Abdominal Wall Defects

Abdominal Wall Defects - Sealed With A Sac

• Omphalocele: Midline defect at umbilical cord insertion; herniated viscera covered by a sac (amnion-peritoneum).
  • Embryology: Failure of embryonic midgut to return to abdomen by 10th-12th week.
  • Contents: Bowel, frequently liver, spleen.
• Associated Anomalies: Common (~50-70%); crucial to screen.
  • Cardiac defects (e.g., VSD, ASD, Tetralogy of Fallot).
  • Chromosomal: Trisomies 13 (Patau), 18 (Edwards), 21 (Down).
  • Beckwith-Wiedemann syndrome (macroglossia, macrosomia, omphalocele, hypoglycemia).
• Maternal Serum AFP: Typically ↑ elevated.
• Delivery: Vaginal delivery possible for small defects; C-section for large defects or liver herniation to prevent sac rupture.
• 📌 Mnemonic: Omphalocele: Organs in sac, Often Other anomalies, Ombilicus is the site.

⭐ Exam Favourite: Omphalocele's association with chromosomal abnormalities (esp. Trisomy 18, 13) is significantly higher than gastroschisis.

Abdominal Wall Defects - Guts Out, No Sac!

• Definition: Full-thickness paraumbilical abdominal wall defect with evisceration of abdominal contents.
• Embryology: Vascular accident theory (e.g., involution of right umbilical vein or omphalomesenteric artery).
• Location: Paraumbilical, typically to the right of a normally inserted umbilical cord.
• Covering Sac: Absent; "Guts Out, No Sac!"
• Contents: Primarily bowel (small & large intestine); rarely liver or stomach.
• Bowel Appearance: Exposed to amniotic fluid → thickened, edematous, matted, foreshortened, often with an inflammatory peel.
• Associated Anomalies: Less common than omphalocele (~10-15%); primarily intestinal atresia/stenosis, malrotation.
• Maternal AFP: Markedly elevated (↑↑) due to exposed bowel.
• Maternal Factors: Young maternal age (<20 years), smoking, vasoconstrictor drug use.
• 📌 Mnemonic: Gastroschisis: Guts out, Generally to the Right, Generally good prognosis if isolated.

⭐ Gastroschisis is NOT associated with chromosomal abnormalities, unlike omphalocele, and generally has a better prognosis if isolated without significant bowel damage or atresia.

Abdominal Wall Defects - Spot The Difference!

📌 Mnemonic: Omphalocele = Outside but Organized (in sac); Gastroschisis = Guts Spilling (no sac).

Abdominal Wall Defects - Tiny Tummy Fix-Up

• Prenatal Management:
  • Diagnosis via USG.
  • Parental counseling.
  • Delivery planning (tertiary center).
• Immediate Postnatal Care:
  • Thermoregulation (prevent heat loss).
  • IV fluids: 1.5-2x maintenance.
  • Sterile covering (bowel bag) for viscera.
  • NG decompression (prevent distension).
  • IV antibiotics (prophylaxis).
• Surgical Repair:
  • Primary closure (small defect, low tension).
  • Staged (Silo) for large defects.
• Post-operative Care:
  • TPN initially.
  • Gradual enteral feeds.

⭐ Gastroschisis typically occurs to the right of an intact umbilical cord and lacks a protective sac, leading to significant fluid and heat loss compared to omphalocele which has a sac and is midline.

High‑Yield Points - ⚡ Biggest Takeaways

• Gastroschisis: Right of umbilicus, no sac, exposed bowel; associated with bowel atresia.
• Omphalocele: Midline defect at umbilical base, sac present (amnion/peritoneum), contains organs.
• Both show ↑ maternal serum AFP.
• Omphalocele frequently linked to chromosomal abnormalities (e.g., Trisomies, Beckwith-Wiedemann).
• Gastroschisis often isolated, generally better prognosis if no severe bowel damage.
• Initial management: Silo for gastroschisis; protect sac in omphalocele, often staged repair.