Neurofilament formation and synaptic activity are delayed in the myenteric neurons of the rat fetus with gastroschisis

Prenatal ultrasound markers for prediction of complex gastroschisis-single-center retrospective cohort study

OBJECTIVE

To evaluate prenatal ultrasound markers for distinguishing simple gastroschisis (sGS) from complex gastroschisis (cGS) and identifying fetuses at risk of complications.

STUDY DESIGN

A retrospective cohort study analyzed 61 fetuses with isolated gastroschisis at a tertiary center from 2011 to 2021, utilizing serial ultrasounds from 14 to 35 weeks' gestation. A general linear model, quantile regression, and logistic regression assessed ultrasound markers, fetal weeks, and gastroschisis risk, yielding predictive models.

RESULTS

IABL dilatation showed the highest PPV but low NPV. Non-free floating bowel loops (NFFBL) indicated the best PPV to NPV ratio. Combinations of markers yielded the highest predictive value for cGS. EABL collapsed and non-free floating bowel loops were significant, consistent risk factors.

CONCLUSIONS

Prenatal ultrasounds can predict cGS risk, particularly using IABL dilatation and NFFBL as markers. Accurate assessment requires considering gestational age, qualitative symptoms, emphasizing experienced perinatologists' role and monitoring, particularly after 30 weeks of gestation.

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.

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.

Does gastric dilation predict adverse perinatal or surgical outcome in fetuses with gastroschisis?

OBJECTIVE

To compare perinatal and infant surgical outcomes in fetuses with gastroschisis with and without gastric dilation in a single-center cohort.

METHODS

This was a retrospective study of all singleton pregnancies with a prenatal diagnosis of gastroschisis managed at University of Toronto perinatal centers between January 2001 and February 2010. Digital prenatal ultrasound images were reviewed to determine fetal gastric size within 2 weeks of delivery. Perinatal and surgical outcomes were compared in fetuses with and without gastric dilation including: gestational age at delivery, mode of delivery, indication for Cesarean section, meconium-stained amniotic fluid, birth weight percentile, Apgar scores at 1 and 5 min, umbilical artery pH, time to full enteral feeding, length of hospital stay, bowel atresia or necrosis and need for bowel resection.

RESULTS

Ninety-eight fetuses with prenatally diagnosed gastroschisis managed at our center were included in the study, of which 32 (32.7%) were found to have gastric dilation. Gastric dilation predicted meconium-stained amniotic fluid at delivery (53% vs. 24%; P = 0.017), but no other adverse perinatal outcome. Surgical morbidity rates (bowel atresia, bowel necrosis, perforation diagnosed postnatally, need for bowel resection, total time to full enteral feeding and length of hospital stay) were unaffected by gastric dilation.

CONCLUSIONS

In gastroschisis, fetal gastric dilation is associated with meconium-stained amniotic fluid at delivery, but is not predictive of any serious perinatal or postnatal complications. Fetal growth and well-being should be serially evaluated on ultrasound using biophysical and Doppler assessment to decide on the optimal timing and mode of delivery.

Gastroschisis in mice lacking aortic carboxypeptidase-like protein is associated with a defect in neuromuscular development of the eviscerated intestine

