Influence of amnioinfusion in a model of in utero created gastroschisis in the pregnant ewe

Experimental Induction of Complex Gastroschisis in the Fetal Lamb: Systematic Review

We systematically reviewed experiments in the fetal lamb model of gastroschisis using PubMed, Embase, Web of Science, and Scopus, seeking for standardized surgical techniques to obtain complex gastroschisis. Eligible were studies where an abdominal wall defect was surgically induced and gross anatomical findings at birth were available. The primary outcome was complex gastroschisis, defined by the presence of bowel stenosis, atresia, volvulus, perforation, and/or necrosis. Secondary outcomes were fetal death and additional readouts reported. Of ten eligible studies, six included lambs that had no additional prenatal manipulations and were assessed at term (35 lambs). Gastroschisis was induced at day 70-80 (term = 140-145), typically (n = 4/6 studies) in the left lower abdomen with defect size ranging from 0.5 to 4.0 cm. Only one study, in which a 1.5 cm diameter silicone ring was utilized, resulted in complex gastroschisis in 100% of term survivors. Fetal loss was more frequent in studies where a silicone ring and/or a right-sided defect were used. No changes unique to complex gastroschisis were identified in additional readouts, including bowel histology. When gastroschisis becomes "complex" following induction is uncertain. This knowledge is essential in studying potential prenatal interventions that may change the natural course.

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.

Is there a role for fetal interventions in gastroschisis management? - An updated comprehensive review

We conducted a comprehensive evidence-based review on the epidemiology and current standard of care of gastroschisis management as well as the pathophysiology, rationale and feasibility of fetal therapy as a viable alternative. Gastroschisis is a periumbilical abdominal wall defect characterized by abdominal viscera herniation in utero. It affects 4 in 10 000 live births, but the prevalence has steadily increased in recent years. Gastroschisis is typically diagnosed on routine second-trimester ultrasound. The overall prognosis is favorable, but complex gastroschisis, which accounts for about 10% to 15% of cases, is associated with a higher mortality, significant disease burden and higher healthcare costs due to long- and short-term complications. The current standard of care has yet to be established but generally involves continued fetal surveillance and multidisciplinary perinatal care. Postnatal surgical repair is achieved with primary closure, staged silo closure or sutureless repair. Experimental animal studies have demonstrated the feasibility of in utero closure, antiinflammatory therapy and prenatal regenerative therapy. However, reports of early preterm delivery and amnioinfusion trials have failed to show any benefit in humans. Further experimental studies and human trials are necessary to demonstrate the potential benefit of fetal therapy in gastroschisis.

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.

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.

Gastroschisis--what should be told to parents?

Gastroschisis is a common congenital abdominal wall defect. It is almost always diagnosed prenatally thanks to routine maternal serum screening and ultrasound screening programs. In the majority of cases, the condition is isolated (i.e. not associated with chromosomal or other anatomical anomalies). Prenatal diagnosis allows for planning the timing, mode and location of delivery. Controversies persist concerning the optimal antenatal monitoring strategy. Compelling evidence supports elective delivery at 37  weeks' gestation in a tertiary pediatric center. Cesarean section should be reserved for routine obstetrical indications. Prognosis of infants with gastroschisis is primarily determined by the degree of bowel injury, which is difficult to assess antenatally. Prenatal counseling usually addresses gastroschisis issues. However, parental concerns are mainly focused on long-term postnatal outcomes including gastrointestinal function and neurodevelopment. Although infants born with gastroschisis often endure a difficult neonatal course, they experience few long-term complications. This manuscript, which is structured around common parental questions and concerns, reviews the evidence pertaining to the antenatal, neonatal and long-term implications of a fetal gastroschisis diagnosis and is aimed at helping healthcare professionals counsel expecting parents.

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.

Bowel-defect disproportion in gastroschisis: does the need to extend the fascial defect predict outcome?

BACKGROUND/PURPOSE

Validated outcome prediction for gastroschisis (GS) permits early risk stratification. The aim of our study was to determine whether the need for GS defect extension: (a) correlates with bowel injury severity at birth, and (b) predicts outcome.

