Intestinal damage in gastroschisis correlates with the concentration of intraamniotic meconium

Anatomy and embryology of abdominal wall defects

Abdominal wall defects are one of the most frequently encountered human congenital anomalies. They are seen in as many as 1 in 2,000 live births with evidence to suggest that their incidence is increasing. While often discussed together abdominal wall defects consist mainly of two entities namely gastroschisis and omphalocele. There are marked differences in their theories of embryo-pathogenesis, clinical presentation/anatomy and overall outcomes. There is no clear consensus explaining the precise embryological mechanisms leading to the development of abdominal wall defects. Many clinicians and embryologists have attempted to explain the genesis of congenital abdominal wall defects because of failure of progression of various phases of normal embryonic development. This review summarizes the mechanisms involved in normal and abnormal development of the ventral abdominal wall leading to the development of gastroschisis and omphalocele.

Prenatal Prediction of Outcome by Fetal Gastroschisis in a Tertiary Referral Center

The aim of this study was to find a prenatal parameter to be able to predict possible prenatal complications or postnatal surgical options, thus allowing the fetal medicine specialist, together with pediatric surgeons and neonatologists, to improve the counseling of the parents and to determine the timing of delivery and therapy. This was a retrospective analysis of prenatal diagnosis and outcome of fetuses with 34 cases of gastroschisis between the years 2007 and 2017. A total of 34 fetuses with gastroschisis were examined and 33 outcomes registered: 22 cases of simple gastroschisis (66.7%) and 11 cases of complex gastroschisis (33.3%). A cut-off value of 18 mm for intraabdominal bowel dilatation (IABD) showed a positive predictive value (PPV) of 100% for predicting simple gastroschisis. IABD gives the best prediction for simple versus complex gastroschisis (cut-off of 18 mm). Extra-abdominal bowel dilatation (EABD) cut-off values of 10 mm and 18 mm showed low sensitivity and specificity to predict complex gastroschisis.

Elective delivery at 34 weeks vs routine obstetric care in fetal gastroschisis: randomized controlled trial

OBJECTIVE

To evaluate whether elective preterm delivery (ED) at 34 weeks is of postnatal benefit to infants with isolated gastroschisis compared with routine obstetric care (RC).

METHODS

Between May 2013 and September 2015, all women with a sonographic diagnosis of fetal gastroschisis referred to a single tertiary center, before 34 weeks' gestation, were invited to participate in this study. Eligible patients were randomized to ED (induction of labor at 34 weeks) or RC (spontaneous labor or delivery by 37-38 weeks, based on standard obstetric indications). The primary outcome measure was length of time on total parenteral nutrition (TPN). Secondary outcomes were time to closure of gastroschisis and length of stay in hospital. Outcome variables were compared using appropriate statistical methods. Analysis was based on intention-to-treat.

RESULTS

Twenty-five women were assessed for eligibility, of whom 21 (84%; 95% CI, 63.9-95.5%) agreed to participate in the study; of these, 10 were randomized to ED and 11 to RC. The trial was stopped at the first planned interim analysis due to patient safety concerns and for futility; thus, only 21 of the expected 86 patients (24.4%; 95% CI, 15.8-34.9%) were enrolled. Median gestational age at delivery was 34.3 (range, 34-36) weeks in the ED group and 36.7 (range, 27-38) weeks in the RC group. One patient in the ED group delivered at 36 weeks following unsuccessful induction at 34 weeks. Neonates of women who underwent ED, compared to those in the RC group, showed no difference in the median number of days on TPN (54 (range, 17-248) vs 21 (range, 9-465) days; P = 0.08), number of days to closure of gastroschisis (7 (range, 0-15) vs 5 (range, 0-8) days; P = 0.28) and length of stay in hospital (70.5 (range, 22-137) vs 31 (range, 19-186) days; P = 0.15). However, neonates in the ED group were significantly more likely to experience late-onset sepsis compared with those in the RC group (40% (95% CI, 12.2-73.8%) vs 0%; P = 0.03).

CONCLUSION

This study demonstrates no benefit of ED of fetuses with gastroschisis when postnatal gastroschisis management is similar to that used in routine care. Rather, the data suggest that ED is detrimental to infants with gastroschisis. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The association between gestational age at delivery, closure type and perinatal outcomes in neonates with isolated gastroschisis

Objective: The objective of this study was to examine the association between gestational age at delivery and closure type for neonates with gastroschisis. In addition, we compared perinatal outcomes among the cases of gastroschisis based on the following two factors: gestational age at delivery and abdominal wall closure technique.Methods: This was a retrospective cohort study of all fetuses with isolated gastroschisis that were diagnosed prenatally and delivered between September 2000 and January 2017, in a single tertiary care center. Neonates were compared based on the gestational age at the time of delivery: early preterm (less than 35^0/7 weeks), late preterm (35^0/7 - 36^6/7 weeks), and early term (37^0/6 - 38^6/7 weeks), using bivariate and multivariate analyses. The primary outcome was the type of abdominal wall closure: primary surgical closure or delayed closure using spring-loaded silo. Secondary outcomes included length of ventilatory support, length of parenteral nutrition, and length of hospital stay.Results: The analysis included 206 pregnancies complicated by gastroschisis. In univariate analysis, no differences were detected in primary closure rates of gastroschisis among the gestational age at delivery groups (67.4%, at <35 weeks, 70.8% at 35^0/7-36^6/7 weeks, 73.7% at 37^0/6-38^6/7 weeks, p = .865). However, for every additional 100 grams of neonatal live birth weight there was an associated 9% increased odds of primary closure (OR 1.09, 95% CI 1.14-1.19, p = .04). Delivery in the early preterm period compared to the other two groups, was associated with longer duration of ventilation support and longer dependence on the parenteral nutrition. Neonates who underwent primary closure had shorter ventilation support, shorter time to initiation of enteral feeds and to discontinue parenteral nutrition, and shorter length of stay. In multivariate analyses, controlling for gestational age at delivery and presence of bowel atresia, primary closure continued to be associated with the shorter duration of ventilation (by 5 days), earlier initiation of enteral feeds (by 7 days), shorter hospital stay (by 17 days) and lower odds of wound infection (OR = 0.37, 95% CI 0.15-0.97).Conclusions: Our study did not find an association between gestational age at delivery and the rates of primary closure of the abdominal wall defect; however later gestational age at delivery was associated with shorter duration of ventilatory support and parenteral nutrition dependence. In addition, we found that primary closure of gastroschisis, compared with delayed closure technique, was associated with improved neonatal outcomes, including shorter time to initiate enteral feeds and discontinue parenteral nutrition, shorter hospital stay, and lower risk of surgical wound infection. Therefore, postponing delivery of fetuses with gastroschisis until 37 weeks may be considered. Other factors besides the gestational age at delivery should be explored as predictors of primary closure in neonates with gastroschisis.

