient.
False. This patient has evidence of possible esophageal perforation. Therefore, surgical evaluation is the treatment of choice.
What is the most appropriate management for a patient who is found to have an ingested foreign body that is embedded in the esophageal wall?
Surgery. If it appears to be removable endoscopically, after consultation with a surgeon, endoscopic removal could be considered.
True/False: Immediate endoscopic removal is the best approach for management of ingested latex packets of cocaine.
False. Endoscopic removal of such drug packets is unwise because of the potential for rupture upon manipulation. If packets fail to progress or if there are signs suggesting leakage, urgent surgical intervention is indicated.
What is the appropriate management of ingested elemental mercury in the intestine?
Observation and possibly cathartics to hasten its elimination as long as there is no evidence of perforation or leakage outside the digestive tract.
What is the best approach to take when an esophageal stricture is found once the foreign body has been removed or pushed into the stomach?
Dilatation of the stricture. If there is local mucosal trauma or bleeding or the patient is not cooperative or visualization of the field is suboptimal, the stricture is best dilated at a later time.
True/False: The location of the perceived discomfort is predictive of the most likely site of a foreign body lodged in the esophagus.
False. As with dysphagia in general, the location of the perceived discomfort does not usually correlate with the anatomic location of the obstructing foreign body.
What size objects should be considered for endoscopic removal?
Long objects >6 cm in children and >10 cm in adults should be removed. Rounded objects <2.5 cm usually pass through the pylorus in adults and can be managed conservatively.
When should endoscopy be utilized in the management of an ingested disc (button) battery?
Endoscopy should be performed promptly if the disc battery is lodged in the esophagus. If it has passed into the stomach, conservative measures may be employed and the patient observed. If the battery has remained in the stomach for more than 48 hours, is >1.5 cm, and has mercury, it should be promptly removed.
How long should you wait before contemplating endoscopic or surgical removal of a foreign body?
Blunt objects such as coins, if located in the esophagus, should be removed urgently. Asymptomatic blunt objects that fail to leave the stomach after 2 weeks should be removed endoscopically. Surgical removal of blunt objects beyond the stomach that fail to advance after 7 to 10 days (sharp objects >3 days) should be considered. Surgical intervention is otherwise indicated if fever, vomiting, overt bleeding, or abdominal pain develops.
True/False: Adults are more likely than children to ingest caustic substances?
False. It is estimated that 17,000 children, half of whom are under 4 years of age, accidentally ingest caustic substances each year. Although relatively uncommon in adults, it predominantly involves adults who are inebriated, mentally retarded, psychotic, or suicidal.
What factors are implicated in the pathogenesis of caustic injury to the gut?
The nature, concentration, and physical state of the agent, the amount ingested, the time of exposure (“dwell time”), as well as the amount of re-exposure secondary to vomiting or reflux are important factors.
Where are common caustic agents implicated in accidental or intentional ingestion found?
The individual’s home. Many household products contain strong alkaline caustic agents. These include drain cleaners, oven cleaners, swimming pool–cleaning products, dishwasher detergents, hair relaxers, bleaches, and lye soaps.
How do alkaline agents cause injury?
Alkaline agents cause liquefaction (saponification) necrosis, which dissolves superficial mucosa, and rapidly diffuse into deeper tissues. Blood vessel thrombosis causes further cellular necrosis potentially resulting in full-thickness burns.
How do acidic agents cause injury?
Acidic agents produce a coagulation necrosis of the surface epithelium and tend to produce less penetration.
What region of the gastrointestinal tract is more commonly affected by acidic agent ingestion?
Acidic agents usually cause extensive damage to the stomach. The esophagus is relatively spared due to a combination of factors including rapid transit through the esophagus, greater resistance of esophageal squamous epithelium to acid, and the protection afforded by superficial coagulation necrosis preventing deeper injury. Nevertheless, 20%–50% of patients may have significant esophageal burns from ingestion of highly concentrated sulfuric or hydrochloric acid.