METHODS

A national dataset was used to study GS babies born between 2005 and 2010. The primary outcome was days of parenteral nutrition (PN). Outcomes were analyzed according to the need for fascial extension to facilitate closure or silo placement as follows: Group 1, no extension; Group 2A, extension <2 cm; Group 2B, extension >2 cm. Univariate and where appropriate, multivariate analyses were used.

RESULTS

Of 507 cases, 402 had complete defect extension data: Group 1, 297 (73%); Group 2A, 67 (17%); Group 2B, 42 (10%). Group 2B patients had higher rates of atresia, perforation and severe matting (P = 0.001) and required more days on PN compared to Group 1 (63.0 ± 100.4 vs. 39.7 ± 44.5 days: CI 1.2-45.1; P = 0.03). Multivariate analysis revealed that the presence of atresia (P = 0.01) and surgical site (P = 0.001) or bloodstream (P = 0.001) infections were predictive of prolonged PN; however, the need for fascial extension was not.

CONCLUSIONS

GS newborns who require fascial extension are more likely to have complicated GS and are at greater risk for adverse outcome, although it is not an independent predictor of the latter.

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.

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

Amniotic fluid exchange is a method for prevention of intestinal damage in gastroschisis, but its techniques are different in studies. We investigated the effects of amnioinfusion exchange on histological changes of intestine and feasibility and safety of amniotic fluid exchange through central vein catheter (CVC) placed in pregnant rabbit uterus. A total of 15 pregnant New Zealand white rabbits were selected. Fetuses were randomly divided into three groups (case, control, sham). On gestational day 25, under general anesthesia with midline laparotomy, the graved bicornuate uterus was exposed. In controls, fetus abdomen was opened by a transverse incision in right lower quadrant region and intestines were eviscerated. In cases, after intestine evisceration, a central venous catheter was passed from mother skin and uterus and fixed to uterus wall. In shams, fetus was delivered on gestational day 32 and its abdomen was opened. In case group, after operation, 1-2 cc of warm saline solution was replaced through catheter every 6 h. On gestational day 32, fetuses of case and control groups were delivered. Mucosal and serosal thickness, muscle thickness, fibrin deposition, serosal collagen and ganglia were compared. Ten fetuses as shams, 7 fetuses as controls and 7 fetuses as case group were studied. Serosal thickness was 4.5 +/- 3.6 microm in shams, 64.2 +/- 28.7 microm in controls and 6 +/- 4.1 microm in cases. Serosal thickness in control group was higher than sham (P < 0.001) and case (P < 0.002) groups. In case group, infiltration of inflammatory cells with mild edema without fibroblast infiltration was seen. Application of the CVC technique was found to be a simple procedure that effectively decreased serosal inflammatory response of intestine in gastroschisis.

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.

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.

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.

Fetal home monitoring for the prenatal management of gastroschisis

BACKGROUND

Fetal distress is a frequent complication of gastroschisis, and could be screened for by home monitoring, as many pregnant women expecting an affected child live far away from a specialized perinatal center. This study was undertaken to audit a policy of fetal home monitoring (FHM) to achieve early detection of fetal heart rate (FHR) abnormalities in gastroschisis.

METHODS

Daily FHM was started at a median age of 30 weeks in 31 pregnant women referred following prenatal diagnosis of isolated gastroschisis. Monitoring was considered abnormal in cases with decelerations, tachycardia, bradycardia, decreased baseline variability or absence of accelerations. When an ominous FHR was detected and confirmed by in-hospital monitoring, an emergency cesarean section (C-section) was indicated. Otherwise, an elective C-section was planned.

RESULTS

In 20 cases FHM remained normal. There were 16 elective C-sections, two emergency C-sections for FHR abnormalities detected by in-hospital monitoring, and two spontaneous premature vaginal deliveries. In 11 cases, an abnormal FHM was detected. There was one intrauterine death with acute ischemic necrosis of the large bowel. The other abnormalities consisted of decreased baseline variability with tachycardia (n = 7) or without tachycardia (n = 3) and were confirmed by in-hospital follow-up in nine cases, leading to emergency C-section.

