Oesophageal atresia is a congenital malformation in which the oesophagus ends in a blind pouch and fails to connect to the stomach, most commonly associated with a tracheo-oesophageal fistula.

Oesophageal Atresia (OA) & Tracheo-Oesophageal Fistula (TOF)

Oesophageal atresia (OA) is a congenital anomaly in which the oesophagus ends as a blind pouch and fails to form a continuous passage between the pharynx and the stomach. It frequently co-exists with a tracheo-oesophageal fistula (TOF/TEF) — an abnormal communication between the trachea and the oesophagus.

Breaking down the name:

Oesophageal = relating to the oesophagus (Greek oisophagos, "gullet")
Atresia = Greek a- (without) + tresis (perforation) → a structure that should be open/patent but is instead closed or absent
Fistula = Latin for "pipe" or "tube" → an abnormal connection between two epithelialised surfaces

So the name tells you the condition: the oesophagus has no opening (atresia), and there is often an abnormal pipe (fistula) connecting it to the trachea.

"TEF and EA are caused by a defect in the lateral septation of the foregut into oesophagus and trachea" ^[1]^[2]

Feature	Detail
Incidence	Around 1 in 3,000 live births ^[2]
Sex	Male > Female (slight male predominance) ^[1]^[2]
Trends	Survival now > 90% overall in tertiary centres with modern neonatal intensive care
Geography	No major ethnic predilection; incidence relatively uniform worldwide
Recurrence risk	~1% for siblings (mostly sporadic)

High Yield

Incidence ~1:3000; Male predominance. Remember these two figures — they are directly from the lecture slides. ^[2]

3. Embryology & Anatomy

Understanding OA/TOF requires understanding normal foregut development:

Week 4 of embryonic life: The primitive foregut is a single tube. The respiratory diverticulum (lung bud) appears as a ventral outgrowth from the ventral wall of the foregut.
Tracheo-oesophageal septum: A lateral ridge of mesenchyme (the tracheo-oesophageal septum/fold) grows medially from each side and fuses in the midline, dividing the foregut into:
- Ventral portion → trachea and lung buds
- Dorsal portion → oesophagus
This septation proceeds in a caudal-to-cranial direction.
Simultaneously, the oesophagus elongates rapidly as the heart descends and the neck lengthens.

"TEF and EA are caused by a defect in the lateral septation of the foregut into oesophagus and trachea." ^[1]

"The fistula tract is derived from a branch of the embryonic lung bud that fails to undergo branching because of defective epithelial-mesenchymal interactions." ^[1]

In other words:

If the tracheo-oesophageal septum deviates posteriorly, too much of the foregut is incorporated into the trachea, and the oesophagus is left deficient → oesophageal atresia
If septation is incomplete, a residual communication persists → tracheo-oesophageal fistula
The combination and extent of these errors produce the different anatomical types (see Classification below)

Structure	Clinical Relevance
Upper oesophageal pouch	Usually ends at ~T2–T4 level; is dilated and thick-walled (muscular hypertrophy from fetal swallowing against a blind end)
Lower oesophageal segment	Thin, narrow; connects to the stomach; if a distal fistula exists, it joins the posterior membranous wall of the trachea just above the carina
Gap length	The distance between the two pouches determines surgical difficulty. A "long-gap" OA (> 3 cm or > 2–3 vertebral bodies) is harder to primarily anastomose
Recurrent laryngeal nerves	Run in the tracheo-oesophageal groove; at risk during surgical dissection
Azygos vein	Crosses behind the right hilum; typically ligated and divided during a right thoracotomy approach
Tracheal blood supply	Segmental; shared with the oesophagus — mobilisation of the oesophagus must be careful to avoid devascularising the trachea

OA/TOF is almost always sporadic with no single identifiable cause, but several associations exist:

Category	Details
Genetic	Rare familial cases; associated with trisomy 18, trisomy 21; Feingold syndrome (MYCN mutations); CHARGE syndrome; anophthalmia-oesophageal-genital (AEG) syndrome
Environmental	Maternal diabetes; advanced maternal age; some teratogen exposure (methimazole, possibly others) — evidence is weak
Multifactorial	Most cases are believed to be multifactorial / non-syndromic

VACTERL Association

The single most important association to remember is VACTERL: ^[1]^[2]

V — Vertebral anomalies (hemivertebrae, butterfly vertebrae)
A — Anal atresia (imperforate anus / anorectal malformations)
C — Cardiac defects (VSD, ASD, Tetralogy of Fallot, right-sided aortic arch — this matters surgically because the thoracotomy is conventionally via the right side)
TE — Tracheo-Esophageal fistula
R — Renal defects (renal agenesis, horseshoe kidney, vesicoureteric reflux)
L — Limb defects (radial ray anomalies, polydactyly)

VACTERL is defined as ≥ 3 of these features. It is an association, not a syndrome (no single unifying genetic/pathophysiological cause identified).

Up to 50% of babies with OA have at least one other congenital anomaly; ~10–20% fulfil criteria for VACTERL.

5. Aetiology & Pathophysiology

As above — defective septation of the foregut. The precise molecular trigger is unknown in most cases. Sonic hedgehog (Shh) signalling, SOX2 transcription factor, and Adriamycin (doxorubicin) animal models have been implicated in research. In humans, it is overwhelmingly sporadic.

5.2 Pathophysiology — Why Do Babies Get Sick?

Think of each problem from first principles:

The baby cannot swallow saliva or feed → saliva pools in the upper pouch → drooling of saliva, frothing, "bubbly" baby ^[1]
Attempted feeding leads to choking and coughing because milk has nowhere to go and overflows into the larynx → aspiration ^[1]
In utero, the fetus cannot swallow amniotic fluid effectively → polyhydramnios (antenatal diagnosis) ^[2]
- Normally, the fetus swallows ~500 mL/day of amniotic fluid in the third trimester. Without a patent oesophagus, this fluid accumulates.

Air from the trachea passes down through the fistula into the stomach → gastric distension and air-filled bowel loops on X-ray (a key diagnostic sign)
Gastric acid refluxes up through the fistula into the tracheobronchial tree → chemical pneumonitis and respiratory distress ^[1]
Positive-pressure ventilation (e.g., bag-mask ventilation) can force air preferentially down the fistula (path of least resistance) → massive gastric distension → splinting of diaphragm → worsening respiratory failure; and risk of gastric perforation. This is why these babies must be intubated carefully.

Inability to feed ^[1]
Recurrent aspiration (from above: saliva overflow; from below: gastric acid via fistula)
Respiratory distress from aspiration pneumonia/pneumonitis ^[1]
If untreated: dehydration, sepsis, death

The oesophagus is continuous → the baby CAN swallow and feed
But the fistula allows intermittent aspiration → recurrent chest infections, coughing/choking with feeds, abdominal distension
Diagnosis is often delayed (weeks to months) because the baby can feed

Classification of TEF and EA according to anatomical configuration ^[1]

The Gross classification (letters A–E) is most widely used. The Vogt classification (Roman numerals) is the historical European system.

Gross Type	Description	Frequency	Key Features
Type A	OA without TOF (pure/isolated atresia)	~8–10%	Long gap between pouches; no gas in bowel on X-ray ("gasless abdomen")
Type B	OA with proximal TOF	~1–2%	Very rare; upper pouch connects to trachea
Type C	OA with distal TOF	~85%	Most common type by far. Upper pouch is blind; lower oesophageal segment connects to the trachea just above the carina. Gas present in stomach/bowel on X-ray
Type D	OA with both proximal and distal TOF	~2–3%	Both pouches communicate with trachea
Type E (H-type)	TOF without OA	~4–5%	No atresia — continuous oesophagus with a fistulous connection. Often presents later with recurrent pneumonia

High Yield — Gross Type C

Type C (OA with distal TOF) is the most common type (~85%). This is the "classic" presentation: blind upper pouch + distal fistula. The baby has a coiled NG tube in the upper pouch on X-ray AND gas in the stomach/bowel. If you see a gasless abdomen, think Type A (pure OA, no distal fistula for air to enter the GI tract). ^[1]

Spitz Classification (Prognostic)

This classifies babies by birth weight and cardiac anomaly to predict survival:

Group	Criteria	Survival
I	Birth weight ≥ 1500 g, no major cardiac defect	> 97%
II	Birth weight < 1500 g OR major cardiac defect	~60–80%
III	Birth weight < 1500 g AND major cardiac defect	~25–50%

This highlights that cardiac anomalies and prematurity are the main determinants of mortality, not the oesophageal anomaly itself.

7. Clinical Features

Feature	Pathophysiological Basis
Polyhydramnios	Fetus cannot swallow amniotic fluid → fluid accumulates in the amniotic cavity. Most reliably seen in pure OA (Type A) or when the fistula is small. In Type C with a large distal fistula, some fluid may drain to the stomach, so polyhydramnios may be less pronounced ^[2]
Absent/small stomach bubble on ultrasound	No fluid reaches the stomach (especially Type A)
Dilated upper oesophageal pouch ("pouch sign")	Seen on prenatal USS in some cases

Exam Pearl

Antenatal diagnosis — polyhydramnios is the key prenatal clue. ^[2] However, note that polyhydramnios has many causes (maternal diabetes, fetal anomalies, twin-twin transfusion, etc.), so it is suggestive but not diagnostic.

All relate to the two core problems: (1) the blind pouch preventing swallowing, and (2) the fistula allowing abnormal air/fluid trafficking.

