AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Background

Gastroschisis and omphalocele are among the most frequently encountered congenital anomalies in pediatric surgery. The combined incidence of these anomalies is 1 in 2,000 births; hence, a pediatric surgeon can expect to see twice as many babies with abdominal wall defects as esophageal atresia/tracheoesophageal fistula.

Although pediatric surgeons and neonatologists initially treat these babies, pediatricians should become familiar with abdominal wall defects, so that they are prepared to care for these patients later in life. If the baby's abdomen was closed during the neonatal period, routine pediatric care may suffice; however, if the abdominal wall defect is only one aspect of a multifaceted anomaly, further care by specialists who are familiar with the child's particular problems may be required. 

A child with gastroschisis may have malabsorption, either from in utero injury to the intestine or from partial bowel obstruction. Anomalies of intestinal fixation accompany abdominal wall defects, and midgut volvulus is a possible complication. Atypical appendicitis may also occur, if the abnormally located appendix was not previously removed. In addition, these children may have symptoms of gastroesophageal reflux, Hirschsprung disease, or both.

Pathophysiology

Embryology

Growth of the fetus and definition of its form are orchestrated by processes that occur at specific times and in specific locations. Growth spurts are punctuated by delays. Cellular proliferation and differentiation and migration and deposition are involved in the formation of new tissue. The embryo is initially a flat disc surrounded by the umbilical ring, which is defined histologically by the junction of the cylindrical epithelium of the epiblast and the cuboidal epithelium of the hypoblast. The epiblast (ectoderm) becomes either neuroectoderm or surface epithelium, and the hypoblast becomes the inner epithelium of gut-derived organs. Creation of a third germ layer, the mesoblast, occurs coincident with a change in the shape of the embryo. The embryonic disc elongates, and longitudinal and lateral enfolding creates a cylinder with a recognizable body plan.

Several processes combine to form the mesoblast cell layer, as follows:

• Apoptotic cell death with disruption of the epithelial basement membrane
• Phagocytosis of the dead cells with enlargement of the intercellular space
• Migration of ectoderm cells from the epithelial layer to the mesodermal layer

These processes take place in the following 3 areas:

• The primitive streak, which is a groove-like structure located in the dorsocaudal portion of the embryo
• The neural crest, which is located in the cranial half of the embryo at the transition of neuroectoderm and surface epithelium
• The umbilical ring

Proliferation of the neuroectoderm and underlying mesoderm, coupled with growth arrest at the umbilical ring, pushes the embryonic disc above the umbilical ring and the underlying yolk sac like a sprouting mushroom. At the same time, the embryo folds ventrally, separating the thoracic and abdominal cavities from the extraembryonic coelom. The amniotic cavity enlarges and bulges over the embryo; and the amnion attaches to the yolk sac and the connecting stalk, forming the umbilical cord. Caudal folding of the embryo incorporates the proximal yolk sac into the hindgut, and the allantois (a diverticulum of the yolk sac) into the urogenital sinus. The cloacal membrane covers the openings of the hindgut and urogenital sinus; the perineum lies between these openings. The primitive gut and the urogenital sinus elongate while the adjacent mesoderm coalesces to form the urorectal septum.

In summary, the human embryo initially has 2 layers and looks like a disc. It becomes cylindrical as it acquires a third cell layer and elongates and invaginates above the umbilical ring.  The body folds (cephalic, caudal, lateral) fuse centrally, where the amnion invests the yolk sac. Defective development at this critical location results in a spectrum of abdominal wall defects. By the sixth week of life, rapid growth of the midgut results in its herniation through the umbilical ring. By the tenth week of life, the abdominal cavity has sufficiently enlarged to accommodate the midgut. As the intestine returns, rotation and fixation occur. This process does not occur in babies with gastroschisis or omphalocele; thus, they are at risk of developing midgut volvulus.

Pathogenesis of omphalocele and gastroschisis

Abdominal wall defects result from failure of the mesoderm to replace the body stalk, which persists in a region usually occupied by somatopleure. Embryonic dysplasia, decreased apoptotic cell death, and inadequate mesodermal development cause insufficient growth at the umbilical ring and enlargement of its diameter. Rather than investing the yolk sac and body stalk centrally at the umbilicus, the amnion remains attached to the margins of the body wall defect, creating a persistent communication between the intraembryonic body cavity and the extraembryonic coelom.

