Embryologic Abnormalities of the Mesentery

Abstract

Embryologic abnormalities of the mesentery that require surgical intervention are most commonly related to abnormal positioning of the bowel within the peritoneal cavity resulting from failure of any of the above 3 steps. These abnormalities are categorized under various forms of malrotation. Malrotation is thought to affect 1:500 live births with the majority becoming symptomatic within the first year of life. Classic malrotation presents as bilious emesis in infancy from duodenal obstruction or midgut volvulus, and it is usually associated with abnormal or absent intestinal fixation by mesenteric bands. The bands, known as Ladd bands, fix the cecum to the posterior body which traps the duodenum leading to obstruction. The duodenojejunal attachment is abnormally short which makes the gut prone to twist counterclockwise around the superior mesenteric vessels leading a volvulus. An upper GI series is the standard of care for diagnosis and will show a variation in the normal positioning of the duodenojejunal junction.