Summary

Oesophageal Atresia (OA) is a congenital anomaly where the oesophagus (food pipe) fails to develop as a continuous tube, ending in a blind pouch. Tracheo-Oesophageal Fistula (TOF) is an abnormal connection (fistula) between the oesophagus and the trachea (windpipe). In 90% of cases, they occur together.

This is one of the "Index Conditions" of neonatal surgery. The survival rate has improved from 0% in 1940 to >95% today in high-income countries. However, it remains a lifelong condition with significant respiratory and gastrointestinal morbidity ("The TOF Child" phenotype).

Key Facts

• Incidence: 1 in 2,500 - 4,000 live births.
• The "VACTERL" Baby: 50% of OA/TOF infants have detailed associated anomalies (Vertebral, Anorectal, Cardiac, Renal, Limb).
• The Initial Danger: Aspiration Pneumonia. Saliva cannot be swallowed and spills over into the lungs. Gastric acid refluxes through the fistula into the lungs.
• The Diagnostic Sign: Failure to pass a Nasogastric Tube (NGT). It hits a "stop" at 10-12cm from the lips (the bottom of the upper pouch).

Clinical Pearls

[!TIP] The Replogle Tube: Once OA is suspected, a simple NGT is insufficient. You must insert a Replogle Tube (a double-lumen sump suction tube) into the upper pouch on continuous suction to prevent saliva aspiration.

[!TIP] Transport Position: Never lie a TOF baby flat. Nurse them 30-45 degrees head-up. This strictly uses gravity to keep stomach acid down and prevent it flowing through the distal fistula into the lungs.

Understanding the defect requires understanding the development of the foregut.

The Foregut Septum

• Day 21: The primitive foregut is a single tube.
• Day 26: The "Lung Bud" (Respiratory Diverticulum) appears on the ventral (front) wall.
• Day 28-36: A septum (Tracheo-Oesophageal Septum) grows longitudinally to separate the ventral Trachea from the dorsal Oesophagus.
• The Error: If this septum deviates posteriorly, it cuts off the oesophagus (Atresia) or leaves a strand connecting the two systems (Fistula).

The Sonic Hedgehog Gene (Shh)

• The Shh signalling pathway is crucial for this separation.
• Disruption of Shh in mouse models replicates the OA/TOF phenotype.
• Adriamycin exposure in rat models also causes OA/TOF, suggesting environmental triggers.

Named after Robert E. Gross (Boston Children's Hospital).

Type C: The Classic (86%)

• Anatomy: Proximal Atresia (blind upper pouch) + Distal TEF (lower oesophagus connects to trachea).
• Pathophysiology:
  • Upper pouch: Saliva pools -> Aspiration.
  • Lower fistula: Air breathes into stomach (Abdominal Distension). Acid refluxes into lungs (Chemical Pneumonitis).
• X-Ray Sign: Coiled NGT + Gas in Stomach.

Type A: Pure Atresia (7%)

• Anatomy: Proximal Atresia + Distal Atresia. No potential connection to airway.
• Pathophysiology: No fistula. No air gets to gut.
• X-Ray Sign: Gasless Abdomen (White Abdomen).
• Challenge: usually "Long Gap" (the ends are very far apart).

Type E: H-Type Fistula (4%)

• Anatomy: Continuous Oesophagus (No Atresia). A fistula connects mid-oesophagus to trachea (looks like letter 'H' or 'N').
• Presentation: often delayed. Choking on fluids. Recurrent Right Upper Lobe pneumonia. "Gas Bloat" (belly swells when crying).
• Diagnosis: Hard to spot. Needs Contrast Swallow (prone) or Bronchoscopy.

Type B (1%)

• Anatomy: Proximal Fistula + Distal Atresia.
• X-Ray Sign: Gasless abdomen (distal atresia) + Pneumonia (upper pouch drains into trachea).

Type D (1%)

• Anatomy: Double Fistula (Proximal and Distal).
• Rarest form.

• Gender: Slight male predominance (1.5:1).
• Twins: Higher concordance in monozygotic twins.
• Genetics:
  • Trisomy 18 (Edwards): Strong association. (Lethal anomaly - affects surgical decision making).
  • Trisomy 21 (Downs): 2-3% association.
  • Feingold Syndrome: MYCN mutation (Microcephaly + Digital anomalies + OA).
  • CHARGE Syndrome: CHD7 mutation.

50% of OA/TOF babies are not "isolated". You must screen for the rest of the VACTERL spectrum.

