Internal Hernia Through a Mesoappendix Defect: A Case Report and Review of the Literature.

Internal hernias are an uncommon cause of small bowel obstruction (SBO). If not identified and treated promptly, they can lead to severe complications. Among these, herniation through a mesoappendix defect is exceedingly rare. To our knowledge, SBO due to a mesoappendiceal defect has only been described in a limited number of cases. In this case, a 76-year-old woman presented to the emergency department with a two-day history of acute lower abdominal pain, accompanied by nausea, vomiting, and abdominal distension. Diagnostic imaging revealed a partial small bowel obstruction with two transition points. During diagnostic laparoscopy, a loop of proximal ileum was found herniating through a mesoappendix defect, resulting in a closed-loop obstruction. The herniated bowel was viable and was successfully reduced, followed by an appendicectomy. The postoperative recovery was uneventful. This case highlights the need to consider internal hernias in the differential diagnosis of SBO, even in patients with prior abdominal surgeries.