PURPOSE: The aim of this study was to describe the dysmorphogenetic process leading to esophageal atresia and tracheoesophageal fistula (EA + TEF) in the recently developed Adriamycin model of the malformation. METHODS: Time-mated pregnant rats were given either Adriamycin (1.75 mg/kg intraperitoneally) or saline on days 6 to 9 of gestation, and their embryos recovered on days 12, 12.5, and 13 were serially sectioned in the transversal plane and studied microscopically after H&E and PAS staining. The findings were compared with those of age-matched untreated embryos. RESULTS: All untreated and saline embryos were normal, whereas 49% of Adriamycin embryos had foregut malformations. Tracheoesophageal separation was complete on day 12 in control embryos, whereas 9 of 10 Adriamycin-exposed embryos had a common esophagotrachea with low emergence of the bronchi at that stage. This pattern had evolved into that of a regular EA + TEF in all nine malformed embryos by day 13. On day 12.5, esophagotrachea was found in 6 of 13 and EA + TEF in 5 of 13 embryos. Two had less well-defined malformations. CONCLUSIONS: Esophagotrachea equivalent to complete tracheoesophageal cleft is the first step leading to EA + TEF in this model. The full-blown malformation is finally acquired by partial loss of the posterior wall of the foregut, which tapers-off in the mediastinal mesenchyme and respiratory differentiation of the anterior wall down to the level of bronchial bifurcation, where it constitutes the fistula and the distal esophagus.
PURPOSE: The aim of this study was to describe the dysmorphogenetic process leading to esophageal atresia and tracheoesophageal fistula (EA + TEF) in the recently developed Adriamycin model of the malformation. METHODS: Time-mated pregnant rats were given either Adriamycin (1.75 mg/kg intraperitoneally) or saline on days 6 to 9 of gestation, and their embryos recovered on days 12, 12.5, and 13 were serially sectioned in the transversal plane and studied microscopically after H&E and PAS staining. The findings were compared with those of age-matched untreated embryos. RESULTS: All untreated and saline embryos were normal, whereas 49% of Adriamycin embryos had foregut malformations. Tracheoesophageal separation was complete on day 12 in control embryos, whereas 9 of 10 Adriamycin-exposed embryos had a common esophagotrachea with low emergence of the bronchi at that stage. This pattern had evolved into that of a regular EA + TEF in all nine malformed embryos by day 13. On day 12.5, esophagotrachea was found in 6 of 13 and EA + TEF in 5 of 13 embryos. Two had less well-defined malformations. CONCLUSIONS: Esophagotrachea equivalent to complete tracheoesophageal cleft is the first step leading to EA + TEF in this model. The full-blown malformation is finally acquired by partial loss of the posterior wall of the foregut, which tapers-off in the mediastinal mesenchyme and respiratory differentiation of the anterior wall down to the level of bronchial bifurcation, where it constitutes the fistula and the distal esophagus.
Authors: L Martinez; M De Ceano-Vivas; S Gonzalez-Reyes; F Hernandez; V Fernandez-Dumont; W M Calonge; E Ruiz; J I Rodriguez; J A Tovar Journal: Pediatr Surg Int Date: 2004-11-27 Impact factor: 1.827