Surgery - congenital malformations

Question 1

What are the clinical features of cleft lip and palate?

Answer 1

cleft lip may be unilateral or bilateral. Due to failure of fusion of frontonasal and maxillary process

Cleft palate is from failure of fusion of palatine processes and the nasal septum

Question 2

Which conditions are associated with cleft lip and palate?

Answer 2

Patau syndrome (trisomy 13)
Edwards syndrome (trisomy 18)
22q11 deletion syndrome (DiGeorge)
Pierre Robin syndrome (cleft palate and small lower jaw)

Question 3

What are the short and long term problems associated with cleft lip and palate?

Answer 3

Cleft palate:
milk aspiration
feeding problems
Speech difficulty (nasal or unclear)

Cleft lip:
Secretory otitis and hearing difficulties more common
(Middle ear conductive hearing loss) and infections

Higher risk of tooth decay long-term

Question 4

What is a diaphragmatic hernia and how does it present?

Answer 4

Presents in newborn

Leak in diaphragm. Usually on left side (80%).
Intestines penetrate into thorax and prevent lung development.

Structural and functional immaturity of lung. Failure to respond to resuscitation or respiratory distress. Pulmonary HTN

Question 5

Describe the embryology of congenital diaphragmatic hernia

Answer 5

diaphragm forms in 6-12 weeks gestation

Bochdalek (posterior lateral) or Morgagni (anterior) types represent most.

BOCHDALEK
Event occurs during the intestinal return to the abdominal cavity (10th week of embryonic life)
At that time, the trigone is composed mainly of membranous tissue with ra
re muscle fibers. The increased intra-abdominal pressure causes the separation of the muscle fibers and creates defect.

MORGAGNI (parasternal)
Failure of crural and sterna portions of diaphragm to fuse.

Question 6

Understand management with ventilation in congenital diaphragmatic hernia

Answer 6

Lung protective strategy (not high volume).Small tidal volumes with permissive hypercapnia (pCO2 = 60-80mmHg)

Fraction of Inspired O2 at 85-88% to maintain preductal saturations (90-95% is acceptable)

Peak inspiratory pressures <25cm H2O

Maintain spontaneous respiration if possible!
High frequency oscillatory ventilation if respiratory deterioration despite these strategies.

Question 7

How is the patient with congenital diaphragmatic hernia stabilised before surgery? Which drugs?

Answer 7

Achieve minimal ventilatory support.
Minimize pulmonary HTN (ECHO).
If refractory, can give nitric oxide (ie FiO2 < 75% or pre- and post-ductal difference consistently >20%).

Anaesthesia: morphine. Muscle relaxant if difficult to stabilise. Consider midazolam if morphine and muscle relaxant are used.

Initiate normal saline if there is hypotension.

Question 8

Understand surgical repair of CDH

Answer 8

Not an emergency, usually delayed to first weeks of life.
If the opening is small, it can be sewn together (primary repair).
If large portion of diaphragm absent, synthetic material is used for “patch repair”. Or “muscle flap repair”, which uses internal oblique or latissimus dorsi.

Question 9

What are the types of tracheo-oesophageal fistulas?

Answer 9

type A: isolated oesophageal atresia (8%)
type B: proximal fistula with distal atresia (1%)
type C: proximal atresia with distal fistula (85%)
type D: double fistula with intervening atresia (1%)
type E: isolated fistula (H-type) (4%)

Question 10

How do patients with tracheo-oesophageal fistulas present?

Answer 10

Should be picked up at birth.
Persistant salivation and drooling from mouth after birth.
If diagnosis not made at this stage, infant will cough and choke at feeding. Cyanotic episodes. Aspiration.

Question 11

What is VACTERL in relation to tracheo-oesophageal fistulas?

Answer 11

Associations with other congenital malformations.
Vertebral
Anorectal
Cardiac
Tracheo-oesophageal
Renal
radial Limb anomalies

Question 12

What is the management of a tracheo-oesphageal fistula?

Answer 12

Tube into oesophagus which provides continuous suction. To reduce aspiration.
Elevation of infants head.

IV fluids.
Intubation if there is respiratory distress.
NO BAG MASK VENTILATION because it can cause gastric distension with fistula.

Antibiotic pulmonary prophylaxis (ampicillin gentamicin)

Gastrostomy tube if surgery needs to be delayed. Parenteral nutrition.

Finally, oesophageal repair and contrast esophagram a few days later.

Question 13

What are the clinical features of gastroschisis?

Answer 13

Defect of abdominal wall, usually right of umbilical cord insertion. Small intestine (sometimes also stomach, colon, ovaries) herniate into amniotic sac.
There is no covering membrane.

High risk of dehydration and protein loss.

Question 14

What are the clinical features of exomphalos?

Answer 14

Also called omphalocoele.
Contents of abdomen herniate into umbilical cord through the umbilical ring.
Viscera can include liver. Covered by membrane:
peritoneum + amnion

Question 15

What are the congenital anomalies associated with exomphalos?

Answer 15

trisomy 13 (Patau)
trisomy 15 
trisomy 18 (Edwards)

Beckwith Wiedemann syndrome

Question 16

What is the classification of anorectal anomalies?

Answer 16

LOW: Anus closed over, in a different position or stenosed. There may be a fistula

HIGH: Bowel has a closed end, not connected to the anus. The bowel may connect into bladder or genitalia. Bladder, Vagina and Rectum may even all empty into the same passage.

Question 17

What are the associations with anorectal malformations?

Answer 17

VATER syndrome (a nonrandom association of birth defects)

Vertebrae
Anus
Trachea
Esophagus
Renal

(sometimes also cardiac and limbs - VACTERL)

Question 18

What is the surgical management of anorectal anomalies?

Answer 18

First of all, NBM and NG tube passed.

LOW - anoplasty. Passing a dilator may be necessary.

HIGH - series of operations.
Loop stoma.
“Pull through” (several months later: stomach joined to newly created anus)
Close stoma (few months later)