Meconium obstruction (MO) in neonates arises from highly viscid meconium and the poor motility of the premature gut. Recently the incidence of the MO in neonates has been increasing, but, the diagnosis and treatment of this disease have not yet been clarified. Between March 2004 and April 2010, 24 neonates were treated for MO at Severance Children's Hospital. Their clinical characteristics and treatment were reviewed retrospectively. Twenty neonates were diagnosed with MO and 4 neonates were diagnosed with Hirschsprung's disease (HD). The mean birth weight and gestational age of the 20 neonates with MO were 1.45±0.90kg and 31.1±4.6 weeks, respectively. Thirteen neonates (65%) diagnosed with MO weighed less than 1.5kg and 10 neonates (50%) weighed less than 1kg. Half of the neonates with MO were treated by non-operative methods and the other half were treated by operative methods. Compared with the group that weighed over 1.5kg, the group that weighed less than 1.5kg were more frequently operated upon (61.5% vs. 28.5%), and contrast enemas were performed later and more frequently. Also the group that weighed less than 1.5kg had a higher mortality rate (15.4% vs. 0%). Three of the four neonates with HD were diagnosed with long-segment aganglionosis. In conclusion, MO occurred in very low birth weight neonates more often and must be differentiated from HD. Also, MO in very low birth weight neonates should be treated with special attention due to more a complicated clinical course.

The etiology of several motility disorders, including persistent megacolon after definitive surgery for Hirschsprung's disease, meconium ileus which is not associated with cystic fibrosis and idiopathic megacolon, is still unclear. Interstitial cells of Cajal (ICC) are thought to modulate gut motility as gastrointestinal pace maker cells. The aim of this study was to evaluate the role of ICC in the bowel walls of the patients (n=15) who had variable motility disorders. The ICC were identified by immunohistochemical staining using an anti-C-Kit antibody and the results were compared with control specimens (n=2). The control group (G1) showed evenly distributed ICC in their bowel walls. The second group (G2, n=5) who had normal bowel movements after Duhamel procedures and the third group (G3, n=4) who had persistent megacolon after Duhamel procedures showed absent or scarcely distributed ICC in their aganglionic bowels. The ICC were identified by immunohistochemical staining using an anti-C-Kit antibody and the results were compared with control specimens (n=2). The control group (G1) showed evenly distributed ICC in their bowel walls. The second group (G2, n=5) who had normal bowel movements after Duhamel procedures and the third group (G3, n=4) who had persistent megacolon after Duhamel procedures showed absent or scarcely distributed ICC in their aganglionic bowels. Whereas ICC were evenly distributed in the ganglionic bowels of G2, they were not seen or scarecely distributed in the ganglionic bowels of G3. Two patients (G4) who suffered from idiopathic megacolon showed absence or decrease of ICC in spite of presence of ganglion cells in their colons. Four neonates (G5) who underwent ileostomy because of meconium obstruction showed absent or markedly decreased ICC in the colon at the time of ileostomy and the distribution of ICC was changed to a normal pattern at the time of ileostomy closure between 39-104 days of age and their bowelmotility were restored after that. The results suggest that lack of ICC caused reduce motility in the ganglionic colons and it may be responsible for the development of various motility disorders. Delayed maturity of ICC may also play a role in the meconium obstruction of neinates.

Meconium peritonitis is a primarily aseptic, chemical peritonitis caused by the spill of meconium into the abdominal cavity through an intestinal perforation during the intrauterine or perinatal period. The perforation is known to be related to intrauterine vascular compromise. Recently, the authors experienced 4 cases of ileal atresia complicated by meconium peritonitis. The male to female sex ratio was 1 : 3, and age at operation was 1 day(2 cases), 3 days(2 cases). Three cases had generalized peritonitis, and one the cystic type of meconium peritonitis. The types of ileal atresia were IIIa(2 cases), IIIb(1 case), and II(1 case). The proximal blind ileal end was perforated in 3 cases, and distal end perforation was in 1 case of cystic type. Postoperative recovery was excellent in all cases.

A 2-day-old male {Premie, Large for gestational age(LGA), Intrauterine period (IUP) 33 weeks, birth weight 2,955 gram} was transferred with marked abdominal distention, bilious return via the orogastric tube, respiratory difficulty, and generalized edema (hydrops fetalis). He was born by cesarean section to a 36 year-old mother. Antenatal ultrasonogram at IUP 31 weeks demonstrated multiple dilated bowel loops suggestive of intestinal obstruction. There was no family history of cystic fibrosis. Simple abdominal films disclosed diffuse haziness and suspicious fine calcifications in the right lower quadrant. Barium enema demonstrated a microcolon. Sweat chloride test was not available in our institution. At laparotomy, there noted 1) a segmental volvulus of the small bowel with gangrenous change, associated with meconium peritonitis, 2) an atresia of the ileum at the base of the volvulus, and 3) the terminal ileum distal to the volvulus was narrow and impacted with rabbit pellets-like thick meconium. These findings appeared to be very similar to those of a complicated meconium ileus. In . summary, the ileal atresia and meconium peritonitis seemed to be caused by antenatal segmental volvulus of the small intestine in a patient with probable meconeum ileus.

Meconium peritonitis is defined as an aseptic, chemical or foreign-body peritonitis caused by spill of meconium in the abdominal cavity related to the prenatal perforation of the intestine. Perforation is usually caused by obstruction from meconium ileus, intestinal atresia, stenosis, volvulus, internal hernia, congenital pertoneal bands, intussusception, or gastroschisis. Less commonly, no evidence of distal obstruction exists. Here, we present two cases of generalized meconium peritonitis of antenatal diagnosis. The first case, detected at 8 months of gestational age, had a perforation of the proximal blind pouch of jejunal atresia, associated with respiratory distress due to severe abdominal distension. This case was successfullY treated with resection and anastomosis and brief period of postoperative ventilatory support. The second case had a distal ileal perforation with thick meconium in the terminal ileum. In this case, there was no dilatation of ileum proximal to the perforation site. Resection and anastomosis was performed and postoperative course was uneventful.