Digestive tract birth defects

The digestive tract begins at the mouth and ends at the anus. The esophagus is the muscular tube that connects the back of the mouth to the stomach. Waste (feces) is stored temporarily in the rectum before being passed out of the body through the anus.

During fetal development, parts of the digestive tract may fail to form properly. Two such birth defects are esophageal atresia (obstruction of the esophagus) and imperforate anus (malformation of the anus). These defects may occur together. Most babies born with esophageal atresia also have a tracheo-esophageal fistula, which means the trachea (windpipe) is connected to the esophagus.

The causes of these malformations are unknown, so prevention is not possible. An excess of amniotic fluid surrounding the baby during pregnancy (polyhydramnios) may sometimes indicate the presence of these defects.

Esophageal atresia#

Esophageal atresia is a group of malformations that block the esophagus. Instead of attaching to the stomach, the esophagus may end in a closed sac, or join with the trachea leading to the lungs. Around one third of affected babies also have other birth defects, including congenital heart disorders and imperforate anus.

Symptoms include excessive dribbling, an inability to feed properly, and vomiting. Esophageal atresia or stenosis (an abnormally narrow esophagus) occurs in around one in every 1,800 births. Diagnosis may involve threading a slender feeding tube down the baby’s esophagus to see whether it reaches the stomach, along with x-rays.

Treatment#

Esophageal atresia requires immediate surgery. If the baby also has a tracheo-esophageal fistula, this needs prompt repair too, and preferably both operations are done at the same time. The atresia is repaired by sewing together the two halves of the tube. If the gap is too large to bridge, the baby may need to be tube fed for some time until the gap narrows. A prolonged hospital stay follows surgery.

Long-term difficulties#

In most cases the child has some feeding difficulties, even after a successful operation. Peristalsis, the muscular movement of the esophagus that massages food down to the stomach, is not as coordinated as normal, so there may be problems with swallowing, and swallowed food may occasionally lodge in the esophagus rather than passing into the stomach. The child may also be prone to reflux or heartburn.

Tracheo-esophageal fistula#

Most babies born with esophageal atresia also have a tracheo-esophageal fistula, where the esophagus is connected to the trachea. This allows swallowed food into the lungs and air into the esophagus.

Symptoms include coughing and choking when feeding, and a blue tinge to the skin caused by a lack of oxygen (cyanosis). An x-ray may reveal air inside the esophagus.

Treatment#

Tracheo-esophageal fistula requires immediate surgery. The fistula is sewn closed, generally during the same operation that repairs the esophageal atresia.

Long-term difficulties#

Long-term problems after repair can include:

• A characteristic cough caused by floppiness of the trachea. The trachea may temporarily collapse during hard breathing, such as crying, leading to noisy breathing and sometimes respiratory difficulty.
• Increased susceptibility to respiratory infections.

Imperforate anus#

Instead of the rectum joining the anal opening normally, several malformations may occur:

• The rectum may end in a closed sac without connecting to the anus.
• The rectum may lead to other areas of the body, such as the vagina or urethra.
• The anus itself may be missing.

In many cases the rectum is also abnormally narrow, which further limits its function. Anorectal atresia (obstruction) and stenosis (narrowing) occur in around one in every 1,800 births.

Symptoms include an absent or unusually located anus, no feces passed within two days of birth, or feces leaving the body through the vagina or urethra. Other problems sometimes seen with imperforate anus include exomphalos (herniation of the intestines and other abdominal organs through a hole in the abdominal wall), esophageal atresia and tracheo-esophageal fistula. The condition is diagnosed by physical examination and x-rays.

Treatment#

Imperforate anus is corrected with surgery, and the technique depends on the nature of the defect. Usually, initial treatment involves sewing the rectum to a surgical hole in the abdominal wall (stoma) and fitting a colostomy bag so that feces can leave the body. Any connections to the vagina or urethra are closed. Anal repair surgery is carried out later, when the rectum is attached to the anus and an opening may need to be made.

Long-term difficulties#

Depending on the presence and functioning of the surrounding nerves and muscles, the child may have problems with bowel continence. Measures to keep the feces soft, along with a special diet, may be needed for several years.

Key points#

• The causes of these malformations are unknown, so prevention is not possible.
• Symptoms of esophageal atresia include excessive dribbling, an inability to feed properly and vomiting.
• Symptoms of tracheo-esophageal fistula include coughing and choking when feeding, and a blue tinge to the skin due to lack of oxygen (cyanosis).

Where to get help#