XI. MALROTATION OF THE MIDGUT
In general, rotational anomalies are associated with any diaphragmatic or
abdominal wall defect where abdominal contents are trapped outside the abdomen, and
therefore preventing normal rotational development.
Malrotation occurs in 1 in 500 live births, 2/3 of patients present in newborn
period. Up to 2/3 of neonates with malrotation may also have midgut volvulus
Embrology
Stage 1: Herniation of midgut
Around 10 weeks of gestation ,the midgut protrudes through vitelline sac into
base of umbilical cord.
Stage 2: Return to abdomen
At 10-12 weeks gestation, midgut returns into abdominal cavity and in the
process rotates 270 degrees counterclockwise around the superior mesenteric
artery. Failure of this process may result in a rotational anomaly such as
incomplete rotation (i.e. malrotation), paraduodenal hernia, or reversed rotation.
Stage 3: Fixation
After 12 weeks gestation, fixation occurs and continues until birth. Failure to
fixate results in mobile cecum or retrocecal appendix.
Clinical Presentation