Gastroschisis: State of the Art in Translating Experimental Research to the Bedside.

The survival rate of newborns with gastroschisis (GS) has been increasing in the past decades; however, the morbidity continues to be high, mainly related to the length of hospitalization due to disturbances of motility, absorption, and risk of intestinal infections. The development of basic research with the creation of experimental models has provided enormous advances in the understanding of the pathophysiology of the disease. These models allowed the study of the target genes involved in the embryology of the defect, the influence of the amniotic fluid, and the use of drugs and fetal therapies in an attempt to reduce the intestinal damage and to provide a rapid return of intestinal motility. Our aim was to describe the main GS models and the translational, historical impact of these research advances on the disease.

The glucagon like peptide-2 'axis': Capacity for production and response following intestinal resection or repair of gastroschisis in infants.

PURPOSE: This study investigates the relationship between the enteric hormone glucagon-like peptide 2 (GLP-2) production, sensitivity, and intestinal adaptation in infants following resection or repair of gastroschisis. METHODS: With IRB approval (UCalgary #10656), consent was obtained from families of infants undergoing surgery for prospective monitoring of nutritional status, GLP-2 levels, and where possible, tissue sampling. RESULTS: Infants who adapted and weaned from parenteral nutrition (PN) had increased GLP-2 (86±32) n=24 vs. controls: 45±20 n=10 and vs. patients on prolonged PN: 42±6 pM, n=10). This was maintained to one year: weaned patients: 72±49 vs. non-weaned: 35±15 pM (p<0.05). Infants with gastroschisis (n=33) had decreased GLP-2 levels until enteral function was achieved and then became elevated: (21±15 with first feeding vs. 102±60 at full feeds and 60±19 pM at one year). There were no changes in the density or distribution of GLP-2 producing L-cells related to gestational age, nor in the expression of the GLP-2 receptor. CONCLUSION: GLP-2 levels correlate with intestinal adaptation in infants, and with recovery of intestinal function in gastroschisis. GLP-2 productive capacity (L-cell expression) and GLP-2 receptor expression do not vary with maturity. The findings support a role for GLP-2 in regulating intestinal function. Further study is suggested.

Chlamydia trachomatis Is Responsible for Lipid Vacuolation in the Amniotic Epithelium of Fetal Gastroschisis.

BACKGROUND: Vacuolated amniotic epithelium with lipid droplets in gastroschisis placentas is an unusual finding. Mass spectrometry of lipid droplets identified triglycerides, ester-linked to an unusual pattern of fatty acids. We hypothesize that these findings result from a Chlamydia trachomatis infection during the periconceptional period. The rising incidence of chlamydia infections has paralleled the increasing prevalence of gastroschisis among women less than 25 years of age. Histologically, young women are at greatest risk for a chlamydia infection due to their immature columnar epithelium, the preferential site for attachment of Chlamydia trachomatis infectious particle (elementary body). METHODS: Chlamydia trachomatis survive in an inclusion, relying on its host to acquire essential nutrients, amino acids, and nucleotides for survival and replication. If essential nutrients are not available, the bacteria cannot replicate and may be trafficked to the lysosome for degradation or remain quiescent, within the inclusion, subverting innate immunologic clearance. RESULTS: Chlamydiae synthesize several lipids (phosphatidylethanolamine, phosphatidylserine, and phosphoatidylglycerol); however, their lipid content reveal eukaryotic lipids (sphingomyelin, cholesterol, phosphatidylcholine, and phosphatidylinositol), evidence that chlamydiae "hijack" host lipids for expansion and replication. CONCLUSION: The abnormal amniotic epithelial findings are supported by experimental evidence of the trafficking of host lipids into the chlamydiae inclusion. If not lethal, what harm will elementary bodies inflict to the developing embryo? Do these women have a greater pro-inflammatory response to an environmental exposure, whether cigarette smoking, change in partner, or a pathogen? Testing the hypothesis that Chlamydia trachomatis is responsible for amniotic epithelium vacuoles will be a critical first step. Birth Defects Research 109:1003-1010, 2017. © 2017 Wiley Periodicals, Inc.

Use of bedside abdominal ultrasound to confirm intestinal motility in neonates with gastroschisis: A feasibility study.

