Histopathologic study of esophageal atresia and tracheoesophageal fistula in an animal model.

A histopathologic study of tracheoesophageal anomalies was conducted on an Adriamycin-treated animal model to determine how closely it resembles the human pattern. Adriamycin was administered (2 mg/kg body weight) to timed-pregnant rats on days 6 through 9 of gestation. The fetuses were recovered at term, dissected and prepared for histological studies. Dissection showed a similar range of variants of tracheoesophageal anomalies as seen in humans. Esophageal atresia with distal tracheoesophageal fistula was by far the most common type. Other varieties were seen such as esophageal atresia without a fistula, tracheal atresia and hypoplastic esophagus with atrophic mucosa, and muscle coat. Serial sectioning of the distal segment showed tracheobronchial elements extending to a variable distance from the origin of the fistula.