During development of the embryo, the structures that will eventually form the respiratory tree and the gastrointestinal tract start off as a small dimple at the base of the mouth. The tissue around this dimple rapidly grows and separates to form these two organ systems. For reasons that aren’t completely understood (though there are lots of theories), this process occasionally goes wrong, so a connection develops between the esophagus and trachea, and in most cases, the proximal and distal portions of the esophagus separate from each other, so the esophagus fails to develop as one continuous, hollow tube. As the embryo grows, the proximal and distal ends of the esophagus separate from each other by a distance which varies from a very little to a large distance. The latter is known as “Long –Gap EA.” Long-Gap EA is a difficult surgical problem, as it makes it difficult for the surgeon to stretch the two portions of the esophagus and connect them back together. It’s important to know that not only are the esophagus and trachea connected (usually in the lower part of both structures), but the tissue around the connection in both the esophagus and trachea are not normally-formed, and this plays an important role in the development of long-term complications.