Esophageal Atresia with and without Tracheo-esophageal Fistula

Definitions:
Esophageal atresia: A failure of the esophagus to form completely.
Tracheo-esophageal fistula (TEF): An abnormal connection between the esophagus and trachea.

Background:
Esophageal atresia and tracheoesophageal fistula are congenital anomalies which occur together in over 90% of cases. In the most common forms, some degree of the mid-portion of esophagus is missing. The upper portion of the esophagus simply ends with a blunt round end.  The lower portion of the esophagus sprouts off of the trachea and continues down to the stomach. Esophageal atresia occurs 1 in 4000 live births and was universally fatal until 1935.

There are 5 different types of TEF/EA. While a classification system does exist, most surgeons prefer to describe them rather than use a lettered classification. The most common type is proximal EA with distal TEF, which accounts for 86% of cases. Isolated EA without a fistula is rare and accounts for only 5% of cases. EA with Proximal and Distal TEF (double fistula) (3%), EA with Proximal TEF (1.5%), H-Type: No Atresia, only TEF (5%).

Etiology:
Of esophageal atresia is unknown, but several theories exist. Most of these theories lack plausible evidence. Intraembryonic pressure (very unlikely), epithelial occlusion, failure of recanalization (complete lack of evidence), vascular accident, differential growth, faulty development of the lateral esophageal ridges, ventral displacement of the dorsal fold.

Embryology:
Esophageal atresia occurs before 34 days gestation, which is often before the mother even knows she is pregnant. Normally the esophagus and trachea start out as one tube, and then divided into 2 completely separate structures. Most theories center on abnormal separation of these structures.

Clinical presentation:
Many infants are now diagnosed by prenatal ultrasound. Since results of antenatal repair are now exemplary, no centers offer fetal surgery. The upper esophageal is often large and pouch-like on ultrasound. The stomach is usually abnormally small (microgastria). Some patients have too much fluid (polyhydramnios) due to inability to swallow amniotic fluid. At birth, the infants often have excessive drooling of saliva and then choke or cough with first attempts at feeding. This may lead to progressive respiratory distress. In contrast, TEF without Esophageal Atresia (H-Type) may be much more subtle. They often present later with milder coughing or choking with feeds or reflux. Normal upper GI’s may miss isolated TEF. Diagnosis is therefore made with either a “pullback” esophagram using a feeding tube, or rigid bronchoscopy. Rigid bronchoscopy is the best test form making the diagnosis, but requires general anesthesia. Flexible bronchoscopy may make the diagnosis, but some cases may be missed with a flexible scope.

Associated anomalies:
The VACTERL Association was first described in 1973 as VATER. It is not a syndrome but a group of non-random associations. Half of patients have associated anomalies, and most deaths are related to associated anomalies.

VATER / VACTERL

• Vertebral anomalies
• Anal (Imperforate Anus)
• Cardiac anomalies
• TEF
• EA
• Renal dysplasia
• Limb anomalies (radial side)

Work-up:
Children with EA need a complete physical exam with special attention to identify associated anomalies. An OG tube is passed from the mouth into the esophagus. If it does not pass into the stomach, the diagnosis is highly suspected. A chest x-ray is then obtained with the OGT in place. This helps confirm placement and allows the surgeon to estimate the gap between the 2 ends of the esophagus. If there is no air in the stomach, no TEF is present. Most isolated EA is “long gap,” and requires multiple staged surgeries to repair. An echocardiogram of the heart must be obtained prior to surgery. A renal ultrasound (for hydronephrosis) is preferably done prior to surgery as well. Other studies such as a spinal ultrasound for tethered cord can be done after surgery. The final confirmation of the diagnosis is made in the operating room with a pre-operative bronchoscopy to confirm the presence of a fistula.

Treatment:
The head of the bed is elevated to decrease aspiration of saliva into the lungs. Antibiotics may be started at the discretion of the neonatologist or surgeon. Timing of surgery is individualized. Large healthy, near-term babies usually undergo repair after the cardiac echo is completed. Sicker babies may be given time to resolve any pulmonary hypertension. This may delay surgery for 24 to 72 hours. Small, ill babies undergo surgery when the treating team feels the infant is optimized and stable enough to tolerate surgery.

Surgery:
Proximal EA with distal TEF (“common type”): Ligate TEF and repair EA. No gastrostomy tube placement. Surgery is done through a right Thoracotomy.
Isolated EA (Long Gap Esophageal Atresia): a G-Tube is placed for feeding. An OGT is placed on constant oropharyngeal suction to clear secretions. After 3 months, a study is done with dye in the stomach under fluoroscopy to determine options for repair or replacement of the esophagus.
H-Type TEF’s: are repaired electively through a neck incision. Bronchoscopy and placement of a feeding tube into the fistula can facilitate repair.

Complications after repair:

• Esophageal Leak: If minor wait several days and re-study. If it is a major leak, consider re-repair or diversion of the esophagus unto the neck.
• Gastroesophageal reflux
• Tracheomalacia: Barking type cough. Cyanosis immediately after feedings. Onset is usually 2 to 3 months post-op. If severe, may require aortopexy to lift trachea away from the esophagus.
• Poor esophageal motility: is common. Nothing can be done to improve this.
• Esophageal Strictures: develop any many patients and can be managed with outpatient dilations if uncomplicated. More severe strictures may require topical mitomycin or resection of the stricture.
• Recurrent TEF
• Dysphagia: difficulty swallowing

Laryngotracheoesophageal Clefts:
Failure of the larynx and esophagus to separate resulting in a common connection between them is termed a laryngotracheoesophageal cleft, or LTE cleft. The classification of LTE clefts is I to IV based on length. Type IV: is nearly always fatal. Several hundred cases have been reported. These are usually managed jointly with a pediatric surgeon and a pediatric otolaryngologist with expertise in congenital airway work. Short Type I clefts: can often be managed endoscopically through the mouth.