Closed Loop Obstruction from Epiploic Appendage Adhesion Mimicking Pericecal Internal Hernia.

Internal hernias involve herniation of viscera into an abdominal compartment through a defect in the mesentery or peritoneum. Herniation may occur through normal anatomic structures or through pathologic defects secondary to congenital abnormality, inflammation, trauma, or surgery. Patients with an internal hernia most commonly present with acute bowel obstruction. While internal hernia is an uncommon cause of bowel obstruction, making up approximately 0.2-0.9% of cases (Choi, 2017), the incidence is increasing due to greater use of techniques such as Roux-en-Y for liver transplant and gastric bypass. There are multiple types of internal hernia, including paraduodenal, Foramen of Winslow, sigmoid mesocolon, pericecal, transmesenteric, transomental, supravesical, and pelvic. We present a case in which a transverse colon epiploic appendage adhesion to the ascending colon mesentery resulted in a closed loop obstruction mimicking a pericecal internal hernia. Radiologists should be aware of the imaging findings of closed loop obstruction related to internal hernia and maintain a high index of suspicion in patients with history of prior abdominal surgery presenting with bowel obstruction. It is useful for radiologists to understand that adhesions may result in internal hernias, which mimic the classically described categories.