CONCLUSION

The high rate of abnormal FHR patterns picked up by FHM in gastroschisis led to a rate of emergency C-sections of 9/31. However, this strategy failed to prevent one intrauterine death due to acute bowel necrosis.

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.

Routine cesarean delivery does not improve the outcome of infants with gastroschisis

BACKGROUND/PURPOSE

The optimal mode of delivery for infants with gastroschisis is controversial. The authors compared the outcomes of infants with gastroschisis born vaginally (VD) or by cesarean section (CS).

METHODS

A retrospective analysis of infants with gastroschisis born between 1990 and 2000 was performed. Assessment included patient demographics, respiratory distress, method of closure, number of surgeries, presence of atresia, feeding parameters, parenteral nutrition days (TPN), time to full feeding (FPO), mortality, and length of stay (LOS). Subgroup analyses were performed for those infants requiring cesarean section for fetal distress. Student's t test/analysis of variance (ANOVA) or chi2/Fisher's Exact tests were used for statistical analysis. Logistic and linear regression analyses were also performed.

RESULTS

One hundred thirteen patients were studied (82 VD and 31 CS). No statistical difference existed between the VD and CS groups for perinatal complications, method of closure, number of surgeries (1.6 each), TPN (40.6 v 46.0 days), FPO (40.4 v 47.1 days), mortality (9.7 v 6.5%) and LOS (53.4 v 61.7 days). CS was associated with increased stenosis (25.8 v 4.9%; P =.003), gastrointestinal dysfunction (25.8 v 11.0%; P =.049), and respiratory distress (16.1 v 3.7%; P =.035). Many of these differences did not persist when infants undergoing CS for fetal distress were excluded from the analysis. However, regression analysis identified CS as an independent risk factor for the development of respiratory distress at birth (odds ratio, 7.11; CI, 1.06 to 47.7), with a trend to increased gastrointestinal dysfunction (odds ratio, 4.35; CI, 0.77 to 24.61).

CONCLUSIONS

The routine use of CS for infants with gastroschisis is not supported by our results because equivalent outcomes were observed with both modes of delivery. CS may be a necessary intervention for fetal distress.

Amniotic fluid inflammatory proteins and digestive compounds profile in fetuses with gastroschisis undergoing amnioexchange

OBJECTIVE

In gastroschisis, an inflammatory process related to the presence of digestive compounds may be involved in intestinal damage. We measured the amniotic fluid concentrations of total protein, ferritin and amylase, lipase, gamma-glutamyl transferase and bile acids before each amnioexchange performed in women whose infants had gastroschisis. We estimated the correlation among total proteins, ferritin and digestive compounds and postnatal outcome.

DESIGN

All women whose infants had gastroschisis in our fetal medicine unit are offered repeated amnioexchange during the third trimester of pregnancy to improve the quality of the exteriorised bowel at birth. Amniotic fluid was sampled at the beginning of each amnioexchange and total proteins, ferritin and digestive compounds were assayed.

SETTING

This study was conducted in the Department of Perinatology of the University Hospital Robert Debré in Paris.

POPULATION

Thirty pregnant women with a gastroschisis affected fetus diagnosed antenatally.

METHODS

The biological results were expressed as multiples of the median with respect to a control population.

MAIN OUTCOME MEASURE

Gestational age at delivery and the outcome of the infants were recorded and correlated with amniotic fluid total proteins, ferritin and digestive compounds.

RESULTS

There was a positive correlation (P < 0.01) between digestive compounds (except amylase at the final amnioexchange) and ferritin on the one hand, and all digestive compounds and total proteins concentration at the final amnioexchange on the other. In addition, among total proteins amylase and lipase, lipase concentrations were related with parameters of short term outcome (P < 0.05).