BACKGROUND: Optimal timing to begin feeds in neonates with gastroschisis remains unclear. We examined if bedside abdominal ultrasound for intestinal motility is a feasible tool to detect return of bowel function in neonates with gastroschisis. METHODS: Neonates born with uncomplicated gastroschisis who underwent closure received daily ultrasound exams. Full motility was defined as peristalsis seen in all quadrants. Average length of time between abdominal wall closure and start of enteral feeds, full ultrasound motility, and clinical characteristics was compared using Student's t-tests. RESULTS: Seventeen patients were enrolled. No differences were found between motility on ultrasound and bowel movements, gastric residuals, or nonbilious residuals. Mean time to enteral feeds (11.82days) was significantly delayed compared to documentation of full motility on ultrasound (8.94days; p=0.012), consistent bowel movements (8.41days; p=0.006), low gastric residuals (9.47days; p<0.001), and nonbilious residuals (9.18days; p<0.001). In the single subject in which feeds were started before full motility was seen on ultrasound, feeds were subsequently discontinued because of emesis. CONCLUSION: Bedside abdominal ultrasound provides real-time evidence regarding intestinal motility and is a feasible tool to detect return of bowel function in neonates with gastroschisis. Future studies are needed to determine if abdominal ultrasound can shorten time to start of enteral feeds. LEVEL OF EVIDENCE: III (diagnosis: nonconsecutive study).

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

OBJECTIVE: Intraamniotic meconium has been responsible for intestinal damage in gastroschisis and meconium-dependent intestinal ischemia has been proposed to induce additional intestinal damage in gastroschisis. This study is aimed to determine the effects of lipid and water-soluble meconium subfractions on the contractility of the superior mesenteric artery (SMA). MATERIALS AND METHODS: The study was conducted on 18-day fertilized chick embryos (Gallus Domesticus). Meconium is fractioned into water and lipid-soluble components. Only one SMA tissue was prepared from each embryo and suspended in the organ bath. Isometric contraction responses (ICR) were created in SMA tissues by one hour of incubation in Krebs-Henseleit solution for each group. Groups consisted of control, meconium, water-soluble meconium subfraction and lipid-soluble meconium subfraction. ICR of the SMA specimens were evaluated with a transducer-amplifier system on a computer. The data were expressed (mean±1SD) as milliNewton (mN). RESULTS: The ICR of the meconium, water-soluble meconium subfraction and lipid-soluble meconium subfraction groups were significantly high when compared to the control group (p<0.01). The meconium and water-soluble meconium subfraction created more contraction response than the lipid-soluble meconium subfraction (p<0.01). The ICR of the meconium group was not different from the ICR of the water-soluble meconium subfraction group (p>0.05). CONCLUSION: Water-soluble meconium subfraction has a profound vasoconstrictor effect on the SMA compared to the lipid-soluble meconium subfraction.

Does a large abdominal wall defect affect lung growth?

BACKGROUND/PURPOSE: Respiratory distress in babies with large abdominal wall defects suggests a relationship to decreased diaphragmatic movement. We evaluated pulmonary development in a fetal lamb gastroschisis model. METHODS: We created gastroschisis in 25 fetal lambs at 60days gestation (group A). Controls were 14 nonoperated lambs. (Group B) were all delivered at term. Lung volume, histology, and type 1 (AT1)/type 2 (AT2) cell ratios (AT1 ratio) were determined. We subdivided group A, comparing lambs with a large defect and scoliosis [group A (S)] with the remainder [group A (NS)]. RESULTS: Twenty-five lambs survived (11 fetuses in group A and 14 fetuses in group B). Lung volume in group A (S) was less than in group A (NS) (p<0.05). The AT1 ratio in group A was lower than in group B (p<0.01), without any difference in radial alveolar counts (RACs) or alveolar growth, and no association between scoliosis and alveolar differentiation. CONCLUSION: Gastroschisis in a sheep model reduces the AT1 ratio but not the RAC. Severe scoliosis affects lung volume but not the AT1 ratio, suggesting reduced diaphragmatic movement in fetuses with large abdominal defects.

Effect of gestational age at birth on neonatal outcomes in gastroschisis.

