Prenatal management of gastroschisis: the place of the amnioexchange procedure

Long-term gastrointestinal morbidity in patients born with gastroschisis: A national register-based cohort study

OBJECTIVES

In gastroschisis, the intestines are exposed to amniotic fluid during pregnancy. The defect in the abdominal wall may also compress the mesentery and impair the intestinal blood supply. There is a varying degree of intestinal damage at birth. Complex gastroschisis is defined as gastroschisis with severe complications such as intestinal atresia, volvulus, necrosis and perforation. The aim of this study was to investigate long-term gastrointestinal morbidity and compare simple and complex cases.

METHODS

A nation-wide retrospective cohort study with data from national registers was conducted. All children born with gastroschisis in Sweden from 1 January 1997 to 31 December 2016 were included in the study. Exposure was complex gastroschisis and the primary outcomes were intestinal failure and bowel obstruction.

RESULTS

The study included 315 cases with gastroschisis, 260 classifieds as simple gastroschisis and 55 as complex. The median time to follow was 8 years. A significantly higher risk of developing intestinal failure (hazard ratio: 11.7) was found in complex cases. Nine percent of the complex cases underwent autologous gastrointestinal reconstructive surgery for intestinal failure, none of the simple cases did. The complex cases had a higher risk for bowel obstruction (hazard ratio: 4.3) with a higher proportion requiring surgery (18.2% vs. 6.9%) compared to simple cases.

CONCLUSIONS

This nationwide study showed that the risk for intestinal failure and bowel obstruction is significantly higher for children with complex gastroschisis compared to simple gastroschisis. Most of the events occurred during the first 2 years of life.

Fetal Surgery for Gastroschisis—A Review with Emphasis on Minimally Invasive Procedures

(1) Background: The morbidity of gastroschisis is defined by exposure of unprotected intestines to the amniotic fluid leading to inflammatory damage and consecutive intestinal dysmotility, the viscero-abdominal disproportion which results in an abdomen too small to incorporate the herniated and often swollen intestine, and by associated pathologies, such as in complex gastroschisis. To prevent intestinal damage and to provide for growth of the abdominal cavity, fetal interventions such as amnio exchange, gastroschisis repair or covering have been evaluated in several animal models and human trials. This review aims to evaluate the reported techniques for the fetal treatment of gastroschisis by focusing on minimally invasive procedures. (2) Methods: We conducted a systematic database search, quality assessment and analyzed relevant articles which evaluate or describe surgical techniques for the prenatal surgical management of gastroschisis in animal models or human application. (3) Results: Of 96 identified reports, 42 eligible studies were included. Fetal interventions for gastroschisis in humans are only reported for EXIT procedures and amnio exchange. In animal models, particularly in the fetal sheep model, several techniques of open or minimally invasive repair of gastroschisis or covering the intestine have been described, with fetoscopic covering being the most encouraging. (4) Discussion: Although some promising minimally invasive techniques have been demonstrated in human application and animal models, most of them are still associated with relevant fetal morbidity and mortality and barely appear to be currently applicable in humans. Further research on specific procedures, instruments and materials is needed before any human application.

Abdominal wall defects

Abdominal wall defects are common congenital anomalies with the most frequent being gastroschisis and omphalocele. Though both are the result of errors during embryologic development of the fetal abdominal wall, gastroschisis and omphalocele represent unique disorders that have different clinical sequelae. Gastroschisis is generally a solitary anomaly with postnatal outcomes related to the underlying integrity of the prolapsed bowel. In contrast, omphalocele is frequently associated with other structural anomalies or genetic syndromes that contribute more to postnatal outcomes than the omphalocele defect itself. Despite their embryological differences, both gastroschisis and omphalocele represent anomalies of fetal development that benefit from multidisciplinary and translational approaches to care, both pre- and postnatally. While definitive management of abdominal wall defects currently remains in the postnatal realm, advancements in prenatal diagnostics and therapies may one day change that. This review focuses on recent advancements, novel techniques, and current controversies related to the prenatal diagnosis and management of gastroschisis and omphalocele.