In babies with omphalocele (see Media file 1, Media file 4), failure of central fusion at the umbilical ring due to defective mesodermal growth causes incomplete closure of the abdominal wall and persistent herniation of the midgut. The abdominal viscera are contained in a translucent sac, which is composed of amnion, Wharton jelly, and peritoneum. The umbilical vessels radiate onto the wall of the sac. In 50% of cases, the liver, spleen, and ovaries or testes accompany the extruded midgut.

Possible explanations of the embryology of abdominal wall defect in gastroschisis (see Media file 3) include the following:

• Defective mesenchymal development at the junction of the body stalk and abdominal wall results in a dysplastic abdominal wall that may rupture with increased abdominal pressure.
• Abnormal involution of the right umbilical vein or a vascular accident involving the omphalomesenteric artery causes localized abdominal wall weakness that subsequently ruptures.
• Rupture of a small omphalocele with absorption of the sac and growth of a skin bridge between the abdominal wall defect and the umbilical cord, as has been chronicled on prenatal sonograms.

Pathogenesis of other abdominal wall defects

In hernias of the umbilical cord, the umbilical ring is oversized but the relation of the amnion to the yolk sac and connecting stalk is normal.

Urachal remnants and omphalomesenteric duct malformations result from absent or deficient apoptotic cell death of the epithelium of the urachus and yolk stalk. In normal embryogenesis, these structures disappear.

Abnormal development of the lower body wall is caused by defective infolding of the caudal pole of the embryo and deficient incorporation of the yolk sac and allantois; this is associated with malformation of external genitalia. Bladder exstrophy (hypogastric omphalocele) has an incidence of 3.3 in 100,000 births. The bladder develops during the fifth to ninth gestational weeks, and urine mixes with amniotic fluid by the tenth week. The bladder is visible on sonography by the end of the first trimester. The bladder mucosa is soft and pliable at birth, but within 48 hours of exposure, it becomes firm and polypoid. Later in life, it may undergo malignant degeneration. Surgical reconstruction aims to restore continence, allow for voluntary urination, and correct associated vesicoureteral reflux.

Characteristic findings include the following:

• Anterior vagina and rectum, which may be prolapsed
• Epispadias, bifid clitoris or penis and scrotum
• Dorsal chordee
• Poor urinary sphincter control
• Waddling gait due to outward and downward rotation of the anterior pelvic ring and pubic symphysis diastasis

Prune-belly syndrome (abdominal wall dysplasia, see Media files 16-17) occurs as a result of increased apoptotic cell death in the body-wall placode, which leads to insufficient deposition of mesodermal cells. Retention of an abnormally large amount of yolk sac causes attenuation of the abdominal musculature. Muscle fibers are absent and replaced by a thick collagenous aponeurosis. Intercellular conduction of electrical impulses is disturbed and leads to faulty muscular contractions and ineffective peristalsis.

Characteristics of prune-belly syndrome include a thin, flaccid abdominal wall and hypertrophy of the bladder wall with dilatation of the bladder, ureters, and renal collecting system, which may be associated with obstruction of the prostate urethra at its junction with the bladder neck. The incidence is 1 case in 30,000-50,000 births. Approximately 95% of patients are male. Patients are infertile because absence of the prostate and seminal fluid precludes normal sperm development. Surgical repair includes reconstruction of the urinary collecting systems and the abdominal wall, along with bilateral orchiopexies.

Faulty development of the urorectal septum leads to anal agenesis and nondivision of the cloaca. Cloacal exstrophy (lower midline syndrome, see Media files 18-24) has an incidence of 1 case in 200,000-400,000 births. Chromosomal abnormalities are associated with low-set ears, fetal uropathy leading to oligohydramnios, pulmonary hypoplasia, and compression abnormalities, such as indented thorax, deformed digits, talipes, bowed limbs, and dislocated hips. Characteristic features include the following:

• Bladder exstrophy with a central strip of everted intestine
• Duplicated colon and appendix, or colonic atresia and imperforate anus (agenesis of the hindgut)
• Sacral and neurologic anomalies, such as myelomeningocele, hydromyelia, and diastematomyelia

Frequency

United States

The combined incidence of omphalocele and gastroschisis is 1 in 2000 births.

