Gastroschisis- Causes, Symptoms, and Treatment

Introduction:

Gastroschisis is a full-thickness abdominal lining defect that is paraumbilical. The bowel is protruded in the uterine cavity. The membrane covering the bowel is absent, resulting in fibrinous inflammatory skin around it. It is rarely a genetically associated disorder. Diagnosis can be made around the 20 th week with an ultrasound showing floating bowel loops in the mother's uterine cavity. The bowel protection is done after birth, an orogastric tube is placed, and the airway is stabilized. The overall survival chances of the cases are more than 90 %.

What Are the Causes of Gastroschisis?

The causes of gastroschisis are not well understood, but several causative factors can be considered. The failure of the formation, growth, and development of the ventral body wall during embryo formation results in protrusion of the bowel in the uterine cavity. The following can be the possible causative factors.

• Consumption of Tobacco: Smoking during pregnancy increases the risk of complications in the development of the body leading to birth defects like gastroschisis.

• Specific Drug Exposures: Prenatal exposure to elements such as nitrosamines can cause many congenital malformations and birth defects in children.

• Decongestants: The use of pseudoephedrine (decongestant) can increase the risk of congenital defects in the fetus.

Which Population Is Affected by Gastroschisis?

It can be seen in higher incidences of young pregnancies, generally less than 20 years. Both male and female infants have an equal chance of exposure. The incidences are increasing worldwide.

What Are the Symptoms of Gastroschisis?

• The most significant clinical finding in newborns with gastroschisis is complete thickness defect (located right to the umbilicus) with protrusion of the bowel.

• The size of the abdominal defect is approximately 4 cm.

• The bowel is not covered with any membrane, often thick.

• The wall thickening and covering are affected by exposure to amniotic fluid.

• There are several in-utero ruptures observed inside the matted bowel.

• Bowel atresias or obstructions can be visualized.

• Other abdominal contents like the stomach, liver, and bladder have the potential to herniate through this defect.

• Improper rotation and hypomotility of the bowel can be seen.

• Due to affected digestion, there can be problems such as slow growth before birth, heart abnormalities, and prematurity.

• Gastroschisis is a concerning finding associated with loss of bowel length, known as vanishing gastroschisis.

How to Diagnose Gastroschisis?

• Ultrasound: Prenatal ultrasound at the 20 th week of gestation helps visualize free-floating bowel loops and defects in the right side of the umbilical cord. The bowel appears thickened and dilated due to over-exposure to amniotic fluid.

• Serum alpha-fetoprotein (AFP) is elevated in mothers with fetuses infected with gastroschisis.

• Infants suffering from gastroschisis may have IUGR (intrauterine growth restriction).

Which Disease Is Similar to Gastroschisis?

Omphalocele:

It is characterized by herniation of internal abdominal organs from the defect of the umbilical ring. The protrusion can be very small with just a few loops out to a larger one with the liver, stomach, and entire intestines herniated. The difference from gastroschisis is the presence of a membranous sac around these organs which is absent in the former.

What Is the Treatment of Gastroschisis?

The treatment of gastroschisis can be planned depending on the stage of diagnosis.

Pregnancy Stage: During pregnancy, if the infant is diagnosed with gastroschisis, then the following measures should be taken. They are,

1. The growth of the infant should be monitored as there is growth restriction in approximately 60 % of cases.

2. Amniotic fluid volume should be recorded every three to four-week intervals starting from 24 weeks.

Oligohydramnios: It is the reduction in the volume of amniotic fluid required for gestational age. This can lead to growth restriction and the risk of cord compression in the fetus.

Polyhydramnios: Excessive volume of amniotic fluid, which can lead to bowel atresia.

Delivery Stage:

1. There is no issue in the vaginal delivery of infants with gastroschisis.

2. The delivery timing is based on gestational age, which includes lung maturity and fetal growth status, bowel appearance, and adequate test results.

3. A group of medical professionals, including the neonatologist, pediatric surgeon, and medicine specialist, are present to monitor the delivery.

4. The average delivery time of infants suffering from gastroschisis is around the 36 th week. The professionals allow a trial of vaginal delivery. A cesarean section is considered only when there is liver herniation.

Neonatal Stage: A few basic phenomenons are observed in the infants just after the delivery.

1. Loss of evaporative fluid through the exposed bowel, 2.5 times more than the healthy infant.

2. There is complete body edema and an increased chance of abdominal compartment syndrome.

3. The initial maintenance and measures to protect the infant include:

• The exposed bowel is protected by placing the lower half of the infant's body in a bowel bag. This also helps to visualize the blood flow and perfusion of the bowel.
• An orogastric tube should be inserted, which decompresses the stomach.
• Antibiotics and essential fluids are provided intravenously.
• Maintenance of airway passage.

Surgical Management: The primary factor for gastroschisis repair is the rearrangement of exposed bowel and new organs inside the abdominal cavity with minimal intestinal injury and maintaining intra-abdominal pressure. There can be two treatment options for gastroschisis, which involve bowel reduction back in the abdominal cavity. They are,

• Primary Closure - It is a sutureless technique to repair gastroschisis. The bowel is reduced back in the abdominal cavity with less antibiotic use, minimum surgical or deep space infections, minimal general anesthesia intake, and decreased ventilator time.

• Delayed Closure - It is a technique utilizing a temporary silo and performing serial reduction of the bowel. This procedure involves sutures. The duration of stay of bowel length outside the cavity and repair time is less than primary closure.

How to Monitor the Treatment of Gastroschisis?

• The bowel should be inspected during reduction to look for obstructing bands, perforation, and atresia.

• The mesentery can be compromised depending on the pressure of the silo, so the perfusion of the bowel should be monitored frequently.

• The abdominal pressure should be regulated as pressure above 20 mm Hg is associated with organ dysfunction and complications.

What Is the Prognosis of Gastroschisis?

Prognosis is the chance of survival, an adaptation of treatment by the body, and the long-term outcome of the disorder.

The survival rate of gastroschisis is much more than other abdominal wall defects. Depending upon the absence or presence of complications such as stenosis, perforations, atresia, and necrosis, gastroschisis can be categorized as "simple" and "complex." Out of the total diagnosed cases, 75 % are simple, and 25 % are complex cases.

Conclusion:

Gastroschisis is a birth defect with no specific known cause. The bowel of the fetus is protruded in the uterine cavity with no membranous covering. The symptoms are observed after the birth, which can be cured if diagnosed on time around the 20 th week of gestation. Proper treatment at every stage of the fetus, from pregnancy to neonatal, reduces the complications, and placement of the bowel back in the abdominal cavity is possible.