• V - Vertebral (30%): Hemivertebrae, Butterfly vertebrae, Scoliosis.
  • Check: Spinal Ultrasound / X-Ray.
• A - Anorectal (15%): Imperforate Anus.
  • Check: Inspect perineum. Is the anus patent? Meconium passed?
• C - Cardiac (30%): VSD, ASD, Tetralogy of Fallot.
  • Impact: Right-sided Aortic Arch makes the standard surgical approach (Right Thoracotomy) dangerous.
  • Check: Echocardiogram (Mandatory pre-op).
• T - Tracheooesophageal: The primary defect.
• E - Esophageal: As above.
• R - Renal (25%): Agenesis, Dysplasia, Horseshoe Kidney.
  • Check: Renal Ultrasound. U&Es.
• L - Limb (10%): Radial Ray defects (missing thumbs? radius?).
  • Check: Examination.

The "NG Tube Test"

• Procedure: Pass a firm, large bore (10Fr) NGT.
• Finding: Resistance felt at 10-12cm.
• Confirmation: Chest X-Ray.
• DANGER: DO NOT use contrast (Barium/Gastrografin) for the initial diagnosis. If aspirated, it causes severe chemical pneumonitis and destroys the lungs for the surgeon. Air is the best contrast.

Pre-operative Echo

• Crucial Question: "Which side is the Aortic Arch?"
• Logic: We operate on the side opposite the arch to see the oesophagus.
  • Left Arch (Normal) -> Right Thoracotomy.
  • Right Arch (5% cases) -> Left Thoracotomy.

The baby is born. The diagnosis is made. Now what?

1. Stop Feeds: Strict NBM.
2. Replogle Tube: Impact a 10Fr Replogle tube into the upper pouch. Connect to continuous suction (-3 to -5 kPa). Flushes with saline every 15 mins to keep patent.
3. Position: 45 degree head-up tilt.
4. Fluids: Maintenance IV fluids (10% Dextrose).
5. Comfort: Analgesia (Paracetamol). Keep baby calm (crying pumps air into stomach).
6. Vitamin K: IV.

To Intubate or Not?

• Avoid if possible: Positive Pressure Ventilation (PPV) will force air through the fistula (the path of least resistance) -> Massive Gastric Distension -> Diaphragm splinting -> Cardiac Arrest.
• If needed:
  • Try to position ETT distal to the fistula (hard to do blindly).
  • Use low pressures.
  • Consider emergency ligation of fistula if gas trapping is severe.

Timing: Usually Day 1-2 of life. Procedure takes 2-4 hours.

Standard Repair (Type C)

1. Incision: Muscle-sparing Right Thoracotomy (4th intercostal space).
2. Approach: Extra-pleural (peeling the pleura off the ribs without entering the chest cavity). Protects lungs if leak occurs.
3. Ligation: The Fistula is identified, looped, divided, and sutured closed on the tracheal side.
4. Mobilization: The upper pouch is dissected free to gain length.
5. Anastomosis: The upper and lower ends are sutured together (primary anastomosis).
6. Trans-Anastomotic Tube (TAT): An NG tube is passed through the nose, through the new repair, into the stomach. This acts as a stent and allows early feeding.

H-Type Repair

• Incision: Cervical (Neck) incision, not thoracic.
• The fistula is usually high up.

Thorascopic Repair (Keyhole)

• Increasingly common. Less scarring, less musculoskeletal deformity (winged scapula). But technically demanding (requires advanced skills).

Definition: A gap > 3-4 vertebral bodies (or >3cm). Usually Type A (Pure Atresia). Problem: Ends cannot reach each other.

Strategy 1: Delayed Primary Repair

• Wait 8-12 weeks.
• Gastrostomy for feeding.
• Replogle for saliva.
• Spontaneous growth of the upper pouch (due to swallowing reflex) may bridge the gap.

Strategy 2: The Foker Process

• Surgical traction sutures placed on both ends.
• Tension applied externally to stretch the oesophagus ("grow it") over 1-2 weeks.

Strategy 3: Oesophageal Replacement

• If native oesophagus is impossible to use.
• Gastric Transposition: Pull the whole stomach up into the chest.
• Colonic Interposition: Use a piece of colon to bridge the gap.
• Jejunal Interposition.

1. Ventilation: Usually ventilated for 24-48h to protect repair (prevent coughing).
2. Neck Position: Keep neck flexed (chin down). Extension stretches the repair ("Chin to chest saves the test").
3. Drain: Chest drain monitors for leak (saliva/milk in drain).
4. Contrast Swallow: Performed Day 5-7 (using water soluble contrast like Iohexol).
   • If no leak -> Start oral feeds.
   • If leak -> NBM, TPN, wait for healing.

• Dysphagia: Need to drink water with meals ("fluid wash"). Incidence of food sticking (Steakhouse Syndrome).
• Respiratory: Higher rates of asthma/bronchitis.
• Barrett's Oesophagus: High reflux risk means surveillance endoscopy in adulthood (metaplasia risk).
• Quality of Life: Generally excellent.