Symptom	Pathophysiological Basis
Drooling of saliva / "bubbly baby" / excessive frothy secretions from the mouth and nose	Saliva cannot pass beyond the blind upper pouch → pools and overflows. This is often the first sign noticed in the delivery room ^[1]
Choking and coughing	Saliva overflows from the upper pouch into the larynx → aspiration reflex triggers cough/choke. Also, aspiration of gastric contents refluxing up through a distal fistula ^[1]
Inability to feed	Milk cannot pass to the stomach; first attempted feed triggers immediate regurgitation, coughing, choking, and cyanosis ^[1]
Respiratory distress	Multiple mechanisms: (1) aspiration of saliva from above, (2) aspiration of gastric acid from below via fistula, (3) air passing through fistula causing gastric distension → diaphragmatic splinting, (4) associated congenital anomalies (e.g., cardiac) ^[1]
Cyanotic episodes ("blue spells")	Aspiration-related laryngospasm or frank aspiration causing desaturation
Abdominal distension (in TOF types)	Air enters the stomach through the distal fistula, especially with crying (increased intrathoracic pressure forces air through the fistula)

Sign	Pathophysiological Basis
Failure to pass a nasogastric (NG) tube	The NG tube meets the blind-ending upper pouch and cannot advance to the stomach. Typically arrests at ~10 cm from the nares (or ~T2–T4 level). This is a key diagnostic manoeuvre and may be performed as a screening test at birth
Coiled NG tube on chest/abdominal X-ray	The tube coils in the dilated upper pouch — diagnostic
Air in the stomach and bowel on X-ray	Indicates the presence of a distal fistula (Type C, D, or E). Air enters the GI tract through the fistula from the trachea
Gasless abdomen on X-ray	Suggests no distal fistula (Type A or B) — air cannot enter the GI tract
Wet, "bubbly" breathing sounds / rhonchi	Aspiration into the tracheobronchial tree
Features of associated anomalies	Imperforate anus (check on initial newborn exam), cardiac murmur, limb anomalies, vertebral anomalies (inspect the spine) — all part of VACTERL screening

Classic Presentation — Know This Cold

A newborn presents within hours of birth with:

Excessive drooling and frothy saliva
Choking and coughing on first feed
Respiratory distress
NG tube cannot be passed — coils in upper pouch on X-ray
Gas present in stomach on X-ray (→ distal TOF present = Type C)

This is the bread-and-butter vignette for OA/TOF in exams.

This is the sneaky one. There is no atresia, so:

The baby CAN swallow and feed (NG tube passes normally)
Presentation is delayed — days to weeks, sometimes months
Recurrent aspiration pneumonia, chronic cough, choking episodes during feeds, abdominal distension from air entering the stomach
Diagnosis requires a prone contrast swallow (tubogram) or bronchoscopy to demonstrate the fistula
Often missed initially — maintain a high index of suspicion in any infant with unexplained recurrent chest infections

Because up to 50% of babies with OA/TOF have associated anomalies, a systematic screen is essential:

System	Anomaly	Screening Investigation
Cardiac (most common, ~35%)	VSD, ASD, ToF, right-sided aortic arch, coarctation	Echocardiography (mandatory before surgery — also determines side of aortic arch, which affects surgical approach)
Anorectal (~10–15%)	Imperforate anus	Physical examination of perineum
Genitourinary (~15–20%)	Renal agenesis, horseshoe kidney, VUR, hypospadias	Renal USS
Vertebral/skeletal (~10–15%)	Hemivertebrae, rib anomalies, radial ray defects	X-ray spine, limb examination
Chromosomal	Trisomy 18, trisomy 21	Clinical suspicion → karyotype
Other GI	Duodenal atresia (especially with trisomy 21)	Clinical + X-ray

Right-Sided Aortic Arch

Echocardiography is mandatory preoperatively. ~2.5% of OA patients have a right-sided aortic arch. The standard surgical approach is a right posterolateral thoracotomy — if the arch is on the right, the surgeon must use a left thoracotomy instead. Missing this can be catastrophic.

When a baby presents with inability to feed, drooling, and respiratory distress, think systematically:

High Yield Summary

Oesophageal Atresia (OA) & Tracheo-Oesophageal Fistula (TOF)

Definition: Congenital discontinuity of the oesophagus (atresia) ± abnormal communication with the trachea (fistula), due to defective lateral septation of the foregut ^[1]
Epidemiology: ~1:3,000 live births; Male > Female ^[2]
Most common type: Gross Type C (OA + distal TOF) — ~85% ^[1]
Antenatal clue: Polyhydramnios (fetus cannot swallow amniotic fluid) ^[2]
Classic postnatal presentation: Drooling / "bubbly baby", choking/coughing on first feed, inability to feed, respiratory distress, NG tube cannot be passed ^[1]
Key X-ray findings: Coiled NG tube in upper pouch; gas in stomach (distal TOF present) vs gasless abdomen (no distal TOF)
VACTERL association: Vertebral, Anal, Cardiac, TE fistula, Renal, Limb — screen all babies with OA ^[1]^[2]
Cardiac anomalies are the most common associated defect and the main determinant of mortality → echocardiography is mandatory
H-type TOF (Type E) has no atresia → delayed presentation with recurrent aspiration pneumonia
Fistula pathophysiology: Distal TOF allows air into the stomach (gaseous distension) and gastric acid into the lungs (chemical pneumonitis)

Active Recall — Oesophageal Atresia

^[1] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf — Gastrointestinal Diseases, Tracheoesophageal fistula and Esophageal atresia section ^[2] Lecture slides: Neonatal Surgery.pdf — Oesophageal atresia slide

Differential Diagnosis of Oesophageal Atresia

When you encounter a neonate who cannot swallow, is drooling excessively, chokes on the first feed, and has respiratory distress, the working diagnosis of oesophageal atresia is usually straightforward — especially when the NG tube will not pass. However, you must still think systematically about:

Other causes of neonatal swallowing difficulty / "failure to feed"
Other causes of neonatal respiratory distress (which may coexist or mimic OA)
Other causes of neonatal intestinal obstruction (particularly relevant when vomiting is the dominant symptom)
Conditions that mimic the individual components (drooling, choking, vomiting, respiratory distress)

The key clinical discriminator is the failure to pass an NG/OG tube, which almost uniquely points to oesophageal atresia. But the exam expects you to reason through the differential logically.

Systematic Differential Diagnosis

Condition	Key Distinguishing Features	Why It Mimics OA
Oesophageal atresia ± TOF (diagnosis in question)	NG tube arrest at ~10 cm; coiled tube on X-ray; ± gas in abdomen	The classic presentation
Choanal atresia (bony/membranous obstruction of posterior nares)	Cyclical cyanosis relieved by crying (baby is an obligate nasal breather); inability to pass a catheter through the nose; NOT through the oesophagus. NG tube passes orally to the stomach	Both cause drooling and respiratory distress. But in choanal atresia the obstruction is nasal, not oesophageal — the baby can swallow if fed orally
Laryngeal cleft (defect in the posterior cricoid lamina allowing communication between larynx and oesophagus)	Feeding-associated aspiration, stridor, weak cry; NG tube passes to stomach; diagnosed by microlaryngoscopy/bronchoscopy	Choking and aspiration with feeds mimics OA/TOF, but swallowing route is intact
Pharyngeal / oesophageal perforation (iatrogenic from vigorous suctioning at birth)	History of traumatic suctioning; NG tube passes but with difficulty or blood-stained aspirate	Can cause drooling and respiratory distress, but oesophagus is patent
Congenital oesophageal stenosis (intrinsic narrowing — fibromuscular thickening, tracheobronchial remnants, or membranous web)	NG tube may pass with resistance or a small-bore tube may pass; contrast swallow shows narrowing, not a blind pouch; usually presents later with progressive dysphagia to solids	Rare; causes dysphagia but not complete obstruction at birth
Oesophageal duplication cyst	Extrinsic compression; NG may pass with difficulty; diagnosed on USS/CT/MRI	Can cause swallowing difficulty and respiratory symptoms from airway compression
Neurological / neuromuscular causes of poor swallowing (birth asphyxia, Möbius syndrome, myasthenia gravis, congenital myotonic dystrophy)	Generalised hypotonia, poor suck, absent/weak gag reflex; NG tube passes normally; neurological signs predominate	Drooling and inability to feed, but oesophagus is structurally patent

The NG Tube Test — Key Discriminator

The single most important bedside manoeuvre is attempting to pass an NG/OG tube. If the tube arrests at ~10 cm from the upper gum and coils in the upper pouch on X-ray, the diagnosis is oesophageal atresia until proven otherwise. In virtually all other conditions on this differential, the tube passes to the stomach. ^[1]^[3]

This is relevant because neonatal vomiting is a broad differential, and exam vignettes may present a vomiting neonate where you must distinguish OA from other causes of neonatal intestinal obstruction (IO).

GC 205 lecture and the Case Study lecture both frame neonatal vomiting/IO as a key differential diagnosis scenario. ^[4]^[5]

The critical distinction is:

In OA: the baby cannot swallow at all — "vomiting" is actually regurgitation of unswallowed saliva/milk from the blind upper pouch. It is non-bilious (bile duct enters the duodenum, which is distal to the obstruction).
In lower intestinal obstruction: the baby may initially feed but develops true vomiting (often bilious — green/yellow) as obstruction manifests.

Condition	Level of Obstruction	Vomitus Character	Abdominal Distension	Key Diagnostic Feature
Oesophageal atresia	Proximal oesophagus	Non-bilious (saliva/milk regurgitation)	Absent (unless distal TOF fills bowel with air)	NG tube arrest; coiled tube on X-ray ^[3]
Duodenal atresia/stenosis	Duodenum (often distal to ampulla of Vater)	Bilious (if distal to ampulla) or non-bilious (if proximal)	Epigastric only	"Double bubble" sign on AXR; associated with Down syndrome (1/3) ^[3]
Jejunal/ileal atresia	Jejunum or ileum	Bilious	Moderate to marked	Multiple air-fluid levels on AXR; caused by in-utero vascular accident ^[3]
Malrotation with midgut volvulus	Variable (mesenteric twist)	Bilious vomiting — surgical emergency	Variable	Upper GI contrast study shows abnormal position of DJ flexure; "corkscrew" or "bird's beak" sign. This is the most dangerous differential because the entire midgut can infarct ^[6]
Meconium ileus	Distal ileum	Bilious	Marked	Associated with cystic fibrosis (almost all cases); ground-glass appearance on AXR (inspissated meconium); no air-fluid levels (meconium is too thick) ^[3]
Hirschsprung disease	Rectosigmoid (most common)	Late bilious vomiting	Marked	Failure to pass meconium within 24–48 hours; rectal biopsy shows absent ganglion cells (diagnostic) ^[3]
Anorectal malformation (imperforate anus)	Rectum/anus	Late	Marked	Absent anal opening on perineal inspection — part of VACTERL association ^[2]^[4]

