Modern endoscopist’s toolbox: Innovations in foreign body removal

Abstract

Foreign body ingestion is a common gastrointestinal emergency, particularly in children, who account for 80% of cases. While most ingested objects pass spontaneously, around 20% require medical intervention. In adults, incidents often occur accidentally during meals, leading to impactions, especially in individuals with underlying esophageal conditions. Endoscopy remains the gold standard for foreign body retrieval, with a success rate exceeding 95%. The type, shape, and location of the foreign body determine the clinical presentation and management approach. Sharp objects, batteries, and large items pose the highest risk of complications, including perforation, obstruction, and chemical injury. Prompt endoscopic removal is guided by established protocols, with emergent intervention required for complete esophageal obstruction and high-risk objects. Various retrieval devices, including forceps, snares, baskets, and overtubes, are used based on the nature of the foreign body. Technological advancements, such as artificial intelligence-assisted imaging and endoscopic ultrasound, are improving diagnostic precision and procedural outcomes. Despite these advances, foreign body ingestion can still lead to severe complications if not managed in a timely manner. Public awareness, preventive measures, and rapid medical response are essential in reducing morbidity and mortality associated with foreign body ingestion.

Key Words: Foreign body removal; Endoscopy; Snare; Forcep; Food bolus; Modern techniques

Core Tip: Foreign body ingestion is a common yet potentially life-threatening emergency, especially in young children and elderly. While most cases resolve spontaneously, some require urgent endoscopic intervention to prevent severe complications like perforation, obstruction, and chemical burns. Advanced endoscopic instruments may be tiny, but they are remarkably smart-capable of maneuvering and extracting foreign objects with precision. Specialized retrieval devices such as forceps, snares, baskets, overtubes, and retrieval nets play a crucial role in safely dislodging and removing impacted items. With evolving technology, endoscopy continues to revolutionize foreign body management, ensuring faster, safer, and more effective patient outcomes.

INTRODUCTION

Gastrointestinal emergencies are critical medical conditions, with foreign body ingestion being one of the most frequently encountered issues. Foreign body ingestion often resolves without intervention, though approximately 20% of cases require medical removal. Foreign body ingestion is significantly more common in children, accounting for approximately 80% of all cases. The highest incidence is observed between 6 months and 3 years of age. In contrast, adults make up the remaining 20% of cases, with most incidents occurring accidentally during meals. This often results in impaction of food items, such as bones or meat boluses, within the gastrointestinal tract. Non-food objects are also impacted in gastrointestinal tract but they are mostly encountered in people with cognitive impairment, psychiatric patients and alcoholics[1]. The urgency of endoscopic removal depends on the nature of the foreign object and the patient’s condition. Endoscopic retrieval is categorized into four urgency levels: Emergency (< 4 hours), urgent (< 24 hours), early elective (< 48 hours), and elective (> 48 hours). Emergency endoscopy, particularly for food bolus impaction and high-risk foreign bodies, should be performed under general anesthesia with airway protection. A trained endoscopist, proficient in handling various retrieval tools, should lead the procedure, supported by a skilled endoscopy team, including at least one qualified nurse. In pediatric cases, specialized nursing skills are essential. If a patient presents with compromised vital signs, airway, breathing, circulation resuscitation must be prioritized before any intervention. In stable cases, a thorough medical history should be obtained, including details of the ingestion, symptoms, object characteristics, and pre-existing gastrointestinal conditions[2].

Endoscopy serves as a cornerstone in the removal of foreign bodies. Endoscopic interventions have been successful in more than 95% of the cases[3]. Clinical manifestation may vary depending on the size of foreign body and location of impaction. Most common site of impaction is upper esophagus, followed by the middle esophagus, stomach, pharynx, lower esophagus, and, finally, the duodenum. Although most foreign bodies pass spontaneously, they may still cause major health complications and mortality. Retained foreign bodies cause significant deaths worldwide if not treated promptly[4]. Therefore, it is essential to understand the management of various foreign body dislodgments and the appropriate devices available for their removal. Advances in endoscopy have significantly enhanced our ability to address these cases efficiently, often with minimal or no complications. Figure 1 represents the graphical abstract of this article and summarizes key features.

