Anomalies and Defects
1. Esophageal atresia and trachea-esophageal fitsula. esophageal atreasia represents a failure of the esophagus to develop as a continuous passage. Instead, it ends as a blind pouch. This happens as a result of a defect in programming of foregut differentiation. Trachea-esophageal fistula represents an abnormal opening between the trachea and the esophagus. Both esophageal atreasia and trachea-esophageal fistulas can occur separately or together. The esophagus often communicates with the trachea either above or below the atresia. Treatment for both cases is surgery to repair the defect.
Figure 7. Esophageal atresia and Tracheo-esophageal fistula. (Sadler, 2010)
2. Pulmonary agenesis and pulmonary aplasia: are rare defects in the development of the lung buds.
3. Pulmonary hypoplasia: is secondary to pulmonary compression during development. May be secondary to diaphragm eventration or congenital diaphragmatic hernia.
Note: Impairment of lung development usually occurs after 16 weeks’ gestation, at a stage when development of the bronchial tree is nearly complete. If the disturbance occurs before 16 weeks, bronchial malformations are also observed.
4. Eventration of the diaphragm: is caused by a defective development of the musculature of the diaphragm. The diaphragm is intact but is very thin due to the lack of musculature.
Figure 8. Eventration of the diaphragm on a normal x-ray. The incomplete formation of the diaphragm is observed, and is usually represented by the elevation of the affected side of the diaphragm. http://www.radswiki.net/main/index.php?title=File:Diaphragmatic_eventration_002.jpg Downloaded on April 8, 2011.