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Background: The cause of duodenal atresia (DA) is not known. Tandler's "solid cord" hypothesis conflicts with current biological evidence. In humans, a genetic aetiology is supported by the association with Trisomy 21. Interruption of Fgf10 is the strongest genetic link to DA in mice, demonstrating an increased incidence and severity as embryos mature. This project aimed to develop an organoid model to facilitate ex vivo DA research on the FGF10/FGFR2b signalling pathway. We hypothesised that DA morphology represents an evolving spectrum of disease and that Fgf10 knockout organoids would vary in growth pattern compared to wild-type., Methods: Organoids were cultured from the duodenum of E12.5 Fgf10 knockout, heterozygous and wild-type embryos, using an air-liquid interface with Growth Factor reduced Matrigel. Organoids were photographed every 48 h to observe growth. Organoids were isolated and fixed after 14 days, then stained with DAPI, KI-67, and cytokeratin to demonstrate proliferation and differentiation., Results: Wild-type duodenum developed into crypt-forming organoids. Fgf10 heterozygous duodenum failed to progress beyond the development stage of spheroids. Fgf10 knockout duodenum failed to demonstrate any growth. Wholemount staining showed the greatest cell proliferation and differentiation in wild-type tissue., Conclusion: This research presents a novel concept for the growth of embryonic gastrointestinal tissue to inform normal biology. The small sample numbers and restricted culture duration limit longer-term growth analysis. While this model serves as a potential ex vivo setting for future research, that research should consider organoid models with greater standardisation and other gastrointestinal regions., Level of Evidence: Animal/laboratory study., Competing Interests: Conflicts of interest The authors of this paper have no conflicts of interest to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Aims/introduction: It was reported that fetuses secrete endogenous incretin; however, the stimulants of fetal incretin secretion are not fully understood. To investigate the association between the passage of amniotic fluid through the intestinal tract and fetal secretion of incretin, we analyzed umbilical cord incretin levels of infants with duodenum atresia., Materials and Methods: Infants born from July 2017 to July 2019 (infants with duodenum atresia and normal term or preterm infants) were enrolled. We measured and compared the concentrations of glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide/glucose-dependent insulinotropic polypeptide (GIP) in the umbilical vein and preprandial blood samples after birth., Results: A total of 98 infants (47 term, 46 preterm and 5 with duodenum atresia) were included. In patients with duodenum atresia, umbilical vein GLP-1 and GIP levels were the same as those in normal infants. In postnatal samples, there were positive correlations between the amount of enteral feeding and preprandial serum concentrations of GLP-1 (r = 0.47) or GIP (r = 0.49)., Conclusions: Our results show that enteral feeding is important for secretion of GLP-1 and GIP in postnatal infants, whereas the passage of amniotic fluid is not important for fetal secretion of GLP-1 and GIP. The effect of ingested material passing through the digestive tract on incretin secretion might change before and after birth. Other factors might stimulate secretion of GLP-1 and GIP during the fetal period., (© 2020 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.)

Isolated fetal ascites was diagnosed at 20 weeks in a primiparous woman with no significant medical history. Progressive fetal ascites worsened after 28 weeks and resulted in fetal hydroceles. Delivery was by caesarian section at 33 weeks, preceded by reduction of fetal ascites under ultrasound guidance. Following delivery, the baby required further reduction of abdominal fluid and endotracheal intubation to provide respiratory support. An extensive set of investigations, including metabolic and genetic screening, was performed; all results were negative. On day two of life, the baby developed bilious aspirates and an abdominal radiograph suggested intestinal obstruction. At laparotomy, an 'apple peel' jejunal atresia, abnormal mesentery with precarious blood supply and a proximal perforation were identified and the perforation 'sewn over'. The postoperative course was unremarkable, with Monogen feeds tolerated three weeks later. The baby continued to thrive at one year, tolerating increasing amount of long-chain fatty acids in diet., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

We report a rare case of late complication of a complex intestinal malformation. At day 1 of life, a baby girl underwent resection of an atretic jejunal segment, associated with an enteric duplication harboring foci of gastric and duodenal heterotopia. After an asymptomatic period of 19 years, the patient presented with acute bowel obstruction. Recurrence of the jejunal occlusion at the previous anastomotic site was caused by mucosa hyperplasia in association with heterotopic gastric and duodenal tissue. A Wnt/β-catenin pathway deregulation was hypothesized but not confirmed by CTNNB1 exon 3 mutation analysis. This case illustrates a rare association of 3 pathologies-namely, intestinal atresia, enteric duplication, and heterotopia, with a late-occurring acute complication.

