2020 Volume 36 Issue 1 Pages 36-45
Bis-diamine was administered at a dose of 200 mg to 40 pregnant rats on the 9th and 10th days of gestation. Following cervical dislocation of these rats on the 21st day of gestation, the fetuses were delivered by cesarean section and then frozen immediately in acetone cooled to −76°C with dry ice. The thorax of each frozen fetus was cut transversely, and the section surface was serially photographed using a stereoscopic microscope (Wild M400 Photomacroscope) at every 500 µm. Among 300 fetuses, congenital heart disease (90％), thymic hypoplasia (100％), and diaphragmatic hernia (40％) were identified. In the 120 fetuses with diaphragmatic hernia, pulmonary and cardiac hypoplasias were recorded as follows. The liver and stomach occupied the left thorax; the heart deviated to the right and was hypoplastic. The left lung was hypoplastic as a result of the invasion of the liver and stomach into the left hemithorax. In cases with the most severe hernia, the liver and stomach occupied the total left hemithorax, resulting in minimal residual left lung. The right lung was also hypoplastic due to a rightward shift of the cardiac and mediastinal structures. In mild cases, only a small portion of the liver invaded the left posterior hemithorax, with mild hypoplasia of the left lung, normal right lung, and near-normal heart structures. These pictures clearly show the variability in cardiopulmonary hypoplasia due to the invading abdominal organs into the left hemithorax.
