Duodenal Duplication Cyst Resection Complicated by Biliary Stenosis: A Case for Choledochoduodenostomy as a Salvage Procedure in a Neonate

Background: Duodenal duplication cysts (DDC) are rare congenital lesions that pose a significant surgical challenge due to their proximity to the pancreaticobiliary system. In neonates, they often present with bilious vomiting, mimicking a surgical emergency like malrotation. Complete surgical excision is the standard treatment, but the complex anatomy creates a risk for iatrogenic injury. This case is reported to highlight this critical risk and to demonstrate the efficacy of choledochoduodenostomy as a definitive salvage procedure for a complete distal biliary stricture in a young infant. Case presentation: A full-term female neonate presented on day 11 of life with bilious vomiting. After imaging ruled out malrotation but revealed a complex cystic mass, an exploratory laparotomy was performed. A non-communicating DDC attached to the second part of the duodenum was completely resected. Initial recovery was uneventful, but the infant represented at two months of age with progressive obstructive jaundice. Re-exploration revealed a complete fibrous obstruction at the ampulla of Vater, presumed iatrogenic. A side-to-side choledochoduodenostomy was successfully performed. The patient's jaundice resolved, liver function tests normalized, and she was discharged in good condition. Conclusions: This case underscores that surgical management of DDCs must prioritize the intraoperative identification and protection of the biliary anatomy to prevent secondary injury. In the event of an iatrogenic distal biliary stricture, a choledochoduodenostomy is a reliable and definitive surgical option, achieving excellent outcomes even in a neonate.