Epidemiologic data compiled over the last 40 years show that the incidence of omphalocele has remained constant and is associated with increased maternal age. An inherited predilection is indicated by its occurrence in twins, in consecutive children, and in different generations of the same family.

The incidence of gastroschisis is increasing, and it is associated with young maternal age and low gravidity. Prematurity and low birth weights, secondary to in utero growth retardation, are commonly seen in babies with gastroschisis.

Mortality/Morbidity

Over the past 30 years, the survival rate of babies with gastroschisis and omphalocele has steadily improved, from approximately 60% in the 1960s to more than 90%. The observed decline in morbidity and mortality has resulted from improvements in the care of low-birth-weight and premature babies, particularly those who, because of open abdominal wounds and extruded intestine (gastroschisis), are especially prone to hypothermia, dehydration, sepsis, and hypoglycemia. Anesthetic management and surgical techniques have improved, and the ability to provide parenteral nutrition for patients with gastrointestinal dysfunction has substantially improved their survival.

• Long-term morbidity from gastroschisis is related to intestinal dysfunction and wound problems.
• A number of factors may cause short-gut syndrome. Antenatal mesenteric vascular accident or constriction of the mesentery of the extruded intestine by a small abdominal wall defect may cause an obstructed, shortened intestine with diminished absorptive capacity. Gut necrosis may complicate excessively tight closure of the abdominal wall defect by impeding splanchnic blood flow with resultant intestinal ischemia and necrotizing enterocolitis (NEC), or it may occur consequent to closed loop obstruction caused by adhesions or midgut volvulus. Loss of intestinal length exacerbates the dysfunction consequent to antenatal exposure of the intestine to amniotic fluid.
• Care of babies with short-gut syndrome has substantially improved as a result of parenteral and enteral nutrition, of obtaining venous access and treating catheter sepsis, and of optimizing gut adaptation with innovative surgical procedures and aggressive treatment of bacterial overgrowth in stagnant intestinal loops. Even so, babies with short gut due to gastroschisis account for a significant percentage of children undergoing intestinal transplantation.
• Poor healing of the abdominal wound usually results in a ventral hernia, which may require secondary surgical repair.
• A paradoxical finding is that babies with small (unimpressive) omphaloceles are most likely to have associated abnormalities, including intestinal problems (Meckel diverticulum, atresia), genetic syndromes (Beckwith-Wiedemann, trisomy 18), and congenital heart disease.
• Babies with giant omphaloceles usually have small, bell-shaped, thoracic cavities and minimal pulmonary reserve. Reduction and repair of the omphalocele frequently precipitates respiratory failure, which may be chronic and require a tracheotomy and long-term ventilator support. The authors recently cared for a baby with giant omphalocele and diaphragmatic hernia. Both conditions are associated with pulmonary hypoplasia, and when they are combined, the severity of the pulmonary deficit precludes survival, even with extracorporeal membrane oxygenation (ECMO) support, as was provided for our patient.
• Even with successful repair and good clinical outcome, the liver of a child with a giant omphalocele is in the epigastrium and lacks the normal protection of the lower rib cage. Hence, it is more vulnerable to traumatic injury than it otherwise would be.

Race

No geographic or racial predilection is reported for omphalocele or gastroschisis.

Sex

The male-to-female ratio is 1.5:1.

CLINICAL

Section 3 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

History

Infants with these defects are often identified prenatally. Associated problems, such as defects in other organ systems or chromosomal abnormalities, are known before birth. See Work-up.

