The effect of chick embryo hyperflexion on tracheoesophageal development.

Chick embryos were hyperflexed by placement of a ligature at two critical stages in the development of the foregut, in order to test the theory that esophageal atresia and tracheoesophageal fistula result from embryonic hyperflexion. Only one "H-type" tracheoesophageal fistula was found. There were no significant disturbances of either tracheal or esophageal growth.