The influence of gestational age, mode of delivery and abdominal wall closure method on the surgical outcome of neonates with uncomplicated gastroschisis

AIM OF THE STUDY

To evaluate if gestational age (GA), mode of delivery and abdominal wall closure method influence outcomes in uncomplicated gastroschisis (GTC).

METHODS

Retrospective review of NICU admissions for gastroschisis, August 2008-July 2016. Primary outcomes were: time to start enteral feeds (on-EF), time to discontinue parenteral nutrition (off-PN), and length of stay (LOS).

MAIN RESULTS

A total of 200 patients with GTC were admitted to our NICU. Patients initially operated elsewhere (n = 13) were excluded. Patients with medical/surgical complications (n = 62) were analyzed separately. The study included 125 cases of uncomplicated GTC. There were no statistically significant differences in the outcomes of patients born late preterm (34 0/7-36 6/7; n = 70) and term (n = 40): on-EF 19 (5-54) versus 17 (7-34) days (p = 0.29), off-PN 32 (12-101) versus 30 (16-52) days (p = 0.46) and LOS 40 (18-137) versus 37 (21-67) days (p = 0.29), respectively. Patients born before 34 weeks GA (n = 15) had significantly longer on-EF, off-PN and LOS times compared to late preterm patients: 26 (12-50) days (p = 0.01), 41 (20-105) days (p = 0.04) and 62 (34-150) days (p < 0.01), respectively. There were no significant differences in outcomes between patients delivered by C-section (n = 62) and patients delivered vaginally (n = 63): on-EF 20 (5-50) versus 19 (7-54) days (p = 0.72), off-PN 32 (12-78) versus 33 (15-105) days (p = 0.83), LOS 42 (18-150) versus 41 (18-139) days (p = 0.68), respectively. There were significant differences in outcomes between patients who underwent primary reduction (n = 37) and patients who had a silo (88): on-EF 15 (5-37) versus 22 (6-54) days (p < 0.01), off-PN 28 (12-52) versus 34 (15-105) days (p = 0.04), LOS 36 (18-72) versus 44 (21-150) days (p = 0.04), respectively.

CONCLUSION

In our experience, late preterm delivery did not affect outcomes compared to term delivery in uncomplicated GTC. Outcomes were also not influenced by the mode of delivery. Patients who underwent primary reduction had better outcomes than patients who underwent silo placement.

Outcomes of gastroschisis early delivery: A systematic review and meta-analysis

BACKGROUND/PURPOSE

Elective preterm delivery (EPD) of a fetus with gastroschisis may prevent demise and ameliorate intestinal injury. While the literature on optimal timing of delivery varies, we hypothesize that a potential benefit may be found with EPD.

METHODS

A meta-analysis of publications describing timing of delivery in gastroschisis from 1/1990 to 8/2016 was performed, including studies where either elective preterm delivery (group 1, G1) or preterm gestational age (GA) (group 2, G2) were evaluated against respective comparators. The following outcomes were analyzed: total parenteral nutrition (TPN), first enteral feeding (FF), length of stay, ventilator days, fetal demise, complex gastroschisis, sepsis, and death.

RESULTS

Eighteen studies describing 1430 gastroschisis patients were identified. G1 studies found less sepsis (p<0.01), fewer days to FF (p=0.03), and 11days less of TPN (p=0.07) in the preterm cohort. Comparatively, G2 studies showed less days to FF in term GA (p=0.02).Whereas G1 BWs were similar, G2 preterm had a significantly lower BW compared to controls (p=0.001).

CONCLUSIONS

Elective preterm delivery appears favorable with respect to feeding and sepsis. However, benefits are lost when age is used as a surrogate of EPD. A randomized, prospective, multi-institutional trial is necessary to delineate whether EPD is advantageous to neonates with gastroschisis.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

The role of water-soluble meconium subfraction and lipid-soluble meconium subfraction on the superior mesenteric artery vasoconstriction in chick embryos

OBJECTIVE

Intraamniotic meconium has been responsible for intestinal damage in gastroschisis and meconium-dependent intestinal ischemia has been proposed to induce additional intestinal damage in gastroschisis. This study is aimed to determine the effects of lipid and water-soluble meconium subfractions on the contractility of the superior mesenteric artery (SMA).

MATERIALS AND METHODS

The study was conducted on 18-day fertilized chick embryos (Gallus Domesticus). Meconium is fractioned into water and lipid-soluble components. Only one SMA tissue was prepared from each embryo and suspended in the organ bath. Isometric contraction responses (ICR) were created in SMA tissues by one hour of incubation in Krebs-Henseleit solution for each group. Groups consisted of control, meconium, water-soluble meconium subfraction and lipid-soluble meconium subfraction. ICR of the SMA specimens were evaluated with a transducer-amplifier system on a computer. The data were expressed (mean±1SD) as milliNewton (mN).

