Endoscopic foreign body removal

The ingestion of foreign bodies is most commonly a problem in young children aged 6 months to 5 years, but can affect children of all ages (those younger than 6 months can occasionally ingest materials with the aid of older siblings during play). It may be an event witnessed by parents. It occurs much less frequently in older children and adults but does affect these groups rarely. It usually occurs accidentally but can result from deliberate ingestion. Patients with mental illness,^[1] intellectual impairment, prisoners^[2] or 'drug-mules'/'body-packers'^[3] (those involved in the smuggling of illicit drugs concealed in the gastrointestinal tract) are prone to problems caused by purposeful ingestion of foreign bodies. Trichobezoar is a rare condition where hair ingestion leads to formation of a hair ball in the stomach.^[4]

Virtually any object small enough to pass through the pharynx may be swallowed. Items commonly ingested by children include coins, small toys, pencils, pens and their tops, batteries, safety pins, needles and hairpins - they are mainly radio-opaque. Food-related items, such as fish and chicken bones, are more often ingested by older children and adults and tend to be radiolucent. In adults, dentures or parts from dentures can be swallowed accidentally and are reported in the literature.^[5] The swallowing of foreign bodies during dental procedures does not occur very often.^[6]

The majority of ingested foreign bodies will pass safely through the gut and be passed with faeces (those that reach the stomach have an 80-90% chance of passage),^[7] but some will cause damage to the gastrointestinal (GI) tract and/or become lodged.^[8]Patients swallowing foreign bodies are usually asymptomatic but symptoms can result. It may even lead to life-threatening obstruction of the upper GI and respiratory tracts.

Epidemiology

It is difficult to estimate the incidence of accidental ingestion of foreign bodies in children, but it is common. A five-year survey in a large urban American emergency department found 255 cases of oesophageal foreign body affecting children, 214 of which followed a witnessed ingestion.^[9] A cross-sectional survey found that of 1,500 parents, 4% reported the swallowing of a coin by their child - the most common object swallowed by youngsters.^[10]

Presentation

This is highly variable and depends on whether it is a child or an adult. In children the event may have been witnessed, reported by the child, or be suspected/discovered subsequently when a child becomes ill. Any symptoms or signs are also largely dependent on where any lodged object is impacted. About 75% of children who have an impacted foreign body will have it at the level of the upper oesophageal sphincter, with roughly 70% of affected adults having impaction at the level of the lower oesophageal sphincter.^[7]

Oropharyngeal foreign bodies

• Overall, about 60% of foreign bodies become trapped at this level (commonly at, or just below, the level of the cricopharyngeus muscle).
• Patients usually have a clear sensation of something being trapped that is relatively well localised.
• Small linear items such as bones and toothpicks are often trapped at this level, from the tonsils/posterior tongue to the vallecula and upper oesophagus.
• There is usually discomfort ranging from mild to quite severe.
• Drooling and an inability to swallow may be present.
• Airway compromise may occur if large objects are trapped.
• A delayed presentation with infection or perforation may occur with objects that become stuck at this level.

Oesophageal foreign bodies

• In adults, there is usually an acute presentation following ingestion of an object or food item that becomes stuck.
• There tends to be a vague sensation of something being stuck in the centre of the chest or epigastric region, indicating that the object is probably at the level of the aortic cross-over or the lower oesophageal sphincter.
• There may be dysphagia for the remainder of the meal, prompting presentation or salivary pooling/drooling if there is complete oesophageal obstruction.
• This presentation appears to be more common in those who use dentures, eat meat and concurrently consume alcohol.^[7]
• Children with oesophageal impaction tend to have a less clear-cut presentation, although there may have been a witnessed swallowing event.
• Gagging, vomiting, retching, neck and/or throat pain are more common presentations in children with oesophageal foreign bodies.
• Children with partial oesophageal obstruction may present with a chronic course featuring inability to feed, failure to thrive, fever, recurrent aspiration pneumonitis/pneumonia or respiratory embarrassment/stridor (due to tracheal impingement).

Sub-oesophageal foreign bodies

These may present with a range of symptoms depending on the degree of progression of the object through the gut. Vague symptoms, such as abdominal distension and discomfort, fever, recurrent vomiting, passing rectal blood/melaena and/or other symptoms of acute or subacute intestinal obstruction, may be present.

