==== Front Ann Saudi MedAnn Saudi MedAnnals of Saudi Medicine0256-49470975-4466King Faisal Specialist Hospital and Research Centre 1805911810.5144/0256-4947.2007.450asm-6-450Case ReportBarium meal followthrough and CT findings in paraduodenal hernia El Sharkawy Mohammed Sherif Al-Nakshabandi Nizar From the Department of Radiology and Medical Imaging, King Khalid University Hospital, Riyadh, Saudi ArabiaCorrespondence and reprint requests: Dr. Mohammed Sherif El Sharkawy, Department of Radiology and Medical Imaging, King Khalid University Hospital, P.O. Box 7805(40), Riyadh 11472, Kingdom of Saudi Arabia, sherif_elsharkawy@hotmail.comNov-Dec 2007 27 6 450 452 01 3 2007 Copyright © 2007, Annals of Saudi Medicine2007This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. ==== Body An internal hernia is defined as the protrusion of the viscus through a normal or abnormal opening within the confines of the abdominal cavity. It constitutes 0.2% to 0.9% of all cases of intestinal obstruction.1 Internal hernias are either congenital or acquired. Acquired hernias usually result from failure to close the mesenteric defect after bowel resection. Congenital hernias are paraduodenal (53%), transmesenteric (12%), at the foramen of Winslow (80%), paracecal (6%) and transomental (<5%).2 Because of the risk of strangulation of the hernia contents, even small hernias are dangerous and may be fatal.3,4 They may also present with vague chronic intermittent abdominal pain.1 Clinical and radiological diagnosis in the asymptomatic stage is probably impossible. With time and repeated episodes of herniation, the mesenteric defects enlarge and long segments of small bowel may herniate more, twist and become obstructed and ischemic.1 Paraduodenal hernia is the commonest type of internal hernia3 and accounts for more than 50% of internal hernias.3,5 It is left sided in 75% of patients3,6 and is believed to occur because of congenital herniation of the small bowel into the left paraduodenal fossa of Landzert,6 which is a peritoneal pocket present in 2% of autopsies.5 Hernias are rarely diagnosed preoperatively.3,4 Several suggestive findings on upper gastrointestinal series include an abnormal position of the third portion of the duodenum, the presence of an ovoid intestinal mass, delayed transit of contrast through the small bowel, and an absence of small bowel in the pelvis.7 In recent years, computed tomography (CT) has begun to play an important role in the diagnostic workup of suspected paraduodenal hernia.8 In this report, we describe the classical specific and diagnostic radiographic features of this disease, which constitutes an uncommon cause of intestinal obstruction, but also can cause bowel ischemia due to prolonged symptoms without a specific preoperative diagnosis. CASE A 38-year-old man presented with a 2-week history of recurrent crampy abdominal pain, distension, nausea and infrequent vomiting. He gave no history of abdominal operation. A small bowel followthrough examination showed a cluster of jejuneal segments on the left side of the upper abdomen giving the appearance of an ovoid mass as if contained in a sac (Figure 1). Under fluoroscopic control, manual palpation failed to displace the cluster of bowel loops or change their position. The pelvic cavity showed nearly absent opacified small bowel loops with the cluster of small bowel loops in the left paraduodenal area compressing the left side of an opacified transverse colon on delayed images (Figure 2). A diagnosis of left paraduodenal internal hernia was made. A confirmatory post-contrast CT study of the abdomen showed an encapsulated cluster or sac-like mass of jejuneal loops between the pancreatic tail and stomach, compressing the transverse colon inferiorly (Figure 3). The inward direction of the mesenteric vessels is seen within the hernia. In both examinations, bowel loops were mildly dilated but gave no evidence of small bowel loop obstruction. Laparoscopic surgery confirmed the presence of a left paraduodenal hernia, which was reduced after excision of the containing sac. DISCUSSION Internal hernias present with a variety of symptoms, ranging from vague abdominal pain up to acute intestinal obstruction. Although internal hernias are rare, paraduodenal hernia, also called congenital mesocolic hernias, mesenterico-peritoneal hernias or retroperitoneal hernias, is the commonest.3,9,10 They result from abnormal rotation of the midgut during embryonic development. 