Overview
Definition:
An omphalocele is a congenital abdominal wall defect characterized by protrusion of abdominal viscera into the peritoneal cavity, covered by a translucent sac composed of amnion and peritoneum, with the umbilical cord inserting into the sac
It represents a failure of normal closure of the lateral abdominal folds during the embryonic period.
Epidemiology:
The incidence of omphalocele varies, with estimates ranging from 1 in 5,000 to 1 in 10,000 live births
It is associated with a higher incidence in males and is often seen as part of a broader spectrum of congenital anomalies, including chromosomal abnormalities (e.g., trisomy 13, 18, 21) and other organ malformations (e.g., cardiac defects, genitourinary anomalies).
Clinical Significance:
Omphalocele repair is critical for neonatal survival and long-term health
Early diagnosis and appropriate surgical intervention are essential to prevent evisceration, infection, dehydration, and thermal instability
The management requires a multidisciplinary approach involving neonatologists, pediatric surgeons, and geneticists.
Clinical Presentation
Symptoms:
The primary presentation is a visible abdominal mass at birth
The infant may exhibit signs of bowel obstruction if the omphalocele sac is compromised or if there are associated intestinal malformations
Respiratory distress can occur due to diaphragmatic compression by the enlarged abdominal contents or associated lung hypoplasia.
Signs:
A midline defect at the base of the umbilical cord, typically containing intestines, liver, and potentially other abdominal organs, enclosed within a glistening, thin membrane
Vital signs may be stable or show signs of shock if complications are present
Palpation of the sac should be avoided to prevent rupture.
Diagnostic Criteria:
Diagnosis is primarily clinical based on the presence of abdominal viscera outside the abdominal cavity within a membranous sac at birth
Prenatal diagnosis via ultrasound is common, identifying the defect during routine obstetric scans
Postnatal diagnosis is confirmed by physical examination.
Diagnostic Approach
History Taking:
Detailed antenatal history is crucial, including maternal health, previous pregnancies, and any detected anomalies on prenatal imaging
Postnatal history focuses on the infant's immediate condition, including breathing effort, signs of distress, and any observed leakage from the sac
Assess for other congenital anomalies.
Physical Examination:
Careful examination of the abdominal wall defect is paramount
Assess the size and contents of the sac, the integrity of the membrane, and the presence of associated anomalies
A complete physical examination, including cardiac, pulmonary, and genitourinary systems, is essential to identify comorbidities.
Investigations:
Karyotyping and genetic counseling are recommended due to the association with chromosomal abnormalities
Echocardiography is essential to rule out congenital heart disease
Abdominal ultrasound may be used to assess intra-abdominal organs if not fully visualized in the sac
Blood tests include complete blood count, electrolytes, and blood glucose monitoring.
Differential Diagnosis:
The primary differential diagnosis is gastroschisis, which presents as abdominal viscera protruding through a full-thickness abdominal wall defect without a sac, typically to the right of the umbilicus
Other differentials include amniotic band syndrome, which can cause limb defects and abdominal wall disruption, and bladder or cloacal exstrophy.
Management
Initial Management:
Immediate management involves covering the omphalocele sac with sterile, saline-moistened gauze and a plastic wrap to prevent dehydration and thermal loss, and to protect the sac from trauma
The infant should be placed in a sterile incubator with appropriate temperature regulation
Intravenous fluid resuscitation and broad-spectrum antibiotics are initiated
Nasogastric tube decompression is essential.
Surgical Management:
Surgical repair is indicated for most omphaloceles
The timing and approach depend on the size of the defect and the presence of associated anomalies
Small omphaloceles may be repaired primarily in the immediate neonatal period
Large omphaloceles may require staged repair using prosthetic material (e.g., Silastic sheeting) to gradually reduce the defect and allow for abdominal expansion, followed by definitive closure when the abdominal cavity has adapted
If liver is extruding, a staged repair is almost always necessary.
Supportive Care:
Comprehensive supportive care is vital, including meticulous fluid and electrolyte management, nutritional support (parenteral nutrition initially), respiratory support if needed, and close monitoring for signs of infection or ischemia of the sac
Neonatal intensive care unit (NICU) admission is mandatory
Pain management is also crucial.
Complications
Early Complications:
Rupture of the omphalocele sac leading to evisceration and peritonitis
Sepsis and wound infection
Ischemia of the extruded organs
Respiratory compromise
Fluid and electrolyte imbalances
Necrosis of the sac.
Late Complications:
Adhesions and bowel obstruction
Incisional hernia at the repair site
Abdominal wall weakness or cosmetic deformities
Long-term feeding difficulties or malabsorption
Pulmonary hypoplasia.
Prevention Strategies:
Careful handling of the omphalocele sac to prevent rupture
Prompt and appropriate surgical intervention
Meticulous sterile technique during surgery and postoperative care
Gradual staged closure for large defects to prevent abdominal compartment syndrome
Early identification and management of associated anomalies.
Prognosis
Factors Affecting Prognosis:
The size of the omphalocele, the presence and severity of associated anomalies (especially chromosomal and cardiac), the integrity of the sac at birth, and the promptness and success of surgical repair are key prognostic factors
Neonatal survival rates are generally higher for smaller omphaloceles without significant comorbidities.
Outcomes:
Survival rates for small omphaloceles without major anomalies are high, often exceeding 90%
For larger omphaloceles or those with significant comorbidities, survival rates are reduced
Long-term outcomes depend on the degree of intestinal involvement and the development of complications such as bowel obstruction or short bowel syndrome.
Follow Up:
Long-term follow-up is essential to monitor for complications such as incisional hernias, bowel obstruction, and growth and developmental milestones
Regular assessments by a pediatric surgeon and pediatrician are required
Nutritional assessment and support may be needed for extended periods.
Key Points
Exam Focus:
Differentiate omphalocele from gastroschisis
Recognize the importance of chromosomal analysis and cardiac evaluation
Understand the principles of staged vs
primary repair
Be aware of immediate management to protect the sac
Identify key early and late complications.
Clinical Pearls:
Always cover the omphalocele sac with sterile, saline-soaked gauze and plastic wrap immediately after birth
Avoid palpating the sac directly
Prioritize multidisciplinary care
Consider abdominal compartment syndrome with large defects and staged repairs.
Common Mistakes:
Mistaking omphalocele for gastroschisis without careful examination
Delaying surgical intervention
Aggressive manipulation of the omphalocele sac
Inadequate fluid resuscitation or temperature management
Failing to investigate for associated anomalies.