Removal of Foreign Bodies

23	Removal of Foreign Bodies W. Schmidbaur

Foreign bodies usually enter the digestive tract through the mouth or the anus. Occasionally they enter transmurally (penetration) or were originally implanted for therapeutic purposes. There seems to be no ingestible object that has not been swallowed at some time and no object that fits in the rectum that has not been placed there (Tab. 23.1).

Principles of Endoscopic Foreign Body Removal

The majority of ingested foreign bodies manage to pass the bowel in the short or long term (a number of hours to several days) without any problem and sometimes even leave the body unnoticed and spontaneously. However, foreign bodies can also persist and can cause obstruction—due to the disproportion between their size and the width of the intestinal lumen, especially at sites of predilection—or injure the bowel wall due to their shape (Tab. 23.2). Therapy indications are influenced by type, size, and localization of the foreign body. Possible procedures include rigid or flexible endoscopy, surgical measures, or a combination of methods. Removal of foreign bodies is the oldest endoscopic intervention procedure in the gastrointestinal tract: not long after Johannes von Miculicz invented the esophagoscope in 1881, Morell Mackenzie removed a piece of bone from the esophagus.

Pre-examination. Only a third of patients explicitly seeks medical attention for an irremovable foreign body in the rectum and in most cases, manipulation is concealed. Patients tend instead to elusively complain of “pain in the anus.” In nearly half of such cases, the foreign body can be detected by digital rectal examination. The remainder of cases requires radiologic evaluation. Indications for the necessity of radiologic studies for diagnosis include atypical sexual behavior, a lax anal sphincter, and blood or mucosal discharge.

**Table 23.1** Definition
Foreign bodies
Foreign bodies in the gastrointestinal tract are all inorganic objects in the bowel lumen, in rare cases also indigestible food masses Foreign bodies are usually ingested or introduced per rectum. Dislodged therapeutic devices (e.g., stents) are uncommon

**Table 23.2** Sites of predilection for persistence of foreign bodies in the colon
Ileocecal valve Appendix Hepatic and splenic flexures Diverticula Rectosigmoid junction Anal canal Existing stenoses, anastomoses

Prior to endoscopy, radiographic studies should attempt to precisely localize the foreign body and exclude perforation. Endoscopic removal of foreign bodies is often very time consuming and sometimes risky. Moreover, patient cooperation cannot always be expected. Anesthesiological support during examination can be prudent.

Removal of Foreign Bodies in the Colon

Method

The set of instruments for colonoscopic recovery of foreign bodies corresponds to these used in the upper gastrointestinal (GI) tract. Various polypectomy snares, special forceps with hooked jaws, multiple-pronged grasping forceps, and baskets are used. For mobilization, a balloon can also be used, inflated distal to the foreign body. The selection of instruments is based on shape, material, and size of the foreign body; very often a range of instruments must be tried out (Figs. 23.1, 23.2).

Snares are especially suited for removal of longer objects. The closed snare should be slid past the foreign body and opened. Ensnarement should be around the end of the object toward the proximal bowel, due to better leverage when withdrawing it toward the endoscope. Passage of curves or flexures is simpler when the foreign body is as close as possible to the endoscope during withdrawal.

Alligator forceps are most appropriate for “digging into” to soft foreign bodies improving grasp. The same is true for multiple-pronged grasping forceps, which also have proved useful for grasping flat objects such as coins or blister packs.

Small baskets can be used universally and are especially good for small, round objects that may also be very hard. Foreign body size is a limitation for all flexible endoscopic devices.

The availability of radiographic equipment can often be very helpful for the procedure.

For mobilization of a foreign body in the colon, additional external compression/massage of the abdomen performed by an experienced endoscopic assistant or a second examiner can be helpful. Occasionally, a combined approach with laparoscopic mobilization of a foreign body that has migrated to the colon followed by transanal removal is necessary (6).

An indication for operative endoscopic or surgical intervention to extract a foreign body is uncommon. In most cases a foreign body will spontaneously pass the colon.