INTRODUCTION: Induced birth of fetuses with gastroschisis from 34weeks gestational age (GA) has been proposed to reduce bowel damage. We aimed to determine the effect of birth timing on time to full enteral feeds (ENT), length of hospital stay (LOS), and sepsis. METHODS: A retrospective analysis (2000-2014) of gastroschisis born at ≥34weeks GA was performed. Associations between birth timing and outcomes were analyzed by Mann-Whitney test, Cox regression, and Fisher's exact test. RESULTS: 217 patients were analyzed. Although there was no difference in ENT between those born at 34-36+6weeks GA (median 28 range [6-639] days) compared with ≥37weeks GA (27 [8-349] days) when analyzed by Mann-Whitney test (p=0.5), Cox regression analysis revealed that lower birth GA significantly prolonged ENT (p=0.001). LOS was significantly longer in those born at 34-36+6weeks GA (42 [8-346] days) compared with ≥37weeks GA 34 [11-349] days by both Mann-Whitney (p=0.02) and Cox regression analysis (p<0.0005). Incidence of sepsis was higher in infants born at 34-36+6weeks (32%) vs. infants born at ≥37weeks (17%; p=0.02). CONCLUSIONS: Early birth of fetuses with gastroschisis was associated with delay in reaching full enteral feeds, prolonged hospitalization, and a higher incidence of sepsis.

Gastroesophageal reflux and congenital gastrointestinal malformations.

Although the outcome of newborns with surgical congenital diseases (e.g., diaphragmatic hernia; esophageal atresia; omphalocele; gastroschisis) has improved rapidly with recent advances in perinatal intensive care and surgery, infant survivors often require intensive treatment after birth, have prolonged hospitalizations, and, after discharge, may have long-term sequelae including gastro-intestinal comorbidities, above all, gastroesophageal reflux (GER). This condition involves the involuntary retrograde passage of gastric contents into the esophagus, with or without regurgitation or vomiting. It is a well-recognized condition, typical of infants, with an incidence of 85%, which usually resolves after physiological maturation of the lower esophageal sphincter and lengthening of the intra-abdominal esophagus, in the first few months after birth. Although the exact cause of abnormal esophageal function in congenital defects is not clearly understood, it has been hypothesized that common (increased intra-abdominal pressure after closure of the abdominal defect) and/or specific (e.g., motility disturbance of the upper gastrointestinal tract, damage of esophageal peristaltic pump) pathological mechanisms may play a role in the etiology of GER in patients with birth defects. Improvement of knowledge could positively impact the long-term prognosis of patients with surgical congenital diseases. The present manuscript provides a literature review focused on pathological and clinical characteristics of GER in patients who have undergone surgical treatment for congenital abdominal malformations.

Effect of Meconium on the Contractility of the Superior Mesenteric Artery: A Clue to Intestinal Damage in Gastroschisis.

INTRODUCTION: Intestinal damage has been shown to occur when intra-amniotic meconium concentration exceeds threshold level. However, the mechanism of the meconium-induced intestinal damage is still unclear. Intestinal ischemia can cause intestinal damage in gastroschisis. This study was aimed to determine the effects of intra-amniotic meconium on the contractility of superior mesenteric artery (SMA). MATERIALS AND METHODS: Eighteen-day-old fertilized chick embryos (Gallus Domesticus) were extirpated and intestines were harvested. The SMA specimens were prepared as 4 mm segments in the organ bath with Krebs-Henseleit buffer. The isometric contraction responses of the SMA specimens were evaluated with norepinephrine, different meconium concentrations, and clear amniotic fluid. Maximum isometric contractions responses (MICR) of the SMA specimens were recorded with an amplifier system on a computer. RESULTS: In the norepinephrine group, MICR was found as 2.92 ± 0.57 mN. While MICR of the 1/100 meconium group (highest meconium concentration) was found as 1.56 ± 0.40 mN, MICR of the clear amniotic fluid group was 0.41 ± 0.07 mN. The MICR of the norepinephrine group was significantly increased compared with the 1/100 meconium and clear amniotic fluid groups. MICR of the 1/100 meconium group was also found to be significantly increased compared with clear amniotic fluid group. No statistically significant difference was found among the meconium subgroups. CONCLUSION: Intra-amniotic meconium in fetuses with gastroschisis might cause ischemic intestinal damage by reducing the intestinal blood flow. Further studies are needed to show the outcomes of the vasoactive effect of meconium on the SMA blood flow.

