Intestinal atresia
Encyclopedia
Intestinal atresia 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.
Duodenal atresia has a strong association with Down syndrome
. It is the most common type, followed by ileal atresia.
that leads to decreased intestinal perfusion
and ischemia
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 another major intestinal artery
, is occluded, large segments of bowel can be entirely underdeveloped. Classically, the affected area of bowel assumes a spiral configuration and is described to have an "apple peel" like appearance; this is accompanied by lack of a dorsal mesentery.
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.
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 (medicine)
may be placed.
Types of intestinal atresia
The different types of intestinal atresia are named after their location:- Duodenal atresiaDuodenal atresiaDuodenal atresia is the congenital absence or complete closure of a portion of the lumen of the duodenum. -Associated conditions:Approximately 20–40% of all infants with duodenal atresia have Down syndrome....
- malformation of the duodenumDuodenumThe duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
, part of the intestine that empties from the stomach - Jejunal atresia - malformation of the jejunumJejunumThe jejunum is the middle section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms middle intestine or mid-gut may be used instead of jejunum.The jejunum lies between the duodenum...
, the second part of the intestine extending from the duodenum to the ileum - Ileal atresia - malformation of the ileumIleumThe ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.The ileum follows the duodenum...
, the lower part of the small intestine - Colon atresia - malformation of the colonColon (anatomy)The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
Duodenal atresia has a strong association with Down syndrome
Down syndrome
Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...
. It is the most common type, followed by ileal atresia.
Cause
The most common cause of non-duodenal intestinal atresia is a vascular accident in uteroIn utero
In utero is a Latin term literally meaning "in the womb". In biology, the phrase describes the state of an embryo or fetus. In legal contexts, the phrase is used to refer to unborn children. Under common law, unborn children are still considered to exist for property transfer purposes.-See also:*...
that leads to decreased intestinal perfusion
Perfusion
In physiology, perfusion is the process of nutritive delivery of arterial blood to a capillary bed in the biological tissue. The word is derived from the French verb "perfuser" meaning to "pour over or through."...
and ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
of the respective segment of bowel. This leads to narrowing, or in the most severe cases, complete obliteration of the intestinal lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
.
In the case that the superior mesenteric artery
Superior mesenteric artery
In human anatomy, the superior mesenteric artery arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas.-Location...
, or another major intestinal artery
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
, is occluded, large segments of bowel can be entirely underdeveloped. Classically, the affected area of bowel assumes a spiral configuration and is described to have an "apple peel" like appearance; this is accompanied by lack of a dorsal mesentery.
Diagnosis
Intestinal atresias are often discovered before birth: either during a routine sonogramSonogram
A sonogram may refer to the following:* A diagnostic medical image created using ultrasound echo equipment, see medical ultrasonography...
which shows a dilated intestinal segment due to the blockage, or by the development of polyhydramnios
Polyhydramnios
Polyhydramnios is a medical condition describing an excess of amniotic fluid in the amniotic sac. It is seen in 0.2 to 1.6% of pregnancies,,...
(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.
Treatment
Fetal and neonatal intestinal atresia are treated using laparotomyLaparotomy
A laparotomy is a surgical procedure involving a large incision through the abdominal wall to gain access into the abdominal cavity. It is also known as coeliotomy.- Terminology :...
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 (medicine)
Stoma (medicine)
A stoma is an opening , either natural or surgically created, which connects a portion of the body cavity to the outside environment...
may be placed.