What is the basic mechanism underlying intestinal malrotation?
Failure of the normal counterclockwise 270 degree rotation of the midgut around the superior mesenteric artery as it returned into the abdominal cavity during embryogenesis.
Why does malrotation predispose to midgut volvulus?
As a result of the malrotation, there is a shorter mesenteric root. This can act as a pedicle around which midgut volvulus may occur. Interestingly, patients with nonrotation have a lower incidence of midgut volvulus than those with other types of malrotation
What is a more often encountered complication of malrotation in an older child or adult?
Intermittent duodenal obstruction due to Ladd's bands (as opposed to midgut volvulus).
What additional congenital abnormalities may be associated with intestinal malrotation?
Duodenal atresia/stenosis/web, congenital diaphragmatic hernia, gastroschisis, omphalocele, heterotaxy, chonal atresia
Frontal and lateral projections from an upper GI study demonstrate abnormal bowel configuration.
On the frontal view, the duodenum is noted to not cross the midline, and the duodenojejunal junction is inferior to the level of the pylorus.
On the lateral view, a "corkscrew" appearance of the proximal small bowel is demonstrated, suggestive of volvulus.
Altogether the findings are in keeping with malrotation with midgut volvulus.