Figure 1 Graphical abstract endoscopist toolbox. EUS: Endoscopic ultrasound.

TYPES OF FOREIGN BODIES

Foreign bodies can be categorized based on their size, shape, and dimensions, with their surface texture and consistency playing a crucial role in their classification and management. Key distinctions include sharp or pointed vs blunt objects, as well as smooth vs rough or traumatic surfaces. Additionally, the composition of the foreign body-whether organic or inorganic, metallic or chemical-holds significant importance, as these properties can directly impact the approach to treatment and removal strategies[5]. Foreign body classification can be categorized into food and non-food items, with true foreign bodies referring to non-food objects and food bolus impactions representing ingested food obstructions[6]. The type of ingested foreign body influences the site of impaction, with sharp objects commonly lodging at acute angles or intestinal narrowings such as the duodenal loop, duodenojejunal junction, appendix, and terminal ileum[4].

The most commonly encountered foreign bodies include coins and meat boluses, followed by less frequent occurrences of pins, chicken or fish bones, nails, tablets, rings, and bezoars[7]. Types of foreign bodies ingested differ between adults and children. In patients under 10 years old, coins constitute 66% of upper gastrointestinal foreign bodies, whereas in individuals over 11 years, food boluses predominate, accounting for 60% of cases[8]. Children often ingest a variety of household objects, including coins, batteries, toys, and other small items within their reach. Due to their diverse compositions, batteries pose unique risks and can lead to different types of injuries. Sodium and potassium hydroxide batteries can cause gastrointestinal mucosal damage through chemical burns, while lithium batteries are particularly hazardous as they generate an electric current, leading to significant tissue injury[4].

Most adults present with food bolus impaction and they usually have underlying esophageal pathology like strictures, esophagitis or motility disorders. Medically introduced foreign bodies are an emerging concern, with several objects contributing to the issue. Some of the most frequently encountered items include capsule endoscopy devices, displaced luminal stents, gastrostomy tubes, catheters, and dental materials, all of which can present challenges in diagnosis and treatment[9]. Patients with history of drug abuse or psychological disorders ingest unusual foreign bodies like pen, spoon, screwdriver, gloves and toothbrush which have been managed endoscopically[6]. Table 1 summarizes various types of foreign bodies according to their characteristics.

Table 1 Classification of types of foreign bodies.

Category	Subcategories	Examples
By physical characteristics	Size & shape: Small vs large, rounded vs irregular	Coins, nails, bezoars, rings
	Surface texture: Smooth vs Rough	Marbles (smooth), chicken bones (rough)
	Sharp vs blunt	Needles, razor blades (sharp) vs Coins (blunt)
By composition	Organic vs inorganic	Food boluses (organic), metal objects (inorganic)
	Metallic vs non-metallic	Screws, forks (metallic) vs plastic toys (non-metallic)
	Chemical composition	Batteries (lithium, sodium hydroxide), medications
By risk level	High-risk objects	Batteries, magnets, sharp objects (e.g., Razors)
	Low-risk objects	Coins, plastic objects, small rounded items
By clinical context	Accidental ingestion (common in children)	Coins, marbles, small objects
	Intentional ingestion (psychiatric/drug abuse)	Toothbrushes, screwdrivers
	Medically introduced foreign bodies	Endoscopic capsules, stents, dental materials

CLINICAL FEATURES

Patients usually present with chest pain, excessive salivation, foreign body sensation and dysphagia. However, in some cases, symptoms develop more gradually, and patients may delay seeking medical attention for several hours, hoping for spontaneous resolution. When taking a history, it is crucial to ask about recent meals and determine whether the ingested food contained sharp material like bones[5]. Sharp foreign bodies usually cause severe pain and discomfort[10]. Luminal obstruction of esophagus may result in reflux, retching or painful swallowing. Compression on trachea can give rise to respiratory symptoms like wheezing, dyspnea and stridor. Presence of air in mediastinum, crepitus or swelling around neck and chest indicates perforation that can occur due to any sharp foreign object[11]. In children, drooling, poor feeding, irritability, and failure to thrive are possible indicators of foreign body ingestion, though they may sometimes remain completely asymptomatic[9].

