In utero intussusception producing ileal atresia and meconium peritonitis with and without free air

Two cases of intestinal atresia due to in utero intussusception are reported. Meconium peritonitis occurred in both cases and in one free air in the peritoneal cavity was also found. Both were managed successfully by resection and end-to-end anastomosis. The intussusceptions were discovered on gross and microscopic examination of the distal ileal segment. These two cases and 33 from the literature are reviewed to determine major features of this seemingly unusual occurrence. The atresia was limited to the ileum and jejunum in all cases and involved the ileum in 77%. The atresia was limited to the gap and fibrous-connecting-cord types in all cases, with the gap type slightly more frequent (57%). In all but 1 of the 35 cases (97%), the intussusceptum was found in the small-bowel segment distal to the atresia; in only 2 were free air and calcium deposits identified at birth on X-ray studies of the abdomen. Prematurity was encountered in only 14% of the 35 cases, suggesting that intussusceptum-induced midgut atresia occurs late in pregnancy. The occurrence of two cases in 2 years in Torrance, California, and three cases in 3 years in Helsinki, Finland, suggest that this occurrence must be more frequent than the sparse incidence reported in the literature would indicate. It is suggested that careful gross and microscopic examination of the small-bowel segment just distal to the atresia be carried out in all cases of jejunoileal atresia of gap or cord types to determine the true incidence and clinical nature of this type of in utero intussusception-induced jejunoileal atresia.