RESULTS

The ICR of the meconium, water-soluble meconium subfraction and lipid-soluble meconium subfraction groups were significantly high when compared to the control group (p<0.01). The meconium and water-soluble meconium subfraction created more contraction response than the lipid-soluble meconium subfraction (p<0.01). The ICR of the meconium group was not different from the ICR of the water-soluble meconium subfraction group (p>0.05).

CONCLUSION

Water-soluble meconium subfraction has a profound vasoconstrictor effect on the SMA compared to the lipid-soluble meconium subfraction.

The intestinal damage induced by lipid soluble meconium subfraction is profound compared to the intestinal damage induced by water soluble meconium subfraction

BACKGROUND

It is unclear which substances in meconium are responsible for intestinal damage in gastroschisis. An experimental study was designed to investigate the effects of the lipid or water soluble subfractions of meconium on the intestines of gastroschisis in a chick model.

METHODS

Meconium was pooled, homogenated, rota-evaporated dry and diluted. Meconium subfractions were obtained from water soluble and lipid soluble extracts of the meconium. Five days old fertilized chick embryos were used and divided into 5 groups: control, sham, water soluble meconium subfraction, lipid soluble meconium subfraction and whole meconium. All embryos were extirpated on the 18days and the intestines were harvested for histopathological examination. Serosal thickness was measured under light microscopy.

RESULTS

Serosal thickness of the meconium (36.36±2.8μm), the water soluble meconium (14.15±0.93μm) and the lipid soluble meconium (23.88±1.69μm) subfractions groups were significantly increased compared with the control (7.47±0.68μm) and the sham (7.48±0.71μm) groups (p<0.001). Serosal thickness of the lipid soluble meconium subfraction group was significantly increased compared with the water soluble meconium subfraction group (p<0.001). Serosal thickness of the meconium group was significantly increased compared to both the water and the lipid soluble meconium subfraction groups (p<0.001).

CONCLUSION

Lipid soluble meconium subfraction induces more intestinal damage compared to water soluble meconium subfraction.

Effect of gestational age at birth on neonatal outcomes in gastroschisis

INTRODUCTION

Induced birth of fetuses with gastroschisis from 34weeks gestational age (GA) has been proposed to reduce bowel damage. We aimed to determine the effect of birth timing on time to full enteral feeds (ENT), length of hospital stay (LOS), and sepsis.

METHODS

A retrospective analysis (2000-2014) of gastroschisis born at ≥34weeks GA was performed. Associations between birth timing and outcomes were analyzed by Mann-Whitney test, Cox regression, and Fisher's exact test.

RESULTS

217 patients were analyzed. Although there was no difference in ENT between those born at 34-36+6weeks GA (median 28 range [6-639] days) compared with ≥37weeks GA (27 [8-349] days) when analyzed by Mann-Whitney test (p=0.5), Cox regression analysis revealed that lower birth GA significantly prolonged ENT (p=0.001). LOS was significantly longer in those born at 34-36+6weeks GA (42 [8-346] days) compared with ≥37weeks GA 34 [11-349] days by both Mann-Whitney (p=0.02) and Cox regression analysis (p<0.0005). Incidence of sepsis was higher in infants born at 34-36+6weeks (32%) vs. infants born at ≥37weeks (17%; p=0.02).

CONCLUSIONS

Early birth of fetuses with gastroschisis was associated with delay in reaching full enteral feeds, prolonged hospitalization, and a higher incidence of sepsis.

Outcomes in infants with prenatally diagnosed gastroschisis and planned preterm delivery

BACKGROUND

The timing and mode of delivery of pregnancies with prenatally diagnosed gastroschisis remains controversial.

AIM

To evaluate the outcome of patients with gastroschisis managed during two time periods: 2006-2009 and 2010-2014, with planned elective cesarean delivery at 37 versus 35 gestational weeks (gw). A secondary aim was to analyze the outcome in relation to the gestational age at birth.

MATERIAL AND METHODS

Retrospective review of all cases with gastroschisis managed at our institution between 2006 and 2014.

RESULTS

Fifty-two patients were identified, 24 during the initial period, and 28 during the second. There were a significantly higher number of emergency cesarean deliveries in the first period. There were no differences between groups with regard to the use of preformed silo, need of parenteral nutrition or length of hospital stay. When analyzing the outcome in relation to the gw the patients actually were born, we observed that patients delivered between 35 and 36.9 gw were primary closed in 88.5% of cases, with shorter time on mechanical ventilation, parenteral nutrition and hospital stay.

CONCLUSION

Planned caesarian section at 35 completed gestational weeks for fetuses with prenatally diagnosed gastroschisis is safe. We observe the best outcome for patients born between 35 and 36.9 gw.

Effect of antepartum meconium staining on perinatal and neonatal outcomes among pregnancies with gastroschisis

OBJECTIVE

To investigate the association between meconium staining and perinatal and neonatal outcomes in pregnancies with gastroschisis.

METHODS

Retrospective analysis of infants with prenatally diagnosed gastroschisis born in two academic medical centers between 2008 and 2013. Neonatal outcomes of deliveries with and without meconium staining were compared. Primary outcome was defined as any of the following: neonatal sepsis, prolonged mechanical ventilation, bowel atresia or death. Secondary outcomes were preterm delivery, preterm-premature rupture of membranes (PPROM) and prolonged hospital length of stay.

RESULTS

One hundred and eight infants with gastroschisis were included of which 56 (52%) had meconium staining at delivery. Infants with meconium staining had a lower gestational age at delivery (36.3 (±1.4) versus 37.0 (±1.2) weeks, p = 0.007), and a higher rate of PPROM (25% versus 8%, p = 0.03) than infants without meconium. Meconium staining was not significantly associated with the primary composite outcome or with any of its components. After adjustments, meconium staining remained significantly associated with preterm delivery at <36 weeks [odds ratio OR = 4.0, 95% confidence intervals (CI): 1.5-11.4] and PPROM (OR = 3.8, 95%CI: 1.2-14.5).

