Paediatric Surgery SC042: The Newborn Baby Cannot Breathe: Esophageal Atresia, Diaphragmatic Hernia, And Other Surgery Of Lung

Question 1

Physiology of newborn

Answer 1

1. Temperature
   - ↑ SA/weight ratio
   - ↓ Fat
   —> ↑ risk of hypothermia
2. Fluid, electrolytes
   - requirements change with age (in a matter of days), insensible loss, immature renal function
3. Respiration
   - ↑ RR
   - prone to apnea
   - hyaline membrane disease in LBW infants
4. Nutrition
   - ↑ metabolic rate + energy requirement
   - ↑ need for parenteral nutrition (if any impediment to enteral nutrition)
5. Sepsis
   - immature defence ↑ risk of sepsis
   - non-specific clinical features (e.g. hypothermia, lethargy) —> require high index of suspicion
6. Surgical complications
   - heal well but poorly tolerated (endocrine, metabolic response exaggerated)

Question 2

Lung embryology

Answer 2

***Earlier the anomaly —> Greater the functional deficiency!!!

2 critical pathophysiological components:
1. **Critical mass of lung tissue
2. **Pulmonary vasculature (causing pulmonary hypertension)

Embryonic (3-8 weeks)
—> Pseudoglandular (8-16 weeks)
—> Canalicular (16-26 weeks)
—> Saccular (>26 weeks)

Embryonic:
- Foregut
- Lung buds

Pseudoglandular:
- Bronchial branching

Canalicular:
- Acini
- Capillaries

Saccular:
- Alveoli
- Surfactant

Question 3

Major advances in Neonatal surgery

Answer 3

1. Technique / Instruments
   - Minimal invasive surgery
   —> Thoracoscope
2. Holistic surgical care
   - Neonatal intensive care (pre / post-operative)
   - Neonatal anaesthesia (e.g. One lung ventilation by use Double lumen ETT —> allow one lung to be deflated)
   - TPN

Question 4

Clinical features of Respiratory distress

Answer 4

1. Tachypnea
2. Dyspnea
   - laboured breathing
   - not CNS problem
3. Stridor
   - inspiratory (pharyngeal, glottic)
   - biphasic (subglottic, trachea)
   - expiratory (bronchial)
4. Cyanosis
5. Tachycardia

Question 5

Initial management of Respiratory distress

Answer 5

1. Resuscitate
   - Airway: suctioning, tongue forward
   - Breathing: oxygenation, intubation, ventilation
   - Circulation: IV fluid
2. Monitor
   - Vital signs
   - Oximetry
3. Diagnosis
   - Antenatal: USG (CDH 90%) —> allow In-utero transfer + planned delivery —> can intubate baby at birth
   - Postnatal: Imaging (CXR) —> safe transfer to specialist unit
4. Specific treatment

Question 6

***Causes of Respiratory distress

Answer 6

Respiratory tract causes:
1. Medical
- Meconium aspiration syndrome
- Transient tachypnea of newborn (TTN)
- Respiratory Distress Syndrome (RDS) (Hyaline membrane disease (LBW))
- Persistent fetal circulation (pulmonary vascular resistance fail to ↓ —> pulmonary hypertension)
- Pneumonia / Pulmonary haemorrhage / Pneumothorax / Phrenic nerve palsy (as a result of birth trauma)

2. Surgical
   - **Anomalies / Obstruction of airway
   - **Anomalies / Obstruction of lungs

Non-respiratory tract causes:
1. Congenital heart diseases

2. CNS disorders (cause apnea)
   - Cerebral haemorrhage
   - Cerebral edema
   - Drugs
3. GI disorders
   - Esophageal atresia (OA) / Tracheo-esophageal fistula (TOF)
   - Gastro-esophageal reflux (can cause sudden infant death syndrome ∵ acid irritation —> bronchospasm)
4. Systemic
   - Metabolic acidosis
   - Sepsis

