Successful Treatment of Rare-Earth Magnet Ingestion via Minimally Invasive Techniques: A Case Series

Introduction

Ingestion of foreign bodies in the pediatric population remains a common clinical problem.^1–3 Ingestion of magnets, and more recently ingestion of rare-earth magnets, has become a cause of significant morbidity.^2,4–8 Rare-earth magnets are commonly made of neodymium boron or samarium cobalt, with magnetic strength of up to 1.5 T, which greatly exceeds those of the more common ferrite variety (“refrigerator magnets”). ⁹ Indeed, rare-earth magnets can attract and lift an object a thousand times their own weight. These magnets are sold alone as Buckyballs^® (Maxfield & Oberton, New York, NY) or Nanospheres (Kringles Toys and Gifts, American Fork, UT) magnets or as part of building sets and play sets. Buckyballs, in particular, are marketed as desk toys/puzzles for adults and come in sets of 100–200 rare-earth magnets. Buckyballs are spherical balls with a diameter of about 5 mm, marketed in black, chrome, and gold finishes, making them inviting for children to play with, and a comfortable size and shape for even young children to put into their mouths and ingest.^2,4 Although the company's Web site warns consumers to keep Buckyballs away from children less than 14 years old and details the risk of bowel injury and tissue entrapment, retail stores often do not post visible warnings. ⁵ Children may gain access to Buckyballs when parents fail to recognize their potential danger and allow children to play with them. Despite warnings displayed on the Web site, journal publications, public health announcements, and newspaper articles, rare-earth magnet ingestion continues to occur. The purpose of this study is to retrospectively examine our recent experience in children with rare-earth magnet ingestions admitted to the only children's hospital in Hawaii.

Patients and Methods

We performed a medical record search of all children admitted to Kapiolani Medical Center for Women and Children, Honolulu, HI, with the diagnosis of magnet ingestion over an 18-month period from January 2011 to July 2012. In addition to medical records review, we supplemented our database with reports, clinical images (Figs. 1 and 2), and follow-up information from the pediatric surgeons and the pediatric gastroenterologist involved in the cases (S.M.J., R.K.W., and J.L.K.). This study was approved by Kapiolani Medical Center for Women and Children's Institutional Review Board, and informed consent was obtained from the parents of all of the children included in this case series.

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FIG. 1.

Case 3. Abdominal radiograph showing 13 magnets strung together in a chain just right of the midline.

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FIG. 2.

Case 7. Intraoperative laparoscopy demonstrates magnetic foreign body erosion through the posterior stomach wall and into the adjacent loop of the small bowel.

Results

We identified eight children admitted to Kapiolani Medical Center for Women and Children with rare-earth magnet ingestion during the 18-month period of the study. The children ranged in age from 2.5 years to 10 years, with a mean age of 5.5 years. None of the children had any significant previous medical history. It is important that there were no children with developmental delays or disabilities, factors that have been associated with foreign body ingestion. ³

Data from the eight children are summarized in Table 1. In addition, two of these children are described below as brief case summaries to highlight the spectrum of presenting signs and symptoms, treatment, and hospital stay. All of the children were treated successfully with minimally invasive surgical techniques, and all were discharged home without any complications. It is important that no child required a laparotomy as part of treatment.

Discussion

To our knowledge, this article represents the largest single-institution case series of rare-earth magnet ingestion in the literature. It also highlights the success of treatment to discharge using minimally invasive techniques to remove the magnets and repair the fistulas in these eight children, thereby avoiding a more invasive surgical approach such as laparotomy.

Rare-earth magnets appeared on the market in 2003 as components of toys and building sets, with ingestion occurring after the magnets were dislodged from the toys. However, subsequent to a published warning from the Centers for Disease Control and Prevention in 2006, a large voluntary recall removed many of these toys from the market. ² Later in 2009, rare-earth magnets were marketed as adult desk toys and packaged as multiple magnet units with trade names such as Buckyballs and Nanospheres. In 2011, the U.S. Consumer Product Safety Commission compiled a report reaffirming the risk of rare-earth magnet ingestions by documenting increasing numbers of ingestion reports. ⁴ Subsequently, the U.S. Consumer Product Safety Commission filed an administrative complaint in an effort to mandate that the company manufacturing Buckyballs notify the public of the hazards of these magnets and offer refunds to their customers. They also asked other manufacturers of rare-earth magnet toys to voluntary recall their products; 11 of 12 companies complied. ⁶