CONCLUSIONS

Among infants with gastroschisis, meconium staining was associated with prematurity and PPROM. No significant increase in other adverse neonatal outcomes was seen among infants with meconium staining, suggesting a limited prognostic value of this finding.

The correlation between the time spent in utero and the severity of bowel matting in newborns with gastroschisis

BACKGROUND

Optimal timing of delivery in fetuses with gastroschisis (GS) is unknown. Some favor early induced delivery to prevent bowel injury. This study evaluates the correlation between bowel injury and the gestational age at birth using the Gastroschisis Prognostic Score (GPS).

METHODS

A national database was analyzed from 2005 to 2013. Patients were pooled based on their gestational age at birth. The mean GPS and % of patients with severe bowel matting were tabulated for each week in utero. Regression modeling was used to evaluate the relationship between the dependent (severe matting and GPS) and independent (gestational age) variables and the R(2) coefficient of determination was derived to evaluate model strength. Additional factors influencing the timing of delivery were evaluated.

RESULTS

Of 780 cases, 88 were excluded because of missing data. A linear relationship is seen between increasing gestational age and decreasing bowel matting (R(2)=0.66) and GPS (R(2)=0.72). For every week in utero, the % of patients with severe matting decreases by 3.6%.

CONCLUSION

Early induced delivery simply to protect the bowel from ongoing in utero damage appears unfounded and should be reserved for evidence of closing gastroschisis or traditional obstetrical/fetal indications.

Is early delivery beneficial in gastroschisis?

PURPOSE

Gastroschisis neonates have delayed time to full enteral feeds (ENT), possibly due to bowel exposure to amniotic fluid. We investigated whether delivery at <37weeks improves neonatal outcomes of gastroschisis and impact of intra/extra-abdominal bowel dilatation (IABD/EABD).

METHODS

A retrospective review of gastroschisis (1992-2012) linked fetal/neonatal data at 2 tertiary referral centers was performed. Primary outcomes were ENT and length of hospital stay (LOS). Data (median [range]) were analyzed using parametric/non-parametric tests, positive/negative predictive values, and regression analysis.

RESULTS

Two hundred forty-six patients were included. Thirty-two were complex (atresia/necrosis/perforation/stenosis). ENT (p<0.0001) and LOS (p<0.0001) were reduced with increasing gestational age. IABD persisted to last scan in 92 patients, 68 (74%) simple (intact/uncompromised bowel), 24 (26%) complex. IABD or EABD diameter in complex patients was not significantly greater than simple gastroschisis. Combined IABD/EABD was present in 22 patients (14 simple, 8 complex). When present at <30weeks, the positive predictive value for complex gastroschisis was 75%. Two patients with necrosis and one atresia had IABD and collapsed extra-abdominal bowel from <30weeks.

CONCLUSION

Early delivery is associated with prolonged ENT/LOS, suggesting elective delivery at <37weeks is not beneficial. Combined IABD/EABD or IABD/collapsed extra-abdominal bowel is suggestive of complex gastroschisis.

To observe the intensity of the inflammatory reaction caused by neonatal urine and meconium on the intestinal wall of rats in order to understand etiology of intestinal damage in gastroschisis

Objectives:

The aim of this experimental study was to observe the intensity of the inflammatory reaction caused by neonatal urine and meconium on the intestinal wall of rats to better understand etiology of intestinal damage in gastroschisis.

Materials and Methods:

A total of 24 adult Wistar rats were used as experimental models to simulate the effect of exposed bowel in cases of gastroschisis. The peritoneal cavity of the rats was injected with substances which constitute human amniotic fluid to study the effect on the bowel. Sterile urine and meconium were obtained from newborn humans. The rats were divided into four groups according to the material to be injected. In Group I (Control group) 3 mL of distilled water was injected, in Group II (Urine group) 3 mL of neonatal urine was injected, in Group III (Meconium group) 5% meconium suspension was injected, while in Group IV, a combination of 5% meconium suspension and urine was injected. A total of 3mL solution was injected into the right inferior quadrant twice a day for 5 days. The animals were sacrificed on the 6^th day by a high dose of thiopentone sodium. A segment of small bowel specimen was excised, fixed in paraffin, and stained with hematoxylin-eosin for microscopic analysis for determination of the degree of inflammatory reaction in the intestinal wall. All pathology specimens were studied by the same pathologist.

Results:

The maximum bowel damage was seen in Group II (Urine group) in the form of serositis, severe enteritis, parietal necrosis, and peeling. A lesser degree of damage was observed in Group III (Meconium group) as mild enteritis (mild lymphoid hyperplasia). The least damage was seen in Group IV (Combination of meconium and urine) and Group I (Control group).

Conclusion:

The intraabdominal injection of neonatal human urine produces significant inflammatory reactions in the intestinal wall of rats.

Intra-amniotic administration of urinary trypsin inhibitor preserves intestinal contractility in meconium induced intestinal damage in chick embryos with gastroschisis

BACKGROUND

Intestinal damage causes intestinal dysmotility in gastroschisis. Urinary trypsin inhibitor (UTI) has been shown to prevent intestinal damage in chick embryos with gastroschisis. The effect of intra-amniotic administration of UTI on intestinal motility in gastroschisis has not been investigated.

METHODS

Five-day-old fertilized chick embryos were used. Gastroschisis was created through the amniotic cavity without opening the allantoic cavity. There were six groups; control, gastroschisis only, gastroschisis plus meconium and three treatment groups. In the treatment groups, 100 IU/mL, 200 IU/mL and 400 IU/mL UTI were instilled into the amniotic cavity of the gastroschisis plus meconium embryos, respectively. Serosal thickness of the intestines in each group was measured histopathologically. The contractions of the intestines were evaluated by in vitro organ bath technique and the responses were expressed as maximal contraction induced by acetylcholine.

