Overview
Definition:
Gastroschisis is a congenital anomaly characterized by a defect in the anterior abdominal wall, typically to the right of the umbilicus, allowing abdominal organs to herniate outside the body
A silo, a temporary artificial covering, is used to protect the eviscerated organs and facilitate gradual reduction
Staged closure refers to a surgical approach where the abdominal wall defect is closed in multiple stages rather than a single operative procedure.
Epidemiology:
The incidence of gastroschisis varies globally, with higher rates in younger mothers and in certain geographic regions
In India, it is a significant cause of neonatal surgical intervention
It is more common than omphalocele and typically not associated with other major congenital anomalies.
Clinical Significance:
Gastroschisis requires prompt surgical intervention to prevent dehydration, hypothermia, infection, and vascular compromise of the extruded bowel
The management strategy, including the use of a silo and staged closure, is crucial for optimizing outcomes, minimizing complications like bowel atresia or ischemia, and ensuring long-term survival and quality of life for affected neonates.
Clinical Presentation
Symptoms:
Visually apparent abdominal wall defect at birth
Eviscerated abdominal organs (intestines, stomach, liver) covered by a thin membrane
Meconium staining of the eviscerated organs may indicate prolonged exposure
Neonates are typically born full-term but may exhibit signs of distress due to exposure.
Signs:
A defect measuring 1-4 cm lateral to the umbilical cord insertion, usually on the right
Organs are typically free-floating in the peritoneal cavity
Abdomen may appear small and underdeveloped
Bowel loops may be distended due to edema and inflammation
Vital signs may reflect hypothermia or shock if untreated.
Diagnostic Criteria:
Diagnosis is primarily clinical, made at birth
Prenatal ultrasound can detect gastroschisis during the second trimester, allowing for planning of delivery and management
Definitive diagnosis is established by visual inspection of the abdominal wall defect and extruded organs.
Diagnostic Approach
History Taking:
Focus on gestational age, prenatal diagnoses, maternal medical history, and any evidence of fetal distress or complications during pregnancy
Postnatal history includes timing of birth, initial assessment of the neonate, and any immediate interventions performed
Assess for signs of bowel compromise or infection.
Physical Examination:
Thorough but gentle examination of the neonate
Assess the size and location of the abdominal wall defect
Carefully inspect the eviscerated organs for color, viability, and any signs of injury or malrotation
Evaluate for associated anomalies, although gastroschisis is typically isolated
Assess vital signs and overall hemodynamic stability.
Investigations:
Laboratory investigations include complete blood count (CBC) to assess for infection and anemia, electrolytes to monitor for dehydration and metabolic derangements, and blood gas analysis to assess for acid-base balance and oxygenation
Imaging is generally deferred until after initial stabilization and placement of the silo, but may include plain abdominal X-rays to assess bowel status, or ultrasound if malrotation is suspected
Echocardiogram and renal ultrasound may be performed to rule out associated anomalies in some centers.
Differential Diagnosis:
Omphalocele (defect contains abdominal organs covered by peritoneum and amnion
often associated with other anomalies)
Umbilical hernia (defect is smaller and covered by skin)
Gastric duplication cyst or other abdominal masses
Prune belly syndrome.
Management
Initial Management:
Immediate stabilization includes covering the eviscerated organs with sterile, saline-soaked gauze and a non-adherent dressing (e.g., polyethylene film) to prevent desiccation and heat loss
Intravenous fluid resuscitation to correct dehydration and electrolyte imbalances
Insertion of a nasogastric tube for gastric decompression
Broad-spectrum antibiotics to prevent infection
Transfer to a specialized neonatal surgical unit.
Surgical Management:
Primary closure is attempted in neonates with small defects and good abdominal wall compliance
However, for larger defects or signs of abdominal compartment syndrome, a silo is created
The silo is typically constructed from a non-reactive material (e.g., Silastic, Gore-Tex) and sutured to the umbilical ring or abdominal skin edges
The eviscerated organs are carefully placed within the silo
Gradual reduction is achieved over days to weeks by daily tightening of the silo purse-string or by mechanical retraction, allowing the abdominal wall to stretch and accommodate the organs
Once all organs are reduced, definitive closure of the abdominal wall defect is performed, which may be staged if the defect is large and the abdominal cavity is not sufficiently capacious
Staged closure may involve leaving a gap and using skin grafts or mesh later.
Supportive Care:
Intensive monitoring of vital signs, fluid balance, and urine output
Nutritional support via total parenteral nutrition (TPN) is essential as enteral feeding is delayed due to ileus and bowel edema
Pain management
Respiratory support may be required
Close monitoring for signs of infection, sepsis, and bowel ischemia
Management of feeding intolerance and slow return of bowel function.
Complications
Early Complications:
Bowel obstruction due to adhesions or strictures within the silo
Bowel ischemia or necrosis from kinking or compression
Sepsis and abdominal compartment syndrome
Fascial dehiscence or wound infection after closure
Necrotizing enterocolitis (NEC).
Late Complications:
Adhesions leading to bowel obstruction
Incisional hernias or ventral hernias at the closure site
Abdominal wall weakness and cosmetic deformities
Chronic feeding difficulties and malabsorption
Strictures of the gastrointestinal tract.
Prevention Strategies:
Careful handling of the bowel during silo placement and reduction
Adequate abdominal wall preparation and gradual reduction to prevent compartment syndrome
Meticulous surgical technique during definitive closure
Early recognition and prompt treatment of complications like sepsis and ischemia
Appropriate nutritional support to promote bowel healing.
Prognosis
Factors Affecting Prognosis:
The size of the abdominal wall defect, the presence and extent of bowel atresia or ischemia, the degree of abdominal distension, the presence of associated anomalies, and the quality of surgical and intensive care
Early diagnosis and intervention are critical.
Outcomes:
With modern management, survival rates for gastroschisis are high, often exceeding 90%
However, significant morbidity can occur, including prolonged hospital stays, need for TPN, and long-term gastrointestinal problems
Outcomes are generally better for gastroschisis than omphalocele due to fewer associated anomalies.
Follow Up:
Long-term follow-up is essential to monitor for late complications such as bowel obstruction, hernias, and growth and developmental issues
This includes regular clinical assessments, nutritional monitoring, and potentially imaging studies as needed
Psychosocial support for the family may also be important.
Key Points
Exam Focus:
Differentiate gastroschisis from omphalocele based on defect location, membrane covering, and associated anomalies
Understand the principles of silo creation and gradual reduction
Recognize the indications for primary closure versus staged closure
Identify potential complications like bowel ischemia and abdominal compartment syndrome.
Clinical Pearls:
Always cover the eviscerated organs with saline-soaked gauze and plastic wrap immediately after birth to prevent desiccation
Use a silo for larger defects to allow gradual abdominal wall stretching
Monitor for bowel viability vigilantly
TPN is critical for nutritional support during prolonged ileus.
Common Mistakes:
Attempting primary closure of large defects without adequate abdominal wall compliance, leading to compartment syndrome
Aggressive reduction of the bowel into the silo, causing ischemia
Delayed recognition of sepsis or bowel necrosis
Inadequate fluid resuscitation and electrolyte management.