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

BACKGROUND: Intestinal damage causes intestinal dysmotility in gastroschisis. Urinary trypsin inhibitor (UTI) has been shown to prevent intestinal damage in chick embryos with gastroschisis. The effect of intra-amniotic administration of UTI on intestinal motility in gastroschisis has not been investigated. METHODS: Five-day-old fertilized chick embryos were used. Gastroschisis was created through the amniotic cavity without opening the allantoic cavity. There were six groups; control, gastroschisis only, gastroschisis plus meconium and three treatment groups. In the treatment groups, 100 IU/mL, 200 IU/mL and 400 IU/mL UTI were instilled into the amniotic cavity of the gastroschisis plus meconium embryos, respectively. Serosal thickness of the intestines in each group was measured histopathologically. The contractions of the intestines were evaluated by in vitro organ bath technique and the responses were expressed as maximal contraction induced by acetylcholine. RESULTS: The serosal thickness was significantly increased in the gastroschisis plus meconium, 100 IU/mL, 200 IU/mL UTI groups compared to control and gastroschisis only groups. The serosal thickness of the 400 IU/mL UTI group was similar to control and gastroschisis only groups. Contractility of the intestines was diminished in the gastroschisis plus meconium, 100 IU/mL and 200 IU/mL UTI groups. There was no significant difference regarding contractility among control, gastroschisis only and 400 IU/mL UTI groups. CONCLUSION: Intra-amniotic administration of UTI preserves intestinal contractility in chick embryos with gastroschisis. However, preservation of intestinal dysmotility by using UTI in the human gastroschisis cases needs further experimental and clinical trials.

Gastric contractility in experimental gastroschisis.

BACKGROUND/PURPOSE: The mechanism of fetal gastric dilation in gastroschisis is controversial. This study was designed to characterize changes in the contractile profile of strips of stomach from rats following experimental gastroschisis. METHODS: Pregnant Wistar rats were operated on day 18.5. Fetuses were divided into three groups: gastroschisis (G), sham (S), and control (C). On day 21.5, gastric fundus and antrum strips were obtained and suspended to a force transducer connected to a digital data acquisition system. They were submitted to increasing concentrations of carbachol (CCh) and weighed at the end of each procedure. Frequency and amplitude of each contraction were evaluated. RESULTS: Under basal conditions, spontaneous oscillatory contractions of antrum and fundus strips of G, S, and C were similar (P>0.05; ANOVA). However, cumulative concentrations of CCh (0.01-100 µM) produced different effects in all groups and were characterized by a significant increase in amplitude and frequency of spontaneous contractions in antral smooth muscle and a sustained increase in tonus in fundic strips. Upon analysis, no significant difference in frequency or amplitude was noted in antral tissues comparing C to G and to S (P>0.05). No significant contractility difference was noted in fundic smooth muscle (comparing all groups, P>0.05), with the CCh-induced curve following a typical sigmoidal format, dependent on increasing concentrations (P<0.001). CONCLUSIONS: Gastric contractile responses to CCh are preserved in experimental gastroschisis. These results do not support the theory that gastric dilation occurs secondary to intestinal inflammation alone.

Enteric nervous system impairment in gastroschisis.

INTRODUCTION: After surgical repair of gastroschisis, most neonates exhibit severe intestinal dysmotility. We hypothesized that impaired development of the enteric nervous system or interstitial cells of Cajal (ICC) network contributes to impaired intestinal motility in gastroschisis. We evaluated this hypothesis in a rat model of gastroschisis. MATERIAL AND METHODS: Gastroschisis was created surgically in rat fetuses on gestational day 18, under general anesthesia, and small bowel was harvested on day 22. Intestinal weight-to-length (IW/L) ratio, and small-bowel wall thickness were assessed. Specimens were processed for hematoxylin-eosin staining or immunohistochemistry with specific markers for neuronal cells (Hoxb5), glial cells (GFAP, S100), and ICCs (c-kit). Myenteric plexus maturation was assessed morphologically and compared with sham and control fetuses. Stage of development of the myenteric plexus was graded from 1 (mature) to 3 (very immature) comparatively with specimens from E16 to E22 control fetuses. RESULTS: Compared with sham-operated or control fetuses, gastroschisis was associated with increases in mean intestinal weight/intestinal length (IW/L) ratio, and mean thicknesses of the total, muscular, and submucosal layers of the small-bowel wall. The myenteric plexus were present in the small bowel from fetuses with gastroschisis, however all exhibited abnormal myenteric plexus maturation. Thus, of the gastroschisis fetuses, 55% had an aspect similar to the immature myenteric plexus of E19-E20 fetuses and 45% to the very immature mesenteric plexus observed in E16-E18 fetuses. When compared with sham and control groups, ICCs were less abundant in eviscerated small bowel in the gastroschisis group and often exhibited weak c-kit staining or an abnormally round shape without branches. Hoxb5, a marker for enteric neuroblasts and neuronal precursors, was expressed similarly in myenteric plexuses in all groups. S100 or GFAP staining showed the presence of glial cells within the myenteric plexuses in all groups. The S100 expression level was similar in all groups. In contrast, the GFAP expression level was higher in the gastroschisis group than in the sham and control groups. CONCLUSION: Our results suggest that delayed maturation of the enteric nervous system combined with impaired ICC network development may largely explain the intestinal dysmotility seen in neonates with gastroschisis.

