A randomised controlled trial of amnioexchange for fetal gastroschisis

OBJECTIVE

Morbidity in fetuses affected by gastroschisis is mainly the result of bowel ischaemic and inflammatory processes. Experimental studies on animal models show that clearing amniotic fluid from the digestive secretions by amnioexchange procedures reduces the inflammatory process. We evaluated the benefit of the amnioexchange procedure for fetal gastroschisis in humans.

DESIGN

Prospective, interventional, randomised study.

SETTING

Eight referral centres for fetal medicine.

POPULATION

Pregnant women carrying a fetus with gastroschisis.

METHODS

We compared, in utero, amnioexchange with a sham procedure. The protocol included, in both arms, steroid injections at 30 weeks of gestation and the use of postnatal minimal enteral feeding.

MAIN OUTCOME MEASURES

The primary outcome was a composite variable based on the duration of ventilation and parenteral nutrition. Secondary outcomes were the effectiveness and safety of the amnioexchange procedure, including the rate of perinatal death, time to full enteral feeding, primary closure, and late feeding disorders.

RESULTS

Sixty-four patients were randomised. There was no difference in the composite criteria between the amnioexchange and control groups. Based on an intention-to-treat analysis, there were no significant between-group differences in pregnancy outcome or complications. When studying the relationship between digestive compounds and amniotic fluid inflammatory markers, a clear correlation was found between bile acid and both ferritin and interleukin 1β (IL1β).

CONCLUSIONS

In humans, amnioexchange, as described in our protocol, is not an option for fetal care; however, we provide supplementary proof of the involvement of inflammation in the pathogenicity of gastroschisis and suggest that future research should aim at reducing inflammation. ClinicalTrials.gov: NCT00127946.

TWEETABLE ABSTRACT

A prospective, interventional, randomised study shows no benefit of amnioexchange for fetal gastroschisis in humans.

Gastroschisis: an update

Gastroschisis (GS) continues to increase in frequency, with several studies now reported an incidence of between 4 and 5 per 10,000 live births. The main risk factor would seem to be young maternal age, and it is in this group that the greatest increase has occurred. Whilst various geographical regions confer a higher risk, the impact of several other putative risk factors, including smoking and illicit drug use, may be less important than when first identified in early epidemiological studies. Over 90% of cases of GS will now be diagnosed on antenatal ultrasound, but its value in determining the need for early delivery remains unclear. There would appear no clear evidence for either routine early delivery or elective caesarean section for infants with antenatally diagnosed GS. Delivery at a centre with paediatric surgical facilities reduces the risk of subsequent morbidity and should represent the standard of care. The relative roles of primary closure, staged closure and ward reduction, with or without general anaesthesia, appear less clear with considerable variation between centres in both the use of these techniques and subsequent surgical outcomes. Survival rates continue to improve, with rates well in excess of 90% now routine. The limited long-term developmental data available would suggest that normal or near-normal outcomes may be expected although there remains a need for further studies.

No free ride? The hidden costs of delayed operative management using a spring-loaded silo for gastroschisis

PURPOSE

The ideal management of gastroschisis (primary vs staged closure) has not yet been established. Despite the ease of silo placement, anecdotal experience shows that silos do not always offer benefit. The aim of this study was to highlight concerns regarding use of spring loaded silos and compare outcomes to primary closure.

METHODS

Thirty-seven neonates with gastroschisis treated with either primary (n = 10) or staged closure with a spring-loaded silo (n = 27) were reviewed (1998-2007). Variables included ventilator days, daily intravenous fluid, hospital days, and complication rates. SPSS (SPSS Inc, Chicago, Ill) was used to perform t test and chi(2) analyses (significance P < .05).

RESULTS

Survival for primary closure was 100% (10/10) compared to 89% (24/27) for staged closure (P = .548). Patients managed with silos required prolonged ventilation (16.1 +/- 4 days vs 3.6 +/- 1 days; P < or = .05) and greater intravenous fluids on days 3, 4, and 5 of life (132 +/- 25 mL/kg per day vs 104 +/- 18 mL/kg per day; P < or = .01). Although there was no difference in the complication rates between the groups, several problems were evident in the silo group: 15% (4/27) required silo replacement, 44% (12/27) required fascial defect enlargement for silo placement, and 19% (5/27) required mesh at closure. No significant differences in recovery of intestinal function were observed. Three silo patients developed ischemic complications because of vascular insufficiency at the level of the abdominal wall, leading to significant intestinal loss, ventilator and total parenteral nutrition dependence, and increased hospital stay.

CONCLUSIONS

Patients managed with a silo had longer ventilator requirements and greater fluid needs. This Specific technical complications leading to bowel ischemia were notable in the silo group. The silo should be carefully placed to avoid bowel twisting and the funnel effect. Larger prospective studies should be performed to provide decision-making criteria for the use of a silo vs primary closure.

In utero repair of gastroschisis in the sheep (Ovis aries) model

OBJECTIVE

Gastroschisis is associated with inflammatory changes in the exposed bowel which leads to intestinal dysmotility after postnatal repair. The insult is a combined effect of amniotic fluid exposure and mechanical constriction. We hypothesized that in utero anatomic repair is possible in a sheep model, and that it may halt the inflammatory damage caused by both mechanisms.

METHODS

Gastroschisis was surgically created in mid-gestation (day 75) in 8 sheep fetuses. On gestational day 100, 2 fetuses underwent open fetal gastroschisis repair, where the eviscerated bowel was returned to the peritoneal cavity, and the abdominal wall was primarily closed. All fetuses were harvested at 135 days of gestation.

RESULTS

Six fetuses survived the initial operation, and both fetuses that underwent gastroschisis repair survived to term. At 100 and 135 days of gestation, the eviscerated bowel showed progressive signs of inflammation and peel development. The gross and microscopic inflammatory changes in the gastroschisis bowel at 100 days of gestation were completely resolved at term following in utero repair.

CONCLUSION

In utero anatomic repair of gastroschisis is possible in mid-gestation in the fetal lamb model, and it appears to ameliorate the inflammatory process.