Evaluation of diluted amniotic fluid effects on histological changes of intestine of rabbit fetus with gastroschisis

miRNA-143 expression is associated with inflammation and time of exposure to amniotic fluid in experimental gastroschisis

OBJECTIVE

Gastroschisis (GS) is a congenital anomaly in the abdominal wall with the intestinal loops exiting laterally to the umbilicus. The contact of the loops with Amniotic Fluid (AF) causes an inflammatory process in the exposed part, leading to an extended hospital stay and an increased risk of morbidity due to alterations related to intestinal motility. The authors aimed to evaluate the time of exposure to the AF in the experimental GS and to search for potential biomarkers of intestinal inflammation by measuring microRNAs.

METHODS

Rat fetuses were divided into three groups: a) CONTROL, b) GS reared on day 18 (GS = 18), and c) GS reared on day 19.5 (GS = 19) (term = 22 days). On day 21.5, the fetuses were removed for biometric parameters and biochemical analyses: 1) Biometrics: Body and Intestinal Weight (BW, IW), and intestinal-body weight ratio (IW/BW); 2) Descriptive histopathology and 3) miR-143 quantification by real-time Polymerase Chain Reaction (PCR).

RESULTS

BW was higher in CONTROL than GS 18 and G19 (p < 0.05). IW, IW/BW, intestinal water, and mRNA-143 were higher in GS 18 and GS 19 than in CONTROL, and GS 18 was higher than GS 19 (p < 0.05). The average of the inflammation score from the intestinal wall with mucosal inflammation and intra-epithelial lymphocytes shows worst in GS 18 and GS 19 vs. CONTROL (p < 0.05).

CONCLUSIONS

The tissue expression of mRNA-143 and the morphological changes in the intestine of GS worsened according to the time of exposure to AF, which could be a possible marker of fetal intestinal damage.

Prenatal repair of gastroschisis using partial carbon dioxide insufflation fetoscopy: lessons learned

We report the long-term outcomes of a case of prenatal gastroschisis repair using a fully percutaneous fetoscopic approach with partial carbon dioxide insufflation. Surgery was performed as an experimental procedure before the scheduled elective birth. The fetal intestines were successfully returned to the abdominal cavity without any fetal or maternal complications. Ultrasonography performed 24 hours later revealed bowel peristalsis and no signs of fetal distress. After 48 hours, partial extrusion of the small bowel was observed, and the fetus was delivered. Gastroschisis repair was immediately performed upon delivery using the EXIT-like procedure as per our institutional protocol. The newborn did not require assisted mechanical ventilation, was discharged at 14 days of age and was then exclusively breastfed. At 3-year follow-up, the patient had no associated gastroschisis-related complications. This is the first case of prenatal repair of gastroschisis, which provides baseline knowledge for future researchers on the potential hurdles and management of prenatal repair.

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.

Novel Approach for Laparoscopically Placed Chronic Amniotic Fluid Catheters in Sheep

INTRODUCTION

Several fetal therapies involve repeated amniotic fluid intervention. We hypothesize that a minimally invasive approach can be used to safely implant an intrauterine catheter infusion system in a fetal ovine model for chronic use during pregnancy.

METHOD

Five pregnant sheep underwent operation between gestational days 110 and 115 (term 145 days). A Codman® implantable infusion pump was adapted for intrauterine use. The chamber was placed in the maternal flank and the tunneled catheter laparoscopically inserted into the amniotic cavity, secured with a pursestring. Three had an additional uterine anchoring suture. Ewes were sacrificed after natural delivery, and the uterus underwent gross and microscopic analyses.

RESULTS

There were no maternal mortalities, abortions, or preterm labor. Pumps were accessed and remained functional throughout gestation. Four ewes delivered healthy term lambs; the other delivered twins with failure to progress and demise. On necropsy, catheters secured with an anchoring suture remained in place, while the other 2 dislodged during labor. There was no chorioamnionitis by culture or histology.

CONCLUSION

Laparoscopically placed intra-amniotic infusion catheters were implanted safely and remained functional until delivery in an ovine model. This novel approach has promise in providing safe, durable amniotic fluid access for the potential treatment of fetal disease.

Multiple cytokine analysis in gastroschisis: Association with adverse outcomes including fetal brain damage

OBJECTIVES

To investigate the distribution of multiple cytokines in gastroschisis and reveal its association with clinical outcomes, including gastrointestinal disorders and fetal brain damage caused by chronic inflammation in gastroschisis.

METHODS

We obtained amniotic fluid and arterial cord blood from 10 patients with gastroschisis, and evaluated the profile of 40 cytokines via multiplex immunoassay. The possible relationship of the cytokines with the time taken to attain full enteral nutrition and cord S100B, a surrogate marker of brain damage, was estimated. Associations among the relevant cytokines were also assessed.

RESULTS

Although clinical characteristics in our cohort had no relevance, several cytokines in cord blood, especially IL-2, IL-8, CCL1, CCL7, CXCL1, CXCL2, and CXCL6, were clearly elevated in patients who took a longer time to attain full enteral nutrition, whereas only IL-16 in cord blood was significantly related to cord S100B and strongly correlation with cord S100B levels. Moreover, our data indicated that IL-16 was considerably less correlated with the other cytokines associated with adverse outcomes.

