FCPS Paediatrics TOACS · Interactive Station

✅ Candidate's structured answer:
• Findings: Midline, central abdominal wall defect, with a membranous sac (amnion and peritoneum) covering the herniated viscera (bowel and liver). Umbilical cord inserts into the sac.
• Diagnosis: Exomphalos (omphalocele).
• Difference from gastroschisis:
- Omphalocele: Midline defect, sac covers viscera, cord inserts into sac, associated anomalies common (cardiac, chromosomal, Beckwith-Wiedemann), may contain liver.
- Gastroschisis: Right-sided defect, no sac, bowel is exposed, cord normal insertion, rarely associated anomalies.

✅ Candidate's answer:
• Failure of the lateral body wall folds to close during the 4th-5th week of gestation → herniation of abdominal contents through the umbilical ring.
• The midgut normally herniates into the umbilical cord (physiological herniation) at 6-8 weeks and returns by 10-12 weeks. In omphalocele, the intestines (and sometimes liver) fail to return to the abdominal cavity.
• The herniated viscera are covered by a sac composed of amnion and peritoneum.
• The umbilical cord inserts into the apex of the sac.

✅ Candidate's answer:
• Exomphalos minor (small omphalocele): Defect <5 cm, contains only small bowel, usually can undergo primary fascial closure.
• Exomphalos major (giant omphalocele): Defect >5 cm, contains liver plus other viscera, abdominal cavity is small, primary closure is not possible (viscero-abdominal disproportion). Requires staged closure (silo) or conservative management.
• This infant has exomphalos major (liver-containing, large sac).

✅ Candidate's answer:
• Associated anomalies occur in 50-70% of omphalocele cases (much higher than gastroschisis).
• Cardiac defects (most common, 30-50%): VSD, ASD, tetralogy of Fallot, hypoplastic left heart syndrome.
• Chromosomal anomalies (30%): Trisomy 13, 18, 21.
• Beckwith-Wiedemann syndrome (10-15%): Visceromegaly, macroglossia, macrosomia, hypoglycemia, ear creases/pits, increased risk of Wilms tumor, hepatoblastoma.
• Pentalogy of Cantrell: Omphalocele + sternal cleft + diaphragmatic hernia + pericardial defect + intracardiac anomaly.
• Cloacal exstrophy, OEIS complex (Omphalocele, Exstrophy, Imperforate anus, Spinal defects).
• Genetic syndromes: Beckwith-Wiedemann (11p15.5 imprinting), Trisomies.

✅ Candidate's structured answer:
1️⃣ Protect the sac: Cover with sterile, moist, non-adherent dressing (saline-soaked gauze) and then a sterile plastic bag (bowel bag) to prevent drying, rupture, and infection. Do NOT attempt to reduce the sac.
2️⃣ Place infant in a sterile plastic bag (from neck down) to maintain warmth.
3️⃣ Orogastric (OG) tube placement to decompress the stomach, prevent aspiration, and reduce distention, on continuous low suction.
4️⃣ IV fluids and broad-spectrum IV antibiotics (ampicillin + gentamicin + metronidazole).
5️⃣ Monitoring: Blood glucose (hypoglycemia – suspect Beckwith-Wiedemann), temperature, blood pressure.
6️⃣ Emergency investigations: Blood gas, electrolytes, blood glucose. Echocardiogram, renal ultrasound, skeletal survey (for associated anomalies).
7️⃣ Urgent pediatric surgery consultation.

✅ Candidate's answer:
• Hypoglycemia risk: Due to Beckwith-Wiedemann syndrome (associated with omphalocele). BWS causes neonatal hyperinsulinism → severe, refractory hypoglycemia.
• Management:
- Frequent blood glucose monitoring (every 1-2 hours initially).
- IV dextrose infusion (starting at 6-8 mg/kg/min) if hypoglycemic.
- Diazoxide (10-15 mg/kg/day) for hyperinsulinism.
- If refractory, consider glucagon or octreotide.
- Untreated hypoglycemia causes brain injury.

✅ Candidate's answer:
• Primary fascial closure: Possible for small (<5 cm) defects (exomphalos minor) after reduction of viscera. Performed in the operating room.
• Staged closure (silo placement): For exomphalos major (large defect, liver-containing) due to viscero-abdominal disproportion. A spring-loaded or preformed silo is placed over the sac to gradually reduce the contents over 3-10 days by gravity and gentle compression, followed by delayed primary closure.
• Conservative (non-surgical) management: For giant omphalocele or infants with severe associated anomalies/inoperable cardiac disease. The sac is left intact, covered with antiseptic (silver sulfadiazine or betadine) to allow epithelialization. Closure is delayed for months (secondary intention), then later repair of hernia.
• Prosthetic mesh (Gore-Tex) may be used for large fascial defects.

✅ Candidate's answer:
• Beckwith-Wiedemann syndrome (BWS): Overgrowth syndrome due to abnormal imprinting on chromosome 11p15.5 (IGF2 and CDKN1C genes).
• Features:
- Macroglossia (large tongue) – as seen in this infant.
- Omphalocele or umbilical hernia (50% of BWS).
- Macrosomia (birth weight >90th percentile).
- Neonatal hypoglycemia (hyperinsulinism).
- Ear creases/pits, nevus flammeus (facial).
- Visceromegaly (hepatomegaly, nephromegaly).
- Hemihyperplasia (asymmetric limb overgrowth).
- Tumor risk: Wilms tumor (nephroblastoma), hepatoblastoma, neuroblastoma, adrenocortical carcinoma. Surveillance: abdominal ultrasound every 3 months until age 7 years, serum AFP every 3 months until age 4 years.
• Omphalocele in BWS results from the same embryopathy (midline defect).