RESULTS

The serosal thickness was significantly increased in the gastroschisis plus meconium, 100 IU/mL, 200 IU/mL UTI groups compared to control and gastroschisis only groups. The serosal thickness of the 400 IU/mL UTI group was similar to control and gastroschisis only groups. Contractility of the intestines was diminished in the gastroschisis plus meconium, 100 IU/mL and 200 IU/mL UTI groups. There was no significant difference regarding contractility among control, gastroschisis only and 400 IU/mL UTI groups.

CONCLUSION

Intra-amniotic administration of UTI preserves intestinal contractility in chick embryos with gastroschisis. However, preservation of intestinal dysmotility by using UTI in the human gastroschisis cases needs further experimental and clinical trials.

Meconium staining of the brainstem with open myelomeningocele

Meconium staining of open myelomeningoceles has been reported to occur both prenatally and postnatally, but meconium staining of the brainstem has not been previously documented. The authors present a case of meconium staining of the brainstem in an infant with a meconium-stained myelomeningocele, Chiari malformation Type II, and hydrocephalus and discuss possible implications for prenatal and perinatal care.

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.

In utero meconium passage in fetuses and newborns with myelomeningocele

OBJECT

The authors retrospectively investigated whether midgestational fetal myelomeningocele (fMMC) repair alters intrauterine meconium exposure.

METHODS

Prior to the National Institutes of Health Management of Myelomeningocele Study, 54 fetuses underwent fMMC repair at the authors' institution. Forty-six fMMC sacs were available for pathological examination and 53 MMC sacs from postnatally repaired MMCs (pMMCs) were available for comparison. The presence and distribution of meconium were blindly evaluated using a grading system defined as follows: absent (no meconium present), mild (<10 meconium-positive histiocytes [MPHs]/hpf), moderate (10-25 MPHs/hpf), and severe (>25 MPHs/hpf). Hall's bile stain was used to confirm meconium and Prussian blue and Fontana Masson stains to exclude hemosiderin and melanin, respectively.

RESULTS

Compared to pMMCs (79%), meconium histiocytosis was less prevalent in fMMC sacs (57%; p=0.017). Meconium staining was completely absent in 43% of the fMMC sacs. Mild meconium histiocytosis was found in 35% fMMC and 61% pMMC sacs (p=0.035). There was no statistical difference between groups with moderate and severe meconium histiocytosis.

CONCLUSIONS

Meconium passage in MMCs can occur early in fetal life. Fetal MMC repair may reduce the duration of meconium exposure, thereby potentially limiting the toxic injury to the vulnerable neural elements.

Scheduled preterm delivery for gastroschisis improves postoperative outcome

There are some evidence to suggest that careful antenatal monitoring, scheduled preterm delivery and immediate abdominal wall closure may reduce gastroschisis morbidity. We hypothesised that the advantages of a scheduled preterm delivery balance possible complications related to prematurity. A retrospective study was performed including all cases of gastroschisis born between 1990 and 2004 (n = 69). Cases were categorised in two groups. Group 1 contained gastroschisis cases born between 1990 and 1997. Group 2 contained cases occurring since 1997, when a new management pathway for gastroschisis was established: weekly evaluation of the foetal gut by ultrasound (>28 weeks), corticosteroids, and delivery by scheduled caesarean section at 35 weeks (before if evidence of bowel compromise was present). The primary endpoints of this study were the initiation of oral feeding and the number of re-operation for intestinal obstruction. There was a significantly faster initiation of oral feeding (P < 0.0001), however, duration of parenteral nutrition (34 vs. 38 days) and hospital discharge (53 vs. 58.5 days) was not reduced. There was no complication due to prematurity in group 2. Postoperative outcome was improved with less need for muscular stretching or prosthetic patch and less re-operation for intestinal obstruction (P < 0.05). Scheduled and elective preterm delivery facilitates surgical procedure and shortens the time to first feeding. A delivery at 35 weeks (preferring vaginal delivery) seems to be a good compromise between risks related to prematurity and complications related to intestinal peel.

Amniotic fluid ferritin as a marker of intestinal damage in gastroschisis: a time course experimental study

BACKGROUND/PURPOSE

Intestinal damage (ID) is closely related to morbidity and mortality in gastroschisis. This study was performed to determine the intraamniotic substances that may correlate ID and also to verify their time course levels that would be useful for determining when ID starts in gastroschisis.

METHODS

In this study, 13-day-old fertilized chick eggs were used. The amnioallantoic membrane was perforated to create amnioallantoic cavity in all embryos. Gastroschisis was created in gastroschisis group to simulate human gastroschisis. Amnioallantoic fluid samples were collected from the embryos on the 13th to 19th gestational days, and the intestines of each group were harvested for evaluation. Amnioallantoic levels of interleukin-8, ferritin, alkaline phosphatase, and amylase were measured. Serosal thickness of the intestines in each group was evaluated.

RESULTS

Increasing amnioallantoic fluid levels of interleukin-8, alkaline phosphatase, and amylase were found in both groups. In contrast to control group, ferritin levels, as a sign of inflammation, were found increased only in gastroschisis group. Histopathologic examination of intestines in the gastroschisis group showed a significant increase in the serosal thickness especially after the 16th day.

CONCLUSION

Increases in amnioallantoic fluid levels of ferritin show promise as a marker for determining ID encountered in gastroschisis but warrant further investigation.

[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.