Question 7

***Anomalies of Airway

Answer 7

Rmb from top to bottom anatomy + intraluminal / intramural / extraluminal

1. Choanal atresia
2. Pierre-Robin syndrome
3. Laryngomalacia
   - floppy larynx
   - improves with age
4. Subglottic stenosis
   - acquired (***post-intubation) (more common) / congenital
   - treatment: conservative, laser, excision
5. Tracheomalacia
   - primary / secondary (TOF)
   - treatment: conservative, stenting, aortopexy (fix aortic arch to sternum —> pull open trachea)
6. Tracheal stenosis
   - treatment: stenting, tracheoplasty (cartilage graft to reinforce / open trachea)
7. Lymphatic malformation / Lymphangioma
   - a kind of hamartoma (benign, local malformation of cells that resembles a neoplasm of local tissue but is usually due to an overgrowth of multiple aberrant cells)
   - cystic hygroma
   - neck (75%), axilla
   - complications: compressive effect, infection, haemorrhage
   - treatment: injection sclerotherapy (OK432, bleomycin, doxycycline), excision (difficult ∵ vital structures around + no clear boundary between normal / abnormal)
   - not go away itself vs Haemangioma (resolve itself)
8. Vascular ring
   - malformation of aortic arch —> vessels (major + minor arch) partly or completely encircle trachea and esophagus
   - diagnosis: MRI, bronchoscopy
   - treatment: division, aortopexy

Question 8

1. Choanal atresia

Answer 8

• Posterior choana complete atresia —> nasal cavity not patent with nasopharynx
• Neonates: Obligatory nasal breathers

Association:
***CHARGE syndrome
- Coloboma of eyelid (cleft eyelid)
- Heart disease
- Atresia choanae
- Retarded development
- Genital hypoplasia
- Ear anomaly

Diagnosis:
- Fail to pass nasal catheter into pharynx
- CT

Management:
- Excision

Question 9

2. Pierre-Robin syndrome

Answer 9

Triad:
1. Micrognathia
2. Glossoptosis (downward displacement / retraction of tongue)
3. Cleft palate (tongue can lodged there)

Improves with age

Treatment:
- Positioning of baby (to allow lower jaw to develop sufficiently)

Question 10

***Anomalies of Lung + Diaphragm

Answer 10

1. Cystic lesions of lung
   - Simple cyst / Cystic involvement of parts of lung
   - ***Congenital pulmonary airway malformation (CPAM) (previously congenital cystic adenomatoid malformation (CCAM)) —> Solid + cystic component
2. Congenital lobar emphysema, Pulmonary sequestration
   - Space-occupying effect + Infection
3. Congenital diaphragmatic hernia (CDH)
4. Diaphragmatic splinting (distended abdomen)

Question 11

1. Congenital pulmonary airway malformation (CPAM) (previously congenital cystic adenomatoid malformation (CCAM))

Answer 11

• 1:5000 live births
• Antenatal diagnosis
• Solid + cystic component

Complication:
- Potential recurrent pneumonia, malignancy

Treatment:
- Lobectomy (definitive treatment)

Question 12

3. Congenital diaphragmatic hernia (CDH)

Answer 12

• 1:4000 live births / 1:2000 births
• Survival 60% (40-95%)
• Left side (80-90%)
• ***Posterolateral defect (Bochdalek hernia)
• ***Earlier the anomaly —> Greater the functional deficiency

Pathology:
1. Left side hernia: intestines, stomach, spleen, liver
2. Right side hernia: liver, intestines
3. **Non-rotation of intestines (∵ intestine sit within thoracic cavity instead of going back to abdominal cavity for rotation —> did not rotate at all)
4. **Pulmonary hypoplasia (∵ compression, ipsilateral / contralateral)
5. ***Pulmonary hypertension —> persistent fetal circulation, immaturity, hypoxia, “honeymoon period” (everything normal until hypoxia / other stress —> trigger primary pulmonary HT —> further hypoxia)
6. Associated anomalies 20-40%, mostly cardiac