Objective: Evaluate accuracy of prenatal ultrasound findings in predicting the risk of bowel atresia in patients with gastroschisis., Methods: A retrospective study was conducted on 18 fetuses with a prenatal diagnostic of gastroschisis treated at University hospital of Saint Etienne France between 2002 and 2012. Ultrasound abnormalities were used to classify them into three groups: no ultrasound abnormality (n=4), oligohydramnios (n=9), intra-abdominal bowel dilatation ≥20.5mm (n=5). Postnatal outcomes were compared between groups. The threshold value of 20.5mm for the prediction of atresia was determined through the receiver operator characteristics curve., Results: In the group with oligohydramnios, intra uterine growth restriction were significantly more frequent (p=0.015) and three newborns had serositis including two with secondary complications after the initial surgery. In the group with major intra-abdominal bowel dilatation, all had a narrow defect <10mm significantly more than other fetuses (p=0.002). Intra-abdominal bowel dilatation reaching 20.5mm started at a mean gestational age significantly lower than that of the other fetuses (23.3 versus 29.7 weeks p=0.02). On the five fetuses presented intra-abdominal bowel dilatation ≥20.5mm, four showed atresia and no other newborn has this complication (p=0.0016). The threshold value of 20.5mm has a sensitivity of 100% and a specificity of 92.9%. The area under the curve was equal to 96.4%., Conclusion: Intra-abdominal bowel dilatation ≥20.5mm seems to be associated with the risk of postnatal atresia. MRI could help to clarify a complicated or uncertain ultrasound aspect., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objective: The accuracy of prenatal ultrasound examination in detecting jejunal and ileal atresia has been reported in the literature to be highly variable, at 25-90%. The aim of this systematic review was to evaluate the accuracy of prenatal ultrasound in detecting non-duodenal small bowel atresia (ND-SBA)., Methods: MEDLINE, EMBASE and The Cochrane Library, including The Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE) and The Cochrane Central Register of Controlled Trials (CENTRAL), were searched electronically. The overall detection rate of jejunal or ileal atresia using ultrasound was reported. The accuracy of using polyhydramnios and dilated loops of bowel as diagnostic signs was also explored., Results: Sixteen studies involving 640 fetuses were included in this review. The detection rate of ND-SBA by prenatal ultrasound was highly variable, with values ranging from 10 to 100%, with an overall prediction of 50.6% (95% CI, 38.0-63.2%). When analyzed separately, the detection rates of jejunal and ileal atresia were 66.3%, (95% CI, 33.9-91.8%) and 25.9% (95% CI, 4.0-58.0%), respectively. Both dilated loops of bowel and polyhydramnios as diagnostic signs for ND-SBA provided a low overall detection rate., Conclusions: The diagnostic performance of prenatal ultrasound in identifying ND-SBA is extremely variable. Large studies are needed in order to identify objective and combined criteria for the diagnosis of these anomalies., (Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.)

Gastrointestinal atresias are a common and serious feature within the spectrum of gastrointestinal malformations. Atresias tend to be lethal, although, now-days surgery and appropriate care can restore function to the affected organs. In spite of their frequency, their life threatening condition and report history gastrointestinal atresias' etiology remains mostly unclarified. Gastrointestinal atresias can occur as sporadic but they are more commonly seen in association with other anomalies. For the syndromic cases there is mounting evidence of a strong genetic component. Sporadic cases are generally thought to originate from mechanical or vascular incidents in utero, especially for the atresias of the lower intestinal tract. However, recent data show that a genetic component may be present also in these cases. Embryological and genetic studies are starting to uncover the mechanism of gastrointestinal development and their genetic components. Here we present an overview of the current knowledge of gastrointestinal atresias, their syndromic forms and the genetic pathways involved in gastrointestinal malformation., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Objectives: To estimate the association between antenatal bowel dilation and postnatal small-bowel atresia in fetal gastroschisis and to establish a threshold at which the risk of adverse neonatal outcome increases., Methods: This was a retrospective cohort study of singleton gestations with an antenatal diagnosis of gastroschisis seen in our ultrasound unit from 2001 to 2010. We reviewed stored images from the last ultrasound examination before delivery, blinded to postnatal diagnoses and outcomes. Fetal intra- and extra-abdominal bowel dilation (IABD and EABD, respectively) and bowel-wall thickness were measured. Previously published definitions of bowel dilation, including > 6, > 10, > 14 and > 18 mm, were evaluated for association with the primary outcome of bowel atresia. The optimal threshold to define fetal bowel dilation was determined by evaluating the significance of association as well as test performance characteristics., Results: Of 109 consecutive patients with fetal gastroschisis, there were four cases of intrauterine fetal demise and three neonatal deaths. Of the 94 live births with complete outcome data, 39 (41.5%) had measurable IABD. There were 14 (14.9%) cases of bowel atresia. Using a threshold of > 14 mm, IABD was significantly associated with an increased risk for bowel atresia (relative risk, 3.1 (95% CI, 1.2-8.2)) with a sensitivity of 57.1%, specificity of 75.0%, positive predictive value of 28.6% and negative predictive value of 90.9%. IABD > 14 mm was also associated with a significantly longer stay in neonatal intensive care unit. There was no significant association between EABD and bowel atresia at any of the thresholds evaluated., Conclusion: IABD > 14 mm is associated with an increased risk for postnatal bowel atresia in fetal gastroschisis. This finding may be useful in counseling patients regarding the anticipated postnatal course for their neonate., (Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.)