CONCLUSION

Amniotic total proteins and ferritin are elevated in fetuses presenting with gastroschisis as a consequence of an inflammatory process. Inflammation may be induced by the presence of digestive compounds in the amniotic fluid. The concentrations of which may constitute a marker of short term outcome of the newborn infant.

Myocardial tissue engineering and regeneration as a therapeutic alternative to transplantation

Ischemic cardiomyopathy leading to congestive heart failure remains the leading source of morbidity and mortality in Western society and medical management of this condition offers only palliative treatment. While allogeneic heart transplantation can both extend and improve the quality of life for patients with end-stage heart failure, this therapeutic option is limited by donor organ shortage. Even after successful transplantation, chronic cardiac rejection in the form of cardiac allograft vasculopathy can severely limit the lifespan of the transplanted organ. Current experimental efforts focus on cellular cardiomyoplasty, myocardial tissue engineering, and myocardial regeneration as alternative approaches to whole organ transplantation. Such strategies may offer novel forms of therapy to patients with end-stage heart failure within the near future.

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.

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.

Esophageal ligature in experimental gastroschisis

BACKGROUND/PURPOSE

Recently, the authors have shown that in human fetuses suffering from gastroschisis, there is an amniotic fluid inflammatory response and that amniotic fluid exchange designed to disrupt the inflammatory loop seems to have a favorable impact on outcome. The authors, therefore, designed in the fetal sheep a model of gastroschisis in which amnioinfusion significantly improved the deleterious process. They hypothesized that regurgitation and presence of digestive enzyme in the amniotic fluid triggers and maintains the process of inflammation.

METHODS

To test this hypothesis, the authors used their model of gastroschisis in the fetal lamb combined with esophageal ligation and compared it with gastroschisis with or without amnioinfusion.

RESULTS

Of 34 fetuses operated on at midgestation (days 70 through 80), 11 died in utero or were stillborn, 8 had gastroschisis and amnioinfusion, 8 had gastroschisis and no amnioinfusion, and 7 had gastroschisis and esophageal ligation. There were 9 control fetuses. Fetuses were killed at day 145 by cesarean section. Extraabdominal bowels with fibrous peel were processed for histologic examination. Thickness of bowel muscularis (micrometers) was 82.7 +/- 19 for controls, 159 +/- 56 for the nonamnioinfused fetuses, 126 +/- 21 for the amnioinfused fetuses (P =.001), and 240 +/- 225.8 for fetuses with esophageal ligature combined with gastroschisis. The same results were obtained for thickness of serous fibrosis and plasma cell infiltration. Assay of amniotic fluid ferritin, lipase, and protein showed that only amnioinfusion lowered ferritin and protein to levels similar to those of controls, thus, illustrating its preventive effect on inflammation and that esophageal ligature did not prevent digestive enzyme presence in the amniotic fluid.

CONCLUSION

In this model of gastroschisis in the fetal sheep, ligature of the esophagus, which was supposed to protect the extruded bowel by preventing oral regurgitation of digestive enzymes and by creating a relative hydramnios, did not improve the inflammatory and deleterious process, which is best prevented by amnioinfusion.

Meconium dependence of bowel damage in gastroschisis

BACKGROUND/PURPOSE

Increasing evidence of physiologic in utero defecation supports the hypothesis that bowel damage in gastroschisis may be meconium dependent. In this study, the author investigated the role of meconium on parameters of bowel damage in a fetal rat model of gastroschisis.

METHODS

Pregnant rats underwent laparotomy at 18 1/2 days gestational age (GA). There were 4 experimental groups of 11 fetuses each; the G(M) group consisted of fetuses with isolated gastroschisis and was considered to have moderate meconium contamination of the amniotic fluid (MCAF); the G(L) group consisted of fetuses with gastroschisis and anal ligation, performed to prevent MCAF; the G(H) group consisted of fetuses with gastroschisis and colon perforation, performed to increase MCAF; and the Sham group consisted of sham operated controls. All fetuses were harvested by cesarean section at 21 1/2 days GA, and the fetal intestine was assessed for peel, intestinal length, intestinal weight per unit length, and histologic appearance.