Investigation:
- CXR

Question 13

Clinical features of CDH

Answer 13

1. Antenatal USG
   - Heart displaced (***Apparent dextrocardia)
   - Intrathoracic intestines
2. Respiratory distress
   - Early onset (∵ pulmonary insufficiency)
3. ***Scaphoid abdomen
4. ***Reduced air entry + Dullness to percussion + Abnormal bowel sound in affected chest
5. Contralateral lung may be compressed
6. Cyanosis

Question 14

***Treatment of CDH

Answer 14

1. Resuscitation
   - O2
   - **NO bagging with mask (∵ inflate stomach even more)
   - **ETT intubation
   - Monitor SaO2 by blood gas, oximetry
2. ***Orogastric tube to decompress
3. Systemic support
   - Fluid
   - Inotropes
4. **Vasodilators
   - **Nitric oxide to reduce pulmonary HT
5. ***Gentle ventilation (to avoid barotrauma to immature lung)
   - HFOV (high-frequency oscillatory ventilation)
   - permissive hypercapnia (pCO2 up to 65 mmHg —> reduce pulmonary vasoconstriction)
6. ***ECMO
7. Surgical repair ***after stabilisation
   - Laparotomy / Thoracoscopy
   - Primary / Patch to close defect
   - Complications: gut malrotation
8. Fetal surgery
   - ***PLUG: plug the lung until it grows
   - obstruct fetal lung fluid (produced by pneumocysts) escape via trachea resulting in lung expansion

Question 15

Esophageal atresia (OA), Tracheo-esophageal fistula (TOF)

Answer 15

• “Epitome of neonatal surgery”
• 1:4000 births
• Associated anomalies (50%): **VACTERL, **CHARGE syndrome
  —> Vertebral defects
  —> Anal atresia
  —> Cardiac defects
  —> Tracheo-esophageal fistula (TOF)
  —> Esophageal atresia
  —> Renal anomalies
  —> Limb anomalies

Types:
- A: Pure OA with no fistula (2nd common)
- B: Proximal TOF
- C: OA + Distal TOF (most common)
- D: Proximal + Distal TOF (Double fistula)
- E: Pure TOF (3rd common) (H-type fistula: present with recurrent aspiration pneumonia)

Prognostic classification:
- Based on Birthweight, Congenital heart disease

Clinical features:
1. **Polyhydramnios, Preterm labour
2. Antenatal USG (18-20 weeks): **Absent stomach bubble
3. **Frothy salivation
4. **Unable to swallow
5. **Respiratory distress, Cyanosis, Choking (∵ **Aspiration, reflux, gastric distension)

Diagnosis:
1. **Arrest of orogastric tube
2. **CXR
- **tube in blind pouch
- **stomach gas (TOF) / gasless (pure OA)
3. Contrast study
4. CT (planning of surgery)
5. Bronchoscopy

Question 16

Treatment of OA, TOF

Answer 16

Preoperative treatment:
1. Oropharyngeal suction (Replogle tube)
2. Electrolyte, crossmatch, IV fluid, antibiotics
3. Specialist centre

Surgery:
1. Division + Ligation of TOF
- life-saving
- thoracotomy / thoracoscopy

2. Short gap
   - Primary anastomosis
3. Long gap
   - Gastrostomy + Delayed primary (1-2 months)
   - Substitution (stomach, colon)
4. Post-op ICU
   - Ventilate for a few days —> reduce stress on anastomosis

Complications:
1. Anastomotic leak, stricture
2. Recurrent TOF
3. Tracheomalacia
4. Gastroesophageal reflux
5. Disordered peristalsis, difficulty swallowing
6. Failure to thrive

Question 17

SpC Interactive tutorial: Paediatric thoracic surgery
Congenital pulmonary airway malformation (CPAM)

Answer 17

A spectrum of disease consisting of:
1. CCAM (Congenital cystic adenomatoid malformation)
2. BPS (Bronchopulmonary sequestration)
3. Bronchial atresia

Question 18

CCAM (Congenital cystic adenomatoid malformation)

Answer 18

• Now put under CPAM spectrum
• Previously considered as a rare condition
• ***Multicystic lung mass
• Pathology: **Harmatomatous proliferation of terminal respiratory **bronchioles

