Description
Gastroschisis is a congenital defect of the anterior abdominal wall, typically occurring to the right of the umbilicus. It involves the herniation of the abdominal contents directly into the amniotic cavity. Unlike omphalocele, another condition involving abdominal wall defect, there is no overlying sac or membrane covering the herniated organs in gastroschisis.
Pathogenesis
The exact cause of gastroschisis is unclear. However, it is thought to arise from a vascular event leading to mesodermal disruption and eventual necrosis of the developing abdominal wall.
Epidemiology, Risk Factors & Associations
Gastroschisis affects approximately 1 in 2000-5000 live births. Young maternal age (<20 years) is a significant risk factor. It’s also more prevalent in smokers and drug users. Unlike omphalocele, gastroschisis is rarely associated with chromosomal anomalies.
Clinical Features
Gastroschisis is usually identified antenatally during routine ultrasound screening. The key clinical feature at birth is the presence of a defect in the abdominal wall, typically to the right of the umbilical cord, with protruding intestinal loops and possibly other organs like the stomach and liver. The intestines are often inflamed, swollen, and covered with a peeling, slimy layer due to exposure to amniotic fluid.
Complications
Potential complications include bowel damage or necrosis, sepsis, failure to thrive, and long-term feeding problems.
Pathological Features
Histopathology
Histologic findings can include inflammation, fibrosis, and necrosis in the herniated organs due to prolonged exposure to the amniotic fluid.
Radiological Features
General Features
- Location: The defect typically occurs to the right of the umbilicus.
- Morphology: Free-floating loops of bowel or other abdominal organs can be seen protruding through the defect.
- Associated Findings: The bowel loops may appear thickened, inflamed, or matted together.
US
- Identification of free-floating bowel loops in the amniotic fluid adjacent to the abdominal wall defect.
- Absence of a covering membrane.
- The umbilical cord insertion site is typically seen separate from the defect.
MRI
- Better delineation of the abdominal organs and their relationship with the abdominal wall defect.
- Helpful in assessing the extent of the herniation.
Grading and Staging
There are no specific grading or staging systems used for gastroschisis.
Differential Diagnosis
- Omphalocele: Another condition involving abdominal wall defect. However, omphalocele has a covering membrane and is often associated with other chromosomal anomalies. The umbilical cord inserts into the covering sac in omphalocele, unlike gastroschisis.
Management
- Management typically involves neonatology and paediatric surgery consultation.
- Initial management includes supportive care, protecting the exposed bowel, and starting intravenous fluids and antibiotics.
- Surgical closure of the defect is performed either immediately or in a staged manner, depending on the size of the defect and the condition of the baby.
- Long-term management may involve nutritional support and monitoring for potential complications.