Introduction
Congenital intestinal obstruction covers mechanical blockage of the bowel that is present from birth because of a developmental malformation of the gut or its mesentery. It is a major cause of neonatal surgical emergencies. The exam answer should cover classification, embryological cause, the typical neonatal picture, the characteristic radiological signs, the principles of pre-operative and operative management, and the main complications and prognosis. Intussusception, mesenteric thrombosis and dynamic ileus are covered in separate topics.
Definition and classification
Congenital intestinal obstruction is a bowel obstruction caused by a malformation that is already present at birth. Malformations are classified by their site and by their pathological form (atresia, stenosis, web, duplication, malrotation). The main types are summarised below.
Aetiology and embryology
- Duodenal atresia results from failed recanalisation of the duodenal lumen after the solid phase of development, at about 8 to 10 weeks of gestation.
- Jejunoileal atresia is thought to follow an in-utero vascular insult to the superior mesenteric territory, leading to segmental loss of bowel. Multiple atresias can occur.
- Meconium ileus is caused by thick, sticky meconium, most often because of cystic fibrosis. It is the earliest intestinal manifestation of that disease and should prompt a sweat test.