Physical

• Omphalocele
• • In babies with omphaloceles, the abdominal wall defect is 4-12 cm, and the defect may be central, epigastric, or hypogastric.
  • Although the ease of accomplishing surgical reduction and repair are correlated with the size of the abdominal wall defect, a small omphalocele is no guarantee of an uncomplicated clinical course. Associated genetic syndromes involving multiple organ systems, or abnormalities of the intestine, such the association of ileal atresia and a patent omphalomesenteric duct, are potential problems.
  • With a large omphalocele, dystocia may occur and result in injury to the baby's liver; hence, cesarean delivery may be indicated.
  • The omphalocele sac is usually intact, though it may be ruptured in 10-20% of cases. Rupture may occur in utero or during or after delivery.
  • Babies with the Beckwith-Wiedemann syndrome (ie, exomphalos, macroglossia, gigantism; see Media file 7) have large, rounded facial features, hypoglycemia from hyperplasia of the pancreatic islet cells, and visceromegaly. They may have genitourinary abnormalities, and they are at risk for Wilms tumors, liver tumors (hepatoblastoma), and adrenocortical neoplasms.
  • Pentalogy of Cantrell (see Media file 8) describes an epigastric omphalocele associated with a cleft sternum and anterior diaphragmatic hernia (Morgagni), cardiac defects (eg, ectopia cordis, ventricular septal defect [VSD]) and an absent pericardium.
  • Babies with giant omphaloceles have large, central abdominal wall defects. The liver is entirely contained in the omphalocele sac. The abdominal and thoracic cavities are small and undeveloped. Restrictive lung disease and pulmonary hypoplasia usually are associated with the diminutive thoracic cavity. Operative closure is difficult.
• Gastroschisis
• • The defect is fairly uniform in size (£5 vertical opening) and location (to the right of the umbilical cord).
  • The amount of inflammation and edema and turgor of the intestines, as well as the size of the abdominal cavity, determines whether reduction of the extruded intestine and closure of the abdominal wall can be accomplished. Inflammation may so distort the appearance of the bowel that it may be difficult to determine if associated intestinal atresia is present (see Media files 5-6).
  • Closure of the abdominal wall defect when the intestines are inflamed requires their temporary placement in a silo to allow the inflammation to resolve. As the intestine softens and becomes pliable, reduction can be accomplished. Correction of associated intestinal atresia is best delayed until several weeks after the initial repair.
  • Intestinal dysfunction takes 4-6 weeks to several months to normalize.
  • If gastroschisis is identified antenatally, serial sonography is indicated to assess intestinal integrity and amniocentesis to monitor lung maturity.

Causes

• Factors associated with high-risk pregnancies, such as maternal illness and infection, drug use, smoking, and genetic abnormalities, can be associated with birth of babies with omphalocele and gastroschisis. These factors contribute to placental insufficiency and birth of premature or small-for-gestational-age (SGA) babies, in whom gastroschisis and omphalocele are most common.
• Folic acid deficiency, hypoxia, and salicylates have caused laboratory rats to develop abdominal wall defects, but the clinical significance of these experiments is conjectural. Elevation of maternal serum alpha-fetoprotein (MSAFP) levels certainly warrants investigation with high-resolution sonography to determine if any structural abnormalities are present in the fetus. If such abnormalities are associated with an omphalocele, amniocentesis is indicated to check for an associated genetic abnormality.
• Polyhydramnios suggests fetal intestinal atresia, and this possibility should be investigated with ultrasonography. Such information ideally prompts referral to a tertiary care facility where the infant can receive expeditious specialty care.

DIFFERENTIALS

Section 4 of 12  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Other Problems to be Considered

Babies with omphalocele have a 35-80% incidence of other clinical problems. These include congenital heart disease, cleft palate, and musculoskeletal and dental occlusion abnormalities. Patent omphalomesenteric duct and small bowel atresias may occur in babies with umbilical cord hernias, where the size of the defect is smaller than 4 cm.

Incidence of associated chromosomal abnormalities is 10-40%. These include trisomies 12, 13, 15, 18, and 21.

Babies with gastroschisis, in which the incidence of chromosomal anomalies is less than 5 percent, may have gastroesophageal reflux disease or Hirschsprung disease, in addition to abnormal intestinal absorption and motility.

WORKUP

Section 5 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Lab Studies

Prenatal diagnosis of abdominal wall defects can be made by detection of an elevation in MSAFP. MSAFP levels are greater in gastroschisis than in omphalocele. MSAFP levels are also increased in spina bifida, which additionally increases the ratio of acetylcholinesterase and pseudocholinesterase.