True/False: There is good correlation between oral/pharyngeal burns and esophageal or gastric injury.
False. The lack of oral or pharyngeal burns does not preclude the possibility of extensive esophageal or gastric injury.
True/False: Gastric lavage with water or administration of emetics plays an important role in the management of caustic ingestions.
False. Gastric lavage is contraindicated in both alkaline and acid ingestions due to increased risk of perforation and aspiration. Emetics should always be avoided due to re-exposure to the caustic agent.
True/False: Administration of acid neutralizers is helpful immediately after caustic ingestion.
False. The heat produced in the neutralization reaction may actually increase tissue injury. Additionally, since most alkali injuries occur very rapidly, acid neutralization is ineffective.
When should endoscopic examination be carried out in patients with suspected caustic ingestion?
Although there are differing opinions, most experts agree on the need to document extent of damage by performing endoscopy within 12 to 24 hours.
How often does endoscopic injury occur in patients with caustic ingestion?
What is the most sensitive imaging study to detect a suspected early perforation following caustic ingestion?
CT scan of the chest and abdomen with oral contrast.
What are the ‘Grades’ of injury caused by caustic ingestion?
The extent of injury can be divided into three degrees of injury. First-degree injury is characterized by mild friability, erythema, and edema only. Second-degree injury extends into the wall, occasionally to the muscularis propria. Ulceration, necrosis, and exudate may be seen. Third-degree injury involves the full thickness of the wall. A dark exudate with sloughing of the mucosa, hemorrhage, ulceration, and necrosis are typically seen.
True/False: Endoscopic findings accurately predict the pathological depth of tissue injury.
False. Grades of injury on endoscopy are not as precise as the pathologic degree of burn.
What is the management and prognosis of patients based on the Grade of endoscopic injury?
Patients with first-degree injury have an excellent prognosis and can be started on a liquid diet, which can be advanced in 1–2 days as tolerated. Patients with second-degree injury develop strictures in >70% of cases, usually within 2–4 weeks, requiring endoscopic or surgical intervention. Patients with third-degree injury have a high mortality and may require urgent surgical intervention.
What is the role of antibiotics and corticosteroids in the management of caustic ingestions?
The lack of controlled trials precludes definitive arguments in support of any therapeutic modality. The use of antibiotics and corticosteroids is fraught with controversy in the literature. However, corticosteroids may be considered if symptoms of laryngeal edema are present. Antibiotics are recommended in proven or suspected infection and in patients with second- and third-degree injury.
When do strictures usually develop following caustic ingestion?
Most strictures (80%) present within the first 8 weeks after injury. However, they can occur insidiously over months to years after the initial event.
What are the usual sites of stricture development in the esophagus and stomach following caustic ingestion?
Strictures tend to develop at sites of pooling such as the cricopharyngeus, aortic arch, bifurcation of the trachea, and lower esophageal sphincter in the esophagus and the antrum of fasting patients and the mid-body in patients who have food present in the stomach at the time of caustic ingestion.
What is another long-term complication of caustic ingestion?
The development of squamous cell carcinoma of the esophagus. The latency period varies from 12 to 41 years and is shorter for injuries occurring after childhood. Specific surveillance protocols have not been defined.
• • • SUGGESTED READINGS • • •
Eisen GM, Baron TH, Dominitz JA, et al. American Society for Gastrointestinal Endoscopy. Guideline for the management of ingested foreign bodies. Gastrointest Endosc. 2002;55:802-806.
Weiland ST, Schurr MJ. Conservative treatment of ingested foreign bodies. J Gastrointest Surg. 2002;6:496-500.
Smith MT, Wong RKH. Esophageal foreign bodies: types and techniques for removal. Curr Treat Op Gastroenterol. 2006;9:75-84.
Poley JW, Steyerberg EW, Kuipers EJ, et al. Ingestion of acid and alkaline agents: outcome and prognostic value of early upper endoscopy. Gastrointest Endosc. 2004;60:372-377.