Foreign Bodies and Impactions

In cases of possible foreign body ingestion or food impaction, when do you need a surgical opinion? Where is a swallowed object most likely to lodge? How do you determine what equipment is most suitable for retrieval? How much more dangerous is a sharp object than a blunt one? These and other issues are addressed.

By Michael F. Byrne, MD, MA, MRCP, Robert M. Mitchell, MB, BCh, MRCP, and John Baillie, MB, ChB, FRCP

 
How common is foreign body ingestion? What kind of objects are most often swallowed?

Ingestion of foreign bodies and food bolus impaction occur frequently. Approximately 1500 people die each year in the United States after swallowing foreign bodies. However, the majority of objects actually pass through the gastrointestinal tract without complication, and intervention in the form of endoscopy or surgery is required in only 10% to 20% of cases. Children account for about 80% of foreign body ingestions. Other groups who are at increased risk include prisoners, psychiatric patients, and the elderly, especially those who have decreased cognitive function, impaired swallowing after a stroke, or poorly fitting dentures.

Objects commonly ingested by children include coins, small toys, and pen caps. In adults, food impaction, especially with meat boluses, is not uncommon, but there is usually a predisposing problem, such as an esophageal web or stricture. Some individuals ingest multiple foreign objects, and repeat episodes may occur.
 

How do these patients present clinically?

Adults and older children will often volunteer details about the foreign body or food bolus; they may also be able to pinpoint an area of discomfort. However, the correlation between a patient's perceived area of discomfort and the actual location of an ingested object is often poor. In other cases, an accidental ingestion may have gone unnoticed or the patient may delay reporting such an event—accidental or otherwise—for hours, days, or even longer until symptoms develop. Children and psychiatric patients may not provide a history at all.

There are many possible presenting symptoms with foreign body ingestion, ranging from chest pain, acute dysphagia, odynophagia, and a foreign body sensation (especially with food bolus impaction) to vomiting, choking, blood-stained saliva, and drooling. Respiratory symptoms such as wheezing, cough, or shortness of breath may suggest that a foreign body has lodged in the upper esophagus, hypopharynx, piriform sinus, Zenker's diverticulum, or trachea.
 

What role do x-rays play in the evaluation of the patient?

Chest and abdominal x-rays may show the presence of a foreign body. However, some commonly ingested items such as most fish and chicken bones or aluminum pull-tops on soda or beer cans are not radio-opaque. It is useful to know that on anterior-posterior neck films, coins in the esophagus may lie in the frontal plane, whereas coins in the trachea often lie in the sagittal plane because of the vocal cords.
 

What should the focus of the physical examination be?

Physical examination should focus on signs of esophageal injury or perforation, such as tenderness, crepitus, or erythema in the neck region. Stridor may indicate upper airway obstruction; unilateral wheezing or decreased breath sounds may suggest lower airway obstruction. In addition, the abdomen should be examined for signs of small bowel obstruction or peritonitis.

If any of the above clinical features is noted, an urgent surgical opinion is mandatory and should not be delayed for endoscopy. Although surgery is often indicated in such circumstances, it is not always necessary to have the patient go straight to surgery, as, for example, in some cases of suspected esophageal perforation. In such situations, if a contrast study shows no gross leak—that is, a "contained" perforation—medical management (with an NPO order and broad-spectrum antibiotics) may suffice.
 

Where in the gastrointestinal tract are ingested objects most likely to become lodged?

Most ingested objects pass spontaneously through the gastrointestinal tract. However, there are several sites where objects are prone to lodge. The cricopharyngeus and ileocecal valve are the most common sites. Objects may also lodge in the mid-esophagus due to compression from the aortic arch or at the lower esophageal sphincter, pylorus, or anal sphincter. A variety of anatomical obstructions, such as esophageal rings or webs, pyloric stenosis, postoperative adhesions, intestinal strictures, and congenital bowel malformations, as well as functional defects of the gastrointestinal tract, such as scleroderma, gastroparesis, and Hirschsprung's disease, may also cause problems with ingested objects.
 