OA/TOF is a "Barometer of Surgery".

• In UK/USA: Survival ~95%.
• In Low and Middle Income Countries (LMIC): Survival <40%.
• Barriers:
  • Lack of Neonatal ICU (TPN, ventilators).
  • Late diagnosis (aspiration already occurred).
  • Lack of paediatric anaesthesia.

• 1670: William Durston describes first case.
• 1939: Ladd & Leven perform first multistage survivor repairs.
• 1941: Cameron Haight (Michigan) performs the first successful primary anastomosis. The patient lived to old age. This marked the dawn of modern neonatal thoracic surgery.

1. Replogle Care:
   • Ensure patency (flush 1-2ml saline q15min).
   • Listen for "sump sound" (bubbling).
   • Tape securely (losing the tube risks aspiration).
2. Sham Feeding:
   • While on TPN/feeds, let baby suck a dummy dipped in milk/colostrum.
   • Preserves the "Suck-Swallow" reflex (crucial for later feeding).
3. Positioning: 45 degrees head up.

• Missed H-Type: Often treated as "asthma" or "recurrent aspiration" for months. Delay leads to lung damage.
• Contrast Aspiration: Using Barium for initial diagnosis during swallow study is negligent. Use water-soluble or air.
• VACTERL Miss: Repairing the OA but missing the anal atresia or renal agenesis.

• TPN: Essential for the first week.
• Gastrostomy:
  • Used in Long Gap OA.
  • Safety vent for H-Type.
  • Allows "Sham Feeding" (oral bolus drains out of G-tube).

Q: Why is my baby foaming at the mouth? A: Because the swallowing tube ends in a pouch. The saliva fills the pouch and overflows.

Q: Did I cause this? A: No. It is a random accident of development in the womb.

Q: Will the scar be big? A: It is usually a neat line under the right armpit. Keyhole surgery scars are tiny dots.

Q: What is the 'TOF Cough'? A: A loud barking cough caused by a floppy windpipe. It sounds scary but is usually harmless and gets better with age.

Q: Can I breastfeed? A: Yes! Express milk now. Once the repair heals, breastfeeding is excellent for TOF babies.

1. Q: What is the most common type of OA/TOF?
   • A: Type C (Proximal Atresia, Distal Fistula). 86%.
2. Q: Why do you get polyhydramnios?
   • A: Fetus cannot swallow amniotic fluid.
3. Q: What is the VACTERL association?
   • A: Vertebral, Anorectal, Cardiac, Tracheooesophageal, Renal, Limb.
4. Q: How do you diagnose OA at the bedside?
   • A: Attempt to pass a wide-bore NGT. It stops at 10cm.
5. Q: What is a Replogle tube?
   • A: Double-lumen sump suction tube.
6. Q: Which side is the thoracotomy usually on?
   • A: Right (opposite the left aortic arch).
7. Q: What is the "Gasless Abdomen" sign?
   • A: Type A (Pure Atresia). No air gets into intestine.
8. Q: What is Tracheomalacia?
   • A: Floppiness of the tracheal cartilage, causing collapse and stridor/cough.
9. Q: What is the treatement for oesophageal stricture?
   • A: Balloon Dilatation.
10. Q: Can you use Barium to diagnose OA effectively?
    • A: No! Risk of severe aspiration pneumonitis. Use air or water-soluble contrast.
11. Q: What gene is implicated in mouse models?
    • A: Sonic Hedgehog (Shh).
12. Q: What is the SpitClassification?
    • A: Prognostic score based on Birth Weight and Cardiac Anomalies.
13. Q: What is the "TOF Cough"?
    • A: The seal-like bark of tracheomalacia.
14. Q: What is a "Long Gap"?
    • A: >3cm gap between ends.
15. Q: What is the Foker procedure?
    • A: Traction induced oesophageal growth.
16. Q: What is H-Type Presentation?
    • A: Choking on fluids, recurrent pneumonia.
17. Q: What is the first line imaging for H-type?
    • A: Tube Oesophagram (prone video fluoroscopy).
18. Q: Why check the kidneys?
    • A: 25% VACTERL renal anomalies (agenesis, horseshoe).
19. Q: Why keep the baby head up?
    • A: Minimize acid reflux into lungs via fistula.
20. Q: What is the survival rate?
    • A: >90-95% (isolated).

