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Definition

Crushing damage to the endoscope by mastication

Risk factors

 Upper airway endoscopy or gastroscopy without endoscope protector

 Inexperience

 Oral endoscopy without a mouth speculum

Pathogenesis

The most common damage is associated with endoscopy of the nasopharynx due to retroflexion of the endoscope into the oral cavity. Damage can occur at the end of the endoscope if the leading edge retroflexes into the oral cavity or it may occur in the body of the endoscope if the scope does not advance through the cranial esophageal sphincter and a loop of the endoscope retroflexes into the oral cavity (Figure 4.1). This would be most common when performing esophagoscopy and gastroscopy, because of the intentional induction of a swallowing reflex to enter the esophagus and the long length of the endoscope used for gastroscopy. Upper airway endoscopy is not immune to oral retroflexion, although the risk is much lower because the esophagus is not intentionally entered. Use of the endoscope to evaluate the oral cavity directly exposes the endoscopy to risk of damage by the teeth. The damage is caused by the horse chewing on the scope and the scope will be immediately non‐functional.

Prevention

This complication can be minimized by awareness of the risk of it occurring during gastroscopy and upper airway endoscopy. The person passing the endoscopy controls the forward motion. This person should be careful when advancing the endoscope until confident in its location. Once seated in the esophagus, the person advancing the scope should make sure that there is aboral advancement of the scope synchronous with advancement of the endoscope into the nasal cavity. Alternatively, a larger diameter hollow tube can be positioned through the nasal cavity and into the esophagus [1]. The gastroscope is then passed through this tube, which prevents any resistance to passage and retroflexion of the endoscope in the nasopharynx [1]. Oral speculums must be used for any oral endoscopy procedures and the scope should be protected by a rigid sheath when in the mouth, if possible.

Figure 4.1 Photograph showing large segment (spanning the 160 cm to 205 cm gradations) of crushing and damage to a 3‐meter gastroscope after a segment of the midbody of the endoscope retroflexed into the oral cavity, where it was chewed by the patient.

Source: Julie E. Dechant.