Closed duodenal loop syndrome in newborns: a rare case report of concomitant pyloric and distal duodenal atresias and focused literature review.

Congenital pyloric atresia (CPA) is a rare cause of neonatal gastric outlet obstruction. Although usually isolated, CPA may coexist with additional gastrointestinal atresias. Its association with distal duodenal atresia (DA) is particularly relevant because the segment between the two obstructions may become a closed duodenal loop into which biliary and pancreatic secretions continue to drain. We report the case of a male newborn delivered at 35 + 3 weeks of gestation after prenatal detection of severe polyhydramnios, recurrent bowel dilatation, abdominal effusion, and a cystic abdominal lesion. Postnatal radiography did not show the classic double-bubble sign. Exploratory laparotomy revealed CPA, marked dilatation of the second duodenal portion, distal DA, extensive adhesions, and jejunal perforations. Surgical management included adhesiolysis, reduction duodenoplasty, gastrointestinal continuity reconstruction, and jejunal perforations repair. The postoperative course was complicated by hemorrhagic-hypovolemic shock, coagulopathy, liver dysfunction, and the need for a second surgery due to increasing abdominal free fluid and suspected pneumoperitoneum, followed by progressive recovery. Follow-up demonstrated adequate gastric emptying and duodenal transit, satisfactory growth, and age-appropriate neurodevelopment. A focused narrative review on concomitant CPA and DA was also conducted. Concomitant CPA and distal DA should be considered when prenatal imaging shows a cystic abdominal lesion associated with polyhydramnios and ascites. Recognizing closed duodenal loop syndrome may improve prenatal counseling, atypical imaging interpretation, and surgical planning.