Omphalomesenteric Duct in a Neonate with Omphalocele Minor

On primary supply following delivery of a hypotrophic preterm boy (gestational age 36 weeks, Apgar 8/9/10, birth weight 1010 g (<1st percentile)), an omphalocele minor (2.5×5 cm) was diagnosed with a central aperture (0.8 cm diameter) emptying meconium (figure 1). Laboratory assessment and organ screening were inconspicuous, and no associated congenital malformation was detected in the otherwise healthy patient. Subsequent laparotomy following physiological adaptation confirmed an omphalocele minor solely containing intestinal loops and identified an omphalomesenteric duct (OMD) opening on the top of the sac (figure 2). The OMD (0.4 cm diameter, 3.8 cm length) was arising from the terminal ileum presenting with a post ductal ileal stenosis (calibre difference 2.5:1). Segmental resection was performed, and ileal continuity was restored. No further intestinal anomalies were detected. Histopathology confirmed normal ileal wall architecture of OMD without tissue ectopia. Further clinical course was uneventful. The neonate passed stools on day 4 following surgery, and transition to enteral feeding was completed on day 10. Omphalocele has an incidence of 1 per 4000 live births and is defined as an anterior abdominal wall defect with evisceration of abdominal cavity contents covered by a membrane consisting of peritoneum, amnion and Wharton’s jelly. Patency of the OMD connecting the yolk sac to the embryonic midgut by the seventh to eighth gestational week results from failed obliteration. Only few reports exist on the occurrence of an open ending OMD in omphalocele minor. 4 5 Resection of OMD and primary closure of abdominal wall defect is considered treatment of choice.