Congenital midgut malrotation results from failure of the midgut to complete the normal 270 degree counter-clockwise rotation that occurs during embryologic development. The result is malposition of the intestine, as well as malfixation of mesentery predisposing to midgut volvulus.
Malrotation often presents during the neonatal period with bilious vomiting. Because midgut volvulus is an acute surgical emergency, an upper GI examination should be performed without delay in a newborn with bilious emesis. Malrotation can be diagnosed on Upper GI exam by failure of the duodenal-jejunal junction to cross to the left of the midline, and by abnormally low position of the D-J junction (normal position is at the level of the pylorus). Midgut volvulus is diagnosed by a spiral or “corkscrew” appearance of the proximal small bowel, or by complete obstruction at the site of volvulus. The findings of midgut volvulus are absent in this case.
This case is a 1-year old child without history of vomiting. The findings include the duodenum and jejunum (including the D-J junction) located entirely on the right side on the spot views, and the 30 minute film confirms position of the jejunum and proximal ileum on the right side. This pattern is one subtype of malrotation, often referred to as “nonrotation”. A subsequent delayed radiograph showed that the colon was in the middle and left abdomen. This type of malrotation is less likely to undergo volvulus, and may be identified in older children or even adults with nonspecific abdominal complaints or as an incidental finding. However, this type of malrotation also includes an abnormal mesenteric pedicle and may undergo volvulus (acute, chronic or intermittent) even in adulthood.