- Neonatal intestinal obstruction can be due to a variety of causes
- Presenting clinical features are often similar
- Bile-stained vomiting is never normal in a neonate and implies obstruction
- 95% of babies pass meconium within the first 24 hours of life
- Failure to pass meconium is also a feature of obstruction
- The degree of abdominal distension is variable
Duodenal atresia
- Occurs in 1 in 10,000 live births
- Site of obstruction is most commonly in 2nd part of duodenum
- Proximal duodenum become hypertrophied
- 50% are associated with polyhydramnios
- 60% of such pregnancies are complicated or end prematurely
- Can often be diagnosed with antenatal ultrasound
- 30% of babies with duodenal atresia have Down's syndrome
- Other associated abnormalities are cardiac anomalies, malrotation and biliary atresia
- Postnatally presents with bilious or non-bile stained vomiting
- X-ray may show a 'double-bubble' and no gas within the bowel distally
Management
- A nasogastric tube should be passed
- Intravenous fluid resuscitation should be given
- Major cardiac and other defects should be excluded
- Duodenoduodenostomy should be performed when resuscitated
Other atresias
- Atresias of the small bowel and colon are less common
- Often associated with polyhydramnios
- Bilious vomiting and distension are key features
- x-ray will show dilated bowel and a gas-free rectum
- A nasogastric tube should be passed
- Intravenous fluid resuscitation should be given
- At operation, dilated proximal bowel should be resected or tapered
- A primary anastomosis may be possible
Meconium ileus
- Commonest cause of neonatal intraluminal intestinal obstruction
- 80% cases are associated with cystic fibrosis
- Cystic fibrosis occurs in 1 in 2000 live births
- Inherited as an autosomal recessive trait
- Viscid pancreatic secretions cause autodigestion of pancreatic acinar cells
- Resulting meconium is abnormal and putty-like in consistency
- Meconium becomes inspissated in the lower ileum
- There is a microcolon
- Presents with bilious vomiting and distension usually on first day of life
- Passage of meconium is delayed
- Meconium filled loops of bowel may be palpable
- X-ray may show a 'ground-glass' appearance, especially in the right upper quadrant
Management
- Gastrografin enemas may be successful in 50% of patients
- If unsuccessful, surgery will be required
- Limited resection and stomas may be required
Malrotation
- Between 4 and 10 weeks of development intestines herniate into umbilical cord
- When returned to abdomen they rotate 270 degrees anticlockwise
- As a result
- Duodenojejunal flexure lies to the left of the midline
- Caecum lies in right iliac fossa
- Transverse colon lies anterior to the small bowel mesentery
- Partial failure of rotation results in malrotation
- Commonest abnormality results in caecum lying close to DJ flexure
- Resulting midgut mesentery is abnormally narrow and liable to volvulus
- Fibrous bands may be present between caecum and DJ flexure (Ladd's bands)
- Two principal clinical presentations
- Presents late with intermittent bile stained vomiting and distension
- Presents early with collapse and acidosis due to intestinal infarction
- Radiological investigations are often unhelpful
Management
- After resuscitation, early laparotomy may be required
- Any volvulus should be reduced
- Resection may be required if there has been small bowel infarction
- Any Ladd's bands should be divided
- The base of the mesentery should be elongated
- Colon should be placed on the left of the abdomen
- Small bowel should be placed on the right
- Inversion appendicectomy should be performed to prevent future diagnostic uncertainty
Picture provided by Osama Bawazir, Alberta Children's Hospital, Calgary, Canada
Bibliography
D'Agostino J. Common abdominal emergencies in children. Emerg Med Clin North Am
2002; 20: 139-153
Della Vecchia L K, Grosfeld J L, West K W et al. Intestinal atresia and
stenosis: a 25-year experience with 277 cases. Arch Surg 1998; 133: 490-496.
Ziegler M M. Meconium ileus. Curr Probl Surg 1994; 31: 731-777. |