RESULTS

The authors achieved the following fetal survival rates: G(M) group, 91% (10 of 11); G(L) group, 78% (7 of 9, the ligation was not successful in 2 fetuses); G(H) group, 82% (9 of 11). Sham group, 100% (11 of 11). Intestinal length was decreased in fetuses with gastroschisis, and this reduction was related directly to the grade of MCAF (Sham, 18.4 +/- 0.6; G(L), 11.5 +/- 0.5; G(M), 10.2 +/- 0.6; G(H), 9.1 +/- 0.6 cm; P <.01). In contrast, intestinal weight per unit length increased in fetuses with gastroschisis, and this increase was related directly to the grade of MCAF (Sham, 7.8 +/- 0.5; G(L), 9.4 +/- 0.5; G(M), 11.3 +/- 0.5; G(H), 16.9 +/- 0.7 mg/cm; P <.01). In comparison with the G(M) group, the degree of peel coverage and bowel adherence were increased markedly in the G(H) group, whereas the fetuses of the G(L) group had neither peel nor bowel adherence.

CONCLUSIONS

All bowel damage parameters were affected by MCAF supporting the hypothesis that bowel damage in gastroschisis is at least partially dependent on meconium exposure. Further research is required to clarify other factors that contribute to bowel damage and to identify risk factors that may allow prenatal identification of severely affected fetuses.

Intestinal damage in gastroschisis correlates with the concentration of intraamniotic meconium

BACKGROUND/PURPOSE

Contact with amniotic fluid (AF) causes intestinal damage in gastroschisis, which has been shown to be caused by intraamniotic meconium. However, whether this intraamniotic meconium-induced intestinal damage is concentration dependent has not been investigated previously. The purpose of this study is to investigate the effects of intraamniotic human meconium at various concentrations on the intestines of chick embryo with gastroschisis.

METHODS

Five-day-old fertilized chick eggs were used. Gastroschisis was created through the amniotic cavity without opening the allantoic cavity. Sterile meconium was obtained from newborn humans. Meconium suspensions at various concentrations were prepared using saline and instilled into the amniotic cavity.

RESULTS

Intraamniotic 1:200 and 1:400 meconium was found to cause intestinal damage. Meconium concentrations lower than 1:400 did not cause intestinal damage. Histopathologic examination of the intestines of the 1:200 and 1:400 meconium groups showed serosal thickening, inflammation, focal fibrin, and collagen deposits. Histopathologic features of the intestines of the 1:600 and 1:800 meconium groups did not differ from the intestines of the control group.

CONCLUSION

Intraamniotic meconium, which is responsible for intestinal damage in gastroschisis, must reach a threshold level to induce intestinal damage. J Pediatr Surg 36:1811-1815.

Improvement of mesenteric superior artery Doppler velocimetry by amnio-infusion in fetal gastroschisis

This study aimed to analyse the influence of amnio-infusion on superior mesenteric Doppler velocimetry and to correlate Doppler data with outcome in fetuses presenting with gastroschisis. Umbilical and intra- and extra-abdominal superior mesenteric artery Doppler velocimetry was measured prospectively before and after amnio-infusion in fetuses with gastroschisis. Doppler index values and changes were correlated with the following outcome parameters: importance of fibrous coating, duration of hospitalization in the neonatal intensive care unit, total duration of hospitalization, duration of parenteral feeding, duration of ventilatory assistance, and the interval to initiation of oral feeding. A significant improvement of diastolic flow was observed in the extra-abdominal superior mesenteric artery with amnio-infusion. No similar change was seen in the intra-abdominal superior mesenteric or in the umbilical artery. Pre-amnioinfusion extra-abdominal mesenteric Doppler index was correlated with maximal diameter of exteriorized bowel and slightly with duration of hospitalization in the neonatal intensive care unit, but no other relation between Doppler index and outcome parameter could be ascertained. Amnio-infusion induces modifications in the vascularization of exteriorized bowel in gastroschisis. This could partly explain the beneficial effect of this procedure on fetal gut.

