Congenital absence of the trachea.

In 1941 Wolman reviewed the data of 11 cases of congenital stenosis of the trachea and recorded one of his own. One of these cases was a stillborn child; seven of the live-born infants died under the age of 6 months. Gruber (1870) recorded the details of the stillborn case. Finkelstein (1924) described the case, cited by Wolman, where death took place at the age of 4 days; in this infant the lumen of the trachea was the size of a pencil lead. In such cases the trachea may be narrowed throughout its length or only for a short segment of 1-2 cm. The case recorded here showed complete absence of the trachea. Discussing the development of the lungs, Snyder and Rosenfeld (1937a and b) believed that intrauterine respiratory movements play a major role in this development, aiding the dilatation of the alveoli. Each alveolus of foetal lung has a lumen, which is not obliterated ; fluid is present in this lumen and its source has been the subject of much discussion. Snyder and Rosenfeld believed its source was from the aspiration of the media in which the foetus is immersed, and is necessary for normal development. However, Potter and Bohlender (1941) have reported two unusual abnormalities of the respiratory system which indicated that the inflow and outflow of amniotic fluid in the foetal respiratory tract is not essential for normal alveolar development. These malformations indicated that the fluid in the foetal alveoli can be a transudation of body fluid through the alveolar walls, and that normal lung development may occur without the inflow of amniotic fluid. One of Potter and Bohlender's cases had a malformation of the cricoid cartilage producing the respiratory obstruction. The lungs in this case were normal histologically with normal alveolar development.