Background: Prenatal ultrasound (US) diagnosis of fetal intra-abdominal calcification (iAC) is frequently caused by an in utero perforation causing meconium peritonitis. Our ability to predict which fetuses will require postnatal surgery is limited. The aim of our study is to correlate iAC and associated US findings with postnatal outcome., Methods: A single centre retrospective review of all cases of fetal iAC diagnosed between 2004 and 2010 was performed. Maternal demographics, fetal US findings, and outcomes (need for surgery and mortality) were collected. Descriptive and comparative statistical analyses were performed., Results: Twenty-three cases of iAC were identified. There were no cases of fetal demise or postnatal deaths. Three liveborns (13%) required abdominal surgery at a median of 2 days (0-3) for intestinal atresia. US findings of iAC and dilated bowel with (p=0.008) or without (p=0.005) polyhydramnios predicted a need for postnatal surgery as did the combination of iAC, polyhydramnios, and ascites (p=0.008). Conversely, iAC alone or associated with oligohydramnios, polyhydramnios, ascites, or growth restriction did not predict need for postnatal surgery., Conclusion: The majority of fetuses with iAC on prenatal US do not require surgery. Associated US findings (bowel dilation) can be used to select fetuses for delivery in neonatal surgical centres., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: We correlate severe bowel damage in gastroschisis to the rare intrauterine event of narrowing of the abdominal wall around the protruding intestines. We describe this "closing gastroschisis" as a distinct entity. Prenatal ultrasound findings as gastric or bowel dilation were compared to the postnatal findings in order to find markers for an early in utero diagnosis of closing gastroschisis. Early diagnosis could prompt timely delivery to save the compromised bowel and avoid short gut syndrome., Materials and Methods: We documented the pre- and postnatal course of our patients with gastroschisis from 2007 to 2009.  Closing gastroschisis was suspected antenatally and confirmed postnatally. We identified 5 out of 18 patients showing closure of the abdominal wall with varying degrees of bowel damage. Prenatal ultrasound findings were correlated to the postnatally confirmed extent of intestinal damage., Results: We could not find consistent ultrasound markers for prenatal diagnosis of closing gastroschisis. In prenatal ultrasound three patients presented significant gastric dilation and then experienced severe courses postnatally due to segmental gut necrosis. One of these three died and the other two developed short gut syndrome. In one case progressive intraabdominal loop dilation with simultaneous shrinking of the extraabdominal loops occurred corresponding to closing gastroschisis with segmental midgut necrosis., Conclusion: Closing gastroschisis must be seen as a special form of gastroschisis. Extended intestinal damage is often life-threatening. In longitudinal observation dynamics of fetal ultrasound findings can lead to the diagnosis of closing gastroschisis. Progressive intraabdominal loop dilation is always highly suspicious and must lead to close follow-up and timely delivery., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Homozygous null mutation of the fibroblast growth factor receptor 2IIIb (Fgfr2IIIb) gene in mice results in 42% of embryos developing duodenal atresias. Retinaldehyde dehydrogenase 2 (Raldh2, a gene critical for the generation of retinoic acid) is expressed in the mouse duodenum during the temporal window when duodenal atresias form. Raldh2 is critical for the normal development of the pancreatoduodenal region; therefore, we were interested in the effect of a Raldh2 mutation on duodenal atresia formation. To test this, we rendered Fgfr2IIIb(-/-) embryos haploinsufficient for the Raldh2 and examined these embryos for the incidence and severity of duodenal atresia., Methods: Control embryos, Fgfr2IIIb(-/-) mutants, and Fgfr2IIIb(-/-); Raldh2(+/-) mutants were harvested at embryonic day 18.5, genotyped, and fixed overnight. Intestinal tracts were isolated. The type and severity of duodenal atresia was documented., Results: A total of 97 Fgfr2IIIb(-/-) embryos were studied; 44 had duodenal atresias, and 41 of these presented as type III. In the 70 Fgfr2IIIb(-/-); Raldh2(+/-) embryos studied, a lesser incidence of duodenal atresia was seen (15 of 70; P = .0017; Fisher exact test). Atresia severity was also decreased; there were 12 embryos with type I atresias, 3 with type II atresias, and 0 with type III atresias (P < 2.81E-013; Fisher exact test)., Conclusion: Haploinsufficiency of Raldh2 decreases the incidence and severity of duodenal atresia in the Fgfr2IIIb(-/-) model. The ability to alter defect severity through manipulation of a single gene in a specific genetic background has potentially important implications for understanding the mechanisms by which intestinal atresias arise., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Background: Jejuno-ileal atresia is one of the main causes of intestinal obstruction in neonates. The origin is vascular accidents in the fetal intestine. It is an entity that requires early and specialist management., Objective: to know the factors related to mortality in neonates with jejunoileal atresia., Methods: Case-control nested in a cohort design, comparative study during ten years, between deceased and survivors analyzing factors related to mortality before surgery and during surgery and in the postoperative course., Results: We analyzed 70 patients in 10 years, there were 10 deaths (14.2%). No one had a prenatal diagnosis. Factors related to mortality were: intestinal perforation with a relative risk (RR) of 4.4, peritonitis (RR: 5.6), the need of stomas (RR: 4.9), the presence of sepsis (RR: 4.6) and when the residual small bowel length was below 1 meter (RR: 7.4)., Conclusion: The delay in diagnosis causes late intervention and increased mortality delayed diagnosis promotes late transport of the neonate and enhances mortality, factors associated with mortality related to intestinal perforation. It is necessary to spread this disease in the medical community to improve prenatal and postnatal diagnosis.

