Midgut volvulus incidentally diagnosed during an outpatient ultrasound

Midgut volvulus, a complication of intestinal malrotation, is a surgical emergency. Due to its embryologic aetiology, it is predominantly seen in neonates; with about 90% of cases involving children under the age of 1. The majority of these are diagnosed within the first month of life. However, midgut volvulus has been reported in adults of varying ages across the literature.

We present a case of a 16-year-old girl with generalised but severe abdominal pain in the central and lower abdomen. Ultrasound revealed a clockwise malrotation of the bowel with involvement of the superior mesenteric vessels, in keeping with the 'whirlpool sign'. The proximal duodenum appeared distended. Within the whirlpool, there was evidence of peristalsis in the bowel loops and blood flow in the mesenteric vessels, suggesting a lack of ischaemia in the involved bowel loops. Three months later, the patient was presented to the emergency department with symptoms of vomiting and severe abdominal pain. Computed tomography scan revealed a mesenteric swirl in the mid-abdomen involving the mesenteric vessels, consistent with the previous ultrasound findings of midgut volvulus, and the proximal duodenum remained distended.

Midgut volvulus is often overlooked in older children and teenagers presenting with abdominal pain, largely due to its rarity in these age groups.

Our case emphasises the importance of clinicians maintaining an open mind and considering imaging, particularly ultrasound, as part of the initial evaluation.