An exercise in radiologic-pathologic correlation.

Abstract

Intestinal obstruction in the newborn can be a difficult diagnostic problem for the radiologist, and on many occasions a precise diagnosis cannot be determined. Because of a lack of specific radiographic signs, the vague diagnosis of small bowel or large bowel obstruction may be as definitive as is possible. The case presented this month can be accurately diagnosed because of its multiple specific signs. Radiologic Findings A supine roentgenogram of the abdomen (Fig. 1) reveals multiple dilated loops of gas-filled bowel, varying in size. Some are greatly distended, while others are only moderately affected. A mottled appearance on the right side of the abdomen suggests the presence of numerous minute bubbles of gas. There is a granular or “ground-glass” appearance of the mid-abdomen. Upright roentgenograms of the abdomen (Figs. 2 and 3) show only a few small airfluid levels, which are less impressive than would be expected in view of the amount of gaseous distension present on the supine films. In addition, the chest is noted to be clear. A postfluoroscopy film taken after a barium enema shows a microcolon of disuse (Fig. 4). Differential Discussion: The radiographic findings indicate an intestinal obstruction in a newborn infant. In addition, one can surmise that the obstruction lies above the colon, since the barium enema shows an unused colon. The common causes of intestinal obstruction in the newborn include the meconium-plug syndrome, stenosis or atresia of the bowel, malrotation with volvulus, imperforate anus, peritoneal band, incomplete type of transverse septum, and meconium ileus. Incomplete types of intestinal obstruction, such as those caused by a peritoneal band, duplication of the gut, incomplete transverse septum, or occasionally midgut volvulus, can all be eliminated because the barium enema examination shows complete disuse of the colon. Volvulus of the midgut causing complete obstruction should be considered. This is an unlikely diagnosis, however, since it is characterized by obstruction of the third portion of the duodenum. In addition, with midgut volvulus the jejunum is displaced into the right upper quadrant and the cecum lies high on the left side (3). Also, the mottled appearance seen on several roentgenograms (Figs. 1 and 2) has not been associated with this disease. The meconium-plug syndrome or meconium-blockage syndrome should be considered and would be compatible with the picture of dilated loops containing small fluid levels as well as the mottled or “bubbly” appearance that we see in our case. Mikity et al. (6) found, however, that a barium enema study will show a colon of normal caliber in the meconium-blockage syndrome with large pieces of meconium measuring 0.1 to 1.5 cm causing radiolucent defects in the barium column.