CONCLUSIONS

We investigated the cytokine characteristics of both amniotic fluid and cord blood in gastroschisis, and found that certain cytokines could affect the adverse outcomes, including fetal brain damage. These findings provide important information that could further clarify the pathophysiology of gastroschisis and propose a novel clinical implication of gastroschisis that could be used to predict adverse outcomes, especially neurodevelopmental disorders.

A Rabbit Model for Optimization of Amniotic Fluid Components in the EXTrauterine Environment for Newborn Development (EXTEND) System

In this model article, we present a protocol for continuous amniotic fluid exchange in rabbits using a novel system to test the effects of growth factor-deficient, artificial amniotic fluid on bowel development.

BACKGROUND

Ideally, the EXTrauterine Environment for Neonatal Development (EXTEND) will provide physiologic support to the extreme premature infant. An important component of that environment is the amniotic fluid. Thus, we developed an animal model to study the growth factors found within amniotic fluid and inform design of a synthetic fluid to optimize fetal development.

METHODS

We designed a model of amniotic fluid exchange within the pregnant rabbit, continuously removing the natural fluid from around 2 fetuses per doe and replacing it with a physiologic electrolyte solution during the final 100 h of gestation. Two fetuses from the contralateral uterine horn were used as sham-operated controls. Thirty-eight fetuses were analyzed, 19 in each group. We analyzed the fetal growth and bowel development.

RESULTS

Ultrasound after 100 h of exchange showed equivalent fluid volumes, p = 0.63. Cultures were negative for bacterial colonization. Final fluid protein concentrations were 11.6% that of control fluid (mean 1,451 ± 224.2 vs. 12,491 ± 849.2 μg/mL). There was no significant difference in fetal growth, with experimental weights 91.4% of control weights, p = 0.07. Fetal bowel weights (90.1%, p = 0.16) and lengths (94.2%, p = 0.49) were also not significantly less compared to controls. There was no significant difference in villous height or crypt depth measurements between the groups, and absorptive capacity of the bowel was not different between groups, p = 0.44.

CONCLUSION

This animal model allows for manipulation of the components of amniotic fluid. Marked reduction of natural amniotic fluid proteins during gestation does not appear to significantly impair fetal growth or bowel development. Further work with this model will assess the importance of amniotic fluid components for normal development to inform design of a synthetic fluid for use during EXTEND.

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.

Isolated prenatal ultrasound findings predict the postnatal course in gastroschisis

PURPOSE

The aim of the study was to identify which prenatal ultrasonographic findings in fetuses with gastroschisis correlate with complicated postnatal outcome.

METHODS

Ultrasound findings at the 30th week of pregnancy and medical reports were statistically analyzed to identify independent prenatal ultrasonographic predictors of postnatal outcome.

RESULTS

Completed prenatal data were gathered from 64 pregnancies. Prenatal intra-abdominal bowel dilatation (cutoff 10 mm) correlated with the presence of atresia (p < 0.01), longer administration of parenteral nutrition, extended hospital stay (median 53 vs. 21 days; 68 vs. 36 days, both p < 0.05), and greater number of additional surgical procedures (p < 0.05). Infants with antenatal presence of thickened bowel wall (greater than or equal to 3 mm) required longer administration of parenteral nutrition (median 34 vs. 20 days; p < 0.01) and prolonged stay (median 44 vs. 37 days; p < 0.05). Presence of oligohydramnion (amniotic fluid index below 8 cm) was connected with longer administration of parenteral nutrition in newborns (median 30 vs. 16 days; p < 0.05).

CONCLUSION

The isolated presence of oligohydramnion with amniotic fluid index below 8 cm, thickened bowel wall equal to or more than 3 mm and the prenatal intra-abdominal dilatation with 10 mm cutoff had significant predictive value for the adverse postnatal outcome of patients with gastroschisis.

Multidirectional and simultaneous evaluation of gastroschisis-related intestinal damage in chick embryos

PURPOSE

In a chick model of gastroschisis, we aimed to investigate the morphological/cellular, molecular, and ultrastructural changes taking place in gastroschisis-related intestinal damage (GRID).

METHODS

13-Day fertilized eggs were divided into two groups.

CONTROL GROUP

chorio-amnio-allontoic membranes opened and abdominal wall exposed. Gastroschisis group: an anterior abdominal wall defect created after opening membranes. Embryos from both groups were surgically removed on post-fertilization day 19. Intestinal samples were obtained for histopathology, immunohistochemistry, molecular biology, and electron microscopy.

RESULTS

The histopathological grade of intestinal damage which primarily involved mucosal structures was significantly higher in the gastroschisis group when compared to the control group (p<0.001). Immunohistochemically, E-cadherin and synaptophysin immunoreactivity in the gastroschisis group was significantly lower than control group (p<0.05 and p<0.01, respectively), whereas there was no significant difference in laminin and type-4 collagen immunoreactivity between the groups (p>0.05). Molecular analyses indicated a significant decrease in NFκB and IκB expression in the gastroschisis group (p<0.05 and p=0.001, respectively). Electron microscopy showed that the gastroschisis group had considerable ultrastructural damage, manifested by apoptosis in all layers.

CONCLUSIONS

GRID affected all layers but was more prominent in mucosa. The damage may depend on E-cadherin and synaptophysin downregulation. Increased apoptotic activity, associated with decreased NFκB and IκB expression, may be an important component of this multifactorial damaging process.