Congenital Lung Anomalies (Raf)

Question 1

Most common type of congenital lung anomaly?

Answer 1

CPAM - congenital pulmonary airway malformation

Question 2

Second most common type of congenital lung anomaly?

Answer 2

Pulmonary sequestration

Question 3

What is the most common cause of stridor in newborns?

Answer 3

Laryngomalacia

Question 4

What is the second most common cause of stridor in newborn?

Answer 4

Vocal cord paralysis

Question 5

What are the symptoms of unilateral versus bilateral vocal cord paralysis?

Answer 5

Unilateral: no airway obstruction, but issues with aspiration and phonation
Bilateral: issues with airway obstruction, no issues with phonation of aspiration

Question 6

Is congenital vocal cord paralysis usually bilateral or unilateral? Is further work up required?

Answer 6

• Bilateral
• MRI brain for look for chiari malformation or hydrocephalus.
  another cause: myasthenia gravis

Question 7

Is acquired vocal cord paralysis usually unilateral or bilateral? Causes?

Answer 7

• Unilateral and more often left sided since longer course of recurrent laryngeal nerve
• Often post op: cardiac surgery, TEF repair , thyroid surgery
• can happen post birth trauma (congenital) or if mediastinal mass is present

Question 8

What is the treatment for a newborn with vocal cord paralysis?

Answer 8

• Unilataral: may medialize the cord, feeding interventions since risk of aspiration, but no permanent interventions for the first year since there can be spontaneous recover
• Bilateral: MOST need tracheostomy, 1/2 of those with an idiopathic cause will spontaneously recover by end of first year (Trach and wait)

Question 9

Which muscle separates vocal cords for normal breathing?

Answer 9

Posterior cricoarytenoid

Question 10

What type of flow volume is seen with vocal cord paralysis?

Answer 10

Variable extrathoracic obstruction

Question 11

What type of flow volume loop is seen with tracheomalacia?

Answer 11

Variable extrathoracic obstruction

Question 12

What can cause fixed extrathoracic airway obstruction?

Answer 12

Tracheal stenosis
Goitre
Subglottic stenosis
Tracheostomy tube

Question 13

Examples of vascular rings? Most common?

Answer 13

Most common: double aortic arch
Second most common: right aortic arch with aberrant left subclavian
Others:
- left aortic arch with aberrant right subclavian and ductus arteriosus
- circumflex aorta

Question 14

Symptoms of vascular ring

Answer 14

More often respiratory than GI presentation

• Esophageal symptoms don’t usually present till patients begin solid food
• Respiratory symptoms: stridor, wheeze, apnea, noisy breathing, barking cough, frequent respiratory infections, cyanosis
• GI symptoms: slow eating, extension of neck during feeds, food being stuck in throat
• Double aortic arch: often presents in first month of life
• Right aortic arch with aberrant left subclavian: usually presents at 1-6 months of age

Question 15

Anomaly associated with pulmonary artery sling?

Answer 15

Complete tracheal rings

Question 16

Pattern of indentation associated with vascular rings?

Answer 16

• Double aortic arch: anterior trachea and posterior esophagus, both with bilateral compression
• right arch with aberrant left subclavian: bilateral anterior trachea and posterior esophagus compression, but compression is greater on right than left side
• Pulmonary artery sling: compress anterior esophagus and posterior trachea (compression of right main bronchus and trachea displaced to right)
• Aberrant right subclavian: posterior esophageal indentation, generally normal trachea on bronch

Question 17

Describe genetics of AAT

Answer 17

• M = normal allele
• PI*MM = homozygous for the normal gene
• PI*ZZ = homozygous for the Z allele, which is the most common mutation. Eg. Z mutation corresponds to a point mutation of Glu342Lys
• PI*SZ = two different mutation of the gene, increased risk for emphysema
• PI*SS = no increased risk of emphysema

Question 18

Indications for genetic testing of AAT

Answer 18

• If a child is symptomatic from liver disease of no clear etiology–>grade A recommendation
• Surpisingly, adolescent with persistent airflow obstuction–?grade B recommendation, though for adults this ends up being a grade A recommendation
• Sibling of an individual with AAT deficiency–>grade A
• Offspring of an individual with AAT deificency–>grade B recommendation
• WHO: early onset COPD or adult onset asthma

Question 19

Follow up for AAT, but asymptomatic

Answer 19

• spirometry every 6-12 months

Question 20

AAT level that would signify deficiency?

Answer 20

<20 micromol/L (ATS 2003 statement(

Question 21

If you are suspicious for AAT, what are the series of steps for diagnosis?

