is a malformation where there is a narrowing or absence of a portion of the intestine. This defect can either occur in the small or large intestine.
Types of intestinal atresia
The different types of intestinal atresia are named after their location:
- Duodenal atresia - malformation of the duodenum, part of the intestine that empties from the stomach
- Jejunal atresia - malformation of the jejunum, the second part of the intestine extending from the duodenum to the ileum
- Ileal atresia - malformation of the ileum, the lower part of the small intestine
- Colon atresia - malformation of the colon
Duodenal atresia has a strong association with Down syndrome. It is the most common type, followed by ileal atresia.
The most common cause of non-duodenal intestinal atresia is a vascular accident in utero
that leads to decreased intestinal perfusion
of the respective segment of bowel. This leads to narrowing, or in the most severe cases, complete obliteration of the intestinal lumen
In the case that the superior mesenteric artery, or other major intestinal artery, is occluded, large segments of bowel can be entirely underdeveloped. Classicaly, the affected area of bowel assumes a spiral configuration and is described to have an "apple peel" like appearance.
Intestinal atresias are often discovered before birth: either during a routine sonogram
which shows a dilated intestinal segment due to the blockage, or by the development of polyhydramnios
(the build up of too much amniotic fluid in the uterus). These abnormalities are indications that the fetus may have a bowel obstruction which a more detailed ultrasound study can confirm.
Some fetuses with bowel obstruction have abnormal chromosomes. An amniocentesis is recommended because it can determine not only the sex of the baby, but whether or not there is a problem with the chromosomes.
Fetal and neonatal intestinal atresia treated with using laparotomy
after birth. If the area affected is small, the surgeon may be able to remove the damaged portion and join the intestine back together. In instances where the narrowing is longer, or the area is damaged and cannot be used for period of time, a temporary stoma
may be placed.