Bilious Vomiting in a Neonate = Surgical Emergency

Any neonate with bilious (green) vomiting must be assumed to have malrotation with midgut volvulus until proven otherwise. This is the single most dangerous cause of neonatal vomiting because the superior mesenteric artery can be twisted off, causing irreversible midgut ischaemia within hours. OA does NOT cause bilious vomiting (the obstruction is proximal to the bile duct). If the vomiting is bilious, shift your differential away from OA and toward duodenal/jejunal atresia or malrotation. ^[5]^[6]

Respiratory distress is a prominent feature of OA/TOF due to aspiration, but many other conditions cause respiratory distress in a newborn. These must be considered, especially if the NG tube passes normally:

Condition	Mechanism of Respiratory Distress	Key Distinguishing Features
Congenital diaphragmatic hernia (CDH)	Abdominal viscera herniate into the thorax → lung hypoplasia + mediastinal shift	Scaphoid abdomen; bowel sounds in chest; NG tube passes to stomach (which may be in the thorax); CXR shows bowel loops in thorax
Respiratory distress syndrome (RDS/HMD)	Surfactant deficiency in premature lungs → atelectasis	Premature infant; ground-glass appearance on CXR; responds to surfactant
Meconium aspiration syndrome	Meconium-stained amniotic fluid aspirated into lungs → chemical pneumonitis + airway obstruction	History of meconium-stained liquor; term/post-term infant; patchy opacities on CXR
Transient tachypnoea of the newborn (TTN)	Delayed resorption of fetal lung fluid	Usually after C-section; self-resolving; "wet" CXR with fluid in fissures
Congenital pneumonia / neonatal sepsis	Infection (often GBS, E. coli)	Maternal risk factors (prolonged rupture of membranes, GBS colonisation); raised inflammatory markers
Tracheomalacia (may coexist with OA/TOF)	Weakness of tracheal cartilage → dynamic airway collapse	Wheezing that varies with position; may cause "dying spells" post OA repair; diagnosed by bronchoscopy ^[7]
Vascular ring (e.g., double aortic arch)	Extrinsic compression of trachea and/or oesophagus	Stridor + feeding difficulty; barium swallow shows posterior oesophageal indentation; CT/MR angiography confirms

This deserves separate mention because H-type TOF does not have atresia and therefore presents very differently:

The NG tube passes normally
The baby can feed initially
Presentation is delayed — recurrent pneumonia, choking episodes, abdominal distension
The differential includes: GORD, laryngeal cleft, swallowing incoordination, tracheomalacia, immunodeficiency (causing recurrent chest infections), and cystic fibrosis
Diagnosed by prone contrast ("tube") oesophagram with careful fluoroscopic screening or bronchoscopy showing the fistula opening on the posterior tracheal wall

Feature	OA (Type C)	Choanal Atresia	CDH	Duodenal Atresia	Malrotation/Volvulus
NG tube to stomach	✗ (arrests)	✓ (oral route)	✓ (stomach may be in thorax)	✓	✓
Vomiting character	Non-bilious regurgitation	None	May have bilious vomiting	Bilious (if post-ampullary)	Bilious
Abdominal distension	Minimal	None	Scaphoid	Epigastric only	Variable
Key X-ray sign	Coiled NG in pouch ± gas in abdomen	Normal CXR	Bowel in thorax	Double bubble	Upper GI contrast abnormal
VACTERL association	Yes ^[2]^[4]	CHARGE association	Associated with malrotation	Down syndrome ^[3]	Associated with CDH, OA

High Yield Summary — Differential Diagnosis of OA

The NG tube test is the key discriminator. If the tube arrests at ~10 cm and coils on X-ray → OA is confirmed. This separates OA from almost all other neonatal conditions.
Bilious vomiting rules out OA — the obstruction in OA is proximal to the ampulla of Vater. Bilious vomiting in a neonate = think malrotation with midgut volvulus first (surgical emergency).
Gas in the abdomen on X-ray = distal TOF present (Type C). Gasless abdomen = pure OA (Type A).
H-type TOF (Type E) is the diagnostic trap — no atresia, NG passes, delayed presentation with recurrent aspiration pneumonia.
Other causes of neonatal drooling/choking: choanal atresia, laryngeal cleft, neurological swallowing dysfunction — all have a patent oesophagus (NG passes).
Always screen for VACTERL associations — up to 50% of OA babies have other anomalies. Cardiac defects are the main determinant of mortality. ^[2]^[4]
For the neonatal IO differential: duodenal atresia (double bubble, Down syndrome), jejunal/ileal atresia (vascular accident), meconium ileus (CF), Hirschsprung disease (absent ganglion cells), anorectal malformation (imperforate anus). ^[3]

Active Recall — Differential Diagnosis of Oesophageal Atresia

References

^[1] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf — Gastrointestinal Diseases, Tracheoesophageal fistula and Esophageal atresia, Diagnosis section ^[2] Lecture slides: Neonatal Surgery.pdf — Oesophageal atresia slide ^[3] Senior notes: Adrian Lui Pediatrics Notes.pdf — Section 2.3.3 Gastrointestinal Disorders (OA, bowel obstruction) ^[4] GC Lecture slides: GC 205. The newborn baby is vomiting repeatedly Neonatal intestinal obstruction and other GI emergencies.pdf — Oesophageal atresia slide ^[5] Lecture slides: Case Study – Paediatric Surgery Bilious vomiting of new-born _ACH Fung.pdf — Case 1, differential diagnosis ^[6] Senior notes: MBBS Final MB (Pediatrics) (Felix PY Lai).pdf — Intestinal malrotation section ^[7] UpToDate reference: Evaluation of wheezing in infants and children — tracheomalacia, TOF associations

Diagnostic Criteria, Diagnostic Algorithm & Investigations for Oesophageal Atresia

Oesophageal atresia does not have a formal "criteria-based" diagnostic framework like, say, SLE or rheumatoid arthritis. It is a structural congenital anomaly whose diagnosis rests on a combination of clinical suspicion and confirmatory investigation. The diagnosis is effectively established when:

Clinical suspicion is raised (drooling, choking, inability to feed, respiratory distress in a neonate)
An orogastric (OG) or nasogastric (NG) tube cannot be passed into the stomach — it arrests at approximately 10–15 cm from the nares ^[1]
A chest/abdominal X-ray confirms the tube is coiled in the upper oesophageal pouch ^[1]
The presence or absence of gas in the abdomen on the same X-ray classifies whether a distal TOF exists ^[1]^[3]

That's it. In the vast majority of cases, no further diagnostic investigation is needed to confirm OA. The diagnosis is clinical + radiological.

Diagnostic Principle

The diagnosis of OA is made at the bedside + on the plain X-ray. It does NOT require contrast studies, CT, or endoscopy for confirmation in the typical case. The tube arrest + coiled tube on X-ray is essentially pathognomonic.

2. The Diagnostic Algorithm — Step by Step

Let's walk through this the way you would in real life, from the moment you suspect OA in a newborn:

When to suspect OA:

Antenatal: polyhydramnios on USS, absent/small stomach bubble ^[2]^[4]
Postnatal (within minutes to hours of birth):
- Persistent frothy salivation and drooling ^[3]
- Coughing, choking ± cyanotic episodes on first attempted feed ^[3]
- Respiratory distress ^[1]
- Inability to swallow secretions

Some centres routinely pass an NG/OG tube in all newborns at delivery as a screening test. This is particularly done if polyhydramnios was noted antenatally or if the baby is "bubbly."

Pass a firm, wide-bore (10 Fr) radio-opaque OG tube via the mouth. ^[1]^[3]

Why wide-bore? A thin, floppy tube can curl on itself inside the pharynx, giving a false impression of arrest. A firm, wide-bore tube will definitively either pass to the stomach or meet the blind pouch.
Why radio-opaque? So you can see it on X-ray.
The tube typically arrests at ~10 cm from the upper gum (nares ~12–15 cm) — this corresponds to the level of the upper pouch, usually T2–T4 ^[1]^[3]
If the tube passes freely to the stomach (> 20 cm with aspiration of gastric contents), OA is excluded (consider other diagnoses — see DDx section)

This is the key confirmatory investigation. A single AP film from neck to pelvis with the OG tube in situ provides all the information you need:

Finding	Interpretation	Why
Coiled OG tube in the upper oesophageal pouch	Confirms oesophageal atresia	The tube has nowhere to go — it coils in the dilated blind-ending upper pouch ^[1]
Gas in the stomach and bowel	Indicates a distal TOF is present (Type C, D)	Air from the trachea passes through the fistula into the GI tract ^[1]^[3]
Gasless abdomen	Indicates no distal TOF (Type A or B — pure atresia)	Without a fistula, air cannot enter the GI tract from the trachea ^[1]^[3]
Vertebral anomalies (hemivertebrae, butterfly vertebrae)	VACTERL screening	Part of the systematic search for associated anomalies ^[2]^[4]
Rib anomalies	VACTERL
Cardiac silhouette abnormality	May suggest congenital heart disease	Associated in ~35%
Lung opacification	Aspiration pneumonia/pneumonitis	From saliva overflow (above) or gastric acid reflux (below via fistula)

High Yield — X-ray Interpretation

"AP view of CXR will demonstrate the catheter curled in the upper oesophageal pouch (arrest of orogastric tube). Presence of stomach gas indicates tracheoesophageal fistula (TOF). Gasless abdomen indicates pure oesophageal atresia (EA)." ^[1]

This is the most testable imaging interpretation for OA. Remember:

Gas present = distal fistula = Type C (85%)
No gas = no distal fistula = Type A (pure OA)

Once OA is confirmed, a systematic screen for VACTERL and other anomalies is mandatory before surgical repair:

Investigation	Target Anomaly	Rationale
Echocardiography	Cardiac defects (VSD, ASD, ToF, coarctation) + side of aortic arch	Most important pre-operative investigation. Cardiac anomalies are the #1 determinant of mortality. A right-sided aortic arch changes the surgical approach from right to left thoracotomy ^[2]^[4]
Renal ultrasound	Renal agenesis, horseshoe kidney, VUR	Renal anomalies in ~15–20%
Spinal X-ray (already on the initial film)	Vertebral anomalies	Hemivertebrae, butterfly vertebrae, sacral agenesis
Perineal inspection	Imperforate anus / anorectal malformation	Simple clinical examination — must not be missed
Limb examination	Radial ray defects, polydactyly, absent thumb	Clinical examination
Chromosomal analysis / karyotype	Trisomy 18, 21	If clinical features suggest; trisomy 18 in particular has a very poor prognosis

Investigation	When Used	Key Findings
CT scan	Surgical planning — to determine the gap distance between the two oesophageal ends ^[3]	Defines whether short-gap (primary anastomosis feasible) vs long-gap (staged approach needed). Also assesses vertebral anomalies in greater detail
Water-soluble contrast study (under fluoroscopy)	Rarely needed; used when diagnosis is uncertain or to define upper pouch anatomy	Confirms presence of OA. Barium is NOT used because it causes pneumonitis if aspirated into the lungs ^[1]
Bronchoscopy	To identify an upper pouch fistula (Type B or D) or to evaluate tracheomalacia	Directly visualises the fistula opening on the posterior membranous tracheal wall
Prone tube oesophagram	Specifically for suspected H-type TOF (Type E) — where there is no atresia and the NG tube passes	The fistula is small and intermittent; careful fluoroscopic study with contrast injected via a catheter pulled slowly upward through the oesophagus demonstrates the fistula. Prone position pools contrast posteriorly where the fistula opens

4. Detailed Investigation Modalities — Key Findings & Interpretation

This is the first and most important imaging investigation. It should be a single AP film from neck to pelvis with the OG tube in situ.