Magnet ingestions can result in significant bowel injury, inflammation, and even death.^2,8,10–16 In 2009, Oestreich ³ reviewed 128 cases of magnet ingestion from 21 countries, including Asia, Europe, and North America, in a 20-year span between 1988 and 2008. Surgical findings reported in the series included intestinal perforation, obstruction, intussusception, ulceration, peritonitis, abscess formation, adhesions, fistulas, volvulus, internal hernia, mesenteric compression, and free magnets in the peritoneum. Surgical therapy and removal of the magnets invariably utilized a formal surgical laparotomy. Although some of the cases reported in this series involved rare-earth magnets (particularly those reported after 2003), no attempt was made to distinguish the effects and potential morbidities associated with different types of magnet ingestion. However, the review did document the frequent delays in referral and diagnosis.

More recent literature has focused specifically on rare-earth magnet ingestions. The North American Society of Pediatric Gastroenterology, Hepatology and Nutrition collected data on the prevalence of rare-earth magnet ingestions through an informal survey of pediatric gastroenterologists throughout the United States. ⁶ Eighty cases of rare-earth magnet ingestion were identified. From the data collected, a proposed algorithm for management of children with rare-earth magnet ingestions was developed. The algorithm detailed a management approach based on presenting symptoms and magnet location including observation, endoscopy, and surgical intervention. Finally, two recent reports in the literature described 3 cases of magnet ingestion in which all three children underwent open laparotomy.^7,8 Endoscopy and laparoscopy were not attempted in these cases.

In our series, three children presented early after they were suspected of magnet ingestion when they were observed playing with the magnets, and medical care was sought promptly. Two of these children were asymptomatic, and one was mildly symptomatic. Removal was accomplished without delay via endoscopy in two, whereas laparoscopy was used in the third child to retrieve magnets that had passed into the proximal small bowel. One of these early-presentation children who had minimal symptoms demonstrated mucosal injury on endoscopy. A fourth child presented late after ingesting nine magnets bound together in the shape of a ring but, probably because of this anomaly, did not suffer fistula formation or mucosal injury as the ring-shaped magnet complex was successfully removed during colonoscopy. The fifth case involved a child who notified his parents of his ingestion 2 days following the ingestion after developing symptoms of abdominal pain and decreased appetite. He was found to demonstrate bowel wall erosion, with early signs of fistula formation. Three of the remaining children presented 5–8 days after ingestion. These children had a variety of symptoms that included abdominal pain, vomiting, and changes in appetite. They were treated successfully with a combination of endoscopy and laparoscopy guided by fluoroscopy. In addition to removing the magnets, all three had associated fistulas, which were successfully closed. Finally, the eight children in this series were all discharged home uneventfully and without complication.

Our institutional experience adds to growing literature that documents the dangers of rare-earth magnet ingestion. We speculate from our experience that prompt intervention may reduce the potential risk of complications such as fistula formation. Strong attractive magnetic forces possessed by rare-earth magnets, when apposed to one another after multiple magnet ingestion, increase the risk of mucosal tissue entrapment, tissue compression, and ultimately fistula formation. Based on the experience gained in this series, we believe that complications occur in a time-dependent fashion, with fistula formation occurring sometime between 2 and 5 days, and that prompt intervention can prevent or reduce impending tissue damage and injury. Moreover, our case series suggests that other factors are also important in determining injury because one of the children who presented within hours of ingestion had evidence of mucosal injury and microhemorrhage, whereas the late-presenting child who ingested the ring-shaped magnet complex had none.

It is important to emphasize that none of the eight children in our series required an open abdominal procedure, as commonly reported in the literature.^{2,4,7,8,12,13,16} They were treated successfully with a minimally invasive approach consisting of endoscopy, laparoscopy with the option of fluoroscopy, and colonoscopy. It is interesting that metallic laparoscopic and endoscopic instruments aided in removal because of their strong attractive forces with the rare-earth magnets. In cases of magnet groups located in different areas of the abdomen, fluoroscopy aided rapid localization of additional magnets. In all cases requiring laparoscopic removal, intraoperative radiographs were used to confirm complete removal of the magnets.

Finally, we recommend that primary healthcare providers, emergency department physicians, and pediatric hospitalists who encounter children suspected of magnet ingestion involve their pediatric gastroenterologists and surgeons early and consider using this menu of minimally invasive surgical approaches as initial therapy before resorting to laparotomy. We also suggest that intervention be initiated early and without delay to avoid the risk of progressive tissue damage, fistula formation, and other more serious morbidities and mortality.