Symptoms due to gastrointestinal (GI) perforation

If an object perforates the oesophagus, it tends to cause acute mediastinitis with chest pain, dyspnoea and severe odynophagia (pain associated with swallowing), along with signs of pneumonitis/pleural effusion.^[11] Perforation below the level of the oesophagus will cause symptoms and signs of acute/subacute peritonitis.

Examination of the patient with definite/suspected foreign body ingestion/entrapment

This is often unhelpful, but careful examination should be carried out for acute clinical and medicolegal reasons:

• Assess the airway and respiratory function to exclude/highlight any compromise.
• Check vital signs to exclude impending catastrophic presentation due to airway obstruction or acute GI perforation, or fever in case of delayed presentation.
• Open the mouth and observe the oropharynx with a bright light.
• Consider indirect laryngoscopy and/or fibre-optic examination of the pharynx if you have appropriate equipment and a sufficiently experienced practitioner available.
• Gently palpate the neck and assess tracheal position/compression.
• Formally examine the chest and listen to the lungs.
• Perform a cardiovascular examination.
• Carefully examine the abdomen.

Differential diagnosis

• This clinical scenario is unlikely to be confused with another illness, with the possible exception of space-occupying oesophageal pathology - eg oesophageal carcinoma causing obstruction of a normal food bolus.
• Always consider the possibility that a foreign body has been inhaled, particularly if a patient presents acutely with respiratory compromise or with chronic chest symptoms.
• An acute presentation of mediastinitis may be due to perforation by a swallowed foreign body, or the primary form of the disease.^[11]
• Retropharyngeal abscess can cause similar symptoms to impacted objects in the upper oesophageal area.
• Pneumomediastinum can present similarly, where there is a pneumothorax into the mediastinal portion of pleura.

Investigations

Blood tests are usually unhelpful, with the exception of chronic presentations or febrile patients where FBC/ESR may provide useful clues as to the cause of symptoms.

• Plain X-rays:
  Where there is a history of a swallowed radio-opaque object that may be located within the upper gastrointestinal (GI) tract, plain X-ray should be carried out to confirm or refute the possibility of oesophageal entrapment. This need not be done urgently if occurring out-of-hours and the patient is well, but should be performed at the earliest opportunity when radiology services are available. If there is a suspicion of swallowing a button battery, then X-rays and further treatment should be performed urgently.
  • Where the ingested object is not radio-opaque, X-ray investigations are unlikely to help and will probably only delay more relevant investigations such as upper GI endoscopy.
  • Very small children can be imaged using a mouth-to-anus radiograph.
  • In adults, a PA and lateral chest radiograph and/or plain abdominal X-ray are more useful.
  • Only about 20-50% of food bones will be visible on X-rays.^[7]
  • Coins in the oesophagus usually appear in a coronal alignment on frontal radiographs (ie seen as a disc).
  • Coins in the trachea are more usually seen in a saggital orientation on frontal radiographs, due to the incompleteness of tracheal cartilage rings posteriorly (ie seen 'edge-on').
• CT scans:
  • CT scanning of the thorax/abdomen is highly useful for locating entrapped objects of various types and considered superior by many to plain X-ray imaging.^[7]
  • CT scanning is the investigation of choice if there is reason to suspect perforation or abscess formation.
  • Not all cases of acute dysphagia/odynophagia due to food bones should have CT scanning, as only a minority (17-25%) of those who have the sensation of a trapped foreign body after eating will actually have one present, the remainder having the sensation due to mucosal injury.
• Endoscopy:
  • Urgent endoscopy is mandatory in cases where there is airway obstruction or evidence of other severe complications.
  • Where there is a clear history of swallowing objects, such as toothpicks and/or aluminium bottle caps/can rings, endoscopy is the investigation/procedure of choice, as there is a high rate of complications with such objects.^[7]
  • Where the history of ingestion of such objects is not so clear-cut, consider CT first to detect the object.^[7]
  • Definite indications for endoscopy are objects that are sharp, non-radio-opaque, elongated, or where there are multiple swallowed objects or a high risk of oesophageal injury (eg button batteries).^[7]
  • Endoscopy is also indicated for gastric or proximal-duodenal foreign bodies that have a diameter of >2 cm, a length of >5-7 cm or are eccentrically-shaped and prone to enlodgement/perforation, such as open safety pins.^[7]
  • Endoscopy is a relatively safe procedure in experienced hands, but costly, and should therefore be avoided as a routine intervention if possible.
• Other tests:
  • Barium swallows are sometimes used to detect non-radio-opaque items but CT is usually preferred, as there is a better yield and barium must be avoided where there is reason to suspect perforation (gastrografin usually being used in its place).
  • Hand-held metal detectors can be used to trace the passage of metallic objects through the GI tract and reduce exposure to ionising radiation during follow-up; their specificity of localisation is poor, particularly in the upper GI tract. They can, however, indicate where it is likely that there is a trapped metal oesophageal object that requires further investigation.