DIAGNOSIS

Radiography serves as the primary imaging method for assessing patients with suspected foreign body ingestion. Approximately 83% of ingested foreign objects are radiopaque, but smaller items may not be clearly visible in areas with greater tissue density. To ensure thorough evaluation, frontal and lateral neck and chest X-rays, along with an abdominal X-ray, should be performed[12]. Computed tomography (CT) is also indicated when there is suspicion of perforation[13]. There are few instances in which foreign body was not visualized on endoscopy and were later diagnosed through CT scan, therefore careful investigation is necessary[14].

TIME OF ENDOSCOPY

The European Society of Gastrointestinal Endoscopy provides clear guidelines on the timing of therapeutic esophagogastroduodenoscopy (EGD) based on the type and location of the foreign body. Emergent EGD (ideally within 2 hours, but no later than 6 hours) is recommended for cases of complete esophageal obstruction, as well as for sharp objects or batteries lodged in the esophagus, due to the high risk of complications. Urgent EGD (within 24 hours) is advised for esophageal foreign bodies that do not cause complete obstruction, as well as for certain gastric foreign bodies, including sharp objects, magnets, batteries, and large or elongated items, which pose a risk of perforation or obstruction. Meanwhile, non-urgent EGD (within 72 hours) is suggested for medium-sized blunt objects in the stomach, as these are less likely to cause immediate harm but still require timely removal to prevent complications[15]. Figure 2 illustrates a flow chart that describes basic management according to high risk and low risk objects.

Figure 2  Flowchart depicting the management steps for foreign body removal.

RETRIEVAL TECHNIQUE AND DEVICES

Guidelines emphasize the importance of having the necessary equipment readily available for endoscopic foreign body removal. Device selection is typically based on the size and shape of the foreign body or the endoscopist’s preference. Commonly used tools include alligator and rat-tooth forceps, retrieval nets, polypectomy snares, tripod forceps, and baskets. For sharp objects, latex cones and overtubes provide additional safety. Endoscopic baskets are particularly useful for retrieving round objects, while retrieval nets offer a more secure grip for coins, batteries, magnets, and food boluses[2]. Gastroscope selection depends on patient age and procedural requirements. In infants under one year, a nasal gastroscope with an external diameter of less than 6 mm and a 2 mm operating channel is recommended, accommodating only small retrieval devices like polypectomy nets, snares, and Dormia baskets. For older children and adults, standard gastroscopes (9.8 mm external diameter, 2.8 mm channel) or therapeutic gastroscopes (≥ 3.2 mm channel) are used for broader instrument compatibility. In specialized cases, double-channel endoscopes enable simultaneous device use, small-caliber scopes allow for transnasal access, and enteroscopes facilitate deeper intestinal examination and retrieval[11]. Foreign body removal from the gastrointestinal tract can be performed using two primary techniques: Endoscopic retrieval and the push technique, each utilizing a variety of specialized instruments for effective management[16].

Selecting the appropriate instrument is essential for the effective removal of foreign bodies, depending on their nature and location. Coins can be easily extracted using forceps, while soft meat boluses are best removed with a retrieval basket. In cases where pins have penetrated the bowel wall, a snare is the preferred tool for safe removal[7]. Forceps are among the most commonly used tools, with rat-tooth forceps being the standard choice, while alligator-tooth and shark-tooth forceps offer additional versatility. Retrieval forceps with 2 to 5 prongs are effective for grasping soft objects like food boluses but lack the secure grip needed for harder or heavier foreign bodies. Biopsy forceps, with their small opening width, are best suited for retrieving small and soft objects. Baskets, such as the Dormia basket with three, four, or six wires, are ideal for round foreign bodies, providing a secure grip. Polypectomy snares and retrieval nets are also widely used. Polypectomy snares, available in sizes ranging from 10 to 30 mm, are inexpensive and effective, while retrieval nets, though more costly, are particularly useful for extracting flat or delicate objects like coins, disc batteries, and magnets[11]. Small intestinal foreign bodies can be removed via balloon-assisted enteroscopy[17]. Figure 3 illustrates pill packet dislodgement in esophagus, which was removed safely using Roth net. The Roth net provided secure coverage to safely extract a sharp, rounded pill packet from the esophagus.