Imaging Studies

• Fetal ultrasonography may suggest a genetic abnormality by showing a structural marker of a karyotypic abnormality.
• Fetal echocardiography may also help in identifying a cardiac abnormality.
• Findings suggestive of a genetic abnormality should be confirmed with amniocentesis.
• If serial ultrasonograms show dilatation and thickening of the intestine in a baby with gastroschisis and if lung maturity can be verified by means of amniocentesis, delivery should be induced.

TREATMENT

Section 6 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Medical Care

• Intestinal inflammation
• • Intestinal inflammation may occur with either gastroschisis or ruptured omphalocele.
  • The eviscerated intestine may be either normal or abnormal in structure and function. The degree of abnormality depends upon the extent of the inflammatory and ischemic injury, manifested by shortened length and surface exudate (peel), which is related to the duration of the intestine's exposure to, and the composition of, the amniotic fluid and fetal urine.
  • Inflamed intestine is thick and edematous, the loops of bowel are matted together, and the mesentery is congested and foreshortened.
  • Histology reveals atrophy of the myenteric ganglion cells.
  • Inflamed intestine is dysmotile, with prolonged transit time and decreased absorption of carbohydrate, fat, and protein. These deleterious effects remit as the inflammation resolves, usually in 4-6 weeks. During this time, total parenteral nutrition (TPN) is required.
• Intact omphalocele
• • Neonates with intact omphalocele are usually in no distress unless associated pulmonary hypoplasia is present.
  • Carefully examine the baby to detect any associated problems, such as Beckwith-Wiedemann syndrome, chromosomal abnormalities, congenital heart disease, or other associated malformations.
  • The baby should receive maintenance intravenous (IV) fluids; the omphalocele sac may be covered with nonadherent gauze, such as Xeroform, then wrapped with Kerlix and a piece of Saran wrap. As an alternative, the baby's lower torso may be placed in a bowel bag. The omphalocele should be supported to avoid excessive traction on the mesentery.
  • Prophylactic antibiotics may be given preoperatively if an associated intestinal anomaly is suspected.
  • Closure of a small or moderate-size omphalocele is accomplished without difficulty.
  • A baby with a ruptured omphalocele is provided with medical care in the same manner as one with gastroschisis.
  • Closure of a giant omphalocele containing the liver is always challenging.
• Gastroschisis
• • Respiratory distress in a neonate with gastroschisis may respond to gastric decompression, though endotracheal intubation may still be needed.
  • Fluid, electrolyte, and heat losses must be minimized and corrected. Because of significant ongoing fluid losses with an open abdominal wall defect, one approach to fluid resuscitation of these infants is to administer an IV fluid bolus (20 mL/kg lactated ringer solution), followed by 5% dextrose 0.25 normal sodium chloride solution at 2-3 times the baby's maintenance fluid rate. The degree of fluid resuscitation is dependent on the ability to successfully enclose the defect, as described below, and is dependent on the time from birth until surgical intervention.
  • The baby should be placed under a radiant heater, and the exposed intestines should be wrapped with moist Kerlix then covered with plastic wrap and supported to minimize traction on the mesentery. As an alternative, the baby's lower torso may be placed in a bowel bag.
  • Insert a urinary catheter to monitor urine output, and perform a rectal exam to dilate the anal canal. Reduction of the herniated viscera is facilitated by evacuating meconium from the sigmoid colon; this can easily be accomplished during the operative procedure.
  • Administer broad spectrum antibiotic therapy to prevent infection.
  • Place a central venous line to provide parenteral nutrition and thus minimize catabolic protein loss during the period of gastrointestinal dysfunction.

