Meckel's Diverticulum

Clinical

Meckel's diverticulum is the failed obliteration of intestinal end of omphalomesenteric duct, a finding reportedly present in 2-3% of autopsies. This true diverticulum (containing all three bowel wall layers) is found 40-150 cm proximal to ileocecal valve, within the ileum. Clinical presentation is variable, and symptomatology can arise in children or adults. 50% contain heterotopic mucosa (usually gastric), and the most common adult manifestation is ulceration and bleeding. In children, SBO (usually from intussusception), pseudoappendicitis (diverticulitis), or rarely, perforation, can also occur.

Radiological

Plain Films

Plain films are nonspecific and include distal SBO, sentinel loop in the right lower quadrant, or occasionally, enteroliths within the diverticulum.

Fluoroscopy

Fluoroscopy is a more sensitive evaluation for Meckel's diverticulum. It usually presents as a contrast-filled outpouching containing a triangular fold pattern or rugae. With inussusception, a polypoid filling defect can be observed projecting into the bowel lumen. When a Meckel's diverticulum presents as bleeding, an ulcer can occasionally be found.

Nuclear Medicine

Technetium-99m pertechnetate selectively localizes to gastric mucosa. Because a large percentage of Meckel's diverticula contain gastric mucosa, Tc-99m pertechnetate can be an effective means of evaluation. The study is dubbed a "Meckel's scan". A positive test entails a "hot spot" of increased activity, usually in the right lower quadrant. Note, however, that because only 50% of Meckel's diverticula contain gastric mucosa, a negative Meckel's scan does not exclude the diagnosis.