Rare-earth magnets are not the most common foreign body that children swallow,but they require special attention because of the hazard they present. In the past ten years, we have seen several reports of serious complications caused by multiple magnet ingestion from many countries3-5. Therefore, the USA government has forced toy companies to recall certain magnetic toys. Accordingly, in some areas of the USA, the incidence of multiple magnet ingestion has decreased6. In China, although there are warning labels on the toy packages, a recent multicenter investigation shown that the incidence of multiple magnet ingestions is increasing7. As our data show, the number of patients in 2019 was approximately four times higher than that in 2015. Previous studies have shown that 80-90% of foreign bodies pass spontaneously, and 1-5% of cases require surgical intervention1,8. However, in our study, the surgical intervention rate was as high as 45.1%. It’s similar to that reported in another multiple magnets ingestion study3.
The magnetic force of the rare-earth magnet is 30-50 times stronger than that of ordinary magnet and each rare-earth magnet can attract 640 times its own weight. After multiple rare-earth magnets were swallowed, they attracted each other tightly, resulting in local compression of the intestinal wall, ischemia, necrosis, perforation, internal fistula, peritonitis, intestinal obstruction and even death9. The rare-earth magnets in toys that children swallow are generally small, and the perforation caused by their ingestion is also small. In some cases, because of the wrapping of the omentum after perforation or the formation of an internal fistula directly, the clinical symptoms are mild and the imaging findings are not typical. In this study, 20 cases had perforation, fistula, and obstruction, but five of them had mild or no symptoms and only four cases had typical changes on the radiographs, which is similar to several other reports4,10-12. Some children cannot provide the exact time of swallowing the magnets, which may delay the diagnosis and treatment. It is one of the causes of serious complications. In this study, a 3-year-old boy had no symptoms and was diagnosed 14 days after he swallowed the magnets when a small intestine perforation had already formed.
For cases with an uncertain number of magnets swallowed, it is necessary to treat them as if multiple magnets have been swallowed; multi-position photography may help to determine the number of magnets. For patients reporting that a single magnet swallowed, follow-up observation is also necessary. If the magnet position is fixed, the necessary intervention should be performed9.
For the treatment of magnetic foreign bodies in the digestive tract of children, different guidelines have different recommendations. The 2017ESGE/ESPGHAN guidelines recommends urgent (<24 hours) removal of all magnets within endoscopic reach. For those beyond endoscopic reach, the guideline advises that close observation and surgical consultation13. The NASPGHAN guideline 2015 recommends different managements approaches based on whether the case is a single magnet ingestion or multiple magnet ingestion. For a single magnet ingestion, this guideline recommends removal if possible or confirmation of passage with serial X-rays. For all multiple magnet ingestions within the stomach or esophagus, this guideline recommends removal by endoscopy if the time is<12 hours from ingestion. In cases >12 hours since ingestion, this guideline recommends consulting pediatric surgery prior to endoscopic removal. For multiple magnets beyond the stomach, the patient could be treated by enteroscopy or colonoscopy for removal if asymptomatic or followed with serial X-ray to check for progression1. However, if symptomatic, the patient should be referred to pediatric surgery1. In this study, patients were managed using the following algorithm(Fig. 1) which was based on the guidelines and the actual experiences at our center. For patients with perforation and fistula found after endoscopic removal, the general treatment is to switch to surgery14. However, one patient in this study had a fistula from the lower esophagus to the cardia. After removal, the fistula contracted, and the wound was small. Therefore, we did not perform surgery but gave gastric tube decompression and stopped his oral diet. No symptoms such as pneumoperitoneum or abdominal pain occurred. After 10 days, the gastroscope was reexamined and the wound had healed well. Then, the patient’s oral diet was restored, and the patient was discharged smoothly. Another case report shows that patients with mild symptoms of fistula did not undergo surgery and recovered smoothly after removal of the magnets by endoscopy15.
In our study, surgical procedures performed in four situations: the magnets were in the upper gastrointestinal tract but cannot be remove by endoscopy; the magnets were removed by endoscopy but gastrointestinal perforation was found after removal; the magnets were far from the upper gastrointestinal tract but the patients had gastrointestinal symptoms during the followed period; the magnets were lodged in the tract. These patients in surgical group had a delayed visit time after ingestions and suffered from a longer duration for fasting, antibiotics use, and hospital stay. Therefore, to reduce the rate of surgery we appeal to patients for early medical consulting in case of magnets ingestions, and to doctors for conducting endoscopy to suspected patients as early as possible within 24 hours. The WBC and CRP of the patients in surgical group were higher than that in non-surgical group, which suggests that if the patients have increased WBC and CRP, the doctors should alert that the patients may under a situation needs surgery.
Our study has several limitations. It was a retrospective chart review from a single hospital, and it was limited by the quality of documentation and the number of cases. In our study, we found the proportion of males in the surgical group was higher compared with the non-surgical group, which we cannot explain the reason. It may be limited by the size of the samples. Moreover, some of the patients were followed for only six months. It may be possible that some of the results cannot be sustained over a longer period.