Ultrasonographic Diagnosis of Midgut Volvulus With Malrotation in Children

Objectives: Midgut volvulus with malrotation is typical in newborns. We present our experience to emphasize the importance of suspecting midgut volvulus as a cause of abdominal pain also beyond infancy, particularly in relation to malrotation, and the relevance of ultrasonographic (US) signs in its diagnosis. Methods: A total of 34 patients (10 boys, 24 girls; ages between 1 day and 12 years) diagnosed as having malrotation or malrotation with volvulus, surgically confirmed, between 2006 and 2013 were retrospectively selected among all of the patients referred to our institution for acute abdomen and bilious vomiting. All of them underwent US and color Doppler examination before surgery. The US examinations were performed with 6 to 10 MHz microconvex and 7.5 to 10Mhz linear transducer. The transducer was placed under xiphoid, and, with axial projection, the presence of anatomic position reversed between superior mesenteric vein (SMV) and superior mesenteric artery (SMA), as a sign of malrotation, and the presence of whirlpool sign (WS) (wrapping of the SMV and the mesentery around the SMA), as a sign of midgut volvulus, were evaluated. Results: In 27 of these 34 patients, midgut volvulus was present; 7 patients had intestinal malrotation. In 2 of 7 (28%) patients with malrotation, SMA and SMV were inverted. Among the patients with volvulus, 2 showed reversed vessel position and 22 patients presented the WS in association with SMA/SMV inversion (22/27, 81%). Conclusions: Midgut volvulus with malrotation can appear beyond the neonatal age group as demonstrated in our case. The WS sign is sufficiently sensitive for its diagnosis and should be routinely researched at all ages of pediatric population. Anatomic inversion between SMV and SMA seems to be not enough sensitive in isolated malrotation diagnosis.