Purpose: The purpose of this study is to evaluate (1) the predictive value of fetal bowel dilatation (FBD) for intestinal atresia in gastroschisis and (2) the postnatal management and outcome of this condition., Methods: A retrospective review of all gastroschisis cases diagnosed in our fetal medicine unit between 1992 and 2010 and treated postnatally in our center was performed., Results: One hundred thirty cases had full postnatal data available. Intestinal atresia was found at surgery in 14 neonates (jejunum, n = 6; ileum, n = 3; ascending colon, n = 3; multiple, n = 2). Polyhydramnios and FBD were more likely in the atresia group compared with infants with no atresia (P = .0003 and P = .005, respectively). Fetal bowel dilatation had 99% negative predictive value (95% confidence interval, 0.9-0.99) and 17% positive predictive value (95% confidence interval, 0.1-0.3) for atresia. Treatment of intestinal atresia included primary anastomosis (n = 5), delayed anastomosis (n = 2), and stoma formation followed by anastomosis (n = 7). Infants with atresia had longer duration of parenteral nutrition, higher incidence of sepsis, and cholestasis compared with infants with no atresia (P = .0003). However, the presence of atresia did not increase mortality., Conclusions: Polyhydramnios and FBD are associated with atresia. Absence of FBD in gastroschisis excludes intestinal atresia. In our experience, atresia is associated with a longer duration of parenteral nutrition but does not influence mortality. These findings may be relevant for antenatal counseling., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: Newborn surgery for meconium peritonitis (MP) is sometimes very difficult owing to severe adhesions and bleeding. The aim of this study was to reveal the benefit of primary anastomosis (PA) for MP by comparing PA with multistep operations (MO)., Patients and Methods: We retrospectively reviewed 38 patients with MP who underwent surgery in our institution from 1983 to 2009. From 1983 to 2000, we essentially used MO. After 2001, we used PA with the exception of 1 patient. We performed MO on 20 patients (group A) and PA on 18 patients (group B)., Results: Mortality was 4 in 20 in group A and 1 in 18 in group B. Three patients in group A and 2 in group B required reoperation because of complications. After 2001, 14 of 16 patients underwent PA. Of the 2 patients for whom PA could not be performed, one was postresuscitation from cardiopulmonary arrest and the other was an extremely low-birth-weight infant. The only mortality among the patients who underwent PA occurred in a very low-birth-weight infant who died from intraoperative hepatic hemorrhage., Conclusion: PA can be performed for almost all patients with MP except for extremely low-birth-weight infants., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The association of colonic atresia with craniofacial anomalies has been well described and probably represents a malformative event that occurs in the early embryonal period. We present a case of an infant with colonic atresia and a frontal encephalocele and believe this to be a newly reported association. We review possible pathogenic mechanisms., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Introduction: Intestinal atresias have long been hypothesized to result from either failure of recanalization of the intestinal lumen or in utero vascular accidents. Recent work in animal models is now calling for a reassessment of these widely held paradigms., Purpose: In this review, we will examine the data that led to the original hypotheses and then evaluate more recent work challenging these hypotheses. Furthermore, we will discuss how defining the mechanism of atresia formation in animal models may provide insight into early intestinal development and the mechanism of lengthwise intestinal growth., Conclusion: Such insight will be critical in developing regenerative therapies for patients with intestinal failure.

Intrauterine intussusception is an uncommon cause of intestinal atresia. We report a case of ileal atresia owing to antenatal intussusception revealed as an intraluminal polypoid lesion after surgical intervention.

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.

The authors present a previously unreported association of different types of intestinal atresia in identical low-birth-weight twins. Both babies were affected by duodenal atresia, associated in the first case with a complete mucosal duodenal membrane and in the second one with an "apple-peel" jejunal atresia. These occurrences may suggest that they were either the consequence of linkage of 2 genes or a pleiotropic expression of a single gene responsible for such rare conditions.

Multiple jejunoileal atresia is a challenge to the pediatric surgeon. The aim of the study is to preserve bowel length and prevent the long-term complications of short bowel syndrome. The authors present a rare case of combined multiple jejunoileal atresia and colonic atresia managed by 9 primary anastomoses over a gastroperineal transanastomotic tube. This technique avoided the use of stomas and their attendant complications.

Familial cases of the various types of intestinal atresia are well described, and we now report an additional family. Based on a review of the literature, a classification system for the different types of familial atresia is presented. Current teaching attributes most jejunoileal atresias to in utero vascular accidents occurring relatively late in gestation (after the 11th or 12th week). Although some cases clearly occur this way, as a result of processes such as volvulus and intussusception, knowledge of the familial form of the disease indicates that most cases of jejunoileal atresia actually result from disruption of a normal embryologic pathway, most likely the development of the superior mesenteric artery and its branches. They should be considered to be true embryologic malformations rather than acquired lesions.