Answer 21

• Start with AAT level in blood, then genetic testing (start with testing common variants, before pursuing gene sequencing). This approach is similar to CF, where we would start with the functional test of the sweat chloride

Question 22

Does PI*MZ have an increased risk for COPD?

Answer 22

If never smoker, then no increased risk for COPD

If they are a smoker, then increased risk for COPD

Question 23

When considering genetic testing in asymptomatic relatives of patient with AAT, what should you consider?

Answer 23

• genetic counselling to discuss risks/benefits (eg. pyschological effect, genetic discrimination)
• informed consent
• consider testing the other parent before testing a child who is unable to consent

Question 24

Inheritance of AAT?

Answer 24

Autosomal co-dominant (but it basically behaves like autosomal recessive)

Question 25

What are associated anomalies you should consider in a TEF patient?

Answer 25

Often associated abnormalities (2/3 of cases), though less likely to have associated abnormalities fo H type - Think about cardiac anomalies - Associated with VACTERL and CHARGE syndrome: - Vertebral, anal, cardiac, tracheoesophageal, renal, radial limb - Coloboma, heart, choanal atresia, retardation of growth, genital hypoplasia, ear - - Associated with trisomy 21, 13, 18 - Can have associated tracheobronchial anomalies: tracheomalacia, lung agenesis, ectopic bronchi

Question 26

Long term complications of TEF?

Answer 26

Even after repair, the trachea and esophagus are still abnormal: - Reflux - Aspiration - Esophageal stricture or obstruction - tracheomalacia - bronchospasm - recurrence of fistula

Question 27

What is the most common type of TEF?

Answer 27

Type C - proximal atresia and distal fistula

Question 28

Which type of TEF does not have esophageal atresia?

Answer 28

H type (which is type E)

Question 29

Which type of TEF does not have a fistula?

Answer 29

Type A - esophageal atresia, but no fistual

Question 30

What are the stages of lung development?

Answer 30

``` Embryonic (3-6 weeks) Pseudoglandular (6-16 weeks) Canalicular (16-26 weeks) Saccular (26-36 weeks) Alveolar (36 weeks to adolescence) (Every pulmonologist can see alveoli) ```

Question 31

Describe the key points of what happens are each stage of lung development

Answer 31

Embryonic: basic branching architecture till 6th generation. Trachea and esophagus are separating Pseudoglandular: form up to terminal bronchiole and primitive acinar structure, but there is no capacity for gas exchange Canalicular: formation of respiratory bronchioles and acinar tubules. Formation of alveolar capillary membrane. If there is preterm birth, then gas exchange can be supported if surfactant is given. (There is a small amount of surfactant production and giving glucocorticoids will increase this) ○ saccular (26- 36 weeks)- surfactant ,thinning of alveolocapillary membrane ○ alveolar(from 36 weeks)-septation, proliferation, and thinning of the alveolar walls and tubular elongation of airways

Question 32

Give examples of lung malformation that can happen at different stages of lung development

Answer 32

``` Embryonic: o Laryngotracheal malformation o TEF o Esophageal atresia, stenosis o Tracheal stenosis o Defects in pulmonary lobe formation o Pulmonary hypoplasia, agenesis o Bronchogenic cyst o Ectopic lobe o Extrapulmonary sequestration ``` Pseudoglandular: - Tracheomalacia - Bronchomalacia - Intralobar bronchopulmonary sequestration - Congenital pulmonary airway malformation - Acinar dysplasia - Alveolar capillary dysplasia +/- misalignment of pulmonary veins - Congenital pulmonary lymphangiectasia - Pulmonary vascular malformation - Diagphragmatic hernia Cannalicular: Alveolar dysplasia, alveolar capillary dysplasia, pulmonary hypoplasia of various causes (CDH, thoracic mass, renal agenesis, oligo)

Question 33

CCHS gene mutation?

Answer 33

PHOX2B | Inheritance: autosomal dominant

Question 34

Monitoring for CCHS patient?

Answer 34

All patients need annual PSG, neurocog assessment, echo, holter, optho evaluation (frequency not specified), clinical assessment for hirscupsrung disease For patient with PARM 28-33/20: annual CXR/abdo U/S to look for neural crest tumor For patients with NPARM: abdo U/S and urine catecholamine q3 month till 2 years, then every 6 months till 7 years

Question 35

Which nerve is responsible for unilateral vocal cord paralysis and which root does it come form?

Answer 35

- Recurrent laryngeal nerve, which comes from vagus nerve (CN 10)