The effect of prenatal treatment with steroids and preterm delivery in a model of myelomeningocele on the rabbit foetus

Damage of neural elements (spinal cord and encephalus) in myelomeningocele (MMC) seems to be progressive during gestation because of amniotic fluid chemical contact and continuous leakage of CSF. We studied the effect of preterm delivery and steroid treatment in a model of MMC in the rabbit foetus. Twelve New Zealand White rabbits underwent laparotomy and hysterotomy at 23 days of gestation. Fifty-nine out of 107 foetuses underwent lumbar laminectomy (three to four levels). Dura was opened to expose the neural elements to the amniotic fluid. Six rabbits underwent caesarean section on gestational day 31 for fetal harvest; three of them had no treatment (group T) and three received corticosteroid treatment (group TC). The other six rabbits underwent caesarean section on gestational day 29 for fetal harvest (preterm delivery); three of them had no treatment (group P) and three received corticosteroid treatment (group PC). Alive newborns were clinically, neurophysiologically and histologically analysed. None of mothers died during the procedure. After birth, animals in group preterm showed statistically significant less deformity than animals in group at term. Lower kyphosis was observed in group PC (preterm and steroids). Pain related and spontaneous mobility of lower extremities was higher in groups treated with corticosteroids (TC and PC). Only newborns at term (T and TC groups) showed response to evoked potentials (CMEPs). The response was earlier and higher in group treated with steroids (TC). Histologically, we observed progressive lesion of the spinal cord. Groups treated with steroids (TC and PC) show less inflammatory response. Arnold-Chiari malformation was present in all groups. Animals in group preterm with steroids show statistically significant less herniation than those group at term. Preterm delivery and prenatal steroid therapy seem to be an effective treatment to get less neural injury (spinal cord and encephalus) in myelomeningocele foetuses.

Biochemical investigations of bowel inflammation in gastroschisis

Neonates with gastroschisis have perivisceritis resulting from contact between the bowel and amniotic fluid. Here, we characterized the mediators involved in this inflammatory process in humans and ewes, to find a reliable marker of this process. We have diagnosed 41 cases of gastroschisis since 1995. Amniotic fluid sampled for karyotyping between 15 and 32 wk of gestation was also used to assay cytokines and inflammatory proteins. The findings were compared with those in 93 age-matched controls. Amniotic fluid cells were analyzed by means of cytology. Histologic examination of the bowel was performed when neonatal appendectomy was performed. The findings were compared with those obtained in a ewe model of gastroschisis. In gastroschisis, amniotic total protein, IL-6, IL-8, and ferritin levels were significantly higher than in controls. Gastroschisis was associated with significantly higher cell counts (mainly mononuclear cells) in amniotic fluid. At birth, macrophages were abundant in the fibrous peel covering the bowel. Similar results were obtained in the ewe model. Gastroschisis may be associated with a subchronic inflammatory process of variable intensity. This inflammation is restricted to the bowel wall and involves inflammatory cells such as macrophages, which may secrete ferritin, neopterin, and calprotectin.

Urinary trypsin inhibitor present in fetal urine prevents intraamniotic meconium-induced intestinal damage in gastroschisis

BACKGROUND/PURPOSE

Contact with amniotic fluid causes intestinal damage in gastroschisis, and intraamniotic meconium has been shown to be responsible. Meconium has been shown to contain a significant amount of IL-8, which may be the responsible cytokine for harmful effects of meconium. Neonatal urine contains high amount of urinary trypsin inhibitor (UTI) compared with adult human urine. Urinary trypsin inhibitor has been shown to exert inhibitory effects on IL-8. Therefore, far from being destructive, presence of fetal urine in the amniotic fluid might be beneficial because human urine contains UTI. An experimental study has been performed to investigate whether presence of intraamniotic human urine (consequently UTI) besides meconium is beneficial on intestines of chick embryo with gastroschisis.

METHODS

Five-day-old fertilized chick eggs were used. Gastroschisis was created through amniotic cavity without opening the allantoic cavity. Sterile urine and meconium were obtained from newborn humans. Study was conducted in 2 stages. In the first stage, gastroschisis was created, and meconium suspensions at minimal harmful meconium concentration were prepared using natural and denatured human neonatal urine and instilled into the amniotic cavity. In the second stage of study, various concentrations of UTI plus meconium suspension at minimal harmful meconium concentration was instilled into the amniotic cavity.

RESULTS

Serosal thickening, inflammation, and focal fibrin deposits were observed in intestines of the groups with meconium and meconium in denatured urine. Histopathologic features of intestines of the group with meconium in natural urine did not differ from the intestines of the control group. Histopathologic examination of intestines of groups with meconium and meconium plus 50 U/mL UTI showed serosal thickening, inflammation, focal fibrin, and collagen deposits. Histopathologic features of intestines of the groups with 1:400 intraamniotic meconium plus 100 and 200 U/mL UTI did not differ from the intestines of control group.

CONCLUSION

Urinary trypsin inhibitor 100 U/mL prevented the intestinal damage via inhibiting IL-8, which is contained by 1:400 concentration of meconium. Therefore, besides the existence of threshold level of meconium, the existence of UTI, which is capable of inhibiting IL-8 contained by threshold level of meconium, may be a factor in the occurrence of intestinal damage in gastroschisis.

Outcome of gastroschisis: a 20-year case review of infants with gastroschisis born in Galveston, Texas

BACKGROUND/PURPOSE

In the past decade, the preferred method of closure of gastroschisis at our institution has been staged reduction using a silo with repair on an elective basis (SR) rather than primary surgical closure (PC). We performed a 20-year case review of infants with gastroschisis at a university hospital to compare these shifts in management and to determine factors affecting outcome.

METHODS

Seventy-two cases were reviewed from 1983 to 2003. Times to first and full feeds were outcome variables for statistical analysis.

RESULTS

The prevalence of gastroschisis increased from 0.03% to 0.1% since 1983. Patients had low birth weights (mean = 2294 g) and were borderline premature (mean = 35.8 weeks). Only 3% of the infants were African American. There was a high rate of cesarean deliveries (57%). Ten patients (15%) had gastroschisis complicated by liver herniation, intestinal atresia(s), and/or necrosis/perforation. Most patients were managed by SR (67%). Eight percent of the infants died, 9% developed necrotizing enterocolitis, and 50% had other gastrointestinal complications. Twenty-seven percent of the infants managed with SR did not need initial mechanical ventilation. However, the patients who underwent SR were ventilated longer after birth as compared with those who underwent PC (P < .08). Infants with a complicated gastroschisis had significantly longer times to first and full feeds (P < .001). Patients managed with SR took significantly longer to reach full feeds (P = .001), and there was a trend of starting feeds later (P = .06). When patients with a complicated gastroschisis were excluded, the differences between the SR and PC groups were even greater (P = .01; P < .001).

