Meconium Obstruction of Prematurity

  • Etiology: Extreme immaturity of the bowel prevents passage of meconium
  • Imaging AXR: Distal small bowel obstruction
  • Imaging Enema: Normal caliber colon with multiple plugs of meconium seen in the colon and small bowel
  • DDX:
  • Complications: Intestinal perforation
  • Treatment: High osmolar water soluble contrast enema (diluted 1 part contrast: 2 parts sodium chloride) which must be refluxed above dilated loops of small bowel in order to be successful
  • Clinical:
    — Seen in extremely premature infants who will have passed only a little meconium
    — Not associated with cystic fibrosis

Radiology Cases of Meconium Obstruction of Prematurity

Enema of meconium obstruction of prematurity
AXR AP (above) shows massively dilated loops of bowel throughout the entire abdomen. AXR AP taken at the beginning of an enema performed with water-soluble contrast (lower left) shows meconium filling almost the entire colon. AXR AP taken later in the exam (lower right) shows reflux of contrast into massively dilated loops of small bowel. Several hours after the enema, the patient passed a large amount of meconium and the abdomen became completely decompressed.
Enema of meconium obstruction of prematurity
AXR AP (above) shows a dilated loop of bowel in the right upper quadrant that was fixed in appearance over 3 days. AP image during a portable enema exam done with water soluble contrast (below left) shows contrast filling a microcolon and refluxing into dilated loops of terminal ileum and distal ileum but not reaching the previously identified dilated loop in the right upper quadrant. AP post evacuation image taken after the enema (below right) shows interval reflux of contrast into the dilated loop in the right upper quadrant. In the hours after the enema the patient passed a large amount of meconium.