A Foreign Body Larger Than the Overtube Diameter: A Case of a Large Cow Foot Bone Causing Esophageal Impaction

Case Report

A 46-year-old, otherwise healthy Dominican woman presented with a foreign body sensation. She had been eating cow foot soup, which contains small pieces of cow foot occasionally made with intact bones, when she felt a large bone become stuck in the back of her throat. She attempted to remove the bone with her fingers but eventually swallowed it. The patient immediately felt a sharp, sticking sensation in her neck and presented to the emergency department for evaluation. She had no history of dysphagia, food impaction, or gastrointestinal surgery. She did not report any difficulty breathing and could tolerate her own secretions.

Upon evaluation, the patient was hemodynamically stable, with a respiratory rate of 16 bpm and an oxygen saturation level of 98% on room air. Her oropharyngeal examination revealed normal dentition, and no stridor, erythema, or subcutaneous emphysema were noted. An abdominal examination was unremarkable, and a chest radiograph did not reveal any abnormalities. Dedicated neck films demonstrated a large radiopaque foreign body lodged in the cervical esophagus (Figure 1).

Figure 1.

Neck plain film revealing a radiopaque foreign body in the esophagus (arrow).

An upper endoscopy revealed what appeared to be a bone just distal to the upper esophageal sphincter (UES), with one end clearly wedged into the posterior wall of the cervical esophagus. The endoscope was unable to pass distal to this obstruction. Using rat-tooth forceps, the bone was dislodged superiorly but could not be removed due to resistance at the UES. The bone was then advanced distally into the stomach, where its triangular shape was noted. Due to the bone's size and shape, significant concerns arose regarding the potential for obstruction or perforation if the bone was allowed to advance into the small bowel.^1,2 Attempts to remove the bone using a Roth net were unsuccessful due to the aforementioned resistance at the UES (Figure 2). A Guardus overtube (US Endoscopy) with a diameter of 16.7 mm was inserted to minimize injury to the upper esophagus during withdrawal of the foreign body. However, regardless of its orientation, the foreign body was larger than the overtube. Attempts to wedge the foreign body into the distal overtube caused the Roth net to be torn. Due to its composition, the bone could not be crushed or cut according to the guidelines developed by Farr and Pratt.³ The bone was captured by a trapezoid, wire, rotatable retrieval basket (Boston Scientific), which provided adequate tensile strength to allow the endoscopist to wedge 2 of its corners into the distal overtube. This action allowed the remaining protruding corner of the bone to be centered directly underneath the overtube, protecting the esophagus from laceration (Figure 3). The foreign body, endoscope, and overtube were all removed en block, without any esophageal injury. The triangular foreign body measured 2.6 cm × 2.5 cm × 2.1 cm (Figure 4). A subsequent esophagram with diatrizoate (Gastrografin, Bracco) did not reveal any esophageal injury or extravasation, and the patient was discharged.

Figure 2.

Endoscopic view of the cow foot bone after it was snared with a Roth net.

Figure 3.

A schematic of the successful maneuvering of the bone into the distal tip of the overtube, which allowed for the bone's successful retrieval.

Figure 4.

The longest dimension of the retrieved cow foot bone measured 2.6 cm (shown above with overtube measurement markers).

Discussion

To our knowledge, this case is the first report in the literature describing esophageal impaction of a cow foot bone with a description of the retrieval process. This case is significant for the distal overtube's ability to accommodate a bone larger than its diameter.

The swallowing of animal bones, particularly fish and chicken bones, has been well described in the litera-ture.^4,5 Esophageal complications due to swallowing sharp animal bones include esophageal perforation, tracheo-esophageal fistula, mediastinitis, and aortic rupture.^6–8 As a result of these risks, sharp objects or objects that become lodged within the esophagus require removal, rather than observation.

The extraction of foreign bodies in the cervical esophagus may be managed by multiple departments, including gastroenterology, otolaryngology, and thoracic surgery, and may often depend upon the availability of local expertise.^5,9,10 Typically, flexible (rather than rigid) endoscopy is preferred, as the former can be performed with conscious sedation, rather than general anesthesia, and is associated with fewer procedure-related complications such as dysphagia and esophageal rupture.¹¹

Although this cow foot bone was easily detected on the plain film of our patient's neck, this imaging modality generally has a poor sensitivity for detecting animal bones. In one study, plain radiography exhibited a sensitivity and specificity of 39% and 72%, respectively, for detecting animal bones.¹² Other studies have recommended discontinuing the use of plain films for identifying impacted fish bones.¹³ In contrast, a study of computed tomography (CT) scans of the necks of patients with suspected esophageal bone impaction had excellent positive and negative predictive values, with positive rigid esophagoscopy findings in 29 of 30 patients with positive CT findings and successful conservative management in 14 of 15 patients with negative CT findings.¹⁴ The high sensitivity of CT scans and minimal adverse events associated with their use have encouraged their use as a first-line diagnostic tool in patients expected to have unrevealing plain films.¹⁵

The use of overtubes during foreign body extraction for the protection of esophageal mucosa from injury and perforation, prevention of aspiration, and creation of a passage for quick, repeated intubations has been well described in the literature.^4,16 A number of overtubes differing in length, diameter, and technical indications are available and have been recently reviewed.¹⁶ Because the use of overtubes can be associated with tears in the mucosa or pinching of the mucosa between the endoscope and overtube, lubrication and proper insertion technique are crucial.¹⁷ Most importantly, the distal tip of the Guardus overtube, which was used in our patient, is made from a soft plastic that can stretch to accommodate objects that exceed its 16.7-mm diameter.¹⁸

Management of our patient was complicated by the size and sharpness of the bone, which prevented simple retrieval through the esophagus. Observation was not an option either, as the patient had a high risk of gastric outlet obstruction and intestinal perforation. We wedged 2 sharp corners of the bone into the overtube, taking advantage of the overtube's flexibility by stretching its 16.7-mm diameter to accommodate the 21-mm wide bone fragment. Safe retrieval of this bone fragment was predicated on the central positioning of the fragment as it was removed from the esophagus. An alternative management strategy could have involved the ear, nose, and throat service, a rigid esophagoscope (which requires general anesthesia), or cutting forceps to pulverize the bone fragment for safe removal.