Pericaecal hernia

Pericaecal hernia (alternative plural: herniae) is a rare type of internal hernia.

Epidemiology

It accounts for only 6-13% of internal abdominal hernias.

Clinical presentation

Clinical symptoms are often characterized by episodes of intense lower abdominal pain, like a colicky right lower quadrant pain very similar to the appendiceal pain, often causing confusion.

Pathology

Four subtypes (ileocolic, retrocecal, ileocecal, and paracaecal) of herniations occur in the pericaecal fossa (located behind the cecum and ascending colon and is limited by the parietocecal fold outward and the mesentericocecal fold inward). It is due to acquired or congenital defects in the cecal mesentery.

Retrocecal hernia is the most common subtype caused by herniation of ileal loops through a defect in the cecal mesentery and the right paracolic gutter.

Radiographic features

Fluoroscopy 

Delayed radiograph series of the small bowel or a barium enema examination may show retrograde opacification of the terminal ileum.

CT

These hernias can often be confidently diagnosed as a cluster of bowel loops (usually ileal) located posteriorly and laterally to the normal cecum, occasionally extending into the right paracolic gutter. In addition, a beaking appearance at the entrance of the hernia, and a dilated afferent small bowel loop and collapsed efferent loop in the transition zone may be seen. There might be evidence of small-bowel obstruction and mass effect displacing the cecum anteriorly and medially.