Figure 3 Demonstrates the use of Roth net in removing foreign body (pill packet) from the esophagus. A: Pill packet is seen dislodged in mid esophagus, with its sharp edges eroding the mucosal lining; B: Roth net is being used endoscopically to retrieve the pill packet. Picture is taken from Endoscopy suite, section of Gastroenterology, Aga Khan University Hospital Karachi.

Overtubes are used to prevent mucosal injury while removing sharp foreign objects. An overtube is a tube-like device with a larger diameter than an endoscope, designed to protect the digestive mucosa, reduce aspiration risk, and facilitate repeated endoscopic access during procedures. It is a semi-rigid plastic device with a soft, tapered distal tip. Overtubes vary in length (23-135 cm) and outer diameter (14.4-21 mm) depending on their application. A 20-25 cm overtube protects the cricopharyngeal area and airway, while a minimum 50 cm length is required for esophageal protection during foreign body removal[18].

A cap-assisted technique is also employed for the endoscopic removal of foreign bodies. In this approach, a cap is attached to the tip of the gastroscope, and continuous suction is applied to extract the foreign object, similar to the method used in endoscopic mucosal resection[19].

Glucagon, sometimes administered with diazepam, has shown variable success in relieving food impaction by relaxing the lower esophageal sphincter (LES). While it is generally considered safe, it can induce vomiting, which may lead to complications such as perforation or obstruction. Some studies suggest that glucagon is a cost-effective alternative to endoscopy as an initial treatment. However, a large meta-analysis indicates that glucagon is associated with a higher risk of adverse events and is not an effective treatment for esophageal foreign body impaction[20,21].

HOW TO CHOOSE APPROPRIATE EQUIPMENT?

Forceps are often preferred over snares when dealing with irregularly shaped or small foreign bodies that require a firm grip. Unlike snares, which are better suited for looping around objects, forceps allow for direct grasping and controlled retrieval, especially in cases where precision is critical, such as with sharp or pointed objects. Alligator forceps have serrated jaws that provide a stronger and more secure grip on smooth or slippery foreign bodies, reducing the risk of slippage during extraction. Biopsy forceps, on the other hand, are designed for tissue sampling and may not provide an adequate hold on rigid objects. A Roth net is preferred when dealing with small, rounded, or fragile objects that need to be enclosed completely to prevent accidental loss during retrieval. Unlike overtubes, which primarily serve as a protective guide, a Roth net securely traps the object, reducing the risk of displacement[4].

Table 2 summarizes commonly used endoscopic retrieval devices, their uses and limitations[4].

Table 2 Uses and limitations of retrieval devices.

Retrieval device	Uses	Limitations
Biopsy forceps	Used for small, firm objects (e.g., coins, tablets, small bones)	Limited grip on smooth or large objects; may not be effective for fragile items
Rat tooth forceps	Effective for sharp or irregular objects like needles, nails, and fish bones	Risk of mucosal trauma or perforation; difficult to use on slippery objects
Alligator forceps	Used for gripping irregularly shaped or sharp objects	Not ideal for large or rounded objects
Snare	Commonly used for food boluses, coins, and larger objects; can be used for piecemeal extraction	Risk of slippage with smooth objects; cannot be used for very sharp items without additional protection
Polypectomy snare	Useful for removing blunt objects and food boluses; can also aid in piecemeal retrieval	Risk of mucosal injury; not ideal for sharp objects
Retrieval net (Roth net)	Used for retrieving small blunt objects, batteries, and sharp objects like razor blades with added protection	Can be difficult to maneuver in tight spaces
Magnetic probe	Useful for metallic foreign bodies like screws, nails, and coins	Only effective for magnetic objects
Stone retrieval basket	Used for removing button batteries and larger blunt foreign bodies	Risk of fragmentation; may not be suitable for sharp objects
Transparent cap-fitting device	Helps with food boluses and facilitates object removal by suctioning foreign bodies into the cap	Limited to small and soft objects
Overtube	Protects the airway during retrieval, prevents accidental aspiration, and assists in the safe removal of sharp objects	Requires experience for proper placement; may be challenging in patients with strictures
Single/double balloon enteroscope	Used for retrieving objects lodged in the small intestine (e.g., retained capsules)	Technically complex; requires specialized equipment and training, only available in few hospitals