5 The diagnosis of internal hernia is difficult to make before abdominal exploration.1 These hernias are often difficult to diagnose preoperatively and often present at surgery or autopsy.1 However, it is important to consider the diagnosis in patients with obstructive symptoms and no history of prior abdominal surgery.7 Because the clinical diagnosis of internal hernia is difficult, imaging studies such as CT and small bowel followthrough play an important role.11 In the absence of a specific radiographic diagnosis, internal hernias may not be evident at surgery because they may be inadvertently reduced.6 The diagnosis of paraduodenal hernia can be made using small bowel contrast studies.10 Several reports describe the CT findings of left paraduodenal hernia.5,8,12,13 However, the bowel loops, on barium study, are seen as an encapsulated circumscribed mass of a few loops of small bowel (usually jejuneal) in the left upper quadrant, lateral to the ascending duodenum. They may have a mass effect, depressing the distal transverse colon and indenting the posterior wall of the stomach11 plus the absence of small bowel loops in the pelvis gives the characteristic appearance (as in our case), which are diagnostic. CT confirms location and allows proper operative design for correction. In our case, in the small bowel followthrough study, the appearance of a well-contained small bowel with well circumscribed borders in an abnormal location with an empty pelvis and compression on the transverse colon was diagnostic and it was confirmed by CT, which showed herniated small bowel loops in Landzert’s fossa. Figure 1 Small bowel followthrough study (SBFT): Cluster of jejuneal loops are seen in an abnormal location in the left upper abdomen giving the appearance of a contained mass (arrow heads). Figure 2 Delayed film of SBFT: The abnormally located small bowel loops (star) are smoothly indenting the transverse colon (long arrow). Note that the pelvic cavity is nearly devoid of small bowel loops (short arrow). Figure 3 Post-oral and intravenous contrast CT of the abdomen: A circumscribed cluster of small bowel loops (star) are seen anterior to the pancreas (P) and posterior-lateral to the stomach (S), containing inward directed mesenteric vessels (arrow). ==== Refs REFERENCES 1 Khan MA Lo AY Vande Maele DM Paraduodenal Hernia American Surgeon 1998 64 1218 22 9843350 2 Manji R Warnock GL Left Paraduodenal hernia: An unusual Cause of Small Bowel Obstruction Canadian Journal of Surgery 2001 44 455 457 3 Blachar A Federle MP Brancatelli G Petersen MS Oliver JH 3rd Li W Radiologist Performance in the Diagnosis of Internal hernia by using Specific CT findings with Emphasis on Transmesenteric Hernia Radiology 2001 221 442 28 4 Blachar A Federle MP Bowel Obstruction Following Liver Transplantation: Clinical and CT Findings in 48 cases with emphasis on internal hernia Radiology 2001 218 384 388 11161150 5 Nishida T Mizushima T Kitagawa T Ito T Toshinori I Suqiura T Matsuda H Unusual Type of left Paraduodenal Hernia caused by a separated Peritoneal Membrane J Gastroenterol 2002 37 742 744 12375149 6 Blachar A Federle MP Internal hernia: An increasingly common cause of small bowel obstruction Seminars in Ultrasound, CT and MRI 2002 23 178 183 7 Dristas ER Ruiz OR Kenedy GM Blackford J Hasl D Paraduodenal Hernia: A report of Two Cases The American Surgeon 2001 67 733 6 11510572 8 Suchato C Pekanan P Panjapiyakul C CT Findings in Symptomatic Left paraduodenal Hernia Abdominal Imaging 1996 21 148 9 8661761 9 Harbin WP Computed Tomographic of Diagnosis of Internal Hernia Radiology 1982 143 736 7079501 10 Rollins MD Glasgow RE Left Paraduodenal Hernia Journal of American College of Surgeons 2004 198 492 3 11 Martin LC Merkle EM Thompson WM Review of internal hernias: Radiographic and clinical findings AJR 2006 186 703 717 16498098 12 Hirasaki S Koide N Shima Y Nakagawa K Sato A Mizuo J Ogawa H Ujike K Tsuji T Unusual Variant of Left Paraduodenal Hernia Herniated into the Mesocolic Fossa Leading to Jejunal Strangulation J Gastroenterol 1998 33 734 8 9773941 13 Petrakis I Sciacca V Vrachassotakis N Chalkiadakis G Separate Sac of Peritoneum: A Case of Unusual Cause of Intestinal Obstruction Am J Gastroenterol 1999 94 518 9 10022658