Douglas Moote;
Connecticut Children's; Hartford Hospital
Background
Congenital internal hernias are an abnormal protrusion of abdominal viscera through an opening within the peritoneal cavity. The orifice can be through a normal foramen, a normal anatomic variant, or through an abnormal opening within the peritoneum. There is a wide spectrum of clinical presentations for congenital internal hernias, ranging from asymptomatic or vague abdominal discomfort to severe abdominal pain due to bowel strangulation. Several types of congenital internal hernias have been described, each varying in location. Appropriate interpretation of imaging studies, such as with barium studies or CT, is essential to accurate diagnosis. We present a case of a 17-year-old boy with a 2-week history of persistent abdominal pain, nausea, emesis, and decreased appetite. Prior to this, he had experienced several months of headache and abdominal pain. A fluoroscopic upper gastrointestinal with small bowel series was obtained, along with an abdominal CT, which demonstrated an internal hernia. The patient subsequently underwent a laparoscopic hernia repair.
Educational Goals / Teaching Points
Congenital internal hernias have been categorized based on herniation through a normal foramen, extension through a peritoneal fossa or recess into the retroperitoneum, or through an abnormal defect within the mesentery or peritoneum. The latter can be further categorized as transmesenteric (fenestra type) or intramesenteric (pouch type). Several types of internal hernias have been described within these categories which include left paraduodenal, right paraduodenal, foramen of Winslow, pericecal, intersigmoid, and transmesenteric hernias. Each type of internal hernia can be identified based on location and characteristic findings on barium studies or CT.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Fluoroscopic small bowel series demonstrates a well encapsulated group of jejunal loops in the right central abdomen consistent with an internal hernia. Coronal CT also demonstrates encapsulated jejunal loops just inferior to the duodenum consistent with a right paraduodenal hernia. Intraoperative image shows small bowel herniating through a defect to the right of the Ligament of Treitz, diagnostic of a right paraduodenal hernia. Axial CT demonstrates a cluster of small bowel in the left upper quadrant of the abdomen. The inferior mesenteric vein is seen anteromedial to the hernia sac. Findings are characteristic of a left paraduodenal hernia. Axial CT demonstrates a cluster of small bowel posterior and lateral to the descending colon, characteristic of an intersigmoid hernia.
Conclusion
Congenital internal hernias are a rare cause of acute or chronic abdominal pain. A clear understanding of radiographic imaging is critical in accurate identification of the specific type of internal hernia, in effort to best guide surgical management.