We encountered one case of duodenal atresia complicated by massive intrauterine hemorrhage due to the perforation of an umbilical cord ulceration (UCU). UCU is an extremely rare complication in the perinatal period. Although the prenatal diagnosis of upper intestinal atresia has been established, little is known about the association between UCU and upper intestinal atresia. In this article, we report our case, review past articles, and discuss the underlying pathophysiological mechanisms of the cause of an UCU. Given the characteristic sites of upper intestinal atresia, we speculate that regurgitation of gastric or intestinal juice into the amniotic fluid could be responsible for the development of UCU. We also believe that close observation is required for patients who have upper intestinal atresia.

Small bowel atresia is associated with a large size discrepancy between the proximal and distal segments of bowel that has traditionally been managed by resection of the dilated segment, tapering enteroplasty, or plication. Longitudinal intestinal lengthening is rarely performed at the time of the initial operation. Many patients with small bowel atresia also have a short length of residual small intestine secondary to in utero resorption. The authors present the clinical application of the novel intestinal lengthening procedure, the serial transverse enteroplasty, in a neonate with proximal jejunal atresia and suggest that it become part of the armamentarium for surgeons treating patients with this anomaly.

Purpose: Duodenal obstruction occurs in 1 of 6000 live births and requires urgent surgical intervention. Duodenal atresia previously has been ascribed to a developmental failure of luminal recanalization; however, the cause of duodenal atresia remains incompletely understood. Although familial intestinal atresias have been described and syndromic associations are known, no specific genetic link has been established. Fibroblast growth factor-10 (Fgf10) is a known regulatory molecule relevant to mesenchymal-epithelial interactions, and mice deficient in Fgf10 demonstrate congenital anomalies in several organ systems including the gastrointestinal tract. The authors hypothesized that Fgf10 could serve a regulatory role in establishing normal duodenal development., Methods: Wild-type mice with beta-galactosidase under the control of the Fgf10 promoter were harvested from timed-pregnancy mothers. The expression of Fgf10 in the duodenum during development was evaluated by developing the embryos in X-Gal solution. Wild-type and mutant Fgf10(-/-) embryos were harvested from timed-pregnancy mothers at 18.5 days postconception (near term) and were analyzed for duodenal morphology (Institutional Animal Care and Use Committee-approved protocol 32-02). Photomicrographs were reviewed., Results: Fibroblast growth factor-10 is active in the duodenum at a late stage of development. The Fgf10(-/-) mutants demonstrate duodenal atresia with a variable phenotype similar to clinical findings. The duodenum fails to develop luminal continuity and has proximal dilation. The phenotype occurs in an autosomal recessive pattern with incomplete penetrance (38%)., Conclusions: Fibroblast growth factor-10 serves as a regulator in normal duodenal growth and development. Its deletion leads to duodenal atresia and challenges traditionally accepted theories of pathogenesis. This novel, genetically mediated duodenal malformation reflects an animal model that will allow further evaluation of the pathogenesis of this surgically correctable disease. By studying the mechanism of Fgf10 function in foregut development, the authors hope to better understand these anomalies and to explore possible therapeutic alternatives.

Background/purpose: Colonic atresia occurs in 1:20,000 live births, offering a neonatal surgical challenge. Prenatal expression of fibroblast growth factor 10 (Fgf10), acting through fibroblast growth factor receptor 2b (Fgfr2b), is critical to the normal development of the colon. Invalidation of the Fgf10 pathway results in colonic atresia, inherited in an autosomal recessive pattern. Classically, disturbance of the mesenteric vasculature has been thought to cause many forms of intestinal atresia. The purpose of this study was to evaluate the role of vascular occlusion in the pathogenesis of colonic atresia., Methods: Wild type (Wt), Fgf10(-/-), and Fgfr2b(-/-) mutant mouse embryos were harvested from timed pregnant mothers. Immediately following harvest, filtered India ink was infused via intracardiac microinjection. The gastrointestinal tract was dissected, and photomicrographs of the mesenteric arterial anatomy were taken at key developmental time points., Results: Photomicrographs after India ink microinjections demonstrate normal, patent mesenteric cascades to the atretic colon at the time points corresponding to the failure of colonic development in the Fgf10(-/-) and Fgfr2b(-/-) mutants. The mesenteric arterial anatomy of the colon demonstrates no difference between the Wt and mutant colonic atresia., Conclusions: The absence of embryonic expression of Fgf10 or its receptor Fgfr2b results in colonic atresia in mice. India ink microinjection is a direct measure of mesenteric arterial patency. Colonic atresia in the Fgf10(-/-) and Fgfr2b(-/-) mutants occurs despite normal mesenteric vascular development. Thus the atresia is not the result of a mesenteric vascular occlusion. The patent colonic mesentery of the Fgf10(-/-) and Fgfr2b(-/-) mutants challenges an accepted pathogenesis of intestinal atresia. Although colonic atresia can occur as a result of vascular occlusion, new evidence exists to suggest that a genetic mechanism may play a role in the pathogenesis of this disease.

