Gastroschisis

Abstract

The term gastroschisis (“belly cleft”) was coined in 1894 by Italian pathologist Cesare Taruffi, who used it in “Storia della Teratologia” to define a variety of congenital malformations in which the abdomen remains open at birth, though the condition had been reported sporadically since 1557. In 1887, William P. Hogue of West Virginia reported the first successful repair by reduction of the viscera and application of plaster strips. The child survived and appeared to have spontaneous closure of the defect by 5 weeks of age. This case provides the first evidence of the hardiness of the infant with gastroschisis, an observation that has been reinforced in the medical literature ever since.

Appendices

Summary Points

Most cases of gastroschisis are suspected by abnormal maternal serology and reliably diagnosed by fetal ultrasound.

The identifying sonographic features of gastroschisis are the findings of multiple loops of bowel floating freely in the amniotic fluid without a membranous covering of the bowel.

The associated anomaly rate for gastroschisis ranges from 10 to 15%.

Term vaginal delivery is preferred for most patients as neither planned early delivery nor Cesarean section has been shown to improve outcomes of fetuses with gastroschisis.

The initial focus for the pediatric surgeon called to participate in the delivery of the gastroschisis newborn is the resuscitation and optimal handling of the exposed viscera.

Silo-assisted staged reduction is associated with fewer complications than early primary repair and should be employed in most cases of gastroschisis.

Post-operatively, the surgeon must remain sensitive to the potential disasters that can result from high intra-abdominal pressures.

Average time to full feedings is about 3 weeks.

Line sepsis can occur in up to 1/3 of patients and necrotizing enterocolitis in up to 10%.

Editor’s Comment

Over the past 10 years or so, three major advances have greatly improved the care of infants with gastroschisis: (1) the defect is now almost always detected antenatally, which allows for appropriate obstetrical and parental preparation; (2) the routine use of the preformed, spring-loaded silo has transformed the care of these infants from an obligatory emergency operation (nearly always in the middle of the night!) to a more relaxed, albeit still urgent, and straightforward bedside procedure; and (3) PICC lines have for the most part supplanted tunneled central venous catheters, which were associated with significantly more infectious and mechanical complications in these newborns who need intermediate- and long-term parenteral nutrition. I am confident that prospective studies will continue to show significant improvement in outcomes.

Infants with gastroschisis have a great deal of “third-space” and insensible fluid losses and therefore require large amounts of intravenous fluids, sometimes up to 80 mL/kg in the first 24 h. Unless tissue perfusion and urine output are monitored closely, there can be serious consequences if adequate replacement for fluid losses is not provided.

Silo placement requires experience, patience, and careful technique to avoid bleeding and bowel injury. If the defect is too small, the fascia (and sometimes skin) should be opened inferiorly in the midline. Fibrous bridges should be carefully lysed with electrocautery or ligated to avoid the bleeding that can result from traumatic disruption when the silo is being placed. At the time of fascial closure, it is important to avoid excessive intra-abdominal pressure and the risk of abdominal compartment syndrome. If it is too tight, it is best to apply a temporary dressing or another silo and delay the repair for a few days. Alternatively, a patch of artificial material can be used at the level of the fascia, but these almost invariably become infected and eventually need to be removed. The best intra-operative sign of excessive pressure is the peak inspiratory pressure needed to maintain adequate minute ventilation: a PIP of 25 or more is too high.

After reduction and fascial repair, return of bowel function can be very prolonged. It has always been assumed that this is due to the obvious injury sustained by the intestine, presumably caused by exposure to amniotic fluid, even though there is no correlation between the apparent degree of injury (induration, foreshortening, exudative peel) and the severity or duration of the bowel dysfunction. An alternative hypothesis posits that the bowel dysmotility is the primary lesion and is therefore the cause of the defect rather than the result (perhaps intestine that is poorly motile in early gestation cannot easily return to the abdominal cavity). Regardless, most infants with gastroschisis eventually respond to slowly advance feeds as tolerated until able to wean from parenteral nutrition, which can take many weeks or, in some cases, months. Infants with gastroschisis who do not tolerate full feeds by 4–6 weeks after fascial closure need to be evaluated for stricture. Contrast enema or upper GI contrast study might reveal a change in caliber of intestine due to an obstruction, but even in the absence of an obvious stricture on an imaging study, one should have a low threshold for empiric laparotomy, lysis of adhesions, and tapering or resection of dilated segments of bowel. Finally, retaining the umbilical stump almost always results in a better cosmetic result than a neo-umbilicus created with a purse-string suture or flap umbilicoplasty. On the other hand, it is never advisable to leave the child with no belly button as this causes anguish for children and their parents and has resulted in lawsuits.

Differential Diagnosis

• Omphalocele

• Gastroschisis

• Complicated gastroschisis

Diagnostic Studies

• Maternal serum alpha-fetoprotein level

• Level II prenatal ultrasound

Parental Preparation

• Prenatal counseling regarding challenges associated with bowel compromise and the possibility of associated anomalies is essential.

• Counseling should introduce options for treatment including early primary closure vs. staged silo-assisted reduction and repair.

• Discuss risks for short-term (bowel ischemia, necrotizing enterocolitis and line sepsis) and long-term complications (gastroesophageal reflux, gut dysmotility, adhesive small bowel obstruction and short bowel syndrome).

Preoperative Preparation

• Orogastric decompression.

• Fluid resuscitation and correction of hypothermia.

• Arterial catheter for intra-operative monitoring.

• Central venous catheter for post-operative nutrition.

• Anal dilatation and evacuation of meconium prior to repair.

Technical Points

The spring-loaded silo should be selected for the smallest diameter that comfortably accommodates the herniated bowel contents.

Once the silo has been positioned, it can be stretched above the infant by tension on the suspension hole at the top of the bag.

Three to five days of serial reduction are needed prior to silo removal and operative repair.

The goal of initial 24–48 h of silo suspension should be to minimize trauma to the bowel and allow natural reduction in edema.

Beginning on the second or third day, the bowel may be manually reduced toward the peritoneal cavity with the silo in place.

The reduction is maintained with an encircling umbilical tape applied around the silo above the level of the partially-reduced bowel.

After the bowel is reduced below the level of the umbilical ring, plans may be made for closure.

Once the bowel is replaced within the peritoneal cavity a limited effort to stretch the abdominal wall is usually helpful.

The fascia may be approximated by either a transverse or longitudinal closure using interrupted simple or Smead-Jones knots of long-term absorbable mono-filament suture.

The umbilical skin is drawn around the cord remnant using a monofilament purse-string suture.