For Educational Purposes Only

Indication: Type C OA/TOF. Day 1 of life. Pre-op Echo: Normal heart, Left Arch. Positon: Left Lateral Decubitus. Arm raised. Incision: Right posterolateral thoracotomy (4th ICS), sparing Latissimus Dorsi. Approach: Extra-pleural dissection. Findings:

• Large Azygos vein (divided).
• Upper pouch: High, blind ending.
• Lower pouch: Connected to membranous trachea 1cm above carina. Procedure:

1. Fistula looped with vessel loop. Transflixed and ligated with 5/0 Vicryl. Divided. Air leak test negative.
2. Upper pouch mobilized proximally to thoracic inlet (care taken of recurrent laryngeal nerve).
3. Myotomy of upper pouch to gain 1cm length.
4. Anastomosis: Single layer, interrupted 5/0 PDS sutures. Posterior wall first.
5. Naso-gastric tube (6Fr) passed by anaesthetist, guided across anastomosis into stomach.
6. Anterior wall completed.
7. Chest drain (10Fr) placed.
8. Ribs approximated. Layered closure. Post-Op: Ventilated. Head flexed.

A realistic timeline for parents.

Day 0-2 (The ICU)

• The Shock: Seeing your baby with tubes everywhere.
• The Wait: Waiting for the surgeon to come out of theatre.
• The Tube: The Replogle tube makes a loud bubbling noise. It's annoying but keeps him safe.

Day 5-7 (The Contrast Test)

• The Swallow: He goes to X-Ray. They watch him swallow dye.
• The Result: "No Leak!" Best news ever.
• First Feed: 1ml of breast milk. The scariest milestone.

Day 14 (Going Home)

• Discharge: Leaving the safety of the hospital.
• The Cough: Late at night, he barks like a seal. We panic, but he settles.

Month 3 (The Stick)

• The Choke: He starts choking on fluids. He's vomiting more.
• The Stricture: Back to hospital. He needs a "stretch" (dilatation) under anaesthetic.
• Relief: He feeds instantly better afterwards.

Year 1 (The Birthday)

• Milestone: Eating cake! He eats slowly and needs water ("The Wash"), but he loves it.
• Reflex: He still spits up, but the Omeprazole helps.

Reflux Management is critical to protect the new anastomosis.

Why does the septum fail?

1. FOXF1: The Forkhead Box F1 gene. Mutations cause "Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins" (ACD/MPV) which often includes OA/TOF. Lethal.
2. SOX2: Sex Determining Region Y-Box 2. Causes "Anophthalmia-Esophageal-Genital (AEG) Syndrome".
   • Sign: Baby born with no eyes (microphthalmia) + OA.
3. CHD7: Chromodomain Helicase DNA Binding Protein 7.
   • The CHARGE Gene.
   • Coloboma, Heart, Atresia Choanae, Retardation, Genital, Ear.
   • Implication: If a TOF baby has funny shaped ears and is deaf -> Check CHD7.

In the 1960s, prominent surgeons debated if these babies should be saved.

• The "Spitz" Era: Developed classifications to predict survival.
  • Group I (>1.5kg, no heart defect): 98% Survival.
  • Group III (<1.5kg + Major heart defect): 50% Survival.
• Modern Ethics:
  • Survival is now assumed.
  • The question is now Quality of Life (QoL).
  • Issues: Chronic cough, severe reflux, multiple surgeries, "failure to thrive".
  • Consensus: Despite morbidity, adult OA patients report QoL scores comparable to the general population.

Why can't they swallow?

• The Wave: Normal swallowing involves primary and secondary peristalsis (waves of muscle contraction).
• The Defect: In OA, the distal oesophagus has dysmotility (it doesn't squeeze coherently).
  • Cause: The vagus nerve branches are often damaged or developmentally abnormal.
  • Result: Food relies on gravity ("The fluid wash"). Lying flat causes stasis and pain.

Anaesthetizing a neonate with a hole in their airway is high stakes.

• Induction: usually Inhalational (Sevoflurane) maintaining spontaneous breathing.
• The Risk: Muscle relaxants (Paralysis). If you paralyze the baby and ventilate, air goes into stomach -> Stomach distends -> Diaphragm goes up -> Baby dies.
• The Golden Rule: Keep Spontaneous Breathing until the fistula is identified and isolated.
• Post-Op: Epidural or Paravertebral block for pain relief (crucial to prevent atelectasis).

• Atresia: Absence or closure of a natural passage.
• Fistula: Abnormal connection between two epithelial surfaces.
• Polyhydramnios: Excess amniotic fluid.
• Thoracotomy: Surgical incision into the chest wall.
• Anastomosis: Surgical connection between two structures.
• Fundoplication: Surgery to wrap stomach around oesophagus to stop reflux.
• Replogle: The specific suction tube used in OA. (Double lumen).
• VACTERL: Vertebral, Anorectal, Cardiac, Tracheooesophageal, Renal, Limb.
• Gap Length: Distance between upper and lower pouches.
  • Short: <1cm.
  • Intermediate: 1-3cm.
  • Long: >3cm.

Review Cycle: Biannual Next Review: Dec 2026 Approving Body: MedVellum Surgical Board