Duodenal haematoma occurs in children with bicycle injuries

Editor—Closed duodenal injury is a good topic to highlight as a lesson of the week. Surgical injuries to the upper abdomen are a fairly rare childhood injury, and few doctors will diagnose them with the necessary speed.¹ Lam et al remind us to examine the paediatric abdomen carefully and frequently after blunt trauma and not to rely too heavily on imaging.

One other type of intra-abdominal damage caused by handlebar injury is not highlighted in this paper. The first and third parts of the duodenum may be crushed between the handlebar and the lumbar spine, causing rupture of the subserosal blood vessels and resulting in a slowly expanding intramural haematoma.² The child may be relatively free of symptoms until the haematoma causes complete obstruction of the duodenal lumen; as a result, the diagnosis is often delayed.

Important clues to the diagnosis include the history of upper abdominal trauma, persistent vomiting, and air-fluid levels in both the stomach and duodenum (the so called double bubble) in a plain erect abdominal x ray film. If doubt still exists, contrast study of the upper gastrointestinal tract will show partial to complete obstruction of the duodenum, with a “stacked coins” or “coiled spring” appearance caused by oedematous mucosal folds proximal and distal to the point of maximum obstruction.

Perhaps the most important reason to confirm this diagnosis is that, as an isolated injury, duodenal haematoma does not require laparotomy. Patients can be successfully managed with free nasogastric drainage and parenteral nutrition, and duodenal patency should return within 10-14 days. Clinical deterioration at any stage, or failure of the condition to resolve with this conservative regimen, should raise suspicion of a misdiagnosis or other concomitant injury.

Road traffic injury was the commonest cause of duodenal haematoma in the small series of nine cases in South Africa that Voss and I reported,² but bicycle injury predominated in a larger series from North America.³ There, as in the United Kingdom, more children are likely to own and ride bicycles than in South Africa, and motor vehicles are driven with more restraint than they are in South Africa.