Systematic reading of the X-ray in suspected OA:

What to Look For	Normal	Abnormal in OA	Interpretation
OG tube position	Tube tip below the diaphragm in the stomach	Tube coiled in the upper mediastinum at T2–T4 level	Confirms upper pouch = oesophageal atresia ^[1]
Gas distribution	Gas in stomach and throughout bowel	Depends on type — see below
↳ Gas in stomach present	—	Gas in stomach + bowel	Distal TOF present (air enters GI tract via fistula) → Type C ^[1]
↳ Gasless abdomen	—	No gas distal to the atresia	No distal TOF → Type A ^[1]
Vertebrae	Normal alignment and morphology	Hemivertebrae, butterfly vertebrae, sacral anomalies	VACTERL — vertebral component ^[4]
Ribs	12 pairs, normal morphology	Absent/fused ribs	Associated anomalies
Cardiac silhouette	Normal size and shape	Cardiomegaly, abnormal contour	Congenital heart disease
Lung fields	Clear	Opacification (esp. RUL)	Aspiration pneumonia — saliva/gastric acid
Diaphragm	Normal domes	Elevated hemidiaphragm, bowel in thorax	Consider congenital diaphragmatic hernia if present

Exam Tip — The 'Gasless Abdomen'

Students often forget this distinction. A gasless abdomen means no distal fistula is present — this is Type A (pure OA) or the very rare Type B. It immediately tells you the surgical challenge will be greater because Type A typically has a long gap between the two oesophageal segments, making primary anastomosis harder.

Parameter	Finding	Clinical Significance
Structural defects	VSD, ASD, Tetralogy of Fallot, coarctation, PDA	~35% of OA babies have cardiac anomalies; affects Spitz prognostic grouping and anaesthetic planning
Side of aortic arch	Right-sided aortic arch in ~2.5%	Standard surgical approach is right posterolateral thoracotomy. A right-sided arch mandates a left thoracotomy instead
Ventricular function	Assess for heart failure	Important for peri-operative risk

"CT for surgical planning (decide how far the two ends locate)" ^[3]

Finding	Interpretation
Gap distance between upper and lower oesophageal pouches	Short gap (< 2–3 vertebral bodies / < 3 cm): primary anastomosis feasible. Long gap (≥ 3 cm): staged approach — gastrostomy + delayed repair or oesophageal replacement ^[3]
Upper pouch size and position	Guides surgical approach
Associated vertebral anomalies	Better defined than on plain X-ray
Vascular anatomy	Confirms aortic arch side; identifies aberrant subclavian artery (relevant for surgical approach)

"Water-soluble contrast can be passed into the oesophageal pouch under fluoroscopic guidance which will confirm presence of EA. Barium is NOT used since it will cause pneumonitis if aspirated into lungs." ^[1]

When to Use	Technique	Key Finding
Diagnostic uncertainty; define upper pouch anatomy; suspected upper pouch fistula	Tiny volume (0.5–1 mL) of water-soluble contrast (e.g., iohexol/Omnipaque) injected via the OG tube under fluoroscopy; immediately aspirated back	Blind-ending upper pouch; possible proximal fistula (contrast entering the trachea)

Why Not Barium?

Barium is NOT used because if it is aspirated into the lungs (which is highly likely given the anatomy), it causes a severe chemical pneumonitis that is far worse than aspiration of water-soluble contrast. Water-soluble contrast is iso-osmolar and much less damaging to the pulmonary epithelium. ^[1]

Indication	Findings
Pre-operative assessment of the trachea and fistula	Fistula opening visible on the posterior membranous wall of the trachea, usually just above the carina
Assess for tracheomalacia	Anterior-posterior collapse of the trachea during expiration — common in OA due to deficient tracheal cartilage rings
Identify proximal fistula (Type B, D)	Fistula opening in the upper trachea
Diagnosis of H-type TOF (Type E)	Small fistula opening; may be difficult to see — often requires concurrent oesophagoscopy and passage of a guidewire through the fistula

Finding	Significance
Renal agenesis (unilateral)	VACTERL — renal component
Horseshoe kidney
Hydronephrosis / VUR	May need postnatal MCUG
Normal	Does not exclude all renal anomalies but reassuring

Indicated if dysmorphic features suggest a syndromic diagnosis (trisomy 18, 21, CHARGE syndrome)
Trisomy 18 carries a very poor prognosis — impacts decisions about surgical intervention
Microarray or karyotype as appropriate

5. Special Diagnostic Scenarios

Polyhydramnios is the key antenatal clue but is non-specific ^[2]^[3]^[4]
Absent or small stomach bubble on USS is more specific but may be normal in Type C (if fluid passes through the fistula)
The "upper pouch sign" (dilated fluid-filled upper oesophagus) on prenatal USS has high specificity but low sensitivity
Antenatal diagnosis of OA is made in only ~30–50% of cases — many are diagnosed postnatally

This is diagnostically the most challenging variant because:

There is no atresia → the NG tube passes normally
The baby can feed → no immediate drooling/choking
Presentation is delayed (weeks to months) with recurrent pneumonia, chronic cough, abdominal distension
Prone tube oesophagram: Patient prone, contrast injected via a catheter being slowly withdrawn from the stomach upward through the oesophagus. The fistula is usually at the level of C7–T2. Prone position allows contrast to pool posteriorly where the fistula opens (the fistula runs obliquely upward from the oesophagus to the trachea in an "H" configuration)
Bronchoscopy can directly visualise the fistula on the posterior tracheal wall

The gap between the upper and lower pouches determines whether primary anastomosis is feasible:

Method	Technique
Plain X-ray with tube in upper pouch + gas in stomach	Rough estimate — count vertebral bodies between the tube tip and the stomach gas shadow
CT scan	More accurate; 3D reconstruction possible ^[3]
Intraoperative assessment	Definitive — direct measurement at surgery

A gap of > 3 cm or > 2–3 vertebral bodies generally defines "long-gap" OA, which requires a staged approach (gastrostomy → delayed primary repair or oesophageal replacement) ^[3].

Before surgical repair, the following baseline investigations are needed:

Investigation	Purpose
Full blood count	Baseline Hb, WCC, platelets
Blood group and crossmatch	For surgery
Coagulation profile	Pre-operative assessment
Blood glucose	Neonates are at risk of hypoglycaemia
Electrolytes, renal function	Baseline; dehydration assessment
Blood gas	Assess respiratory status
Blood culture	If sepsis suspected (aspiration pneumonia)
Echocardiography	Cardiac anomalies + aortic arch side — MUST be done before surgery
Renal USS	VACTERL renal screening
Spinal X-ray (from initial film)	VACTERL vertebral screening

High Yield Summary — Diagnosis of Oesophageal Atresia

Diagnostic manoeuvre: Pass a firm, wide-bore (10 Fr) radio-opaque OG tube — it arrests at ~10 cm from the gum in OA ^[1]^[3]
Confirmatory imaging: Plain X-ray (CXR + AXR) showing a coiled tube in the upper oesophageal pouch ^[1]
Subtyping on X-ray: Gas in stomach = distal TOF present (Type C). Gasless abdomen = no distal TOF (Type A) ^[1]^[3]
Pre-operative essentials: Echocardiography (cardiac defects + aortic arch side), renal USS, spinal X-ray, perineal + limb exam for VACTERL ^[2]^[4]
CT for surgical planning — determines the gap length between the two oesophageal ends ^[3]
Water-soluble contrast (NOT barium) under fluoroscopy if diagnostic uncertainty — barium causes pneumonitis if aspirated ^[1]
H-type TOF: diagnosed by prone tube oesophagram or bronchoscopy — NG tube passes normally, delayed presentation
Antenatal: polyhydramnios + absent stomach bubble on USS — but only ~30–50% diagnosed antenatally

Active Recall — Diagnosis & Investigations of Oesophageal Atresia

References

^[1] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf — Tracheoesophageal fistula and Esophageal atresia, Diagnosis section ^[2] Lecture slides: Neonatal Surgery.pdf — Oesophageal atresia slide ^[3] Senior notes: Adrian Lui Pediatrics Notes.pdf — Section 2.3.3 Gastrointestinal Disorders (OA diagnosis and management) ^[4] GC Lecture slides: GC 205. The newborn baby is vomiting repeatedly Neonatal intestinal obstruction and other GI emergencies.pdf — Oesophageal atresia slide

Management of Oesophageal Atresia & Tracheo-Oesophageal Fistula

The management of OA/TOF follows a logical sequence:

Immediate stabilisation — prevent aspiration and dehydration (the baby cannot swallow)
Pre-operative work-up — define the anatomy, screen for associated anomalies, and assess fitness for surgery
Definitive surgical repair — close the fistula and restore oesophageal continuity
Post-operative care and long-term follow-up — manage complications

The urgency of surgery depends on the Spitz group (prognosis based on birth weight and cardiac status), the gap length, and the presence of life-threatening associated anomalies. OA is a surgical emergency but not usually a "minutes-to-theatre" emergency — careful stabilisation first improves outcomes.

