Differentiating between clinically similar conditions that can cause abdominal pain, distention, and an intestinal obstruction is important. Adhesive bands are the most common cause for adult intestinal obstruction. Imaging often reveals markedly distended fluid-filled small bowel loops, with a distinct transition to adjacent collapsed loops distal to the band responsible for the obstruction. Additionally, no specific orientation of the bowel loops is noted, as seen in cases of paraduodenal hernia.
A volvulus demonstrates a closed dilated segment of the small intestine, with a "C"- or "U"-shaped configuration of the bowel loops and fusiform tapering at the point of torsion. Other types of hernias may be either external or internal. External hernias are diagnosed by demonstrating the hernial sac bulging through the specific abdominal wall defect for each hernia, which can contain omentum only, bowel, or even solid organ outside the abdominal cavity. Common types include inguinal hernia, in which the hernial sac bulges into the inguinal canal; femoral hernia, in which the hernial sac bulges into the femoral canal; obturator hernia, in which the hernial sac bulges into the obturator canal; ventral hernia, in which the hernial sac bulges through the anterior or lateral abdominal wall; and spigelian hernia, in which the hernial sac bulges intramuscularly between the external abdominal aponeurosis (which remains intact) and internal abdominal muscles, lateral to the rectus sheath muscle.
Internal hernias, as described above, are diagnosed as protrusions of bowel loops through a congenital or acquired defect of mesentery within the abdominal cavity. In addition to paraduodenal hernias, another type of internal hernia is a transmesenteric hernia, in which the bowel loops are seen in the right iliac fossa adjacent to the ileocecal valve.[3,5,6,7] Hernias in the mesentery, mesocolon, mesosigmoid, Winslow foramen, and defects of the falciform ligament have been described.
Imaging modalities reveal specific findings in the setting of a paraduodenal hernia. Plain abdominal radiographs may show markedly distended segments of bowel in cases wherein the hernia is associated with a small bowel obstruction (ie, closed loop). Fluoroscopic-guided small-bowel follow-through reveals crowding bowel loops in an abnormal location either to the right or left of the colon. In a left paraduodenal hernia, it reveals a circumscribed ovoid mass of jejunal loops in the left upper quadrant region lateral to the ascending duodenum. In a right paraduodenal hernia, it reveals a circumscribed ovoid mass of jejunal loops lateral and inferior to the descending duodenum.
Varying degrees of small-bowel obstruction may be present, and a transition point may also be observed. The mass of bowel loops are fixed; the clustered loops cannot be separated or displaced by manual palpation or change in position. The preferred imaging modality, however, is abdominal CT scanning, which reveals evidence of any degree of intestinal obstruction and/or an encapsulated cluster of bowel loops (usually jejunal) in the left upper quadrant region lateral to the ascending duodenum. Displacement of the stomach anteriorly is common, with inferior displacement of the transverse colon and inferomedial displacement of the duodenojejunal junction. The mesenteric vessels are often crowded and engorged, with associated mesenteric inflammatory changes (stranding).[1,2,3,5,7]
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Cite this: Ehab H. Youssef. A 70-Year-Old Woman With Progressive Abdominal Pain - Medscape - Aug 09, 2016.