Surgical Care

• Omphalocele
• • Ambroise Pare, the 17th-century French surgeon, accurately described omphalocele and the dire consequences of opening the sac to attempt surgical closure. His admonition certainly encouraged conservative treatment (ie, squeezing the sac to reduce the herniated viscera or painting the sac with escharotic agents to promote epithelization).
  • The problem with this approach is that it is slow. During this time the sac may rupture, resulting in a wound infection. Even if complications do not occur, the healing of such a large wound exacts a clinically significant metabolic and nutritional toll.
  • Healing may be hastened by mobilizing skin flaps to cover the omphalocele sac (Gross technique); however, this results in the creation of a large ventral hernia.
  • In 1967, Schuster developed a technique that may be used in initially treating a baby with a giant omphalocele or in correcting the ventral hernia created by skin flap closure.
  • • A circumferential incision is made along the skin-omphalocele junction; the omphalocele membrane is left intact. The abdominal wall defect is extended in the midline, and the rectus fascia is exposed from xiphoid to pubis. Teflon sheets are sutured along the edge of the fascia and approximated over the omphalocele sac.
    • As reduction is effected, the rectus muscles are elevated over the anterior aspect of the liver and gradually approximated. At an appropriate time, the Teflon sheets are removed; the omphalocele sac is excised, and a DualMesh patch (Gore-Tex), is sutured circumferentially to the rectus fascia.
    • The patch is larger than the abdominal wall defect so that the anterior abdominal wall is concave. Skin flaps are mobilized laterally and approximated over the patch.
    • A rigid patch (Gore-Tex) attached to the margins of the abdominal wall defect (superiorly to the costal arch, inferiorly to the pubis, and laterally to the rectus fascia) stimulates growth of the abdominal wall and elevates the costal arch and expands the thoracic cavity.
    • A Gore-Tex patch requires skin coverage, whereas an AlloDerm patch (acellular human dermis) is vascularized by the underlying liver. It may be left exposed and dressed with topical antimicrobials; like a partial thickness burn wound, it is eventually epithelialized. This is a real advantage in regard to wound healing because one does not have to worry about infection of the patch requiring its removal. However, AlloDerm is not rigid, and the disadvantage of using this patch is the development of a huge ventral hernia, which ultimately requires repair with a rigid patch (see Media files 26-28).
• Gastroschisis
• • In 1969, Allen and Wrenn adapted Schuster's technique to treat gastroschisis.
  • Silastic sheets are sutured to the full thickness of the enlarged abdominal wall defect and closed over the eviscerated intestine, whose reduction is facilitated by stretching the abdominal musculature, emptying the stomach and bladder, and manually evacuating the colon.
  • The major factor permitting reduction of the extruded viscera is resolution of the intestinal inflammation; the rigid, congealed mass is transformed to multiple soft, pliable loops of intestine, which can fit into the nooks and crannies of the abdominal cavity.
  • Too tight a closure of the abdominal wall must be avoided, for this limits excursion of the diaphragm and necessitates increased inspiratory pressure to compensate for the increase in airway resistance. In general, peak inspiratory pressures (PIPs) higher than 25 mm Hg should be avoided. High-frequency oscillatory ventilation may be an alternative to conventional ventilation if intra-abdominal pressures are markedly increased.
  • In addition, tight closure of the abdominal cavity impedes venous return to the heart, compromising cardiac output and decreasing renal blood flow and glomerular filtration rate. Renal vein thrombosis and renal failure may ensue.
  • Diminished mesenteric blood flow may facilitate the development of NEC.
  • In order to avoid these problems, techniques have been developed to monitor central venous pressure (CVP), intraabdominal pressure, intravesicular pressure, and intragastric pressure (which should not exceed 20 cm of water).

Consultations

• Neonatologists and pediatric surgeons are responsible for the treatment of babies with these anomalies.
• Consult with a cardiologist, pulmonologist, gastroenterologist, and geneticist may be indicated.

Diet

• Babies with omphaloceles usually have normal gastrointestinal tracts and do not require special formulas. The occasional intestinal atresia, perhaps associated with a patent omphalomesenteric duct, is typically not associated with short gut.
• Babies with gastroschisis, on the other hand, may require elemental, crystalline amino acid, or protein hydrolysate formulas, nonlactose carbohydrate, and medium-chain triglycerides because the associated gut inflammation results in substrate malabsorption and a tendency to develop a food allergy.
• Babies with short-gut syndrome absorb medium-chain triglycerides more readily than long-chain triglycerides; however, the latter are more valuable with regard to gut adaptation.