Medical management of motility disorders in patients with intestinal failure: a focus on necrotizing enterocolitis, gastroschisis, and intestinal atresia.

BACKGROUND: Intestinal failure (IF) is the dependence upon parenteral nutrition to maintain minimal energy requirements for growth and development. It may occur secondary to a loss of bowel length, disorders of motility, or both. Short bowel syndrome (SBS) is a malabsorptive state resulting from surgical resection, congenital defect, or diseases associated with loss of absorptive surface area. A particularly vexing problem is associated with whole bowel and/or segmental intestinal dysmotility. Motility disorders within the context of SBS and IF may relate to rapid intestinal transit secondary to loss of intestinal length, dysmotility associated with loss or poor antegrade peristalsis, or gastroparesis. Therapy may be classified into medical (prokinetic and antidiarrheal agents) and surgical to deal with the overdistended poorly motile bowel. METHODS: We performed a systematic review of the literature pertaining to IF, SBS, and dysmotility in the pediatric population with gastroschisis, necrotizing enterocolitis, and intestinal atresia. In addition to the available treatment options, we have provided a review of the literature and a summary of the available evidence. CONCLUSION: Despite relatively poor level of evidence regarding the application of promotility and antidiarrheal medications in patients with SBS and IF, these agents continue to be used. Herein, we provide a review of the physiology and pathophysiology of intestinal motility/dysmotility and available strategies for the use of promotility and antidiarrheal agents in patients with IF/SBS.

Antenatal diagnosis of bowel dilatation in gastroschisis is predictive of poor postnatal outcome.

PURPOSE: Although gastroschisis infants usually have a good outcome, there remains a cohort of babies who fare poorly. We inquired whether the presence of bowel dilatation in utero is predictive of postnatal course in infants with gastroschisis. METHODS: We compared the clinical course of infants who had bowel dilatation with those who did not. Bowel dilatation was defined as more than 20 mm in cross-sectional diameter on ultrasound at any gestational age. Outcome measures used were length of time of parenteral nutrition, death, and surgery for intestinal failure. RESULTS: A review of 170 infants with gastroschisis identified 74 who had dilatation of more than 20 mm (43.5%). There was no significant difference in the incidence of intestinal atresia in those with bowel dilatation and those without (P = .07). Those with bowel dilatation spent a longer period on parenteral nutrition. There were significantly more deaths in the group with bowel dilatation (P = .01). There was no significant difference in the number of infants requiring surgery for intestinal failure between the 2 groups (P = .47). CONCLUSIONS: We found that sonographically detected bowel dilatation more than 20 mm in utero in fetuses with gastroschisis may have value in predicting clinically significant adverse postnatal outcomes.

The embryologic origin of ventral body wall defects.

Ventral body wall defects include ectopia cordis, bladder exstrophy, and the abdominal wall malformations gastroschisis and omphalocele. The etiology of ectopia cordis, gastroschisis, and bladder exstrophy is not known, but they may be linked to abnormalities in the lateral body wall folds responsible for closing the thoracic, abdominal, and pelvic portions of the ventral body wall. These folds form in the fourth week (postfertilization) of development as a combination of the parietal layer of lateral plate mesoderm and overlying ectoderm and must move ventrally to meet in the midline. There are differential rates of cell proliferation in the folds and asymmetries in their movement that may be involved in teratogenic effects of toxic factors. Also, the fusion process between the folds is complex, involving cell-to-cell adhesion, cell migration, and cell reorganization and all of these phenomena may be targets for disruption, leading to malformations. In this regard, closure of the ventral body wall is likened to neural tube closure and involves similar processes. It also encompasses a similar time frame during development, such that most neural tube and ventral body wall defects have their origins during the fourth week of development. Omphalocele is a separate entity whose etiology is known. This defect is attributed to a failure of gut loops to return to the body cavity after their normal physiological herniation into the umbilical cord from the 6th to 10th week of development. Thus, the origin of this defect is completely different from that of the ventral body wall malformations.

Gastroschisis: a gene-environment model involving the VEGF-NOS3 pathway.