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.

Insights into the etiology and embryology of gastroschisis

The development of gastroschisis has long remained an area of interest and controversy. Successive theories about its pathogenesis are herein reviewed and discussed. Two historical assumptions, that omphalocele results from a persistent umbilical hernia, and that gastroschisis does not involve the umbilical cord, are dismissed. Therefore, one can envision gastroschisis for what it is, i.e. a ruptured physiological hernia. The causal agents for this intrauterine accident to occur are yet to be determined. Further bowel damage and complications can be explained by the mesenteric insult.

Gastroschisis: A Review of Management and Outcomes

We performed an evidence-based review of the obstetrical management of gastroschisis. Gastroschisis is an abdominal wall defect, which has increased in frequency in recent decades. There is variation of prevalence by ethnicity and several known maternal risk factors. Herniated intestinal loops lacking a covering membrane can be identified with prenatal ultrasonography, and maternal serum α-fetoprotein level is commonly elevated. Because of the increased risk for growth restriction, amniotic fluid abnormalities, and fetal demise, antenatal testing is generally recommended. While many studies have aimed to identify antenatal predictors of neonatal outcome, accurate prognosis remains challenging. Delivery by 37 weeks appears reasonable, with cesarean delivery reserved for obstetric indications. Postnatal surgical management includes primary surgical closure, staged reduction with silo, or sutureless umbilical closure. Overall prognosis is good with low long-term morbidity in the majority of cases, but approximately 15% of cases are very complex with complicated hospital course, extensive intestinal loss, and early childhood death.

Diagnosis of abdominal wall defects in the first trimester

PURPOSE OF REVIEW

To review prognostic parameters reported recently in the evaluation of abdominal wall defects in the first trimester.

RECENT FINDINGS

Evaluation of abdominal wall defects in the first trimester is based principally on associated structural or chromosomal anomalies. In the case of gastroschisis, which is rarely associated with other anomalies, evaluation of prenatal or postnatal outcome is based mainly on the course of pregnancy. In the case of isolated omphalocele in the first trimester, recent studies have evaluated parameters that could help predict prenatal or postnatal outcome.

SUMMARY

We review recent studies using new parameters to diagnose abdominal wall defects in the first trimester and to provide early prenatal counselling to parents regarding prenatal and postnatal prognosis.

Abdominal wall defects: prenatal diagnosis, newborn management, and long-term outcomes

Omphalocele and gastroschisis represent the most frequent congenital abdominal wall defects a pediatric surgeon is called to treat. There has been an increased reported incidence in the past 10 years mainly due to the diffuse use of prenatal ultrasound. The early detection of these malformations, and related associated anomalies, allows a multidisciplinary counseling and planning of delivery in a center equipped with high-risk pregnancy assistance, pediatric surgery, and neonatology. At present times, closure of defects, even in multiple stages, is always possible as well as management of most of cardiac-, urinary-, and gastrointestinal-associated malformations. The progress, herein discussed, in the care of newborns with abdominal wall defects assures most of them survive and reach adulthood. Some aspects of transition of medical care will also be considered, including fertility and cosmesis.

Fetal abdominal wall defects

The most common fetal abdominal wall defects are gastroschisis and omphalocele, both with a prevalence of about three in 10,000 births. Prenatal ultrasound has a high sensitivity for these abnormalities already at the time of the first-trimester nuchal scan. Major unrelated defects are associated with gastroschisis in about 10% of cases, whereas omphalocele is associated with chromosomal or genetic abnormalities in a much higher proportion of cases. Challenges in management of gastroschisis are related to the prevention of late intrauterine death, and the prediction and treatment of complex forms. With omphalocele, the main difficulty is the exclusion of associated conditions, not all diagnosed prenatally. An outline of the postnatal treatment of abdominal wall defects is given. Other rarer forms of abdominal wall defects are pentalogy of Cantrell, omphalocele, bladder exstrophy, imperforate anus, spina bifida complex, prune-belly syndrome, body stalk anomaly, and bladder and cloacal exstrophy; they deserve multidisciplinary counselling and management.

