Omphalocele vs gastroschisis

In general, omphaloceles and gastroschisis are abdominal wall defects noted at birth with exposed viscera, which puts neonates at risk for dehydration due to severe fluid loss, the potential to develop partial bowel obstructions, potential for infections, and heat loss from exposed abdominal compartment. Patients with these conditions should be cared for expeditiously to avoid these associated complications. However, patients should be optimized from a fluid, heat, and electrolyte standpoint, prior to presenting to surgery. These patients, especially patients with an omphaloceles, should also be evaluated by an echocardiogram to look for cardiac anomalies prior to surgical correction.

Gastroschisis is a phenomenon that occurs in about 1 in 15,000 births, with a periumbilical defect resulting from occlusion of the omphalomesenteric artery. In contrast to omphaloceles, in gastroschisis the visceral contents are not covered by peritoneum. About 10-15% of neonates with gastroschisis have associated congenital anomalies. Neonates with gastroschisis are at high risk for inflammation of the exposed viscera, significant edema, and a dilated and foreshortened gut.

Omphaloceles occur in about 1 in 6000 births and is due to a defect within the umbilical cord that causes a failure of gut migration from the yolk sac to the abdomen. In contrast to gastroschisis, patients with omphaloceles have peritoneum covering their otherwise exposed viscera. About 40-60% of patients with omphaloceles will also have other congenital anomalies, most commonly congenital heart disease which affects about 20% of these patients. Another relatively common anomaly found in these patients is exstrophy of the bladder. A small percentage of patients with omphaloceles are also found to have Beckwith-Wiedemann syndrome, which is notable for hypoglycemia, macroglossia, gigantism, and polycythemia hyperviscosity.

Key Points

Gastroschisis

● Location of defect: Paraumbilical/lateral defect

● Pathogenesis: Thought to be due to ischemic bowel insult in utero, specifically occlusion of omphalomesenteric artery

● Characteristics: No membranous covering; bowel is exposed, typically intestines are the only herniated contents (only 6% contain liver)

● Treatment: Primary closure in first few days of life

● Associated pathology: ~85% are isolated defects, with no extraintestinal abnormalities

● NB: High risk for dehydration and sepsis due to uncovered/exposed bowel¹

Omphalocele

● Location of defect: Umbilical/midline

● Pathogenesis: Failure of gut migration from yolk sac to abdomen

● Characteristics: 3-layer membranous covering consisting of amnion, Wharton’s jelly, and peritoneum; herniation of intestines usually with part of liver (80% contain liver)

● Treatment: Silo reduction followed by delayed closure

● Associated pathology: Congenital heart disease, GU anomalies, cleft lip/palate, neural tube defects, syndromes (Beckwith-Wiedemann Syndrome), aneuploidy

● NB: Echo prior to OR due to high risk of CHD2