Opposites attract: operative considerations in magnet ingestion

Abstract

Magnets are found commonly in children's toys and pose a risk of ingestion. Rare earth-transition metal magnets, such as ironneodymium, have a much greater coercivity than normal magnets. 1 Hence their ingestion is more likely to cause bowel injury. There have been a few case studies describing magnetic attraction between adjacent loops of bowel leading to pressure necrosis and perforation. [2][3][4][5][6][7] There is limited information on surgical technique and precautions in such cases. We report a case of bowel perforation following neodymium magnet ingestion and the operative approach.A 10-year-old boy presented to the emergency department with 24 h of colicky central abdominal pain with associated nausea. His abdomen was soft and non-tender without signs of peritonism. The blood results were normal. The impression was gastroenteritis.He represented 5 days later with persistent colicky abdominal pain. On further questioning he admitted to swallowing seven neodymium magnetic ball-bearings, on two separate occasions, 7 days ago. His abdomen was mildly distended with peri-umbilical tenderness. A plain abdominal radiograph showed metallic foreign bodies in the upper central abdomen (Fig. 1). He was observed overnight, but the abdominal pain progressed and there was evidence of peritonism. Repeat abdominal X-ray showed the magnets to be in the same position. There was concern that the magnets in adjacent loops of small bowel had united together causing pressure necrosis of the bowel wall.He came forward for an emergency laparotomy. This revealed fistulization of three magnetic balls between the proximal jejunum and the transverse colon (Fig. 2). The magnets were adherent and had necrotized and perforated through the bowel wall. The magnets were removed to find seven perforations in total, all of which were oversewn. The extracted magnets were then placed in the cut end of a glove and run over the bowel (Fig. 3). There was resistance over the second part of the duodenum and a further four magnetic balls were removed via an enterotomy. The duodenum was then oversewn. An intraoperative radiograph was performed and this did not show any further foreign bodies. The patient had a good recovery and was discharged on day 5 post operation.A recent systematic review found 98 cases of magnet ingestion in 17 countries. Ninety-six of these had resulted in bowel injury requiring bowel resection or fistula repair. In all such cases there were varying degrees of delay in diagnosis and treatment. 2 Direct questioning about foreign body ingestion may help in early diagnosis, however the history maybe unreliable in children because of their age and unwillingness to admit to foreign body ingestion. 8 Appropriate and timely imaging may be the only way of identifying magnet ingestion. 4 There is a high risk of bowel injury if more than one magnet has been ingested; hence early surgical intervention is indicated. 2,4-7 Fig. 1. Radiograph of ingested magnetic balls. Fig. 2. Fistulization of a magnet through the transverse colon.

A nationwide questionnaire survey on accidental magnet ingestion in children in Japan

“…We collected reports of accidental magnet ingestion from 2012 to 2019 using the following search formulations: “magnets”[MeSH Terms] OR “magnets”[All Fields] OR “magnet”[All Fields]) AND (“eating”[MeSH Terms] OR “eating”[All Fields] OR “ingestion”[All Fields]) AND (“child”[MeSH Terms] OR “child”[All Fields] OR “children”[All Fields]. A total of 54 patients 3,5,11‐47 were identified (Table 4). Fifty patients ingested multiple magnets.…”