There are several rare and unusual cases of foreign body ingestion documented in medical literature. These cases are distinctive and offer a valuable opportunity to learn various endoscopic retrieval techniques while managing complex and challenging scenarios. One such case involved nail clippers lodged in the cecum, which were successfully removed using a snare and colonoscope[22]. Another example of an unusual foreign object is a magnetized watch, which was extracted using a snare. The snare was employed to maneuver the watch into the esophagus, where it was then securely captured using an end-on lassoing technique around its groove[23]. One interesting case featured the removal of a foreign body from the pancreatic parenchyma using an endoscopic ultrasound (EUS) guided technique. In this procedure, foreign body forceps were passed through the working channel of the echoendoscope and inserted into the entry site of the foreign body[24]. EUS has also been utilized for the removal of embedded esophageal foreign bodies, such as a fish bone[25]. Flouroscopic imaging can also be used to assist in endoscopic removal of foreign bodies[26].

Table 3 shows examples of some unusual foreign bodies and retrieval devices used to extract them[27-35].

Table 3 Examples of unusual foreign body retrieval.

Type of foreign body	Retrieval device
Wire[27]	Biopsy forcep
Sewing needle[28]	Flexible forceps
Multiple razor blades[29]	Raptor grasping device and overtube
Crack pipe[30]	Snare, forceps and overtube
Metal dinner fork[31]	Double wire-loop snare technique
Food bolus[4,19]	Snare, Transparent cap fitting device
Screws in Cecum[32]	Roth net and snare
Wristwatch[33]	Esophageal overtube
Razor blade[34]	Modified overtube
Prune pit[35]	Snare

EMERGING DEVELOPMENTS AND FUTURE PERSPECTIVE

Innovative techniques are being employed for foreign body removal, exemplified by the use of a self-expanding metal stent (SEMS) in a challenging case. Endoscopy revealed a bunch of keys lodged in the gastric antrum, with initial extraction attempts using rat-tooth forceps and a snare failing due to an inability to pass through the LES. To facilitate safe retrieval, a fully covered 23 mm × 125 mm SEMS was strategically deployed across the cardia, simultaneously dilating the LES and shielding the esophageal mucosa from potential laceration. By securing the largest key at its distal end and aligning it parallel to the esophagus, the team successfully guided the entire bundle through the cardia within the stent, ensuring a controlled and atraumatic removal[36]. Another novel approach involved the use of endoscopic scissors for foreign body removal. This technique allowed the foreign body to be carefully fragmented into smaller pieces, facilitating safer and more efficient extraction[37]. Advanced endoscopic techniques, such as EUS, have proven effective in extracting embedded foreign bodies. With proper training and expertise, even more complex and challenging cases can be successfully managed[24,25]. In a remarkable case, endoscopic dissection was successfully utilized to remove an embedded, perforating foreign body from the duodenum, ultimately preventing the need for major surgery[38].

With technological advancements, the role of artificial intelligence (AI) in detecting foreign bodies is being actively explored, paving the way for innovative management approaches. AI-powered imaging can precisely identify the location and classify the type of foreign body, enabling the preparation of appropriate measures and specialized devices for effective intervention[39]. Developing online applications powered by AI technology, combined with the review of standard guidelines and the creation of specialized algorithms, can effectively assist physicians in managing cases of foreign body ingestion[40].