Mice lacking aortic carboxypeptidase-like protein (ACLP) exhibit a gastroschisis (GS) like abdominal wall defect. The objectives of this study were to evaluate the pathophysiological features of GS in ACLP mice and to characterize the neuromuscular development of the eviscerated intestine (EI). ACLP mice were created by heterozygous mating from previously generated mice with targeted disruption of ACLP. Specimens were processed for H&E, and immunohistochemistry for smooth muscle cells [SMC, alpha-smooth muscle actin (alpha-SMA) antibody], interstitial cells of Cajal (ICC, c-kit-antibody), neural crest cells (NCC, Hox-b5-antibody), and enteric neurons (EN, PGP9.5-, alpha-internexin, and synaptophysin antibody). From 47 fetuses genotyped, 13 (27.7%) were wild type, 20 (42.5%) were heterozygous, and 14 (29.8%) were ACLP homozygous. In GS mice, expression of c-kit, Hox-b5, PGP-9.5, alpha-internexin, and synaptophysin were almost completely absent and only faint alpha-SMA expression was seen in the EI. In contrast, c-kit, Hox-b5, PGP9.5, alpha-internexin, synaptophysin, and alpha-SMA expression in intra-abdominal intestine in GS fetuses was the same as control intestine. The defect observed in ACLP mice closely resembles GS. Absence of ICC, NCC, EN, and immature differentiation of SMC supports an associated defect in neuromuscular development that is restricted to the EI.

A new rat model of prenatal bowel obstruction: development and early assessment

PURPOSE

Although intestinal motility disorders often complicate the postoperative surgical management of newborns with congenital intestinal atresia, their pathogenesis remains unclear. Animal models of prenatal intestinal obstruction have been mainly developed in the lamb and the chicken. Despite new insights brought by these models, they have one or more limitations, such as high fetal mortality rates, high costs, long gestation periods, and an insufficient number of fetuses per litter. Moreover, some species are phylogenetically distant from mammals.

METHODS

We developed a reproducible model of prenatal intestinal obstruction in the rat to study the histologic changes induced by the obstruction. We report, the technical devices and the first assessment of this atresia model in a didactic way to allow other researchers to easily reproduce the model.

RESULTS

Prenatal intestinal obstructions in this study fulfilled all the macroscopic and histologic criteria usually listed by other models of prenatal intestinal obstruction that have been developed in other species. Furthermore with our model, we obtained a high success rate at a low cost.

CONCLUSIONS

We presented in this study a reproducible model of prenatal intestinal obstruction in the rat with the macroscopical and histologic features of prenatal intestinal obstruction.

Myenteric plexus alterations downstream from a prenatal intestinal obstruction in a rat model

The enteric nervous system maturation occurs during embryonic life and continues after birth. Some prenatal events on the digestive tract such as intestinal atresia have been shown to dramatically alter this maturation. Thus, we developed a fetal rat model of intestinal atresia by surgically obstructing the small bowel at embryonic day E18. Fetuses were removed at day E21, and small bowels sections were examined by immuno-histochemistry. Synaptophysin and smooth muscle actin staining was used to define the cellular aspect. Labeling revealed marked alterations of the myenteric plexus in the lower extremity of the occluded small bowel. At day E21, the myenteric plexus of the lower part and the 2 muscle layers surrounding it, retained the staining pattern observed at day E17. This cellular pattern was classified as: immature (aspect at day E17) vs. mature (aspect of day E21) by 3 pathologists not familiar with the study. The number of samples with an immature cellular pattern at the lower end of the occluded bowel was different from that observed for the upper end (Mac Nemar test, p<0.008). Our study suggests that a prenatal obstruction induces a maturation delay of the myenteric plexus downstream of the obstruction. This might be important for pediatric purposes.

Delayed development of interstitial cells of Cajal in the ileum of a human case of gastroschisis

