Meconium Plug Syndrome

Etiology: Immature enteric plexus causing functional immaturity of colon
Imaging AXR: Distal small bowel obstruction with distended air-filled loops of distal ileum
Imaging Enema:
— Normal caliber of rectum
— Narrow caliber left colon to level of splenic flexure
— Dilated proximal colon with a long meconium filling defect or cast in colon
DDX:
Complications: Intestinal perforation
Treatment: High osmolar water soluble contrast enema (diluted 1 part contrast: 2 parts sodium chloride) which must be refluxed into terminal ileum in order to be successful
Clinical:
— Seen in infant of diabetic mother and infant of mother who has had MgSO4
— Usually spontaneous resolution after enema but 25% have underlying Hirschsprung disease so if obstructive symptoms persist after enema perform rectal biopsy

Radiology Cases of Meconium Plug Syndrome

Enema of meconium plug syndrome — Enema shows the left colon to be smaller in caliber than the rest of the colon. There is a long meconium filling defect throughout the colon.

Barium enema of meconium plug syndrome — AXR shows a distal bowel obstruction. Water-soluble contrast enema shows normal caliber of the ascending and transverse colon and rectum, but decreased caliber of the descending (left) colon.

Enema of meconium plug syndrome — AXR AP (above left) shows a dilated bowel gas pattern. AP image from an enema (above right) shows a normal caliber colon with the descending colon being slightly smaller in diameter than the rest of the colon. Large filling defects representing meconium are seen throughout the colon. The terminal ileum was refluxed. Clinical image (below) shows a foot-long piece of meconium that was evacuated by the patient after the exam.

Radiology Cases of Meconium Plug Syndrome and Malrotation Without Midgut Volvulus

Enema of meconium plug syndrome — AP image from a contrast enema exam (left) shows a long filling defect in the colon within a normal caliber colon. The cecum was noted to be in the left mid abdomen. The terminal ileum was not refluxed. AP image from an upper GI exam (right) shows that while the duodenal jejunal junction projects over the left pedicle of the spine it is much lower in position than the duodenal bulb.

Clinical Cases of Meconium Plug Syndrome

Clinical image of meconium plug — Clinical image shows a contiguous plug of meconium that was expelled by the patient after a water-soluble contrast enema.

Clinical image of meconium plug — Clinical image shows a contiguous plug of meconium that was expelled by the patient after a water-soluble contrast enema.

Clinical image of meconium plug — Clinical image obtained after performance of a high osmolar water soluble enema and subsequent evacuation of contrast shows a one foot long continuous plug of meconium.