Background/purpose: Duodenal atresia (DA) occurs in 1 in every 6,000 live births and represents a significant surgically correctable cause of intestinal obstruction in the neonate. Familial or congenital DA has been reported, implying that at least some cases of DA are the result of genetic, heritable abnormalities. The genes controlling duodenal development are incompletely understood. Fibroblast growth factor receptor 2IIIb (Fgfr2b) is known to play a critical role in the development of multiple organ systems including other gastrointestinal tract (GIT) structures. This study shows the key role of Fgfr2b in normal duodenal development and the pathogenesis of DA., Methods: Wild type (Wt) and Fgfr2b-/- embryos were harvested from timed pregnant mothers at stage E18.5 and were analyzed for duodenal phenotype., Results: Inactivation of Fgfr2b results in DA. DA is present in the Fgf2b-/- mutants with a 35% penetrance. The duodenal phenotype of the Fgf2b-/- mutants ranges from normal to a mucosal web, type I, and type III atresia., Conclusions: Fgfr2b is a critical regulatory gene in the development of the duodenum. Fgfr2b invalidation (Fgfr2b-/- mutant) results in a reproducible, autosomal recessive duodenal atresia phenotype with incomplete penetrance and a variable phenotype.

A spectrum of congenital anomalies have been described in an adriamycin-treated model with common features to the human pattern. Multiple intestinal atresias was part of this spectrum occurring in 25% of full-term experimental rat fetuses. The aim of this study was to examine the underlying developmental mechanism that results in intestinal atresia. Virgin timed-pregnant Sprague-Dawley rats were injected with Adriamycin i.p. at a dose of 2 mg/kg on days 6-9 of gestation. Embryos were removed on different gestational days during organogenesis and serial transverse histologic sections were examined and compared with control specimens. In experimental embryos, hindgut atresia was seen in day 12 embryos. Attachment of the intestine with the notochord was obvious observation resulting in abnormal position of the intestine. In some specimens the atretic intestine was splitting the dorsal aorta or even located behind the dorsal aorta. It is concluded that in the adriamycin-animal model, notochord-intestinal failure of detachment resulted in intestinal atresia during the beginning of organogenesis period. The possible underlying mechanisms are pinching of some endodermal cells as well as interference with normal intestinal circulation resulting in ischemic necrosis.

Background/purpose: Prenatal exposure to Adriamycin in a rat model (ARM) has been reported to lead to a spectrum of tracheoesophageal and associated malformations of the gastrointestinal tract, including multiple intestinal atresias. An abnormal relationship of the notochord with the foregut has been implicated in the formation of esophageal atresias. The authors hypothesised that midgut atresias arise from abnormal notochord development in the region of the midgut. This study was designed to examine the gut-notochord relationship during early embryonic development., Methods: Timed pregnant Wistar rats were given 1.75 mg/kg of Adriamycin intraperitoneally on days 7, 8, and 9 of gestation. Embryos were recovered at 12-hour intervals from days 9.5 to 14, and at term. A control group was given saline instead of Adriamycin. Embryos were embedded in resin or wax, sectioned, and studied using light microscopy, paying particular attention to the notochord and surrounding structures., Results: The notochord appeared identical in controls and experimental embryos on day 9.5. However, on day 10.5 the notochord was diffusely abnormal in ARM, distorted, and tethered to foregut as well as midgut compared with controls. This abnormality was not seen in control embryos. On day 12 the notochord abnormalities were more exaggerated in the region of the midgut in ARM embryos. Full-term ARM animals had esophageal and multiple intestinal atresias., Conclusions: The notochord is abnormal in the region of the developing midgut, and this may account for the occurrence of atresias found in this region., (Copyright 2002, Elsevier Science (USA). All rights reserved.)

It was proposed that the pathogenesis of multiple intestinal atresias (MIA) in human fetuses is a consequence of malformative processes of the gastrointestinal tract rather than an ischemic process. Recently, MIA has been described in adriamycin-exposed rat fetuses. The aim of this study was to describe the embryogenesis of hindgut atresia (HA) in the adriamycin animal model. Timed-pregnant Sprague-Dawley rats were injected with adriamycin on days 6-9 of gestation. Embryos were removed on different gestational days during organogenesis and histologic sections were examined and compared with control specimens. In experimental embryos, HA was seen on day 13; however, the lumen was patent on day 12. HA was associated with abnormal vascular anatomy that was obvious on days 12 and 13. It is concluded that HA in adriamycin-exposed embryos occurs at the beginning of organogenesis. Although it was associated with an obvious vascular anomaly, further studies are required to find out whether it is ischemic in origin.