1. Immediate Pre-Operative Management (Stabilisation)

This is the critical first step. Think about what the two problems are (blind pouch → saliva pooling; fistula → gastric acid entering lungs and air entering stomach) and how to address each:

Intervention	Rationale / Mechanism
Head-up positioning (30–45°)	Gravity reduces gastric acid reflux through the distal fistula into the trachea; also helps saliva drain from the upper pouch rather than overflowing into the larynx
Avoidance of bag-mask ventilation (if possible)	Positive pressure from bag-mask ventilation preferentially inflates the stomach through the distal fistula (path of least resistance) → gastric distension → diaphragmatic splinting → worsening respiratory failure + risk of gastric perforation
Intubation technique	If intubation is required, the endotracheal tube tip should ideally be positioned distal to the fistula (i.e., into one or both main bronchi initially, then withdrawn to just above the carina) to prevent air leak through the fistula. In practice, careful positioning with the cuff (if cuffed ETT) beyond the fistula opening helps
Supplemental oxygen / respiratory support	As needed for aspiration pneumonitis or respiratory distress; gentle ventilation with lowest possible pressures to minimise air leak through the fistula

"Continuous suction: using Replogle tube" ^[3]

Intervention	Rationale / Mechanism
Continuous low-pressure suction of the upper oesophageal pouch using a Replogle tube	A Replogle tube is a double-lumen tube: one lumen drains saliva, the other serves as an air vent ^[3]. This prevents saliva from pooling in the upper pouch and overflowing into the larynx/trachea → reduces aspiration risk. The air vent prevents the suction from collapsing the tube against the pouch wall (which would be painful and ineffective)
Intermittent gentle suctioning if Replogle unavailable	Alternative, but continuous suction is superior

The Replogle Tube — Must Know

"Replogle tube is a double lumen tube in which one is for saliva drainage and the other as air vent." ^[3] This is a favourite exam detail. The dual-lumen design is what makes it effective for continuous suctioning — without the air vent, the single lumen would suction the mucosa and block.

"NPO + IV fluid" ^[3]

Intervention	Rationale
NPO (nil by mouth)	The baby cannot swallow — any oral feed will pool in the upper pouch and be aspirated. Feeding is absolutely contraindicated until surgical repair restores oesophageal continuity ^[3]
IV fluid resuscitation and maintenance	To correct and prevent dehydration. Neonates have high insensible water losses and limited glycogen stores — they need IV dextrose-containing fluids (e.g., 10% dextrose with appropriate electrolytes) to prevent hypoglycaemia ^[3]
Total parenteral nutrition (TPN)	If surgery is delayed (e.g., premature infant, long-gap OA, or awaiting cardiac surgery), TPN provides calories, amino acids, and lipids for growth. Neonates cannot tolerate prolonged starvation

Intervention	Rationale
Broad-spectrum antibiotics	If aspiration pneumonia is present or suspected; also as pre-operative prophylaxis ^[8]
Temperature control (servo-controlled incubator)	Neonates, especially premature, are at high risk of hypothermia → increased metabolic demands → metabolic acidosis
Vitamin K	Standard neonatal prophylaxis (prevents haemorrhagic disease of the newborn)
Blood glucose monitoring	Neonates at risk of hypoglycaemia, especially if premature or small-for-gestational-age

As detailed in the Investigations section, but summarised here for the management algorithm:

Investigation	Purpose
Echocardiography	Cardiac anomalies + side of aortic arch (determines surgical approach) ^[2]^[4]
Renal USS	VACTERL renal screening
Spinal X-ray	VACTERL vertebral screening
Perineal + limb exam	Imperforate anus, radial ray defects
CT	Gap length assessment for surgical planning ^[3]
Bloods	FBC, group & crossmatch, coagulation, glucose, electrolytes, blood gas

3. Definitive Surgical Management

The surgical approach depends on two key factors:

Gap length — short gap vs long gap
Associated anomalies — cardiac, prematurity

"Short gap (majority): divide fistula + primary anastomosis (thoracoscopic in QMH)" ^[3]

"Short gap — Divide TOF. Repair oesophageal atresia." ^[5]

This is the standard operation performed in the first 24–48 hours of life (once stabilised):

Surgical Steps:

Step	Details	Rationale
1. Approach	Right posterolateral thoracotomy (extrapleural approach) OR thoracoscopic (minimally invasive — used at QMH) ^[3]	Right side preferred because the aortic arch is on the left in most patients; extrapleural approach avoids contamination of the pleural cavity if an anastomotic leak occurs
2. Azygos vein	Ligated and divided	Crosses the operative field behind the right hilum; must be divided to expose the oesophagus and trachea
3. Division of the fistula	The distal TOF is identified, ligated, and divided flush with the trachea	Eliminates the abnormal communication between the trachea and oesophagus → stops air leak into the GI tract and gastric acid reflux into the lungs ^[1]^[3]^[5]
4. Tracheal closure	The tracheal defect is closed with interrupted sutures	Prevents air leak and recurrent fistula
5. Primary oesophageal anastomosis	The upper and lower oesophageal segments are mobilised and anastomosed end-to-end	Restores oesophageal continuity so the baby can eventually feed orally ^[1]^[3]^[5]
6. Trans-anastomotic tube (TAT)	A fine nasogastric tube is passed across the anastomosis into the stomach	Allows early enteral feeding while the anastomosis heals; also acts as a stent
7. Chest drain	Placed extrapleurally near the anastomosis	Detects anastomotic leak early (saliva/milk in the drain = leak)

Key Surgical Principles:

Mobilise the upper pouch extensively (it is thick-walled and can tolerate mobilisation) but mobilise the lower segment minimally (its blood supply is segmental and tenuous — excessive mobilisation risks devascularisation and ischaemic stricture)
A tension-free anastomosis is the goal — tension increases leak and stricture risk
Thoracoscopic approach is now used at QMH (Queen Mary Hospital, Hong Kong) — this is minimally invasive with potentially less pain, shorter recovery, and better cosmesis ^[3]

High Yield — Surgical Management of Type C OA/TOF

"Divide TOF + primary oesophageal anastomosis" — this is the bread-and-butter operation for the most common type (Type C, ~85%). ^[3]^[5]

Key points:

Right posterolateral thoracotomy (unless right-sided aortic arch → left thoracotomy)
Thoracoscopic approach at QMH ^[3]
Divide fistula flush with trachea + end-to-end oesophageal anastomosis

"Long gap: gastrostomy feeding → grow and reassess for esophageal replacement (e.g. stomach, colon)" ^[3]

"Long gap — Gastrostomy. Grow and reassess, delayed primary anastomosis. ? Oesophageal replacement" ^[5]

When the gap between the two oesophageal segments is > 3 cm (or > 2–3 vertebral bodies), primary anastomosis is not feasible because the tension would be too great → high risk of anastomotic leak and stricture.

Management Strategy:

Phase	Intervention	Rationale
Phase 1: Stabilisation	Gastrostomy (surgical or percutaneous) for enteral feeding	Allows the baby to receive enteral nutrition (breast milk/formula) directly into the stomach while the oesophagus cannot be used. Enteral feeding is superior to TPN for gut development and immune function ^[3]^[5]
	Continued upper pouch suctioning (Replogle)	Prevents aspiration
	Upper pouch "sham feeding" (optional)	Saliva is fed into the gastrostomy to maintain gut exposure to oral secretions; also helps baby develop sucking/swallowing coordination
Phase 2: Growth and Reassessment	Allow the baby to grow for weeks to months	The oesophageal segments may elongate with growth, and the gap may narrow over time. Serial imaging reassesses gap length
	Foker process (in some centres)	External traction sutures placed on both oesophageal ends, gradually pulling them together over days to weeks → induces oesophageal growth → allows delayed primary anastomosis
Phase 3: Definitive Repair	Delayed primary anastomosis (if gap has closed sufficiently)	Preferred if achievable — uses the native oesophagus, which has the best long-term functional outcome ^[5]
	Oesophageal replacement (if gap remains too large)	Options (see below) ^[3]^[5]

Oesophageal Replacement Options for Irreducible Long-Gap OA:

Technique	Conduit Used	Advantages	Disadvantages
Gastric pull-up (gastric transposition)	Entire stomach mobilised and pulled up to the neck to anastomose with the upper oesophageal pouch	Single anastomosis; robust blood supply; commonly used	Large conduit in the chest → reflux problems; risk of aspiration; stomach loses reservoir function
Colon interposition	Segment of colon (usually left colon or transverse colon) placed in the oesophageal position	Good length; isoperistaltic segment possible	Requires three anastomoses (more complex); risk of conduit redundancy, graft necrosis, and late dilatation
Jejunal interposition	Segment of jejunum on a vascular pedicle	Good calibre match with oesophagus	Technically demanding; limited length; tenuous blood supply in the chest

Long-Gap OA — Staged Management

"Long gap: gastrostomy feeding → grow and reassess for esophageal replacement (e.g. stomach, colon)" ^[3]^[5]

The key message is: do not force a primary anastomosis under tension. A tension-free repair is paramount. If the gap is too long:

Gastrostomy for feeding
Allow growth → reassess
Delayed primary anastomosis OR oesophageal replacement (gastric pull-up, colon/jejunal interposition)

No atresia → the oesophagus is in continuity, but the fistula must be closed
Surgical approach: Usually via a cervical incision (low collar incision on the right side of the neck) because the H-type fistula is typically at the C7–T2 level (higher than the distal TOF in Type C)
The fistula is identified, ligated, and divided
No oesophageal anastomosis is needed (oesophagus is intact)

Gross Type	Surgical Approach
Type A (Pure OA, no TOF)	Long-gap management: gastrostomy → delayed repair or oesophageal replacement
Type B (OA + proximal TOF)	Divide proximal fistula + long-gap management (usually long gap)
Type C (OA + distal TOF — 85%)	Divide distal TOF + primary end-to-end oesophageal anastomosis (if short gap) ^[3]^[5]
Type D (OA + double TOF)	Divide both fistulae + primary anastomosis (if short gap) or staged (if long gap)
Type E (H-type TOF, no OA)	Cervical approach: divide fistula; no oesophageal anastomosis needed

