Prenatal occlusion of the superior mesenteric artery results in a distinct type of distal duodenal or proximal jejunal atresia in which the dorsal mesentery is absent and the distal small bowel assumes a spiral configuration around its vascular stalk, strongly resembling an apple peel. In some instances the condition is transmitted genetically as an autosomal recessive disorder. The mortality rate is much higher than in either simple duodenal or jejunal atresia because of deficient collateral circulation to the small intestine. The authors tell of 2 patients who died of necrotizing enterocolitis, a disease related to vascular insufficiency.