✅ Candidate's answer:
1️⃣ Echocardiogram – to rule out congenital heart disease (30-50%).
2️⃣ Renal ultrasound – to detect renal anomalies (agenesis, cystic dysplasia).
3️⃣ Spine X-ray or ultrasound – for vertebral anomalies, neural tube defects.
4️⃣ Karyotype / chromosomal microarray – for trisomies 13, 18, 21 (especially if other dysmorphic features).
5️⃣ Methylation analysis (11p15.5) – for Beckwith-Wiedemann syndrome (if macroglossia, macrosomia, hypoglycemia, or ear creases present).
6️⃣ Ophthalmology exam – if BWS suspected (routine).
7️⃣ Limb and facial examination – for hemihyperplasia, nevus flammeus.

✅ Candidate's answer:
• Initially NPO (nil per oral) – NG/OG tube on suction to decompress stomach. Start IV fluids and parenteral nutrition.
• After surgical closure: Ileus is common; enteral feeds are started when bowel function returns (passage of flatus/stool, decreasing NG output). Typically 5-10 days after primary closure, longer after silo/staged closure.
• Breast milk or formula – start with small volume continuous feeds, then progress to bolus.
• Slow advancement: May have feeding intolerance, GERD, delayed gastric emptying.
• If gastrostomy tube placed at time of repair, use for enteral feeding.
• In BWS with macroglossia: Feeding difficulty due to large tongue may require nasogastric or gastrostomy feeds temporarily.

✅ Candidate's answer:
• Isolated exomphalos minor (small defect, no other anomalies): Excellent prognosis. Normal survival, normal gastrointestinal function, good cosmetic outcome after primary closure.
• Exomphalos major (giant, liver-containing): Higher morbidity (prolonged ventilation, feeding difficulties, abdominal compartment syndrome). Overall survival >90% with modern care, but may have longer hospital stay and need for silo/staged closure.
• Beckwith-Wiedemann syndrome: Prognosis depends on tumor surveillance. Normal intelligence (85-90%). Tumor risk (Wilms, hepatoblastoma) requires strict surveillance (abdominal US q3 months, AFP q3 months). Hypoglycemia usually resolves by infancy.
• Associated cardiac or chromosomal anomalies: Prognosis determined by those anomalies.
• Long-term follow-up: Multidisciplinary (pediatric surgery, genetics, oncology (tumor surveillance), endocrinology (hypoglycemia), cardiology, developmental pediatrics).

✅ Candidate's answer:
• Yes, commonly diagnosed prenatally at 18-22 weeks ultrasound.
• Findings:
- Midline defect with herniated viscera (liver, bowel) covered by a membrane.
- Umbilical cord insertion into the sac.
- Elevated maternal serum AFP (but not diagnostic).
- Associated anomalies: cardiac (most common), neural tube defects, chromosomal abnormalities.
- Signs of Beckwith-Wiedemann: Polyhydramnios, macrosomia, placentomegaly, macroglossia, visceromegaly.
• Management: Detailed anomaly scan, fetal echocardiogram, amniocentesis for karyotype/microarray (trisomy 13,18,21), methylation analysis for BWS if features present.
• Counsel parents: Plan delivery at tertiary center with NICU, pediatric surgery, and subspecialties.

✅ Candidate's answer:
• Early complications:
- Abdominal compartment syndrome (tight closure → increased intra-abdominal pressure → renal failure, respiratory compromise, bowel ischemia).
- Wound infection, dehiscence, sac rupture (if not protected).
- Sepsis, prolonged ileus, necrotizing enterocolitis.
- Respiratory failure (due to decreased diaphragmatic excursion).
• Late complications:
- Recurrent omphalocele / incisional hernia – may require repeat repair.
- Intestinal obstruction (adhesions, malrotation).
- GERD and feeding intolerance.
- Cosmetic deformity (scar, lack of umbilicus).
• In BWS: Late-onset tumors (Wilms, hepatoblastoma) – requires surveillance.

✅ Candidate's structured answer:
• “Your baby has a condition called exomphalos (omphalocele) – a hole in the middle of the belly where the intestines and liver are covered by a sac. It is a rare birth defect.”
• “The large tongue (macroglossia) and large size suggest an associated condition called Beckwith-Wiedemann syndrome – an overgrowth syndrome that increases the risk of low blood sugar (hypoglycemia) and later kidney or liver tumors.”
• “We will protect the sac, start IV fluids, antibiotics, and monitor blood sugar closely.”
• “Surgery to put the bowel back into the belly may be done in one operation or gradually over several days using a plastic silo (a temporary pouch). We will work with the pediatric surgeon to decide the best approach.”
• “The outlook is good. Most babies survive, especially if there are no major heart defects. Your baby will need long-term follow-up: blood sugar management, tumor screening (ultrasounds every 3 months until age 7 years), and checkups for growth and development.”
• “You did nothing wrong – this is not anyone’s fault. We have a team of specialists (neonatology, surgery, genetics, endocrinology, oncology) to support your baby and your family.”