Activity

• The liver of a child with a repaired giant omphalocele is located in the epigastrium.
• In this location, it is more vulnerable to trauma.
• Avoidance of contact sports is prudent.

MEDICATION

Section 7 of 12  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Drug therapy currently is not a component of the standard of care for this condition. See Treatment.

FOLLOW-UP

Section 8 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Further Inpatient Care

• Omphalocele
• • Babies with omphalocele usually have rapid return of intestinal function after surgical repair, even if intestinal atresia occurs concomitantly because no associated gut inflammation is present.
  • Babies with giant omphaloceles usually have a protracted hospital course, and their overall morbidity and mortality rates are high. Multiple surgical procedures are necessary to close the abdominal wall defect.
  • Respiratory compromise may complicate the repair and require prolonged support and possibly a tracheotomy. Ventilator management, tracheotomy care, and decannulation ultimately require close cooperation by the neonatologist, the pulmonologist, and the pediatric surgeon.
• Gastroschisis
• • Even if primary closure of the abdominal wall defect is obtained, several weeks of intestinal dysfunction (ileus) usually follows as a result of the associated gut inflammation. Parenteral nutrition is required, followed by gradual introduction of enteral feeds. Continuous drip feedings are often required, at least initially.
  • If use of a silo (see Media file 9) is required to reduce the herniated intestine, it should be removed within 5-7 days. The baby requires parenteral nutrition until gastrointestinal function returns. If the period of ileus lasts longer than 3 or 4 weeks, intestinal obstruction is presumed, and a contrast-enhanced study is obtained to document intestinal transit.
  • If intestinal obstruction is present, laparotomy must be performed.

Further Outpatient Care

• After hospital discharge, babies require close follow-up care to assess their growth and weight gain.
• Patients usually have gastroesophageal reflux and may require medical therapy, but fundoplication is usually not necessary.
• Hirschsprung disease (aganglionic megacolon) may also occur. Physicians should consider this diagnosis in a child with constipation associated with failure to thrive.

Transfer

• The best way to treat the exposed intestines in a baby with gastroschisis who is being transported to a tertiary center includes the application of a moist lap pad.
• The moist lap pad is placed over the intestines, which are gently wrapped and held in place with Kerlix wrap applied around the baby's torso.
• The goal is to prevent traction on the bowel mesentery.
• A warm, wet lap pad placed in a bowel bag with the eviscerated intestine soon becomes a cold, wet lap pad, and the intestine falls alongside the baby.

Complications

• Poor nutritional status can result from the omphalocele acting as a metabolic drain. As a result, obtaining a positive nitrogen balance and adequate growth is challenging.
• The need for prolonged parenteral nutrition can lead to hepatomegaly and significant cholestasis, complicating abdominal closure.
• Pulmonary insufficiency or hypoplasia that often requires prolonged ventilator support and tracheotomy can occur. This is complicated by attempts at abdominal closure that put additional pressure on the diaphragm.
• Increased risk of sepsis is present, which is worsened by the patient's often poor nutritional status, chronic ventilatory requirements, and presence of a central line catheter.

Prognosis

• Omphalocele
• • The patient's prognosis depends on the severity of the associated problems. Babies with omphalocele are considerably complex, with involvement of multiple organ systems.
  • Giant omphaloceles can be closed; however, multiple surgical procedures are usually necessary. In addition, these infants usually have significant additional medical problems and complications that make caring for them quite challenging.
  • The critical factor affecting the survival of babies with giant omphaloceles is the diminutive size of their thoracic cavities associated with pulmonary hypoplasia and the resultant chronic respiratory failure. Even so, the fact that pulmonary growth and development continue well into childhood encourages optimism regarding the ultimate prognosis of babies with this condition.
• Gastroschisis
• • The patient's prognosis depends on the severity of the associated problems, such as prematurity, intestinal atresia, short gut, and intestinal inflammatory dysfunction.
  • Many pediatric surgeons believe that the prognosis has improved because of maternal sonographic diagnosis and monitoring, which leads to expeditious delivery of babies at tertiary centers.
  • Years ago, obtaining primary closure of a baby with gastroschisis was unusual. It was usually necessary to use a silo. Now, primary closure is commonly attained. This progress may be attributed to improved prenatal and obstetrical care.