Investigation:
- Detected as echogenic lung mass in antenatal ultrasound
- NOT visible on CXR —> ***CT thorax to delineate

Clinical features:
- Usually **asymptomatic at birth
- High risk of **recurrent chest infection
- Potential of ***malignant change

Treatment:
1. Excision (Segmentectomy / Lobectomy)
- elective at >=3 months of age
- prevent recurrent chest infection (3.2-10%) / malignant change (1-3%)
- possibility of ***compensatory lung growth if done early

Question 19

BPS (Bronchopulmonary sequestration)

Answer 19

• Histologically similar but different pathophysiology than CCAM
• Same antenatal history as CCAM
• Sequestration: **Non-functioning lung tissue not connected to main airway —> **not participate in respiration
• Can mix with CCAM to form hybrid lesion —> under same umbrella term of CPAM

Pathology:
- Aberrant direct arterial supply from **descending aorta (pathognomonic) to segment of sequestration
- Risk of **recurrent chest infection
- Potential of ***malignant change

Classification:
- Extralobar (outside of normal lung, separate pleural covering —> easier to operate)
- Intralobar (share same pleural covering with other lobes)
- Hybrid

Question 20

Chest wall deformities

Answer 20

Pectus excavatum:
- M>F
- Most common type of congenital chest wall abnormality

Symptoms:
- Asymptomatic
- Breathlessness on exertion: Lung / Cardiac function compromised
- Cosmesis / Psychological

Surgical correction:
1. Ravitch operation (conventional open approach)
2. ***Nuss procedure (minimally invasive approach)
- Nuss bar inserted below sternum (potential allergy to material (nickel / steel / chromium —> titanium (but more expensive))

Pre-op assessment:
1. **Haller index
- Transverse diameter / AP diameter (at level of most significant depression)
- >3.25 = abnormal
2. **Pulmonary function test
- Restrictive pattern
3. ***Echocardiogram
- Reduced ejection fraction

Pectus carinatum:
- Treatment by pressure device

Question 21

Palmar hyperhydrosis

Answer 21

Dysfunction of sympathetic nervous system

Treatment:
1. Conservative treatment (usually unsuccessful)
2. ***Sympathectomy (T3 level) (Thoracoscopic)

Indications for surgery:
1. Social anxiety and embarrassment
2. Affect activities of daily living (e.g. cannot hold pen / pencil for school, cannot hold knife as a chef etc.)
3. Failed conservative treatment

Test:
- ***Starch test
—> Classical test to define dermatomes affected
—> Dried iodine will turn starch to dark blue when moisturised by sweat

Axillary hyperhydrosis:
- T1 level (cannot destroy —> cause Horner’s syndrome)
- can try ligate T2 level
- potential compensatory sweating from other regions (e.g. back, buttock, groin, feet)

Question 22

SpC Case study: Paediatric Surgery: Thoracic surgical conditions in children
Pneumothorax: Treatment algorithm

Answer 22

Pneumothorax
—> Large amount —> Chest drain (16/20F)
—> Persistent air leak —> Thoracoscopic pleurodesis +/- Bullectomy
—> No air leak —> Observe —> Discharge (Recurrence: Thoracoscopic pleurodesis +/- Bullectomy)

—> Small amount —> Observe —> Discharge (Recurrence: Thoracoscopic pleurodesis +/- Bullectomy)

Question 23

Empyema: Treatment algorithm

Answer 23

Empyema
—> Chest drain
—> USG / CT
—> Little pus —> Continue antibiotics
—> Thick pus present —> Thoracoscopic **decortication (+/- Intrapleural instillation of **fibrinolytic agents —> dissolve fibrinous clots and membranes —> prevent fluid sequestration —> improve drainage)

Question 24

Thoracic tumours in children

Answer 24

Benign tumours:
1. Foregut duplication
2. Bronchogenic cyst
3. Cystic hygroma
4. Ganglioneuroma

Malignant tumours:
1. Mediastinal masses
2. Thoracic masses
3. Lung tumours
- Primary / Secondary