Aspect	Details	Rationale
Ventilation	Elective post-operative ventilation for 24–48 hours; avoid excessive neck extension (puts tension on the anastomosis)	Allow recovery from anaesthesia; protect the fresh anastomosis
Trans-anastomotic tube (TAT) feeding	Enteral feeding commenced via the TAT (fine NG tube passed across the anastomosis at surgery) from day 1–2	Early enteral feeding promotes healing, maintains gut function, and reduces need for TPN
Upper pouch suction	Continue low-pressure suction of the upper oesophagus above the anastomosis via a separate tube	Prevents saliva from bathing the fresh anastomosis before it heals
Contrast study (day 5–7)	Water-soluble contrast swallow to check anastomotic integrity before starting oral feeds	Confirms no leak; if intact, oral feeding can commence
Antibiotics	Peri-operative course (usually 5–7 days)	Prevent surgical site infection; aspiration pneumonia
Chest drain monitoring	Watch for saliva or milk in the drain	Early sign of anastomotic leak
Anti-reflux treatment	Proton pump inhibitor (PPI) or H2 receptor antagonist	Gastro-oesophageal reflux is almost universal after OA repair due to disordered oesophageal motility and disrupted lower oesophageal sphincter function; acid reflux can cause anastomotic stricture

OA is not a "fix and forget" condition. These patients need lifelong follow-up for a range of sequelae:

Complication to Monitor	Follow-Up Strategy
Anastomotic stricture	Contrast swallow / OGD if feeding difficulties or dysphagia; treated with balloon dilatation
Gastro-oesophageal reflux (GORD)	PPI therapy; fundoplication if refractory; annual OGD screening for oesophagitis / Barrett's
Tracheomalacia	Bronchoscopy if "dying spells" or recurrent wheeze; aortopexy if severe
Recurrent TOF	Suspect if recurrent aspiration pneumonia after initially successful repair; diagnose with contrast study / bronchoscopy
Oesophageal dysmotility	Lifelong — intrinsic to OA (the repaired oesophagus never has normal peristalsis); advise careful chewing, small boluses, adequate fluids with meals
Respiratory	Recurrent chest infections, reactive airway disease (OA children have increased rates of "asthma-like" symptoms due to chronic aspiration and tracheomalacia)
Nutritional / growth	Monitor growth; dietetic input; feeding difficulties are common in the first years of life

The prognosis of OA is determined primarily by birth weight and associated cardiac anomalies, not by the oesophageal anomaly itself:

Spitz Group	Criteria	Survival
I	BW > 1500 g AND no major cardiac defect	> 95% ^[3]
II	BW < 1500 g OR major cardiac defect	~60% ^[3]
III	BW < 1500 g AND major cardiac defect	~20% ^[3]

Spitz Classification — High Yield

The Spitz classification drives home the point that cardiac anomalies and prematurity are the main killers, not the oesophageal atresia itself. In Group I (good weight, no cardiac defect), survival exceeds 95%. This is why echocardiography is mandatory before surgery. ^[3]

Situation	Management Modification	Rationale
Right-sided aortic arch	Left thoracotomy instead of right	The aorta is on the right → surgical access from the right is obstructed
Major cardiac defect requiring urgent surgery	May delay OA repair; gastrostomy + upper pouch suction to temporise	Cardiac repair may take priority if life-threatening (e.g., critical coarctation, interrupted aortic arch)
Extreme prematurity (< 1000 g)	May delay surgery; gastrostomy + TPN + upper pouch suction	The baby may not tolerate thoracotomy; allow stabilisation and weight gain
Severe aspiration pneumonia	Treat pneumonia first; delay repair until respiratory status improved	Operating on a baby with active pneumonia increases anaesthetic and surgical risk
Trisomy 18	Careful discussion with family regarding prognosis; surgical repair may not be offered	Trisomy 18 has a very poor overall prognosis (median survival ~14 days without intervention); surgical repair of OA may not change the outcome and may cause suffering

High Yield Summary — Management of Oesophageal Atresia

Immediate stabilisation: NPO + IV fluids; continuous upper pouch suction using a Replogle tube (double-lumen: one for drainage, one as air vent); head-up positioning; avoid bag-mask ventilation ^[3]
Pre-operative essentials: Echocardiography (cardiac defects + aortic arch side); CT for gap assessment ^[3]^[4]
Short-gap OA with distal TOF (Type C): Divide TOF + primary end-to-end oesophageal anastomosis via right posterolateral thoracotomy (or thoracoscopic at QMH) ^[3]^[5]
Long-gap OA: Gastrostomy for feeding → grow and reassess → delayed primary anastomosis OR oesophageal replacement (gastric pull-up, colon interposition, jejunal interposition) ^[3]^[5]
H-type TOF (Type E): Cervical approach to divide the fistula; no oesophageal anastomosis needed
Post-operative: Trans-anastomotic tube feeding; contrast study at day 5–7; anti-reflux therapy (PPI)
Long-term: Lifelong follow-up for anastomotic stricture, GORD, tracheomalacia, recurrent TOF, oesophageal dysmotility, and growth
Prognosis (Spitz): Group I (BW > 1500 g, no CHD) > 95% survival; Group II (BW < 1500 g OR CHD) ~60%; Group III (BW < 1500 g AND CHD) ~20% ^[3]

Active Recall — Management of Oesophageal Atresia

References

^[1] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf — Tracheoesophageal fistula and Esophageal atresia, Treatment section ^[2] Lecture slides: Neonatal Surgery.pdf — Oesophageal atresia slide ^[3] Senior notes: Adrian Lui Pediatrics Notes.pdf — Section 2.3.3 Gastrointestinal Disorders (OA management and prognosis) ^[4] GC Lecture slides: GC 205. The newborn baby is vomiting repeatedly Neonatal intestinal obstruction and other GI emergencies.pdf — Oesophageal atresia slide ^[5] Lecture slides: Neonatal Surgery.pdf — Surgical management slide ^[8] Senior notes: MBBS Final MB (Pediatrics) (Felix PY Lai).pdf — Intestinal atresia, Treatment section (general approach)

Complications of Oesophageal Atresia & Tracheo-Oesophageal Fistula

Complications of OA/TOF can be divided into:

Pre-operative complications — from the anomaly itself before surgical repair
Early post-operative complications — occurring in the first days to weeks after surgery
Late / long-term complications — lifelong sequelae of the condition and its repair

The key conceptual point is this: even after a technically perfect repair, the oesophagus is never truly normal. The repaired oesophagus has disordered peristalsis (the intrinsic myenteric plexus is disrupted), the anastomosis is a site of potential stricture, and the relationship between the oesophagus and trachea remains abnormal (tracheomalacia). These patients need lifelong follow-up.

These occur before any surgical intervention and are direct consequences of the blind pouch and fistula:

Complication	Pathophysiological Basis
Aspiration pneumonia	Reflux of gastric contents through the TOF results in aspiration pneumonia and contributes to morbidity ^[1]. Additionally, saliva overflows from the blind upper pouch into the larynx → aspiration. Two routes of aspiration: (1) from above (saliva), (2) from below (gastric acid via fistula). The right upper lobe is most commonly affected because the right main bronchus is wider, shorter, and more vertical
Respiratory distress / respiratory failure	Combination of aspiration pneumonitis, air leak through fistula causing gastric distension (splinting the diaphragm), and any co-existing pulmonary hypoplasia or cardiac anomaly
Dehydration and electrolyte imbalance	The baby cannot swallow → no enteral intake. Neonates have high insensible losses and limited glycogen reserves → rapid dehydration and hypoglycaemia if IV fluids are not commenced promptly
Gastric distension / perforation	Air enters the stomach via the distal fistula, especially during crying or (catastrophically) during bag-mask ventilation. Massive gastric distension can compromise ventilation and, rarely, cause gastric perforation

2. Early Post-Operative Complications (Days to Weeks After Repair)

These are surgical complications related to the repair itself:

Anastomotic leak ^[1]^[3]

Feature	Detail
Incidence	~10–20% of repairs; more common when the anastomosis was under tension (long gap)
When	Typically days 3–7 post-operatively
Pathophysiology	The freshly sutured oesophageal anastomosis breaks down → saliva and gastric contents leak into the mediastinum or pleural cavity. Why? The oesophagus has no serosa (unlike the rest of the GI tract), so it heals more slowly and has less tissue strength to hold sutures. Tension on the anastomosis further compromises healing
Clinical features	Saliva or milk appearing in the chest drain; fever; sepsis; respiratory deterioration; pneumomediastinum or pleural effusion on X-ray
Detection	Chest drain output (saliva/milk); contrast swallow at day 5–7 before initiating oral feeds
Management	Small, contained leaks: conservative (NPO, antibiotics, chest drain, TPN) — most heal spontaneously. Large leaks or mediastinitis: re-operation

Why Does the Oesophagus Leak More Than Other GI Anastomoses?

The oesophagus lacks a serosal layer. In the rest of the bowel, the serosa provides an outer fibrous covering that holds sutures well and heals quickly (serosal apposition). Without this, oesophageal anastomoses rely solely on the muscularis and mucosa for integrity, making them inherently more prone to leakage.