Establishment of reference values of five amniotic fluid enzymes. Analytical performances of the Hitachi 911. Application to complicated pregnancies

OBJECTIVES

to evaluate the analytical performances of the Hitachi 911 analyzer (Roche Diagnostics, F) for gamma-glutamyl-transferase, 5'nucleotidase, amylase, aspartate-amino-transferase and total-alkaline-phosphatase assay in amniotic fluid. To establish reference intervals for these five enzymes throughout gestation. To determine their antenatal diagnostic value.

DESIGN AND METHODS

amniotic fluid samples were collected between 14 and 35 weeks of gestation. Weekly numbers ranged from 31 to 92. Techniques developed for serum enzyme assays were applied to amniotic fluid. Two pools of amniotic fluid containing low and high marker levels were used. Within-day and between-day variations were calculated, together with the limits of detection and linearity. Reference ranges were established on 508 amniotic fluid samples, including 23 samples from pregnancies with chromosomal aberrations, 14 with gastrointestinal tract defects and 5 with gastroschisis.

RESULTS

the assay technique for total-alkaline-phosphatase assay had to be adapted to amniotic fluid, but no adaptation was necessary for the other markers. The within-day CV ranged between 2.2 and 11.2% for low-level samples and from 1.1 to 3.4% for high-level samples. The between-day CV ranged from 6.3 to 13.3% for low-level samples and 1.2 to 4.7% for high-level samples. Total-alkaline-phosphatase activity fluctuated throughout gestation. Amylase levels and aspartate-amino-transferase levels increased whereas gamma-glutamyl-transferase and 5'nucleotidase levels fell until delivery. All trisomy 18 and trisomy 13 pregnancies, 65% of Down's syndrome pregnancies and all pregnancies with digestive tract defects were associated with marked changes in the level of at least one enzyme.

CONCLUSION

The Hitachi 911 is suited to rapid, reliable quantification of amniotic fluid enzymes with only minor adaptation. Useful reference intervals can be obtained throughout gestation. Gamma-glutamyl-transferase, 5'nucleotidase, total-alkaline-phosphatase and amylase assay can help to confirm echographic evidence of bowel disorders and thereby improve patient management especially in case of gastroschisis.

Fetal protein loss in gastroschisis as an explanation of associated morbidity

OBJECTIVE

Our purpose was to examine whether protein deficiency in utero develops in fetuses with gastroschisis.

STUDY DESIGN

Twelve infants with prenatally diagnosed gastroschisis were compared with 29 control infants without gastroschisis and 2 infants with exomphalos who were delivered between 35 and 42 weeks of gestation. The groups were compared for birth weight, cord serum total protein and amniotic fluid total protein, and alpha-fetoprotein concentrations. The amniotic fluid samples were collected when the amniotic membranes were ruptured either during cesarean delivery or at artificial rupture of the membranes, and umbilical cord blood was obtained after delivery.

RESULTS

In the 10 cases of gastroschisis in which cord serum total protein was measured, the median concentration was 51 g/L (range, 43-61 g/L) and was significantly lower than the median level of 62 g/L (range, 47-78 g/L) in the control group (P <.001). In the 8 cases of gastroschisis in which amniotic fluid total protein and alpha-fetoprotein concentrations were measured, the respective median levels were 5.1 g/L (range, 4.3-18.4 g/L) and 5.0 g/L (range, 2.4-13.2 g/L), which were significantly higher than the median levels of 2.0 g/L (range, 0.5-5.4 g/L) and 0.8 g/L (range, 0.5-1.7 g/L) in the control group (P <.0001). The ratio of amniotic fluid to cord serum total protein was significantly higher than that in the cases of exomphalos and in the control group (P <.001). The median birth weight in the neonates with gastroschisis was 2400 g (range, 1192-3155 g) and was significantly lower than the median value of 3535 g (range, 2520-4680 g) in the control group (P <.0001).

CONCLUSIONS

Fetuses with gastroschisis have protein loss that could partly explain associated morbidity. However, whether this is a major contributor to poor fetal outcome remains to be shown.