In the future, we could develop AI-based applications to enhance the safety and efficiency of endoscopic foreign body removal. AI-powered image recognition can improve real-time detection and classification of foreign bodies, assisting endoscopists in selecting the most appropriate retrieval strategy. Smart navigation systems with AI-driven overlays may provide precise guidance, reducing procedural risks. Additionally, robotic-assisted endoscopy, integrated with AI, could enable more controlled and delicate retrieval, minimizing mucosal injury. Machine learning algorithms could predict the likelihood of spontaneous passage and assess complication risks, optimizing decision-making. AI-enhanced training simulations using virtual reality could improve endoscopists' skills in handling complex cases. Furthermore, AI-driven documentation and decision-support systems could standardize protocols and improve patient outcomes. As these innovations progress, AI has the potential to transform endoscopic foreign body removal, making procedures safer, more efficient, and highly precise.

These advanced modalities come with their own limitations, requiring extensive research and development. Significant investment in time and funding is necessary to refine these technologies and ensure their safety, effectiveness, and widespread accessibility.

COMPLICATIONS

Tear in esophageal mucosa, deep lacerations with minor bleeding, ulcer formation, perforation, and abscess development are the most common complications of foreign body ingestion. The likelihood of endoscopic complications or procedural failure is influenced by key risk factors, particularly the sharpness of the object and an impaction duration exceeding 12 hours[16,41]. The timing of symptom onset, time of medical consultation, and promptness of same-day treatment are crucial factors affecting the risk of complications in endoscopic foreign body removal[42]. Complications depend on the type of foreign body impacted. Batteries can cause chemical damage of mucosa, necrosis and stricture formation. Perforation and peritonitis are more likely to occur with sharp objects like fish bone[4]. Toxic effects of drugs have been observed, such as burns in the upper airway that can occur from ingesting a crack cocaine pipe[43]. Hemorrhagic bullae have also been reported post endoscopy[44]. In a large cohort of 586 patients, major complications occurred in 7.7% of patients, four of them required surgery for perforation[13]. Serious long-term complications can arise from foreign body ingestion, particularly in young children. These include chronic stricture formation and injuries extending beyond the esophagus, such as airway obstruction, tracheoesophageal fistula, vascular damage (e.g., aortoesophageal fistula), retropharyngeal abscess, mediastinitis, pericarditis, and vocal cord injury. A study by Leinwand et al[45] reported 13 cases of severe complications, with perforation occurring in 30.8% of cases, stricture formation in 23.1%, and aortoesophageal fistula leading to exsanguination and mortality in 23.1% of cases. Notably, over 90% of these complications occurred in children aged five years or younger, particularly with batteries 20 mm or larger in diameter and prolonged impaction[45].

CONCLUSION

Foreign body ingestion remains a prevalent and potentially serious gastrointestinal emergency, particularly in children and high-risk adult populations. While many cases resolve spontaneously, timely diagnosis and intervention are crucial to preventing life-threatening complications such as perforation, obstruction, and chemical injury. Endoscopy has revolutionized the management of foreign body retrieval, offering a safe and highly effective means of extraction in the majority of cases.

Advancements in medical technology, including AI and endoscopic innovations, continue to enhance diagnostic accuracy and procedural efficiency, paving the way for improved patient outcomes. With the development of AI-assisted imaging and novel retrieval techniques, the future of gastrointestinal foreign body management promises even greater precision and safety. Gastroenterologists are now being trained to utilize these newer modalities, further expanding the scope of minimally invasive interventions and improving success rates. However, the availability of advanced endoscopic retrieval devices remains limited to larger medical centers, highlighting the need for broader accessibility. It is essential to organize training sessions for aspiring young doctors to help them develop the necessary expertise and skills. Additionally, efforts should be made to secure funding for essential endoscopic equipment, which plays a critical role in emergency situations. By providing both proper training and advanced medical tools, we can enhance the quality of patient care and ensure that doctors are well-prepared to handle complex medical challenges.

Prevention remains paramount-public awareness, parental vigilance, and early medical intervention can significantly reduce the incidence and complications associated with foreign body ingestion. As medical science evolves, a multidisciplinary approach integrating cutting-edge technology with clinical expertise will be instrumental in ensuring optimal patient care.