The Interstitial Cells of Cajal (ICC) are responsible for rhythmic electrical activity. A paralytic ileus is present in gastroschisis (GS), a malformation due to a defective closure of the abdominal wall through which part of the intestine herniates during pregnancy. In experimental GS, ICC morphological immaturity was shown in the rat foetus at-term but it could not be demonstrated whether differentiation is accomplished post-natally. For this purpose we morphologically investigated ICC, as well as enteric neurons and smooth muscle cells, in a case of human GS at birth and 1 month later when peristaltic activity had initiated. A 36 weeks gestation female was born by c/section with prenatal diagnosis of GS and possible volvulus of the herniated intestine. At birth, the necrotic intestine was resected and both ileostomy and colostomy were performed. The intestine continuity was restored after 4 weeks. Intestinal specimens, taken during both operations at the level of the proximal stoma, were immunostained with c-kit, neuron-specific-enolase and alpha-smooth-muscle-actin antibodies and some processed for electron microscopy. ICC were present at the myenteric plexus only. At birth, these cells were rare and ultrastructurally immature; 1 month later, when partial enteral feeding was tolerated, they formed rows or groups and many of them were ultrastructurally differentiated. Neurons and smooth muscle cells, immature at birth, had developed after 1 month. Therefore, ICC differentiation, as well as that of neurons and smooth muscle cells, is delayed at birth and this might explain the paralytic ileus in GS. One month later, differentiation quickly proceeded at all cellular levels paralleling the increasing tolerance of enteral nutrition.

Effects of intrauterine treatment on interstitial cells of Cajal in gastroschisis

AIM

An experimental study was performed to investigate the effects of amnio-allantoic fluid exchange and intrauterine bicarbonate treatment on intestinal damage and interstitial cells of Cajal (ICC) in gastroschisis.

MATERIALS AND METHODS

Thirteen-day-old fertilized chick eggs were randomly allocated into 4 groups as control, gastroschisis, gastroschisis + amnio-allantoic fluid exchange, and gastroschisis + bicarbonate treatment groups. In the treatment groups, amnio-allantoic exchange and bicarbonate treatments were performed for 3 days, after creating gastroschisis. Specimens were processed for hematoxylin-eosin and c-kit immunohistochemistry on the 18th day of incubation, after macroscopic examination. The intestines were evaluated with light microscopy for the presence of mucosal congestion and muscular and serosal edema. Mean muscular thickness and density of ICC were measured.

RESULTS

Mean muscular thickness significantly increased in the gastroschisis group when compared with control and treatment groups. Labeling intensity, morphology, and localization of the ICC were similar in all groups. Mean ICC density significantly decreased in the gastroschisis group when compared with the control group (P < .01), and it significantly increased after amnio-allantoic fluid exchange treatment (P < .01).

CONCLUSIONS

The decrease in ICC density encountered in damaged intestinal loops in gastroschisis was prevented with intrauterine treatment. The beneficial effects of amniotic exchange on intestinal motility may depend on both prevention of intestinal damage and preservation of ICC density and function. The density of ICC might be a reliable numeric parameter both to predict intestinal motility disorders in gastroschisis and to compare the effectiveness of intrauterine treatment methods.

Impact of corticosteroid on intestinal injury in a gastroschisis rat model: morphometric analysis

BACKGROUND/PURPOSE

The goal in the treatment of gastroschisis is to prevent intestinal injury. Corticosteroids are known by their effects at the inflammatory response and by the improvement on the intestinal maturity. The authors evaluated the effects of maternal corticosteroid administration on the intestines of rats that underwent fetal gastroschisis.

METHODS

A Correia-Pinto-modified gastroschisis rat model was used. Two groups were assessed: the control group (group 1) and the dexamethasone group (group 2). Each group was composed of control and sham fetuses, and fetuses with gastroschisis. Fetal body weight, intestinal weight, intestinal length, and protein were assessed. Histologic analysis involved measures of intestinal loop diameter, total intestinal wall, mucosa and submucosa, both circular and longitudinal muscle layers, and serosal thicknesses. Differences between groups and subgroups were tested by the analysis of variance method with a significant P value less than .05.

RESULTS

Dexamethasone decreased in all the morphometric data except in the intestinal length. Dexamethasone increased the intestinal protein content in fetuses with gastroschisis, and control and sham fetuses. In both groups, all histologic parameters were increased in fetuses with gastroschisis (P < .0001).

CONCLUSIONS

Dexamethasone caused a substantial decrease in intestinal weight in GFs, increased the intestinal protein content, and it may be useful in decreasing the intestinal damage of gastroschisis.