Breastfeeding success in infants with giant omphalocele

Infants born with a giant omphalocele often require multiple surgeries requiring a lengthy hospital stay. These vulnerable infants may experience a long period of being NPO (nothing by mouth), followed by slowly advancing to enteral feeds. Human milk is the ideal method of nutrition for all infants and should be used to initiate enteral feeds in infants recovering from omphalocele closure surgeries. Human milk provides immunological, nutritional, and developmental benefits for high-risk infants and may play a critical role in preventing associated morbidities often associated with infants born with giant omphalocele. Because of the stress of hospitalization, mother-infant dyads should be targeted to receive extensive lactation support, which can help ensure maintenance of milk supply and successful transition to breastfeeding once the infant is healthy enough to do so. Two case studies are presented as exemplars, demonstrating that the provision of human milk for even the most vulnerable infants can be achieved.

Advances in surgery for abdominal wall defects: gastroschisis and omphalocele

Abdominal wall defects (AWDs) are a common congenital surgical problem in fetuses and neonates. The incidence of these defects has steadily increased over the past few decades due to rising numbers of gastroschisis. Most of these anomalies are diagnosed prenatally and then managed at a center with available pediatric surgical, neonatology, and high-risk obstetric support. Omphaloceles and gastroschisis are distinct anomalies that have different management and outcomes. There have been a number of recent advances in the care of patients with AWDs, both in the fetus and the newborn, which will be discussed in this article.

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.

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.

[Prenatal care and postnatal outcome for fetuses with laparoschisis]

OBJECTIVES

To assess the relevance and the quality of gastroschisis's care in a mid level referral centre.

METHOD

A retrospective analysis was performed for infants diagnosed or born with gastroschisis between 1992 and 2003 at the Citadelle hospital, Department of Obstetrics and Gynaecology, University of Liège.

RESULTS

Twenty-four cases of gastroschisis were identified. For 22 of them (92%) antenatal sonographic diagnosis was performed at a mean gestational age of 23 weeks. Antenatal diagnosis did not allow to identify additional malformation or chromosomal anomaly. Postnatal diagnosis allows to identify 3 infants with minor cardiac anomalies without functional consequence and one X fragile syndrome. One pregnancy was electively terminated at 24 weeks and one late intrauterine death was reported at 35 weeks. Bowel atresia, stenosis or ischemia were present at birth for 8 cases (33%). Out of 24 cases 22 were live born. 10 infants out of 22 (45%) underwent uncomplicated primary surgical repair. Three infants out of 22 (14%) underwent delayed closure without complications. Nine infants out 22 (41%) underwent multiple surgery (2 to 6). In this group all had postnatal complications, some with multisystem complications, including 3 deaths, 6 with infectious complications, 5 with gastrointestinal complications and 2 with genitourinary or haematological complications. Hospital stay range from 19 to 378 days (median, 51 days). Length of stay and time to full enteral feeding were longer if oligohydramnios or sonographic signs of intestinal damage were found. Among infants born before 35 weeks, only those with intestinal damage at birth had length of stay or time to full enteral feeding longer. Out of 22 live born infants 19 survived (86%) after one year. Survival rate without handicap due to gastroschisis is 84%.

CONCLUSION

Sonographic examination is a valid method for prenatal diagnosis and surveillance. Our survival rate agrees with recent data in the literature. It has to be noticed that hospital stay is lengthy and complications are frequent. The most important prognostic factor is the condition of the bowel at birth and there is no antenatal means to predict severe damage.

Amnioexchange for fetuses with gastroschisis: is it effective?

BACKGROUND/PURPOSE

Amniotic fluid of fetuses with gastroschisis (GS) contains inflammatory mediators, gastrointestinal, and urinary waste products. Dilution and removal of such harmful substances have been advocated to prevent damage to the herniated intestine. We evaluated the effectiveness of serial amnioexchange procedures in 8 consecutive fetuses with GS.