CONCLUSIONS

In our patient population, the prevalence of gastroschisis increased by more than 400% since 1983. The defect was rare in African-American infants. Management by SR was associated with longer ventilation times and longer times to first and full feeds for both uncomplicated and complicated gastroschisis cases.

A randomized controlled trial of elective preterm delivery of fetuses with gastroschisis

BACKGROUND

Elective preterm delivery of the fetus with gastroschisis may help to limit injury to the extruded fetal gut and thus promote faster recovery of neonatal gut function and earlier hospital discharge. This hypothesis has not previously been tested in a prospective randomized controlled trial.

METHODS

Between May 1995 and September 1999, all women referred to a single tertiary center before 34 weeks' gestation with a sonographically diagnosed fetal gastroschisis were invited to participate in a randomized controlled trial. Eligible patients were randomized to elective delivery at 36 weeks or to await the onset of spontaneous labor. The method of delivery was not prescribed by the trial. Primary outcome measures in the neonate were the time taken to tolerate full enteral feeding (150 mL/kg per day) and duration of hospital stay.

RESULTS

Of 44 eligible women, 42 were randomized, 21 to elective delivery and 21 to await spontaneous labor. There were 20 liveborn infants in each group. Four babies in the elective group and 4 in the spontaneous group delivered before 36 weeks' gestation but were included in the analysis on an intention-to-treat basis. Mean gestational age at delivery was 35.8 weeks in the elective group and 36.7 weeks in the spontaneous group. Primary closure of the gastroschisis was achieved in a similar proportion (80%-85%) of infants in both groups. Two babies in the elective group died from short gut complications. In the survivors, there was a trend in favor of a shorter median time to achieve full enteral feeding (30.5 vs 37.5 days) and a shorter median duration of hospital stay (47.5 vs 53 days) in the elective group, but this was not statistically significant. These findings remained unaltered when the data were reanalyzed after (a) excluding infants with intestinal atresia or (b) excluding infants born before 36 weeks' gestation.

CONCLUSIONS

Although limited by the small number of patients, this randomized controlled trial demonstrates no significant benefit from elective preterm delivery of fetuses with gastroschisis.

Congenital Abdominal Wall Defects: An Update

OBJECTIVE

To review published peer-reviewed literature regarding abdominal wall defects including gastroschisis and omphalocele.

METHODS

Review of published peer-reviewed literature using Med Line 1985-2003 and textbooks.

RESULTS

Gastroschisis and omphalocele literature is reviewed using pathology, incidence and epidemiology, prenatal evaluation, pregnancy and delivery management, postnatal outcome and fetal therapy.

CONCLUSION

Gastroschisis and omphalocele are common abdominal wall defects and have significant morbidity and mortality.

Surveillance and outcome of fetuses with gastroschisis

OBJECTIVES

Infants with gastroschisis have a high survival rate. However, the rate (10-15%) of intrauterine fetal death (IUFD) is considerable, and the association with fetal distress is well known. The aim of this study was to describe the outcome of fetuses with a prenatal diagnosis of gastroschisis. The impact of correct prenatal diagnosis, surveillance and signs of complicating risk factors were evaluated.

METHODS

All fetuses with prenatally diagnosed gastroschisis at the National Center for Fetal Medicine from January 1988 to August 2002 were registered and prospectively evaluated with regular ultrasound examinations. From 34-36 completed gestational weeks the fetuses were monitored daily to every second day with cardiotocography (CTG).

RESULTS

Gastroschisis was diagnosed in 64 fetuses at a mean gestational age of 19 + 2 weeks. All had normal karyotype. Associated anomalies were found in four cases (6.3%). Three pregnancies (4.7%) were terminated, all for reasons other than gastroschisis. One fetus (1.6%) died in utero. Thirteen fetuses (22%) had abnormal CTG leading to subsequent Cesarean sections. Mean gestational age at delivery was 36 + 1 weeks. Mean birth weight was 2586 g. Thirteen infants (22%) were small for gestational age (SGA). In 15 cases (25%) meconium-stained amniotic fluid was found; 14 of these had abnormal CTG and/or were SGA. Small bowel atresia was found in four infants (6.7%). Four infants died postnatally at the age of 0-9 months.

CONCLUSIONS

CTG surveillance of fetuses with gastroschisis may improve the outcome through detection of fetal distress thereby reducing the risk of IUFD. Other clinical situations of importance that are associated with gastroschisis are described and discussed.

Prenatal management of gastroschisis: the place of the amnioexchange procedure

Gastroschisis is a malformation of the anterior abdominal wall that consists of a right paraumbilical defect with bowel loops bathed in the amniotic fluid. The survival rate is now greater than 90% and the prognosis relies mainly on morbidity attributable to bowel dysfunction. Recent research has examined gastrointestinal waste present in amniotic fluid that induces bowel toxicity and an inflammatory process. The amnioexchange procedure (changing the amniotic fluid regularly) involves a new therapeutic approach: reducing bowel injuries in the fetuses. This article shows that there is an inflammatory reaction in human gastroschisis and in the authors' model, and that the clinical and biological data plead for the practice of amnioexchange in human beings. A randomized, controlled study is now needed.

Effects of prenatal dexamethasone on the intestine of rats with gastroschisis

BACKGROUND/PURPOSE

Intestinal lesions observed in gastroschisis (Gx) are accompanied by neonatal gastrointestinal dysfunction. This study examines the effects of transplacental dexamethasone on the eviscerated intestine of fetal rats with Gx.