When is intervention warranted?

The decision to "wait-and-see" or to intervene depends on several factors, such as the type of object ingested, the patient's age and condition, and the location of the object in the gastrointestinal tract. The clinician also needs to determine the urgency of the intervention, if indicated, with regard to the anticipated risk of perforation, aspiration, or obstruction. For example, alkaline button batteries and sharp objects should be removed within hours, if possible. Only about 1% of foreign bodies ingested result in intestinal perforation, but impending perforation is difficult to determine. It is likely that many objects removed endoscopically or surgically because of a perceived risk of perforation would not result in perforation if left to pass spontaneously.

If the patient has symptoms suggestive of impaction in the esophagus, such as dysphagia and excessive drooling, early intervention is mandatory to relieve symptoms and prevent aspiration. Objects longer than 6 cm should also be removed endoscopically because they may lodge in the C-loop of the duodenum. In fact, some authorities suggest that objects longer than 3 cm should be removed.

Prompt diagnosis and treatment of foreign bodies trapped in the gastrointestinal tract decreases mortality and length of hospital stay. From several series, the incidence of foreign bodies requiring operative removal ranges from 1% to 14%.
 

What endoscopic methods are used for foreign body retrieval?

If objects are at or above the level of the cricopharyngeus, rigid esophagoscopy, requiring general anesthesia, or direct laryngoscopy can be performed. Rigid esophagoscopy provides a much better view of the hypopharynx, cricopharyngeus, and the first few centimeters of the cervical esophagus. The scope is easier to control than a flexible scope, facilitating removal of large sharp objects such as dentures. However, it also carries a greater risk of perforation.

For objects below the level of the cricopharyngeus, flexible endoscopy is usually preferred. Dentures and other sharp or irregular objects, however, should be removed with a rigid scope even if they are below the level of the cricopharyngeus.

A variety of accessories can be used through the endoscope to attempt foreign body removal, including polypectomy snares, foreign body extraction forceps, stone-retrieval baskets, tri-prong grasping devices, banding device caps, and retrieval nets. If an object has a hole in it—a ring or a key, for example—a forceps can be used to pass a thread through the hole and thus retrieve the object.
 

Should an overtube be used?

As a general rule, an overtube should be considered for foreign body removal. Endotracheal intubation is an alternative, but it requires general anesthesia. These practices allow for airway protection and facilitate multiple passes of the endoscope, which may be necessary if there is a food bolus impaction or more than one ingested object. In cases of a sharp ingested object, a foreign body protector hood fitted to the end of the endoscope can also be used. It should be remembered, however, that overtube insertion can be uncomfortable for the patient and may injure the esophagus, especially in children. (One trick is to pass the overtube over a dilator.)
 

How should ingested blunt objects such as coins be dealt with?

Blunt objects such as coins that have passed into the stomach do not need to be removed because virtually all of them will be eliminated spontaneously. However, it should be noted that objects that are more than 2.5 cm in maximum diameter are unlikely to pass beyond the pylorus. If the coin is in the esophagus, it can be removed endoscopically using a forceps or retrieval net. Some authorities suggest that it may be better to push the coin into the stomach, where it is easier to grasp or where it can be left to pass spontaneously.

Weekly x-rays should be performed. If an object remains in the same place between weekly films, surgical intervention may be necessary. Lodged foreign bodies can cause hemorrhage, perforation, or a fistula. The time to spontaneous passage is variable and unpredictable, but the mean is four days or so. However, one third of ingested coins were still in the stomach two weeks after ingestion in one series. Objects remaining in the stomach longer than three weeks should be removed endoscopically.
 

What about ingested sharp objects?

