Tracheoesophageal Fistula

Definition And Epidemiology

Esophageal Atresia (EA): Lack of communication between proximal and distal esophagus.
Tracheoesophageal Fistula (TEF): Abnormal communication between trachea and esophagus.
Incidence: Occurs in 1 in 2440 to 5000 live births, with a slight male and preterm infant predominance.

Embryology: Arises from faulty division of the foregut into separate tracheal and esophageal channels during the first month of embryonic development.
Anatomic Changes: The proximal segment forms a dilated, blind-ended pouch with hypertrophied muscles, while the distal segment is atretic with thin walls.
Aspiration Risk: The distal fistula allows gastric acid to reflux directly into the lungs, causing severe pneumonitis, whereas the proximal pouch overflows, leading to salivary aspiration.
Sphincter Dysfunction: Features an incompetent gastroesophageal sphincter with defective neural innervation.

Type (Gross/Vogt)	Anatomical Description	Frequency	Radiographic Finding
Type A (Type 2)	Pure EA (isolated); "long gap"; no fistula.	7-8%	Gasless, scaphoid abdomen.
Type B (Type 3A)	EA with proximal TEF.	1-2%	Gasless abdomen.
Type C (Type 3B)	EA with distal TEF (most common).	85-88.8%	Gastric air present on radiograph.
Type D (Type 3C)	EA with both proximal and distal TEF.	1-2.8%	Gastric air present on radiograph.
Type E (Type H)	H-type TEF (fistula without EA).	4-4.2%	Gastric air present on radiograph.

Antenatal: Polyhydramnios occurs due to fetal inability to swallow amniotic fluid. Ultrasound may reveal an absent or small fetal stomach bubble after 26 weeks gestation and an upper neck pouch sign.
Postnatal (Typical EA/TEF): Infant presents with frothing and bubbling at the mouth and nose immediately after birth. Feeding triggers episodes of coughing, choking, cyanosis, and respiratory distress.
Abdominal Examination: Distension occurs if a distal fistula transmits air; a scaphoid, flat abdomen indicates pure EA without a fistula.

Presents late with recurrent pneumonia and chronic respiratory problems.
Features refractory bronchospasm, recurrent aspiration, and coughing triggered by feeding.

Anomalies are present in up to 50% of infants with EA/TEF.

Category	Specific Associations
VACTERL Association	Vertebral, Anorectal, Cardiac, Tracheal, Esophageal, Renal, and Limb anomalies (present in 15% of cases).
Cardiac Anomalies	Most common association (30-32%); includes ventricular septal defect, patent ductus arteriosus, and tetralogy of Fallot.
Other Systems	Vertebral anomalies (24%), imperforate anus (10%).
Syndromic	CHARGE syndrome, Feingold syndrome, Trisomy 18, and Trisomy 21.

Tube Test: Failure to pass a nasogastric or orogastric tube; it meets resistance or coils in the proximal pouch.
Radiography: Chest and abdominal X-rays demonstrate the coiled tube. Air in the stomach confirms a distal TEF, while a gasless abdomen confirms pure EA.
Contraindication: Barium swallow is generally avoided in EA due to high aspiration risk.

H-Type TEF: Diagnosed via a pull-back esophagogram under pressure, bronchoscopy, or methylene blue dye testing.
Preoperative Screening: Mandatory VACTERL workup includes an echocardiogram, renal ultrasound, and spinal ultrasound/radiographs.

Airway And Decompression: Maintain a patent airway and keep the infant strictly nil per os (NPO). Place a Replogle tube (sump catheter) in the proximal pouch with continuous suction to prevent salivary aspiration.
Positioning: Prone or semi-upright positioning minimizes gastric acid reflux through the distal fistula.
Medical Therapy: Initiate intravenous fluids, broad-spectrum antibiotics, and acid suppression (H2 blockers or proton pump inhibitors).
Ventilation Warning: Avoid endotracheal intubation with positive pressure ventilation if possible, as it increases gastric distension and rupture risk.

Standard Repair: Right-sided extrapleural thoracotomy or thoracoscopy to ligate the fistula and perform primary end-to-end esophageal anastomosis.
Unstable/Premature Infants: Delayed primary repair involving initial fistula ligation and gastrostomy, deferring anastomosis until stability is achieved.
Long Gap EA: Defined as a gap >3-4 cm; managed by temporizing gastrostomy feeds to allow growth, followed by surgical lengthening myotomies, gastric pull-up, or colonic interposition.

Phase	Complications
Early	Anastomotic leak, anastomotic stricture (most common, requiring balloon dilatations), recurrent TEF, mediastinitis, pneumonitis.
Late	Severe gastroesophageal reflux disease (GERD) requiring Nissen fundoplication. Tracheomalacia presenting with a "barking" cough or cyanotic spells. Barrett's esophagus and long-term dysphagia.

Survival heavily depends on birth weight (BW) and concurrent major congenital heart disease (CHD).