Gastroschisis is a severe major malformation in which an infant is delivered with a portion of intestines and possible other abdominal organs extruding through a defect in the abdominal wall, usually to the right of the umbilical cord. Etiologies of gastroschisis are largely unknown, and even its pathogenesis is poorly understood. Several recent epidemiological studies have identified interactions between maternal smoking during pregnancy, genetic variants of endothelial nitric oxide synthase, and risk for gastroschisis. We present a brief review of the endothelial nitric oxide synthase pathway and its relationship to vasculogenesis, suggesting that disruption of this pathway by environmental exposures or by genetic variation may represent one pathogenetic model for gastroschisis.

Left-sided gastroschisis: higher incidence of extraintestinal congenital anomalies.

PURPOSE: The purpose of this study was to present 3 cases of left-sided gastroschisis and review the literature concerning this rare condition. METHODS: Charts of 3 previously unreported patients with left-sided gastroschisis were reviewed. A literature review of all cases of left-sided gastroschisis was completed. RESULTS: Sixteen patients with left-sided defects were identified, only 12 of whom had classic periumbilical defects. We present 3 additional patients. Eleven of 15 patients were female, with 1 patient's sex not reported. Forty percent had extraintestinal anomalies. CONCLUSIONS: Left-sided gastroschisis is more common in females and associated with a higher incidence of extraintestinal anomalies compared with right-sided lesions. Although the etiology remains unknown, it may differ from that of right-sided gastroschisis.

Splanchnic perfusion pressure: a better predictor of safe primary closure than intraabdominal pressure in neonatal gastroschisis.

BACKGROUND/PURPOSE: Both measured intraabdominal pressure (IAP) and calculated splanchnic perfusion pressure (SPP) have been advocated for use in operative management of gastroschisis. We directly compared these 2 clinical indices. METHODS: Institutional review board-approved multi-institutional retrospective review from 3 centers with 112 subjects. Splanchnic perfusion pressure was recorded as mean arterial pressure-IAP. We compared the clinical utility of IAP and SPP using univariate and multivariate regression analyses. RESULTS: Calculated mean SPP was higher among neonates requiring silo placement compared to those without (39.0 +/- 1.9 vs 33.7 mm Hg, P < .01). Measured IAP levels were similar between groups (11.5 +/- 1.1 vs 10.0 +/- 0.5, mm Hg, P < .4). On a receiver operating characteristic curve, the inflection point for more than 90% specificity for silo placement was at an SPP of 44. In multivariate regression analysis adjusting for all factors below, SPP was independently associated with silo placement (odds ratio 1.2, 95% confidence interval 1.1-1.3, P < .01), and IAP was not (odds ratio 1.2, 95% confidence interval <1.0-1.5, P < .1). CONCLUSIONS: These data suggest that SPP is a stronger predictor than IAP for the ability to achieve primary closure in the management of neonatal gastroschisis. We infer from these data that intraoperative SPP of more than 43 mm Hg may obviate the need for silo placement.

Erythropoietin restores bowel damage and hypoperistalsis in gastroschisis.

BACKGROUND AND PURPOSE: Despite the decreased mortality in gastroschisis (Gx), patients experience postoperative intestinal hypoperistalsis, malabsorption, and shortened bowel length. The trophic effects of recombinant human erythropoietin (rEpo) in the developing small bowel have been reported, increasing the length and height of the villi, and villous surface area. This study investigated the effects of rEpo on intestinal malfunction in the chick embryos with Gx. METHODS: Thirteen-day-old fertilized chicken eggs were used to create Gx model. Study groups included the following: group 1, control; group 2, Gx-only; group 3, Gx + 0.075% saline exchange; group 4, Gx + 10 IU rEpo exchange; group 5, Gx + 20 IU rEpo exchange. The bowels were evaluated by in vitro muscle strip technique, and the response was expressed as a percentage of the maximum carbachol-evoked contraction (Emax). In addition, parasympathetic ganglion cells per 10 plexuses and villi height were determined by light microscopy. Results were evaluated statistically by Mann-Whitney U, chi2, and Fisher's Exact test tests. RESULTS: Saline exchange had no effect on ganglion cell number (P = .63) and villi height (P = .10). In group 4, ganglion cell number was not increased (P = .82), but villi height increase was significant (P = .03). In Gx + 20 IU rEpo group, both the number of ganglia (P = .0001) and villi height (P = .002) were significantly increased. The decrease in contractility in group 2 (P = .0121) was significantly reversed by rEpo 20 IU treatment (P = .0216), no significant difference was obtained in groups 3 (P = .0809) and 4 (P = .1516) compared with group 2. CONCLUSION: These data suggest that rEpo has prokinetic effects on hypoperistalsis and restores bowel damage in Gx.