Although sharp objects, such as toothpicks, chicken and fish bones, and needles, present a greater risk of intestinal perforation than blunt objects, they pass through the gastrointestinal tract without complication in 70% to 90% of cases. If a sharp object lodges in the esophagus, however, it is a medical emergency and urgent endoscopy should be performed, unless the object is lodged at or above the cricopharyngeus, in which case direct laryngoscopy or rigid esophagoscopy may be preferred. Because the risk of perforation anywhere within the gastrointestinal tract is about 15% to 20% with sharp objects, endoscopic removal should be attempted if the object is still within reach of the endoscope (in the stomach or proximal duodenum, for example). If the object has moved farther down in the gastrointestinal tract or removal is not successful, the patient should be followed with daily abdominal x-rays until the object is expelled.

If the patient develops signs consistent with perforation, such as severe abdominal pain, a rigid abdomen, or absent bowel sounds, or a sharp object does not move for three days, intervention should be considered. Objects such as razor blades and open safety pins should be removed through an overtube. Dental partial plates, with their exposed wires, present a particular danger for perforation and warrant aggressive action.
 

Why are ingested batteries a potential emergency?

Button or disk alkaline batteries should be removed promptly because they can cause severe coagulation necrosis and perforation. Use of an overtube or endotracheal tube is mandatory; removal can be accomplished using a stone retrieval basket or a balloon passed beyond the battery.
 

How should food bolus impactions be managed?

Food bolus impactions almost always occur as a result of esophageal narrowing, such as a reflux stricture. If a patient is very uncomfortable or drooling, urgent endoscopy should be performed; if the patient is not uncomfortable, it is advisable to wait a while because many boluses will pass spontaneously into the stomach. Again, with endoscopic removal, use of an overtube should be considered. A food bolus can be removed using a snare, basket, or grasper. Some clinicians prefer to apply strong suction to the end of an overtube or to use a banding device on the end of the endoscope.

The practice of blindly pushing a food bolus into the stomach is not recommended because of the risk of perforation. Gentle pressure can be applied with the tip of the scope to advance a food bolus into the stomach, but only after the scope has been passed beyond the bolus to determine the anatomy on the other side. Intravenous glucagon (1 mg, followed by 2 mg 20 minutes later if there is no response), IV metoclopramide (10 mg), or sublingual nifedipine (10 mg) may help by relaxing the esophagus. Proteolytic enzyme preparations, such as papain, should never be used as meat tenderizers because of the risk of hypernatremia, severe pulmonary complications, and esophageal perforation.
 

Should foreign bodies containing illicit drugs be removed endoscopically?

Smugglers of illicit drugs may ingest condoms or plastic bags containing cocaine or other narcotics. This practice of "body packing" can often be detected by plain abdominal films or computed tomography. Under no circumstances should endoscopic removal of such objects be attempted, because rupture of the packets can be fatal. A cautious wait-and-see policy should be adopted, and surgery performed if there is any sign of packet rupture or bowel obstruction or if the packets fail to progress along the gastrointestinal tract. Symptoms of packet rupture include tachycardia, hypotension or hypertension, diaphoresis, hyperthermia, psychomotor agitation, seizures, arrhythmias, and, with high doses, respiratory depression and coma. Current recommendations for asymptomatic body-packers include use of activated charcoal and whole bowel irrigation with polyethylene glycol.
 

What are gastric bezoars and how should they be treated?

Gastric bezoars are fibrous aggregations of vegetable or meat foodstuffs that develop in patients with delayed gastric emptying, such as gastroparesis or pyloric stenosis. Occasionally, they can be broken up into smaller pieces using snare or forceps devices, but lavage using a large-bore tube is probably the best management option.
 

How successful is endoscopic removal of ingested foreign bodies?

Endoscopic removal of foreign bodies is often attempted early because of its perceived success rate and safety, but endoscopic failure is not uncommon, being as high as 48% in some series. In addition, the complication rate from endoscopic extraction may be as high as 6%. Patients in whom endoscopic retrieval of foreign bodies failed are often referred for surgical extraction, but there are no good data to support this invasive policy.
 

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