Patient Education

• Instruct parents regarding the importance of bilious (green) vomitus because babies with this sign may have developed adhesive small-bowel obstruction or midgut volvulus.
• Inform parents that their child's appendix is probably in an unusual location and that CT scanning may be the most reliable way to diagnose acute appendicitis.

MISCELLANEOUS

Section 9 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Special Concerns

• With the increased availability of ultrasonography, prenatal diagnosis is made more frequently.
• To diagnose omphalocele, further workup to determine if an associated genetic abnormality is present, in which case appropriate counseling is necessary.
• When gastroschisis is diagnosed, serial ultrasonography should be performed to detect signs of intestinal injury (decreased peristalsis or bowel distension).
• The patient's parents should be given information concerning their baby's anomaly before delivery. Also, optimal management requires the obstetrician to understand the particular needs of these babies and to ensure that they are delivered in a facility where neonatal, pediatric anesthesia, and pediatric surgery services are available.

FURTHER READING

Section 10 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

See the eMedicine topic Gastroschisis and the Children's Hospital of Philadelphia's article Gastroschisis.

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Media file 1:  Baby with an omphalocele.
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Media file 2:  Baby with an umbilical cord hernia.
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Media file 3:  Baby with gastroschisis.
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Media file 4:  Baby with a ruptured omphalocele.
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Media file 5:  Baby with gastroschisis and associated intestinal atresia.
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Media file 6:  Baby with gastroschisis and colon atresia. Bulbous proximal end of the atretic colon is excised, and a colostomy is created at the abdominal wall defect. An anastomosis of the proximal, dilated colon to the distal microcolon (in view of its small caliber) would not function properly. The colostomy can be closed 4-6 weeks later. (Gastrostomy tubes are no longer routinely used.)
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Media file 7:  Note the enlarged tongue in this baby with Beckwith-Wiedemann syndrome.
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Media file 8:  Baby with pentalogy of Cantrell.
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Media file 9:  Silo closure of a baby with gastroschisis.
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Media file 10:  Completed reduction of the bowel contained within the silo; the silo is about to be removed and the abdominal wall closed.
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Media file 11:  Baby with a giant omphalocele.
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Media file 12:  Same patient as in Image 11. Closure of the giant omphalocele using a synthetic patch.
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Media file 13:  Same patient as in Images 11-12. Tightening the abdominal wall closure
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Media file 14:  Same patient as in Images 11-13. Flank flaps were used to close the giant omphalocele in the baby whose patch became infected.
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Media file 15:  Same patient as in Images 11-14. The flank wounds were skin grafted and closure of the giant omphalocele obtained.
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Media file 16:  Baby with prune-belly syndrome.
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Media file 17:  Note the laxity of the abdominal wall in this baby with prune-belly syndrome.
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Media file 18:  Baby with cloacal exstrophy.
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Media file 19:  Note the bifid genitalia in this baby with cloacal exstrophy.
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Media file 20:  In the repair of cloacal exstrophy, the ileum in the middle of the bifid bladder is excised and used to create an ostomy, and the bladder halves are approximated.
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Media file 21:  Closure of the bladder exstrophy.
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Media file 22:  Baby with bladder exstrophy and epispadias; note the appearance of the bladder mucosa, indicating chronic inflammation.
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Media file 23:  Another view demonstrating the epispadias shown in Image 23.
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Media file 24:  Baby with isolated epispadias.
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Media file 25:  An operative photo from the repair of a draining umbilicus.
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Media file 26:  Closure of a giant omphalocele with an Alloderm patch.
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Media file 27:  Two months after implantation: epithelialization of the Alloderm patch
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Media file 28:  Eight months after implantation: epithelization is nearly complete, but a huge ventral hernia has developed.
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Media file 29:  Persistent drainage from the umbilicus.
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Media file 30:  Baby with an omphalocele.
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REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• MEDICATION
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

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Article Last Updated: Sep 6, 2007