Differences between intentional and accidental ingestion of foreign body in China

Foreign body (FB) ingestion, including food bolus impaction, is a common clinical problem in China [1, 2]. Although ingestion of FB by adults is generally accidental, the intentional ingestion of FB occurs in some adults such as prisoners [3], patients with psychiatric disorders or mental retardation.

European guidelines reported that 80–90% of ingested FBs can spontaneously pass through the gastrointestinal tract, while 10–20% of ingested FBs may need to be removed endoscopically [4]. However, a recent study reported FBs were encountered at endoscopy in almost half of the cases [5]. The management of FB depended on a number of factors, such as the type, size, shape of the body, time elapsed since ingestion and symptoms or signs of complications. The patients who intentionally ingested FB form a special group. The study reported that the most commonly intentionally ingested objects included razor blades, batteries, and other sharp metallic items, which were not usually reported in the general population, and there was a greater demand for endoscopic and surgical interventions [6].

To our knowledge, very few studies have focused on the intentional ingestion of FBs in China, therefore we aimed to compare the prevalence of different age groups, gender, types of objects, locations and managements of FB ingested between intentional and accidental ingestion groups among Chinese people.

Foreign-body ingestion is a common clinical problem in China. However, there are no reports which focus on Chinese patients who intentionally ingest FBs. In adults, intentional ingestion of FBs commonly occurs among those with psychiatric disorders, pica and prisoners [7, 8]. In our report, the number of patients who intentionally ingested FBs was not large, but the characters of these patients were very different from those who accidentally ingested FBs.

Most of the patients in our study who intentionally ingested FBs were male; however, there was no significant difference between male and female in the general population [2, 9]. Most of the patients with intentional ingestion were prisoners in custody, and they could be considered as seeking secondary gains through access to a medical facility or even manipulative attempts to escape incarceration, which was similar to findings in a previous study [3].

In our report, most of the patients accidentally ingesting FBs were elderly (≥60 years old), which was different from those described in previous reports [2, 10], because the most common foreign body in our study was date pits. The types of FBs ingested were influenced by differences in the characteristics of the study groups, such as age and dietary habits [11]. In Northern China, people’s eating habits include eating pasta; meanwhile, date cakes or soups containing many dates are also very popular. Date pits in Northern China are usually larger than those in Southen China. However the elders’ masticatory function is usually decreased. Therefore, the elders were more likely to ingest this kind of date pit accidentally. Most of the people who intentionally ingested FBs were younger than those who accidentally ingested them in our study.

As for the type of FBs, most of the FBs in the general population were food-related, which was consistent with previous reports [12‐14], but in different countries and regions, there were various differences in food related FBs due to different eating habits and types of food. In the group with intentional FBs ingestion, metallic objects are more common, among which steel wire accounts for 21.1% and other metallic materials for 57.8%.In a study of intentional swallowing of FBs conducted at Rhode Island Hospital, Huang and associates [8] found the most commonly ingested FBs were pens (23.6%), batteries (28; 9.2%), knives (22; 7.2%), razor blades (21; 6.9%), other metal objects (20; 6.6%), pencils (19; 6.2%), toothbrushes (18; 5.9%), spoons (15; 4.9%), and coins (13; 4.2%),which also indicated there were no food-related FBs and metal objects were very common among these patients. So X-ray could play an important diagnostic role in this situation [15].

In the general population, most of the FBs were in the esophagus, which was consistent with previous reports [1, 2, 10]. In patients who intentionally ingested FBs, the FBs were usually in the stomach, and the proportion in the duodenum was also higher than that of the general population. A study by Poorvi et al. reviewed 141 episodes of intentional FB ingestion and found most items were also located in the stomach [16]. Swallowing intentionally might help the FBs to pass through the esophagus. However the FBs in patients with intentional ingestion were longer and sharper, so it was more difficult for those to pass through the pylorus. The patients who had intentional ingestion had longer time to present, which allowed an object to transit from the esophagus into the stomach for more time. The patients with accidental ingestion were more likely to have esophageal disease than those with intentional ingestion, which prevented the food from esophagus to the stomach.

Endoscopic intervention remains the preferred modality of foreign-body extraction with a high success rate [16‐19]. However the failure rate among patients who intentionally ingest FBs is significantly increased. In our reports, there was a 10% failure rate of endoscopic treatment in the patients who intentionally ingested FBs, while there was only a 0.5% failure rate among patients who accidentally ingested FBs. In our reports, both failure rates were lower than those in previous studies, because the data originated from the Digestive Endoscopy Center. In our hospital, before the patients came to the Digestive Endoscopy Center, they had been previously assessed by the doctor of the emergency, and radiography had been done. The patients who were not suitable for endoscopic treatment were not referred to the Digestive Endoscopy Center. And the patients whose FBs had passed through the ligament of Treitz or the patients with perforation before endoscopic treatment were not refferred to the Digestive Endosccopy Center. Our reports also showed that the failure of endoscopic treatment was related to the type and size of FBs. Long FBs and complicated or sharp FBs were difficult to be removed by endoscopy. In our study, most FBs were able to be removed with FB forceps and a FB cap. We also found that the FB cap was very useful, as it could keep the visual field clear and safely improve the management of sharp FBs [20]. Different endoscopic methods and equipment were used according to the shape, size or sharpness of the FBs. Snares and net baskets were used more frequently in the patients with accidental ingestion. Palta et al [17] reported that the results of their stuy did not allow them to determine which endoscopic accessory worked best for foreign-body removal, and all devices had a high success rate. The choice of endoscopic accessory should be individualized for the specific type of FBs and several different accessories should be available when performing endoscopy in patients with FBs ingestion.

The duration of FBs in upper gastrointestinal tract was different between the patients with intentional ingestion and those with accidental ingestion. Previous research showed that as the time after ingestion increased, the rate of successful FB removal by endoscopy decreased. Long delays between ingestion to presentation and intervention might account for the relatively high rates of surgery, perforation, and mortality [17, 21]. Hong et al. showed that impaction duration and sharpness of FBs were the two important risk factors for the development of major complications and in particular, impaction duration of over 12 h had a 2.4-fold increased risk of major complications [13]. In our study, most of the patients who intentionally ingested FBs were prisoners and they usually took longer time to be noticed than those with accidentally ingested FBs. Sharp metal objects were commonly intentionally ingested by prisoners, which also decreased the rate of successful FB removal by endoscopy. On the contrary, patients who accidentally ingested FBs usually sought for medical help as soon as possible.

In our study, patients who intentionally ingested FBs were mainly prisoners, FBs were mainly sharp metal objects, the duration of FB impaction was longer, and the rate of successful endoscopic treatment was lower than that of the general population. Attention should be focused on these patients because their intentional deeds are preventable.