METHODS

Amnioexchange was performed bimonthly during the third trimester. Amniotic fluid collected before each procedure was tested for pH, osmolarity, urea, creatinine, cystatin-C, proteins, albumin, bilirubin, biliary salts, pancreatic amylase, serum amyloid A, C-reactive protein, alanine transaminase (ALT), alcaline phosphatase (ALP), gamma-glutamyl transpetidase (gammaGT), tumor necrosis factor alpha, interleukin 2, interleukin 6, epidermal growth factor, transforming growth factor beta, and myeloperoxidase.

RESULTS

A total of 25 samples (median, 3 per fetus) were examined. Biochemical or inflammatory markers did not correlate with gestational age, nor was any trend observed in values from individual patients during the course of amnioexchange treatment. There was no correlation between biochemical or inflammatory markers and clinical outcome, including time to full enteral feeding.

CONCLUSIONS

Serial amnioexchanges did not modify the biochemical or inflammatory status of amniotic fluid nor appeared to prevent injury to the herniated gut. Because repeated amnioexchanges may carry some risks, their use in fetuses with GS is not recommended outside the setting of a prospective randomized trial.

What is the evidence on the practice of mucous fistula refeeding in neonates with short bowel syndrome?

A systematic review of literature was performed on the practice of mucous fistula refeeding in neonates with short bowel syndrome. No randomised controlled studies were identified. Case series reports of 30 infants showed improved weight gain (from -2.36 +/- 1.24 to 21.06 +/- 3.02 g/d) and reduced need for total parenteral nutrition. Randomised controlled trials are required to establish the benefits of mucous fistula refeeding in this condition.

Can levels of interleukins and matrix metalloproteinases in the amniotic fluid predict postnatal bowel function in fetuses with gastroschisis?

PURPOSE

The aim of this study was to determine whether interleukin or matrix metalloproteinase (MMP) levels in the amniotic fluid can predict the postnatal condition of the bowel in fetuses with gastroschisis (GS).

METHODS

Eleven pregnant women with a fetus with GS underwent amniocentesis. Levels of IL-1alpha, IL-1beta, and IL-6 were measured in 10 of 11 specimens, and MMP-1, MMP-3, and MMP-8 levels were measured in 7 of 11 specimens. Neonates who tolerated complete oral feeding within 21 days were considered to have good bowel status (GS/good: n = 4, 4 in interleukin study or 3 in MMP study); those who did not were considered to have poor bowel status (GS/poor: n =7, 6 in interleukin study or 4 in MMP study). Seventy-eight women undergoing amniocentesis for other reasons served as controls.

RESULTS

Interleukin-1 levels were considerably lower in the pregnancies complicated by GS than in controls. Matrix metalloproteinases 3 and 8 levels were significantly higher in the GS pregnancies than in controls. Neonates with poor bowel status had higher MMP-3 and MMP-8 levels than those with good bowel status.

CONCLUSION

Amniotic fluid MMP-3 and MMP-8 levels may prove useful to assess the condition of the bowel in fetuses with GS.

Amniotic fluid: not just fetal urine anymore

Amniotic fluid (AF) is a complex substance essential to fetal well-being. This article reviews recent discoveries and the current understanding of the origin and circulation of AF and its nutritive, protective, and diagnostic functions. Future directions for AF research are also discussed.

Finally, a sense of closure? Animal models of human ventral body wall defects

Malformations concerning the ventral body wall constitute one of the leading categories of human birth defects and are present in about one out of every 2000 live births. Although the occurrence of these defects is relatively common, few detailed experimental studies exist on the development and closure of the ventral body wall in mouse and human. This field is further complicated by the array of theories on the pathogenesis of body wall defects and the likelihood that there is no single cause for these abnormalities. In this review, we summarize what is known concerning the mechanisms of normal ventral body wall closure in humans and mice. We then outline the theories that have been proposed concerning human body wall closure abnormalities and examine the growing number of mouse mutations that impact normal ventral body wall closure. Finally, we speculate how studies in animal models such as mouse and Drosophila are beginning to provide a much-needed mechanistic framework with which to identify and characterize the genes and tissues required for this vital aspect of human embryogenesis.