Ingested foreign bodies

As a result of the eating habit, ingested foreign bodies are extremely common amongst the Chinese. The presentation

Figure 20.9. Fish bone in the tongue base.

varies depending on whether the patients can make a clear complaint. Thus in the prelingual children and in the mentally retarded patients, the presentations may be refusal of feed, vomiting or they may present with complication such as a neck abscess. Otherwise patients always present with foreign body sensation immediately following the episode of foreign body ingestion. The commonest foreign body ingested is fish bone (Fig. 20.9). Others include pig's bone, chicken bone, skeleton of shrimps and lobsters, etc. The commonest metallic foreign body is coin.

A careful history is very useful both in making a diagnosis and localization of the foreign body. Symptoms that lateral-ize to one side and localize at a site at or higher than the cricoid are usually very accurate. Symptom that migrates downward is pathonomonic of an ingested foreign body.

There will be hardly any physical signs in the uncomplicated cases. Therefore, the purpose of physical examination is to confirm or exclude the presence of any foreign body. Larger and more blunt foreign bodies, for example coins, chicken or pig's bone tend to be trapped by the narrowest part of the upper aerodigestive tract at the cricopharyngeus. Smaller and sharp foreign bodies such as fish bone may be impacted anywhere from the tonsils, tongue base to anywhere down the oesophagus. Most of the impacted foreign bodies will be found on clinical examination with a tongue depressor or a laryngeal mirror. When no foreign body is found, a direct flexible pharyngolaryngoscopy should be performed. This gives a better and dynamic view of the hypopharynx as the patients are instructed to phonate and swallow. Most ingested foreign bodies can be removed by simple means with a pair of Tilly's forceps or with flexible laryngoscopy. Oesophagoscopy may occasionally be required to remove foreign bodies. Rigid oesophagoscopy gives a better view of the cervical oesophagus while flexible oesophagoscopy is preferred below the thoracic inlet.

The usefulness of a plain lateral X-ray of the neck depends on the type of foreign body and the site of impaction. Thick

Figure 20.10. Plain X-ray of the neck showing free gas in the retro-pharyngeal space due to perforation of the oesophagus after oesophagoscopy.

bones like chicken bone, pig's bone, pigeon's bone, etc. are radio-opaque and will readily be picked up by a plain X-ray. Similarly, metallic foreign bodies such as coins will be clearly shown on plain X-rays. Most fish bones are radiolucent and therefore can easily be missed by plain X-rays. When foreign bodies are impacted above the cricopharyngeus, radiological investigations will not be as accurate as clinical examination. Foreign bodies impacted below the thoracic inlet is difficult to be shown on plain X-rays as the view will inevitably be overlapped by the vertebrae and the thoracic skeleton. The cervical oesophagus is the only segment of the upper digestive tract that plain X-rays are reliable enough to be clinically useful.

Complications of 'ingested foreign bodies' may arise as a result of the impaction or passage of the foreign bodies. They can also be iatrogenic from attempts to remove the foreign bodies. These include perforation of the pharynx or oesophagus (Fig. 20.10), retropharyngeal or mediastinal abscesses. Coexisting fever and leucocytosis should be taken as warning signs of a potential serious complication. Surgical emphysema either clinical or radiological is diagnostic of a perforation in the pharynx or oesophagus.

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