Esophageal atresia tracheoesophageal fistula-(Esophageal atresia / tracheoesophageal fistula)
Esophageal atresia / tracheoesophageal fistula (EA / TEF) is a condition due to congenital abnormal development of the esophagus. In early development, the esophagus and trachea start as a single tube which is subsequently divided into the two adjacent ducts at four to eight weeks after conception. If this separation does not occur correctly, the result is the EA / TEF.
Esophageal atresia (EA), the upper esophagus is not connected to the lower esophagus and stomach. Almost 90% of newborns with esophageal atresia have a tracheoesophageal fistula (TEF), implying that the esophagus and trachea bind abnormally, allowing fluid from the esophagus to reach the airways and interfere with the breathing. A small number of newborns have only one of these abnormalities.
There are several types of EA / TEF, classified by the location of the malformation and structures that are affected. In over 80% of cases, the lower section of malformed esophagus is connected to the trachea (EA with distal TEF). Other possible forms include the upper section of malformed esophagus connected to the trachea (EA with proximal TEF), having the upper and lower section of the esophagus connected to the trachea (EA with proximal and distal TEF) having a malformed esophagus not connects to the windpipe (EA isolated), and having a connection to the tracheal esophageal moreover (H type TEF without EA).
Although the EA / TEF arises during embryonic development, this malformation is usually evident shortly after birth. Saliva, fluids feeding the newborn, or digestive fluids may enter the trachea through tracheoesophageal fistula, causing coughing, cyanosis and respiratory distress. Esophageal atresia blocking the entry into the stomach of fluid feeding the newborn, so that they are ejected upward, sometimes together with fluids of the respiratory tract. The EA / TEF is a condition that endangers life, so affected babies usually require surgery to correct the defect in order to allow food and prevent lung damage from repeated exposure of esophageal fluids. In approximately 40% of affected individuals, the EA / TEF occurs in isolation. In other cases it occurs with other birth as part of a genetic syndrome (EA / TEF not isolated or syndromic) defects.
It is considered that the EA / TEF isolated is a multifactorial process, which means that multiple genetic variations and environmental factors probably contribute to its appearance. In most cases, they have not determined conclusively specific genetic changes or environmental factors as grounds for the disease.
Forms uninsulated or syndromic EA / TEF may be due to changes in specific genes or chromosomes, or may be due to multifactorial causes. For example, about 10% of people with CHARGE, which generally is due to mutations in the gene CHD7 has EA / TEF. About 25% of individuals with trisomy 18 are born with EA / TEF. The EA / TEF also occurs in association VACTERL a multifactorial disorder characterized by vertebral defects, anal atresia, cardiac abnormalities, tracheoesophageal fistula, renal anomalies and extremities. People diagnosed with VACTERL association generally have at least three of these characteristics and between 50 and 80% has a tracheoesophageal fistula.
When the EA / TEF occurs as a characteristic of a genetic syndrome or chromosomal abnormality can be grouped into families in accordance with the inheritance pattern for that particular process. Often the EA / TEF is not inherited, and only has identified an affected individual in a family.