Anastomotic leak or stricture ^[3] Esophageal stricture ^[1]

Feature	Detail
Incidence	~30–40% of repairs require at least one dilatation
When	Weeks to months post-operatively; can recur over years
Pathophysiology	Scar tissue (fibrosis) forms at the anastomotic site as part of the healing process. Tension at the anastomosis, ischaemia of the oesophageal ends, and gastro-oesophageal reflux (acid injury) all promote excessive fibrosis → luminal narrowing. Think of it as "the wound healing too enthusiastically"
Clinical features	Progressive dysphagia (initially to solids, then liquids); food impaction; regurgitation; choking episodes; poor weight gain
Diagnosis	Contrast swallow showing narrowing at the anastomosis; OGD directly visualises and allows treatment
Management	Endoscopic balloon dilatation — first-line; may need repeated sessions. Intralesional steroid injection (triamcinolone) to reduce fibrosis if recurrent. Mitomycin C application (topical antifibrotic) for refractory strictures. Rarely: surgical revision or resection

Recurrent TOF ^[1]^[3]

Feature	Detail
Incidence	~5–10%
When	Weeks to months after initial repair
Pathophysiology	The divided fistula recanalises — this happens because the tracheal and oesophageal walls are in close apposition after repair, and if there is local inflammation, infection, or anastomotic leak, the healing tissues can fuse and re-form a fistulous tract
Clinical features	Recurrent aspiration pneumonia; coughing/choking with feeds (especially liquids); recurrent cyanotic episodes — essentially the same symptoms as the original fistula
Diagnosis	Prone contrast oesophagram; bronchoscopy (visualise the fistula opening on the posterior tracheal wall)
Management	Repeat surgical division of the recurrent fistula, usually with interposition of a tissue flap (e.g., pleural flap, pericardial flap, or intercostal muscle flap) between the trachea and oesophagus to prevent re-recurrence. Why a tissue flap? It physically separates the two structures so they cannot fuse again

Complication	Mechanism
Wound infection / mediastinitis	Contamination of the surgical field from saliva/gastric contents, especially if an anastomotic leak occurs
Pneumothorax	Injury to the pleura during thoracotomy; or from positive-pressure ventilation in a fragile neonatal lung
Chylothorax	Injury to the thoracic duct during surgery → chyle (lymphatic fluid) accumulates in the pleural cavity. Presents as milky drain output, especially after feeds are commenced
Recurrent laryngeal nerve injury	The recurrent laryngeal nerves run in the tracheo-oesophageal groove and are at risk during dissection → hoarseness, weak cry, aspiration (vocal cord paralysis)
Vocal cord paralysis	Related to recurrent laryngeal nerve injury — unilateral is more common; bilateral is rare but can cause stridor and airway compromise

3. Late / Long-Term Complications

These are the complications that make OA/TOF a lifelong condition requiring ongoing follow-up. Every one of them is listed in the lecture slides and senior notes:

Tracheomalacia ^[1]^[3]

Feature	Detail
Incidence	Present in up to 75% of OA/TOF patients (often subclinical); clinically significant in ~10–20%
Pathophysiology	The tracheal cartilage rings at the level of the fistula are congenitally deficient (the same embryological insult that caused the OA/TOF also affected normal tracheal development). The posterior membranous wall of the trachea is also widened. This results in a floppy trachea that collapses during expiration (when intrathoracic pressure rises and compresses the trachea from outside)
Clinical features	"Dying spells" — episodes of cyanosis, apnoea, and bradycardia (often triggered by feeding, crying, or agitation when increased expiratory effort causes tracheal collapse); barking cough ("TOF cough" or "brassy cough"); recurrent wheeze; recurrent lower respiratory tract infections
Diagnosis	Bronchoscopy (gold standard) — shows anterior-posterior collapse of the trachea during expiration, typically at the level of the former fistula site
Management	Mild: observation (often improves with growth as tracheal cartilage matures — most resolve by age 2–3 years). Moderate: prone positioning during sleep, continuous positive airway pressure (CPAP). Severe (life-threatening dying spells): aortopexy — the ascending aorta is sutured to the posterior aspect of the sternum, pulling the anterior tracheal wall forward and splinting the airway open. Some centres use posterior tracheopexy (suturing the membranous trachea to the vertebral body)

Tracheomalacia — 'TOF Cough' and 'Dying Spells'

Tracheomalacia is probably the most clinically important long-term complication of OA/TOF. The characteristic barking, brassy cough ("TOF cough") is very recognisable. "Dying spells" (ALTE — apparent life-threatening events) are the feared severe manifestation. Always think of tracheomalacia in a child with repaired OA/TOF who has recurrent wheeze, cough, or cyanotic episodes.

Gastroesophageal reflux ^[1]^[3]

Feature	Detail
Incidence	Virtually universal after OA repair (~40–70% clinically significant)
Pathophysiology	Multiple factors: (1) intrinsic oesophageal dysmotility — the repaired oesophagus has abnormal peristalsis (disrupted myenteric plexus) → impaired acid clearance; (2) shortened oesophagus — surgical mobilisation may reduce the intra-abdominal length of the oesophagus; (3) disrupted lower oesophageal sphincter (LES) mechanism — surgical dissection around the hiatus and oesophageal mobilisation damages the anti-reflux barrier; (4) altered angle of His
Clinical significance	GORD promotes anastomotic stricture (acid bathing the anastomosis → chronic inflammation → fibrosis); aspiration pneumonia (acid reflux into the tracheobronchial tree, especially if tracheomalacia is also present); oesophagitis; long-term risk of Barrett's oesophagus ^[1]
Management	Proton pump inhibitor (PPI) — first-line; often started immediately post-operatively and continued long-term. Anti-reflux surgery (fundoplication — Nissen or partial) if PPI-refractory or complicated by severe stricture/aspiration

Disordered peristalsis ^[3]

Feature	Detail
Incidence	Present in essentially 100% of patients after OA repair
Pathophysiology	The oesophagus in OA/TOF patients has intrinsically abnormal motility from birth (the same embryological defect that caused the atresia also impaired normal oesophageal innervation). Surgical division and re-anastomosis further disrupts the myenteric (Auerbach's) plexus → aperistalsis or uncoordinated peristalsis in the distal oesophageal segment. The upper pouch may have some contractions, but the lower segment below the anastomosis typically has very poor motility
Clinical features	Dysphagia — especially to solids; food bolus impaction; need to eat slowly, chew well, and take fluids with meals. Patients learn to adapt throughout childhood ^[1]
Management	Behavioural: careful eating habits (small bites, thorough chewing, upright positioning, sips of water with meals). No pharmacological treatment effectively restores peristalsis. This is a lifelong issue

Barrett's esophagus ^[1]

Feature	Detail
Incidence	Up to 6–11% of adult OA survivors
Pathophysiology	Chronic GORD → repeated acid injury to the oesophageal squamous epithelium → metaplasia to intestinal-type columnar epithelium (Barrett's). This is a pre-malignant condition with risk of progression to oesophageal adenocarcinoma
Clinical significance	OA survivors have a higher-than-population-baseline risk of oesophageal adenocarcinoma. This is why lifelong surveillance OGD is recommended in many centres, starting in adolescence or early adulthood

Failure to thrive ^[3]

Feature	Detail
Pathophysiology	Multifactorial: (1) oesophageal dysmotility → difficulty swallowing → reduced oral intake; (2) GORD → feeding aversion, vomiting; (3) anastomotic stricture → dysphagia; (4) recurrent aspiration pneumonia → increased caloric expenditure; (5) associated anomalies (e.g., cardiac disease increasing metabolic demand)
Management	Dietetic input; high-calorie feeds; management of underlying causes (stricture dilatation, anti-reflux treatment); gastrostomy feeding if oral intake is insufficient

Asthma ^[1]

Feature	Detail
Incidence	OA survivors have a ~2–3x increased risk of wheeze / "asthma-like" symptoms compared to the general population
Pathophysiology	(1) Tracheomalacia → dynamic airway collapse → wheeze; (2) chronic micro-aspiration from GORD and disordered swallowing → airway inflammation; (3) recurrent lower respiratory tract infections → bronchial hyperreactivity. Note: this is often labelled "asthma" but is mechanistically different from atopic asthma — it is structural and aspiration-related
Management	Treat the underlying cause (GORD, tracheomalacia); bronchodilators/inhaled corticosteroids may help symptomatically but are often less effective than in true atopic asthma

Timing	Complication	Key Mechanism
Pre-operative	Aspiration pneumonia ^[1]	Saliva overflow + gastric acid reflux via fistula
	Dehydration, hypoglycaemia	Cannot swallow; high neonatal metabolic demand
	Gastric distension/perforation	Air via distal fistula; bag-mask ventilation
Early post-operative	Anastomotic leak ^[1]^[3]	No serosal layer; tension on anastomosis
	Anastomotic stricture ^[1]^[3]	Fibrosis at repair site; worsened by GORD
	Recurrent TOF ^[1]^[3]	Recanalisation of divided fistula
	Chylothorax, wound infection	Surgical injury to thoracic duct; contamination
	Recurrent laryngeal nerve injury	Nerve runs in tracheo-oesophageal groove
Late / long-term	Tracheomalacia ^[1]^[3]	Congenital deficiency of tracheal cartilage at fistula site
	GORD ^[1]^[3]	Oesophageal dysmotility + disrupted LES + shortened oesophagus
	Disordered peristalsis ^[3]	Intrinsic oesophageal dysmotility + surgical disruption of myenteric plexus
	Dysphagia ^[1]	Combination of dysmotility, stricture, and GORD
	Barrett's oesophagus ^[1]	Chronic GORD → intestinal metaplasia → pre-malignant
	Failure to thrive ^[3]	Multifactorial: poor intake, GORD, recurrent infections
	Asthma / recurrent LRTI ^[1]	Tracheomalacia + chronic micro-aspiration + bronchial hyperreactivity

High Yield Summary — Complications of OA/TOF

The six complications most commonly tested (all from the lecture slides / senior notes):

Anastomotic leak or stricture — most common early surgical complication; stricture often requires endoscopic balloon dilatation ^[1]^[3]
Recurrent TOF — recanalisation of divided fistula; presents like original TOF; requires re-operation with tissue flap interposition ^[1]^[3]
Tracheomalacia — congenital cartilage deficiency; "brassy/barking TOF cough" and "dying spells"; aortopexy for severe cases ^[1]^[3]
Gastro-oesophageal reflux (GORD) — virtually universal; promotes stricture and Barrett's; treat with PPI ± fundoplication ^[1]^[3]
Disordered peristalsis — lifelong; 100% of repaired OA; causes chronic dysphagia ^[3]
Failure to thrive — multifactorial consequence of all the above ^[3]

Additional long-term: dysphagia, asthma/recurrent LRTI, Barrett's oesophagus ^[1]

These patients need lifelong follow-up — OA/TOF is not a "fix and forget" condition.