Multiple gastrointestinal atresias (MGA) have been reported to account for 6% to 32% of all intestinal atresias. Controversy exists regarding the pathogenesis. Many investigators believe MGA to be the result of multiple ischemic infarctions of the intestinal tract. However, some have suggested that MGA results from a malformative process early in fetal life. Prenatal exposure to adriamycin in a rat model has been reported to lead to a spectrum of tracheoesophageal and associated malformations of the gastrointestinal tract, including intestinal atresias, identical to these observed in humans. The aim of this study was to determine the incidence and histopathologic findings of MGA in order to understand the pathogenesis. Timed-pregnant Sprague-Dawley rats were injected with adriamycin (1.75 mg/kg) in nine different gestational-day protocols. MGA was only seen in those rats who received adriamycin on gestational days 7, 8, and 9. The litters were recovered on day 21 by cesarean section. The digestive tracts (DT) of the fetuses were harvested for macroscopic and microscopic examination. Ten rats who received adriamycin on gestational days 7, 8, and 9 produced 87 newborns; 1 was damaged during dissection. DT anomalies occurred in 80 (93%) of the 86 newborns; 94% of these demonstrated MGA. There was a very high incidence of associated anomalies in newborns with MGA. Histologically, the blind-ending atresias showed different degrees of villous hyperplasia with or without intraluminal material. This is the first report demonstrating a high rate of occurrence of MGA in the adriamycin rat model. The injection of adriamycin early in gestation, the high incidence of associated malformations, and the anatomic and histologic findings in MGA indicate that MGA is a result of a malformative rather than an ischemic process.

The management of a case of antenatally diagnosed meconium peritonitis (MP) due to intrauterine intestinal perforation secondary to bowel atresia is reported. The literature is reviewed with reference to the significance and outcome of antenatally diagnosed MP.

A child with loss of the third and fourth part of the duodenum and of the proximal jejunum was found to have an apple peel configuration of the remaining small bowel. The complete absence of branches from the superior mesenteric artery impaired the blood supply of the distal duodenum. An annular pancreas was found in this patient with Down's syndrome. This anomaly may have impaired the flow through the pancreaticoduodenal arcade, which would normally compensate for the distal vascular occlusion. According to current understanding, duodenal atresia is a primary malformation. The current case suggests, however, that in rare circumstances vascular accidents may be the underlying cause for duodenal atresia.

The embryogenesis of pancreaticobiliary maljunction is inferred from the embryogenesis of duodenal atresia. The epithelial cells of the duodenum begin to proliferate and completely plug the lumen, but a process of vacuolation recanalizes the duodenum. Recanalization of the common duct frequently appears with two lumina and openings into the duodenum with two orifices. These two major canals create a narrow segment of the duodenum and this narrow zone is the area in the duodenum that is most prone to faulty recanalization and atresia formation. A bifid biliary system inserts at blind upper and lower pouches of the duodenum, and the common bile duct inserts in a Y fashion. The common bile duct inserts at the stenotic segment, and the end result is a T-shaped formation in patients with duodenal stenosis. During the development of the bile duct, abnormal fusion may occur between the bile duct and branches of the right ventral pancreatic duct. The site in the bile duct where a branch of the pancreatic duct joins is likely to develop atresia due to disturbance of the recanalization process, as seen in duodenal atresia. Severe impairment of vacuolation causes divided atretic bile duct at the site where the pancreatic duct inserts in a Y-fashion into the upper and lower bile duct. Moderate impairment of vacuolation causes a stenosis at the site where the pancreatic duct inserts in a T-shape, with a moderate dilatation of the bile duct.

Embryological development of duodenum is believed to go through a "solid core" stage which subsequently vacuolizes. Failure of vacuolization is thought to be the cause of duodenal atresia. This study examines the embryological development of rat duodenum. Thirty-six time-mated Sprague-Dawley rats were studied. Six fetal duodenal specimens were obtained for each gestational day from day 9 to day 20. These specimens were fixed with formalin, sectioned, stained with haematoxylin and eosin and examined under microscope. The duodenal diameters and the lumen diameters at each gestational date were measured. The foregut started to form at the gestation stage of day 10. The lumen was narrowest on days 12 and 13, but the duodenum did not become a "solid core". No vacuolization was detected through out the development of the duodenum. Embryological development of rat duodenum did not go through a "solid core" stage.

Colonic atresia (CA) has been reported in association with Hirschsprung's Disease (HSCR) on 11 previous occasions. In most reported cases the atresia has involved the right side of the colon; but in this, the twelfth case report, the atresia involved the left side of the colon, with aganglionosis of the entire distal gut. In addition, the child had an absent hand. The authors believe that this triad has not been reported previously. The literature is reviewed, and possible mechanisms are discussed.

The 'double bubble' sign in prenatal diagnosis is most often associated with duodenal atresia. However, other causes of upper intestinal obstruction and cystic abdominal masses need to be considered. One possible diagnosis that can mimic the 'double bubble' sign of duodenal atresia is duodenal duplication, but little information is available to guide sonologists in the prenatal diagnosis of this rare congenital anomaly. In this case report we describe the successful prenatal diagnosis of duodenal duplication, by relying on the early gestational age of presentation, the lack of polyhydramnios, the failure to consistently demonstrate a 'double bubble' on transverse images, and the presence of a normal distal bowel pattern.

A newborn with a mummified right paraumbilical intestinal remnant, closed abdominal wall, and loss of most of the midgut raises important questions concerning embryonic abdominal wall closure and the intrauterine events leading to gastroschisis and "congenital" short gut syndrome.

