Right retrocolic intrasaccular duodenum: Is it a novel variant of isolated duodenal nonrotation? A case report

Background: Almost all of the studies on anomalies of the midgut rotation and fixation in the literature and related sections in textbooks were designed according to Dott's classification. Focusing only on common rotation anomalies has led to the exclusion and neglect of other rare variants. Isolated pure duodenal nonrotation is such a variant.Case Presentation: We report a case of an unusual form of isolated pure duodenal nonrotation, in a 3-day-old newborn presenting with bilious vomiting. Ultrasonographic examination revealed the sign of 'whirlpool'. When this finding was evaluated together with bilious vomiting, midgut volvulus was considered and the patient was operated on urgently. Peroperatively, it was observed that the jejunum entered between the leaves of the terminal ileum mesentery. Proximally, the duodenum was located posterior to the right colon in a "sack". This "sack" was surrounded by thick Ladd's bands laterally, mesentery of the ascending colon medially, the posterior surface of the cecum and ascending colon anteriorly, and by the posterior abdominal wall posteriorly.Conclusion: In isolated duodenal nonrotation, the duodenum may be completely retro-colic. Consequently, the duodenojejunal junction and the ileocecal region may almost overlap. Unlike isolated duodenal nonrotation cases, in the surgical treatment of this variant, separation of Ladd bands alone is not sufficient, additionally, the right colon should be placed in a nonrotation position and care should be taken not to kink the terminal ileum under the cecum.