Active Recall — Complications of Oesophageal Atresia

References

^[1] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf — Tracheoesophageal fistula and Esophageal atresia, Complications section ^[2] Lecture slides: Neonatal Surgery.pdf — Oesophageal atresia slide ^[3] Senior notes: Adrian Lui Pediatrics Notes.pdf — Section 2.3.3 Gastrointestinal Disorders (OA complications) ^[4] GC Lecture slides: GC 205. The newborn baby is vomiting repeatedly Neonatal intestinal obstruction and other GI emergencies.pdf — Oesophageal atresia slide

High Yield Summary

Oesophageal Atresia (OA) & Tracheo-Oesophageal Fistula (TOF)

Definition: Congenital discontinuity of the oesophagus (atresia) ± abnormal communication with the trachea (fistula), due to defective lateral septation of the foregut ^[1]
Epidemiology: ~1:3,000 live births; Male > Female ^[2]
Most common type: Gross Type C (OA + distal TOF) — ~85% ^[1]
Antenatal clue: Polyhydramnios (fetus cannot swallow amniotic fluid) ^[2]
Classic postnatal presentation: Drooling / "bubbly baby", choking/coughing on first feed, inability to feed, respiratory distress, NG tube cannot be passed ^[1]
Key X-ray findings: Coiled NG tube in upper pouch; gas in stomach (distal TOF present) vs gasless abdomen (no distal TOF)
VACTERL association: Vertebral, Anal, Cardiac, TE fistula, Renal, Limb — screen all babies with OA ^[1]^[2]
Cardiac anomalies are the most common associated defect and the main determinant of mortality → echocardiography is mandatory
H-type TOF (Type E) has no atresia → delayed presentation with recurrent aspiration pneumonia
Fistula pathophysiology: Distal TOF allows air into the stomach (gaseous distension) and gastric acid into the lungs (chemical pneumonitis)

High Yield Summary — Differential Diagnosis of OA

The NG tube test is the key discriminator. If the tube arrests at ~10 cm and coils on X-ray → OA is confirmed. This separates OA from almost all other neonatal conditions.
Bilious vomiting rules out OA — the obstruction in OA is proximal to the ampulla of Vater. Bilious vomiting in a neonate = think malrotation with midgut volvulus first (surgical emergency).
Gas in the abdomen on X-ray = distal TOF present (Type C). Gasless abdomen = pure OA (Type A).
H-type TOF (Type E) is the diagnostic trap — no atresia, NG passes, delayed presentation with recurrent aspiration pneumonia.
Other causes of neonatal drooling/choking: choanal atresia, laryngeal cleft, neurological swallowing dysfunction — all have a patent oesophagus (NG passes).
Always screen for VACTERL associations — up to 50% of OA babies have other anomalies. Cardiac defects are the main determinant of mortality. ^[2]^[4]
For the neonatal IO differential: duodenal atresia (double bubble, Down syndrome), jejunal/ileal atresia (vascular accident), meconium ileus (CF), Hirschsprung disease (absent ganglion cells), anorectal malformation (imperforate anus). ^[3]

High Yield Summary — Diagnosis of Oesophageal Atresia

Diagnostic manoeuvre: Pass a firm, wide-bore (10 Fr) radio-opaque OG tube — it arrests at ~10 cm from the gum in OA ^[1]^[3]
Confirmatory imaging: Plain X-ray (CXR + AXR) showing a coiled tube in the upper oesophageal pouch ^[1]
Subtyping on X-ray: Gas in stomach = distal TOF present (Type C). Gasless abdomen = no distal TOF (Type A) ^[1]^[3]
Pre-operative essentials: Echocardiography (cardiac defects + aortic arch side), renal USS, spinal X-ray, perineal + limb exam for VACTERL ^[2]^[4]
CT for surgical planning — determines the gap length between the two oesophageal ends ^[3]
Water-soluble contrast (NOT barium) under fluoroscopy if diagnostic uncertainty — barium causes pneumonitis if aspirated ^[1]
H-type TOF: diagnosed by prone tube oesophagram or bronchoscopy — NG tube passes normally, delayed presentation
Antenatal: polyhydramnios + absent stomach bubble on USS — but only ~30–50% diagnosed antenatally

High Yield Summary — Management of Oesophageal Atresia

Immediate stabilisation: NPO + IV fluids; continuous upper pouch suction using a Replogle tube (double-lumen: one for drainage, one as air vent); head-up positioning; avoid bag-mask ventilation ^[3]
Pre-operative essentials: Echocardiography (cardiac defects + aortic arch side); CT for gap assessment ^[3]^[4]
Short-gap OA with distal TOF (Type C): Divide TOF + primary end-to-end oesophageal anastomosis via right posterolateral thoracotomy (or thoracoscopic at QMH) ^[3]^[5]
Long-gap OA: Gastrostomy for feeding → grow and reassess → delayed primary anastomosis OR oesophageal replacement (gastric pull-up, colon interposition, jejunal interposition) ^[3]^[5]
H-type TOF (Type E): Cervical approach to divide the fistula; no oesophageal anastomosis needed
Post-operative: Trans-anastomotic tube feeding; contrast study at day 5–7; anti-reflux therapy (PPI)
Long-term: Lifelong follow-up for anastomotic stricture, GORD, tracheomalacia, recurrent TOF, oesophageal dysmotility, and growth
Prognosis (Spitz): Group I (BW > 1500 g, no CHD) > 95% survival; Group II (BW < 1500 g OR CHD) ~60%; Group III (BW < 1500 g AND CHD) ~20% ^[3]

High Yield Summary — Complications of OA/TOF

The six complications most commonly tested (all from the lecture slides / senior notes):

Anastomotic leak or stricture — most common early surgical complication; stricture often requires endoscopic balloon dilatation ^[1]^[3]
Recurrent TOF — recanalisation of divided fistula; presents like original TOF; requires re-operation with tissue flap interposition ^[1]^[3]
Tracheomalacia — congenital cartilage deficiency; "brassy/barking TOF cough" and "dying spells"; aortopexy for severe cases ^[1]^[3]
Gastro-oesophageal reflux (GORD) — virtually universal; promotes stricture and Barrett's; treat with PPI ± fundoplication ^[1]^[3]
Disordered peristalsis — lifelong; 100% of repaired OA; causes chronic dysphagia ^[3]
Failure to thrive — multifactorial consequence of all the above ^[3]

Additional long-term: dysphagia, asthma/recurrent LRTI, Barrett's oesophagus ^[1]

These patients need lifelong follow-up — OA/TOF is not a "fix and forget" condition.

Oesophageal Atresia

1. Definition

2. Epidemiology

3. Embryology & Anatomy

3.1 Normal Embryology of the Foregut

3.2 Pathological Embryology in OA/TOF

3.3 Relevant Surgical Anatomy

4. Risk Factors

5. Aetiology & Pathophysiology

5.1 Aetiology

5.2 Pathophysiology — Why Do Babies Get Sick?

A. The Blind Upper Pouch (Atresia)

B. The Fistula (Distal TOF — Type C, most common)

C. Combined Effect

D. Isolated TOF (H-type, no atresia)

6. Classification

7. Clinical Features

7.1 Antenatal Features

7.2 Postnatal Symptoms

7.3 Postnatal Signs

7.4 Special Consideration: Isolated H-Type TOF (Type E)

8. Associated Anomalies — Expanded

9. Approach to the Neonate Who Cannot Swallow

Active Recall — Oesophageal Atresia

References

Framing the Differential

Systematic Differential Diagnosis

A. Conditions Causing Failure to Swallow / Drooling / Choking in a Neonate

B. Other Causes of Neonatal Vomiting / Intestinal Obstruction

C. Other Causes of Neonatal Respiratory Distress (Which May Coexist or Be Confused with OA)

D. Isolated H-Type TOF (Type E) — A Special Diagnostic Challenge

Diagnostic Decision Flowchart

Summary Table: Key Differentiators

Active Recall — Differential Diagnosis of Oesophageal Atresia

1. Diagnostic Criteria

2. The Diagnostic Algorithm — Step by Step

Step 1: Clinical Suspicion

Step 2: The NG/OG Tube Test (Bedside Diagnostic Manoeuvre)

Step 3: Plain Radiograph (CXR + AXR — Single Film)

Step 4: Screening for Associated Anomalies (Pre-Operative Work-Up)

Step 5: Additional Investigations (If Needed)

3. Complete Diagnostic Algorithm — Mermaid Diagram

4. Detailed Investigation Modalities — Key Findings & Interpretation

4.1 Plain Radiograph (CXR + AXR)

4.2 Echocardiography

4.3 CT Scan

4.4 Water-Soluble Contrast Study (Fluoroscopy)

4.5 Bronchoscopy

4.6 Renal Ultrasound

4.7 Chromosomal / Genetic Testing

5. Special Diagnostic Scenarios

5.1 Antenatal Diagnosis

5.2 Diagnosis of H-Type TOF (Type E) — The Delayed Presentation

5.3 Long-Gap OA — How to Determine Gap Length

6. Pre-Operative Baseline Investigations

Active Recall — Diagnosis & Investigations of Oesophageal Atresia

Overview — Management Philosophy

1. Immediate Pre-Operative Management (Stabilisation)

A. Airway and Respiratory Support

B. Upper Pouch Suctioning

C. Nil Per Os (NPO) + IV Fluids

D. Other Stabilisation Measures

2. Pre-Operative Work-Up (Before Definitive Surgery)

3. Definitive Surgical Management

3.1 Short-Gap OA with Distal TOF (Type C — the Majority)

3.2 Long-Gap OA (Pure OA — Type A, or Type C with Long Gap)

3.3 Isolated H-Type TOF (Type E)

3.4 Role of Specific Approaches by Type

4. Post-Operative Management

5. Long-Term Follow-Up

6. Management Algorithm — Mermaid Diagram

7. Prognosis — Spitz Classification

8. Contraindications and Special Considerations

Active Recall — Management of Oesophageal Atresia

Framing the Complications

1. Pre-Operative Complications (From the Anomaly Itself)

2. Early Post-Operative Complications (Days to Weeks After Repair)

2.1 Anastomotic Leak

2.2 Anastomotic Stricture

2.3 Recurrent Tracheo-Oesophageal Fistula