Management

• Act quickly to locate and remove any object that may be causing acute upper airway obstruction.
• Where airway obstruction is life-threatening and an object cannot be removed then obtain urgent senior A&E/anaesthetic/ENT advice and/or consider cricothyroidotomyas a life-saving procedure.
• Patients outside of hospital with significant airway/gastrointestinal (GI) obstruction should be transferred as an emergency, in a sitting position, with a suction catheter available for them to use to remove obstructed saliva.
• Children with upper GI obstruction and/or airway compromise should be allowed to stay in their parent's arms whilst being transferred to, or assessed in, hospital, to reduce anxiety and worsening airway embarrassment.
• Indications of instability or a need for urgent transfer to hospital include:
  • Airway compromise.
  • Drooling.
  • Inability to swallow fluids.
  • Sepsis.
  • Suspicion of intestinal perforation.
  • Evidence of active bleeding.
  • Clear history of ingestion of a button battery.
• Those with objects lodged in the oesophagus will usually require some form of intervention to prevent ulceration and/or other complications; options include endoscopy, removal with a Foley® catheter, bougienage (use of a stiff rod to push objects such as coins past the lower oesophageal sphincter) and medical therapy to dilate the lower oesophageal sphincter.
• Stable patients who have swallowed small, smooth objects, who have no evidence of oesophageal entrapment, otherwise negative imaging, and with no evidence of damage, can often be managed conservatively with follow-up at 24 hours or so to check that they remain well; passage of objects in stool may take days to weeks and parents should observe for their presence.
• Patients with stomach or small-intestine foreign bodies of width <2 cm or length <6 cm can be discharged home with instructions on symptoms that should prompt their re-attendance; patients with larger or sharp objects in these areas should be referred to a gastroenterologist who may carry out serial X-rays.
• Narcotic 'body packers'/'drug mules' should be followed up and monitored as inpatients due to the risk of drug toxicity; they may need bowel irrigation and/or surgical intervention if there is any evidence of systemic effects of leaking narcotics (endoscopy is not recommended, as it tends to release drugs from the packages).^[3][7]
• Adult patients with oesophageal entrapment of food bolus or other food-related objects should be considered for referral to a gastroenterologist, as there is a significant incidence of oesophageal lesions such as carcinoma in these patients.^[7]Hyoscine may be useful in cases of food bolus obstruction.^[12]

Complications

• Oropharyngeal foreign bodies:
  • Scratches and lacerations of oropharyngeal mucosa.
  • Perforation.
  • Retropharyngeal abscess.
  • Soft-tissue infection or abscess.
• Oesophageal foreign bodies:
  • Scratches, lacerations or abrasions of mucosa.
  • Oesophageal necrosis (beware swallowed button batteries in children).
  • Retropharyngeal abscess.
  • Oesophageal stricture.
  • Oesophageal perforation and subsequent para-oesophageal abscess.
  • Mediastinitis.
  • Pneumothorax and/or pneumomediastinum.
  • Pericarditis/cardiac tamponade.
  • Tracheo-oesophageal fistula (especially swallowed button batteries in children).
  • Aorto-oesophageal fistulae or other mediastinal vascular injury.
• Gastric/small-intestine foreign bodies:
  • Entrapment of an object within a Meckel's diverticulum.
  • Perforation leading to peritonitis and advanced sepsis.
  • Acute or subacute small-intestinal obstruction.
  • Metal poisoning (coins).^[13]

Prognosis

On the whole, prognosis is good, especially with appropriate investigation, management and follow-up. Most patients with ingested foreign bodies will suffer no significant sequelae. However, a minority of people will have complications and, given that this is a relatively common phenomenon, a significant number of people die as a result of foreign body ingestion - estimated at 1,500 deaths annually in the USA.^[7]