Lockdown dilemma: ingestion of magnetic beads presenting as right iliac fossa pain and subacute small bowel obstruction

Background

Right iliac fossa (RIF) pain is a common general surgical presentation, of which acute appendicitis is of clinical relevance due to the need for early operative intervention.1 Ingestion of magnetic objects has been reported to present with RIF pain, and some patients have even gone on to have appendectomies only to later present again with bowel obstruction.2 The use of ultrasound scan is common in women presenting with RIF to exclude gynaecological pathologies. However, this modality has poor specificity and sensitivity in the diagnosis of acute appendicitis.3 While MRI scan is an excellent imaging modality, care needs to be taken in children as they might have swallowed metallic objects which are a contraindication to MRI due to potential harm.4 Serial ingestion of multiple magnetic objects has been reported to cause fistula formation, volvulus, bowel perforation, abdominal abscess and even death.5

We report a rare case of the ingestion of magnetic beads presenting with RIF pain and subacute small bowel obstruction, so as to highlight the dangers of these toy magnetic beads and to sensitise clinicians as to the importance of thorough history taking and examination over reliance on imaging modalities.

Case presentation

A 13-year-old girl presented with a 3-day history of generalised abdominal pain which had localised to the RIF in the last 24 hours; the pain was described as a constant dull ache, worse on movement and 9 out of 10 in severity. There was associated nausea and reduced appetite but no vomiting; bowel habit was normal—no fever, no flu-like symptoms. She had no symptoms suggestive of COVID-19 infection nor contact. There were no urinary symptoms, no bleeding per vaginam nor discharge, and her last menstrual period was a month ago, though she noticed some spotting a few days before presentation. There was no family history of inflammatory bowel disease, and she had no underlying medical conditions nor previous abdominal surgeries. On examination, her abdomen was not distended, moved with respiration and tender in the RIF with no rebound tenderness, and Rovsing’s sign was negative. Her full blood count and electrolytes were within the normal range, and her observations were stable with a Paediatric Early Warning Score of 0. Urinalysis was normal, and beta-human chorionic gonadotrophin (bHCG) was negative. She proceeded to have an ultrasound scan, and it was reported as ‘small amount of free fluid is noted in the pelvis. At the RIF, there is a tubular echogenic structure with an irregular end; a ruptured appendix cannot be excluded. Please correlate clinically.’ The scan revealed no gynaecological pathology. The findings of the scan were explained to the child’s parent, and due to the fact that the clinical picture was not in keeping with complicated appendicitis, a provisional diagnosis of non-specific abdominal pain or possible early appendicitis was made, and the patient was discharged with clear safety netting advice and analgesia; antibiotics were not commenced as there was no clinical indication.

The patient presented again 6 days later with worsening abdominal pain which had not settled with simple analgesia, now associated with multiple episodes of non-bilious vomiting; her bowels were still opening. Other signs and symptoms were similar to her previous presentation—temperature was 35.9°C, heart rate of 88 beats per minute, white cell count of 10.3×10⁹/L (reference range: 4.5–13.0), neutrophils of 8.1×10⁹/L (1.8–8.0) and C reactive protein of 5 mg/L (0–5). She had a repeat ultrasound scan, and an MRI scan was recommended for further assessment. The clinical decision was made to proceed to a diagnostic laparoscopy due to ongoing pain.

Investigations

On readmission, the second ultrasound scan was reported as follows:

Free fluid in the right paracolic gutter, tracking into the pelvis along with prominent lymph nodes in the right iliac fossa, the largest of these measures up to 8 mm in short axis diameter, there is a minimally peristaltic tubular structure over the area of maximal tenderness as indicated by the patient with sonographic features indicative of inflammation. Owing to the limitations of this study is difficult to ascertain whether this is inflammation of the terminal ileum or the appendix. Clinical and biochemical correlation is suggested. Depending on the index of suspicion, further evaluation of the bowel with an MRI study can be considered.

Differential diagnosis

On initial presentation, the possibility of acute appendicitis was suspected; however, due to the overall clinical picture, a provisional diagnosis of non-specific abdominal pain or mesenteric adenitis was also entertained. The ultrasound scans raised the possibility of retrograde menstruation as her menstrual period was also due.

Treatment

Diagnostic laparoscopy revealed normal-looking appendix, ovaries and uterus—200 mL of reactive serous fluid in the pelvis which was suctioned, a loop of bowel attached to the ascending colon and a tangle of small bowel loops attached to omentum (figure 1); the liver and gallbladder appeared normal with the stomach dilated; hence, a nasogastric tube (NG) was passed for decompression. Careful and gentle blunt dissection revealed an enterotomy that magnetised the laparoscopic instruments, first raising the suspicion of ingested foreign body. On further blunt dissection, an interloop fistulous tract was noticed with a chain of five magnetic beads in-between bowel loops (figure 2), while another tract had three magnetic beads and a further six magnetic beads were found in adjacent bowel loops. Intraoperative X-ray images were taken to ensure all the magnetic beads were retrieved (figure 3). The caecum and ascending colon were mobilised to reduce the need for a full laparotomy. A midline 3 cm infraumbilical incision was made, and on further inspection, nine enterotomies were identified with a total of 14 magnetic beads extracted. A wedge resection and double layer closure of the ascending colon enterotomy were performed, while other small bowel enterotomies were repaired using single layer sutures. The small bowel was inspected to ensure no fistulous tract or enterotomy was missed. A drain was left in situ, and the midline wound was closed with interrupted non-absorbable sutures. Total operative time was 3 hours, 19 min.

Outcome and follow-up

On the first postoperative day, her NG tube output was 110 mL in 24 hours. Her observations and blood tests showed no significant derangement; she had a good urine output, the pain was under control, her bowels were not yet opened and she was not passing wind.

Over the course of the next couple of days, her NG tube was removed and oral intake was established and tolerated; she started passing wind, the abdominal drain was removed as the output was haemoserous and less than 50 mL in 24 hours. Due to her excellent recovery, she was discharged on the third postoperative day.

A telephonic consultation 1 week post operation revealed no significant complaints.