Non-Rotation of the Midgut in Adults

Abstract

Two cases of non-rotation of the midgut were detected in cadaveric bodies from the Department of Anatomy, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. They were both female, aged 83 and 32, respectively. In both cases, the duodenum, jejunum, ileum, and colon lay in the unrotated position with the small intestine occupying the right half and the large intestine occupying the left half of the abdominal cavity. Additionally, the duodenojejunal junction remained on the right side of the abdomen, whereas the caecum and ascending colon lay in the midline, with the terminal ileum entering the right side of the caecum. The appendix entered the left side of the caecum. Interestingly, they had had no clinical symptoms during life. These abnormalities implied that midgut rotation during embryonic period occurred only as far as 90-degrees counterclockwise instead of the usual 270-degree rotation.

To our knowledge, this is the first report of asymptomatic non-rotation of the midgut in Thailand. The variation found in the present study provides additional information concerning the variation seen in human anatomy and should be considered in patients with atypical symptoms related to the gastro-intestinal tract.