Internal hernia through a congenital fibrolipomatous omental ring causing jejunal incarceration and acute intestinal obstruction: a case report

Background Internal hernia is an uncommon cause of small bowel obstruction, accounting for fewer than 2% of cases, with congenital forms being particularly difficult to diagnose preoperatively due to nonspecific symptoms. Herniation involving the greater omentum is exceptionally rare, and cases in which an omental ring itself serves as the constricting agent have been scarcely reported. Methods We describe a case of a 69-year-old female with no prior abdominal surgery who presented with acute upper abdominal pain, nausea, and vomiting. Physical examination revealed peritoneal signs and laboratory tests showed leukocytosis. Contrast-enhanced computed tomography (CT) was performed, followed by emergency exploratory laparotomy. The constricting omental ring was completely excised and submitted for histopathological examination. Results CT imaging revealed dilated small-bowel loops, free peritoneal fluid, a mesenteric “whirl sign,” and a low-density ring-like structure in the right abdomen compressing the bowel. Intraoperatively, a well-formed ring-like structure (=5 cm in length) at the lower edge of the greater omentum was found to have tightly incarcerated a 120 cm segment of jejunum. The incarcerated bowel was congested and edematous but remained viable after release. The patient recovered uneventfully and was discharged on postoperative day 7. Histopathology of the resected ring demonstrated fibrolipomatous hyperplasia with degenerative changes and proliferating vessels, consistent with a hamartomatous lesion of congenital origin. Conclusions This case represents a rare entity characterized by jejunal internal hernia secondary to a suspected congenital fibrolipomatous ring within the greater omentum. Surgery is an important modality for both diagnosing and treating incarcerated hernia complicated by acute intestinal obstruction. This report broadens the etiological spectrum of internal hernia and highlights the importance of recognizing occult congenital omental anomalies in patients with closed-loop obstruction and no surgical history.