[Nonrotation of the midgut with abnormality of the superior mesenteric artery].

This report describes an anomalous case of nonrotation of the midgut with two superior mesenteric arteries in a 74 year-old Japanese female cadaver at the anatomical laboratory of Kanazawa Medical University. The characteristics of this nonrotation case were as follows: all the small bowel shifted to the right side and all the large bowel to the left side of the abdomen; cecum and appendix vermiform were situated to the left lower abdomen; and ligament of Treiz was absent. There were three arteries originating from the abdominal aorta for blood supply of abdominal organs: 1) the celiacomesenteric trunk with the first superior mesenteric artery, 2) the second superior mesenteric artery, 3) the inferior mesenteric artery. This case had two superior mesenteric arteries. The first one arose from the celiacomesenteric trunk. The second one arose from the left wall of the abdominal aorta about 95.0 mm below the origin of the celiacomesenteric trunk and 23.0 mm above the origin of the inferior mesenteric artery. The first superior mesenteric artery with five branches supplied the inferior portion of the duodenum and the superior portion of the small bowel. The second superior mesenteric artery had five small intestinal arteries supplying the inferior portion of the small bowel, and five large intestinal arteries supplying the cecum, the ascending colon, the transverse colon and the superior portion of the descending colon. The authors believe that the existence of the two superior mesenteric arteries caused the malformation in the nonrotation of the intestinal tracts in this cadaver.