Definition of Atresia
Atresia is a condition in which a body orifice or passage in the body is abnormally closed or completely absent. Atresia can affect many structures in the body, including:
- Anal atresia -- congenital absence of the anus (also called imperforate anus).
- Aortic atresia -- congenital absence of the valvular opening into the aorta.
- Biliary atresia -- absence of the major bile ducts.
- Choanal atresia -- congenital failure of nasal passages to open.
- Esophageal atresia -- a birth defect in which part of esophagus is not hollow.
- Intestinal atresia -- obliteration of the hollow of the small intestine, involving the ileum or the jejunum or duodenum.
- Laryngeal atresia -- congenital failure of the laryngeal opening to develop.
- Pulmonary atresia -- congenital absence of the pulmonary valve opening in the heart.
- Tricuspid atresia -- congenital lack of the tricuspid valve opening.
- Vaginal atresia -- congenital occlusion of the vagina or subsequence adhesion of the walls of the vagina occluding it.