METHODS

Gx was created surgically in rat fetuses on gestational day 18, and the dams were treated either with 0.4 mg/kg intraperitoneal dexamethasone or with vehicle only on days 19 and 20. The intestine recovered on day 21 were processed for total DNA and protein. Immuno-histochemical staining for ki-67, TUNEL, and synaptophysin were used for assessing the proportions of proliferating and apoptotic cells and the density of intramural ganglia. Analysis of variance (ANOVA) was used for comparison among groups. Significance level was set at P less than.05.

RESULTS

Body weight was reduced in Gx fetuses in comparison with controls. Intestinal weight per centimeter and mucosal and seromuscular layer thicknesses were increased in Gx and Gx + dexa groups. Total intestinal DNA was diminished in Gx animals but it was near normal in Gx + dexa ones. Total intestinal protein was similar in all groups. DNA and protein per centimeter of bowel were very increased in Gx animals but only slightly in Gx + dexa ones. Proliferating cells were decreased in Gx animals and increased in Gx+dexa ones, whereas the opposite was observed for apoptosis. Density of intramural ganglia was decreased significantly in both Gx groups.

CONCLUSIONS

Late intrauterine exposure to dexamethasone of rat fetuses with Gx decreased wall thickening, normalized total DNA, and induced proliferation in the exposed bowel while limiting apoptosis. This medication could have some yet incompletely defined beneficial effects on the wall of the eviscerated bowel in Gx.

Effects of amnio-allantoic fluid exchange on bowel contractility in chick embryos with gastroschisis

BACKGROUND/PURPOSE

Intestinal damage in patients with gastroschisis is characterized by bowel wall thickening, intestinal dilatation, mesenteric shortening, and a fibrous peel. The prevention of intestinal damage in gastroschisis by amnio-allantoic fluid (AAF) exchange has been reported using histologic and macroscopic evaluation of intestines, but the effects of this treatment on bowel contractility have not been investigated. The current study was performed to determine the effect of AAF exchange on the intestinal contractility in chick embryos with gastroschisis.

METHODS

Thirteen-day-old fertilized chick eggs were used. Gastroschisis was created through amnio-allantoic cavity. There were 3 study groups: control group, gastroschisis-only group, and gastroschisis-plus-exchange group. The bowels were evaluated by an in vitro muscle strip technique, and the response was expressed as a percentage of the maximum acetylcholine evoked contraction (E(max)) in each tissue obtained. Additionally, parasympathetic ganglion cells per 10 plexus at the intestinal wall were counted. Differences between groups were analyzed by analysis of variance (ANOVA) followed by Tukey-Kramer. Probabilities of less than 5% were considered significant.

RESULTS

The intestines were thickened and covered by fibrous peel in the gastroschisis-only group when compared with the control group and the gastroschisis exchange group morphologically. There was a statistically significant decrease in contractility in the gastroschisis-only group compared with the control group (P <.05). It exerted 42.03 +/- 46.73% contraction of control group's E(max). This decrease in contractility was significantly reversed in the exchange group (P <.05; E(max) value of gastroschisis plus exchange group was 71.45 +/- 23.54% of control group's E(max)). Although the number of ganglia per 10 plexus was 76.7 +/- 4.3 in the control group, it was measured 28% less in the gastroschisis-only group (P <.05). There was no significant difference between the ganglion numbers of control and exchange groups.

CONCLUSIONS

Prenatal AAF exchange treatment prevents decreased bowel contractility in gastroschisis. Gastroschisis does not affect intestinal ganglia morphology, but the number of ganglion cells decreases. AAF exchange prevents these functional and morphologic adverse effects of disease. By these findings the expectancy of a better clinical result in gastroschisis with intrauterine pretreatment by amniotic fluid exchange increases.

Induction of fetal diuresis with intraamniotic furosemide increases the clearance of intraamniotic substances: An alternative therapy aimed at reducing intraamniotic meconium concentration

BACKGROUND/PURPOSE

Contact with amniotic fluid (AF) causes intestinal damage in gastroschisis. Intraamniotic meconium has been shown to be responsible for intestinal damage, and occurrence of this damage has been shown to depend on the concentration of intraamniotic meconium. When intraamniotic meconium concentration is lowered below threshold level by exchanging AF with saline in gastroschisis, intestinal damage can be prevented. Theoretically, induction of fetal diuresis with intraamniotic furosemide may increase AF volume and fetal swallowing rate, thus, increase absorption of AF by intestines; therefore, the clearance of meconium from the AF may increase. An experimental study was planned to investigate the effects of intraamniotic diuretic injection on the clearance of intraamniotic substances.

METHODS

Pregnant rabbits on the 23rd to 25th gestational day were divided into 2 groups as furosemide and control. Technetium tc99m labeled "tin colloid" was injected into the amniotic cavity, and AF sample was taken 10 minutes later. Furosemide was injected into the amniotic cavity afterwards. Two and 6 hours later, AF samples were obtained. Intestines were harvested at the end of the study. Control group received intraamniotic saline instead of furosemide. Radioactivities of the AF samples and intestines were determined by gamma counter. Clearance of the radioisotope from AF and intestinal accumulation were calculated.

RESULTS

The clearance of the radioisotope from AF was increased significantly in the furosemide group (n = 10) compared with the control group (n = 8; P <.01). Gastrointestinal accumulation of the radioisotope in the furosemide group was 4-fold higher than that the control group (P <.01).

CONCLUSIONS

Induction of fetal diuresis with intraamniotic furosemide accelerates the clearance of intraamniotic substances. This is probably caused by increased urinary output rate, which increases AF volume and consequently results in increased fetal swallowing of AF. In the diseases like gastroschisis and myelomeningocele, in which the contact with AF causes tissue damage, the elimination of meconium from AF in a somewhat natural manner like this method, should be studied further because it may be an alternative minimal invasive in utero treatment modality.