Omphalomesenteric duct (OMD)

• omphalomesenteric duct (OMD) appears at the beginning of embryonic life as a long, tubular structure that connects the midgut to the yolk sac
  • the OMD normally regresses during the 5th-9th weeks of fetal development, leaving a solid cord that runs from the ileum to the umbilicus
  • if the lumen of the OMD has not completely disappeared at birth, various abnormalities can result including a fistula between the ileum and the umbilicus, an omphalomesenteric duct sinus emerging from the umbilicus and blind ending, a cyst representing a remnant of a patent segment of the OMD, a diverticulum whose enteric portion is patent, that is, Meckel's diverticulum, or an umbilical polyp
  • approximately two percent of the population may have an OMD remnant, and the commonest variant is an asymptomatic Meckel's diverticulum

Reference:

• 1) Khati NJ et al. Imaging of the umbilicus and periumbilical region. Radiographics 1998;18 (2): 413-431