Gastroschisis and Omphalocele

Question 1

Differentiate Gastroschisis from Omphalocele

Answer 1

Congenital defects of the abdominal wall. They differ in their presentation (peritoneal covering) and location relative to the umbilical cord

Gastroschisis
1. Herniated abdominal organs without sac (peritoneum)
2. Umbilical cord insertion unaffected
3. 10-20% have associated anomalies
–> GIT (Intestinal stenosis/atresia)
–> GIT (Meckel’s, intestinal duplication)
–> URO (Undescended testes)
4. Chromosomal abN uncommon
5. Survival > 90%

Omphalocele
1. Herniated abdominal organs with membrane (peritoneum)
2. Umbilical cord attaches to the membrane
3. 50 - 70% associated anomalies
–> Cardiac (30 - 50%): ASD, TOF
–> Syndromes
–> Uro: renal/bladder/cloacal
–> Airway: Cleft palate
–> Skeletal
4. Trisomy’s: 13 , 14, 15, 18, 21
5. Survival: 40 - 70%

Question 2

How is Gastroschisis/Omphalocele diagnosed

Answer 2

1. Ultrasound - prenantal
2. Maternal AFP elevated (more in gastroschisis)

Question 3

How do these abdominal wall defects occur

Answer 3

Intestinal tract migrates out of the abdominal cavity into the umbilical cord at ±6 week gestation and returns ±10 - 12 weeks.

1. Gastroschisis
   - Ischaemic insult to developping body wall –> degeneration and failure of the anterior wall to close
2. Omphalocele
   - Bowel fails to return into the abdomen and remains in the umbilical cord. Likely failure of abdominal wall infolding.

Question 4

Why is early delivery planned for these cases?

Answer 4

High risk for prenatal complications
1. Prenatal death
2. IUGR
3. Preterm delivery
4. Gastroschisis
- bowel injury
- volvulus
- oligohydramnios
- fetal asphyxia and death

Question 5

Why is these cases delivered by c-section

Answer 5

Prevent damage to the bowel and prevent dystocia during delivery

Question 6

Describe the surgical techniques to fix gastroschisis

Answer 6

Delivery: Plastic bag: visceral contents and lower half of neonate (prevent fluid/electrolyte/thermoregulatory abN)

Surgery
1. Primary repair
2. Spring-loaded silo for staged reduction
3. Sutureless closure technique (umbilical cord = biological dressing)
–> usually staged procedure over 7 - 10 days

Question 7

Which is more urgent to fix and why

Answer 7

Gastroschisis.

In omphalocele, if the membrane is intact there is no urgency to perform surgical closure. There is time to optimize co-existing anomalies and abnormalities

Question 8

What are the surgical options for closure of omphalocele

Answer 8

1. Primary surgical closure
2. Epithelization of the sac
   - Silver sulfadiazine is applied to the membrane which allows epithelization –> after several months, when the sac is sturdy, the contents are reduced and a ventral hernia repair is performed. closure can occur between 6 - 12 months

Question 9

What are the preoperative considerations in the management of Gastroschisis and omphalocele

Answer 9

Fluid. Electrolytes. Haemodynamic. Cardiopulmonary issues addressed and optimized (associated anomalies)

NG suction to decompress stomach

Question 10

What are the intraoperative considerations in the management of Gastroschisis and omphalocele

Answer 10

1. Heat and insensible fluid loss (electrolytes)
2. Slight reverse trendelenburg
3. Rapid intubation strategies (Aspiration risk)
4. Avoid N20
5. Muscle relaxation assists with ventilation and abdo wall closure.
6. Monitor for abdominal compartment syndrome
7. UsualL Glucose, temp, elecs etc