Objective: This study was carried out to evaluate the significance of amniotic fluid protein ingestion and absorption on fetal growth., Methodology: Neonates with small bowel atresia during a 30 year period were studied retrospectively., Results: There were 56 patients enlisted, 17 with duodenal atresia, 18 with jejunal atresia and 21 with ileal atresia. The percentage of mothers with polyhydramnios and the percentage of premature babies decreases as the intestinal atresia becomes more distal. The mean gestational age and the mean birthweight increase as the intestinal atresia becomes more distal. On the other hand, the percentage of the neonates with birthweight below the 50th and the 10th percentiles do not differ significantly as the intestinal atresia becomes more distal., Conclusions: It appears that the variation of birthweights in babies with different levels of small bowel atresia may be due to the difference in gestation caused by polyhydramnios. The effect of amniotic fluid protein absorption on fetal bodyweight could not be demonstrated clinically in this study.

A collaborative study was performed to determine the different types and mechanisms of intestinal abnormalities during gestation. Cases had to fulfill one or more of the following three criteria: (1) meconium ileus, (2) intestinal stenosis or atresia, and (3) meconium peritonitis. Esophageal atresia, anorectal atresia, and abdominal wall defects were excluded. One hundred two cases were reviewed from the autopsies of 42 induced abortions, 22 stillborns, and the surgical findings in 38 neonates. Meconium ileus was detected mainly during the second trimester (28/38), and was associated with cystic fibrosis (15), fetal blood deglutition (4), infection (6), or multiple-abnormalities (10), in which three chromosomal aberrations were found. Intestinal stenosis or atresia was more commonly detected during the third trimester of gestation (46/56). Sixteen of the 30 duodenal malformations were associated with trisomy 21, whereas in the 26 small intestinal atresias, signs of distress or ischemia were most frequently detected. Only 8 of 25 meconium peritonitis cases were isolated. A total of 20 cystic fibrosis cases could be proved. In this series, functional abnormalities were observed predominantly in the second trimester and associated mainly with cystic fibrosis or amniotic fluid abnormalities. Anatomic lesions were commonly detected later on and associated with ischemic conditions, chromosomal aberrations, and even cystic fibrosis.

To investigate the effect of normal fetal swallowing and amniotic fluid ingestion on small intestinal disaccharidase development, 13 pregnant New Zealand White rabbits underwent operation on day 24 of a normal 31-day gestation. The right ovarian fetus in the bicornuate uterus underwent esophageal ligation (EL), while the contralateral left fetus underwent cervical exploration only, and served as the control (C). Rabbits were sacrificed on gestational day 31, fetal somatic measurements obtained, and the midjejunum removed for determination of disaccharidase activity and protein content. There was one maternal death, and 9 of 12 fetal pairs survived the entire study period (75%). Results are reported as mean +/- SEM, analyzed by two-tailed Student's t testing with P < .05 being considered significant. Fetal weight was decreased in EL (48.6 +/- 2.7 g) versus C (51.4 +/- 3.2 g) (P = .06). Small intestinal length decreased in EL (49.2 +/- 2.0 cm) versus C (54.9 +/- 1.1 cm) (P = .01). Midjejunal protein content (mg/mL homogenate) was also significantly decreased in EL (38.4 +/- 3.4) versus C (46.2 +/- 3.7) (P = .05). Sucrase activity was not detectable in either group. Lactase activity in jejunal mucosa was not effected when expressed as units of enzyme per milliliter of homogenate (EL = 0.357 +/- 0.03 v C = 0.373 +/- 0.04; P = .70) and units enzyme per gram of protein (EL = 38.8 +/- 4.2 v C = 34.2 +/- 4.6; P = .44). We have confirmed previous studies demonstrating decreases in somatic growth, small intestinal length, and mucosal nutrient transport in rabbit fetuses following esophageal ligation.(ABSTRACT TRUNCATED AT 250 WORDS)

This paper examines the effects of experimental prenatal intestinal obstruction on the growth and blood composition of chick embryos. Intestinal atresia (IA) was produced by bipolar bowel electrocoagulation in fertile eggs on the 14th day of incubation. The chicks sacrificed on the 19th day were measured, weighed and blood-sampled. Twenty-three control, 10 sham-operated and 11 IA chicks were studied. Animals with IA were severely undernourished by weight (43.4 +/- 4.7 vs 70.3 +/- 7.6% of egg weight, p < 0.001) and length (15.3 +/- 1.1 vs 18.1 +/- 9 mm. tibial length, p < 0.001) in comparison with sham-operated ones. Their haematocrit was slightly lower, and total protein increased. Pre-albumin was absent in their sera and albumin, alpha and beta globulins were significantly decreased whereas gamma-globulin was greatly increased. Sodium, potassium chloride, urea and glucose remained within normal limits. The lack of placenta in the avian embryo precludes any supply of nutrients by this route and the ingestion of amniotic fluid, which is protein-rich after the 13th day of incubation, when the opening of the sero-amniotic connection allows albumen to be mixed with it, becomes the main source of nutrients until hatching. Obstruction of the main incoming avenue by IA induces severe malnutrition in this model which relies on this route to a greater extent than the human foetus. In spite of the obvious biological differences between the avian embryo and the human foetus, the present evidence supports the hypothesis that prenatal interruption of the amniotic fluid transit contributes to foetal undergrowth in IA.