European Paediatric Surgeons' Association Survey on the Management of Hirschsprung Disease.

Aim This study aims to define patterns of Hirschsprung disease (HD) management. Methods An online questionnaire was sent to all European Paediatric Surgeons' Association (EUPSA) members. Results A total of 294 members (61 countries) answered (response rate: 61%). DIAGNOSIS: All respondents perform rectal biopsies (61% rectal suction [RSBs], 39% open full-thickness), 96% contrast enema, and 31% anorectal manometry. At RSB, 17% take the most distal biopsy 1 cm above the dentate line, 34% take 2 cm, 30% take 3 cm, and 19% take > 3 cm. Rectal biopsy staining's are hematoxylin/eosin (77%), acetylcholinesterase (74%), calretinin (31%), S100 (2%), nicotinamide adenine dinucleotide-tetrazolium reductase (2%), succinate dehydrogenase (1%), and neuron-specific enolase (1%). A total of 85% respondents recognize entities including hypoganglionosis (69%), intestinal neuronal dysplasia (55%), and ultrashort segment HD (50%). SURGERY: Pull-through (PT) is performed at diagnosis by 33% or delayed by 67% (4 months or > 5 kg). Awaiting definitive surgery, 77% perform rectal irrigations, 22% rectal dilatation/stimulations, and 33% perform a stoma. The preferred type of PT is the Soave approach (65%), performed with transanal technique by 70% respondents. If symptoms persist after PT, most opt for conservative approach (enemas/laxatives = 76%; botulinum toxin = 27%), 30% would redo the PT. Total colonic aganglionosis: PT is performed in neonates (4%), at 1 to 6 months (29%), 6 to 12 months (37%) or older (30%). If required, a stoma is sited in the ileum (31%), according to intraoperative biopsies (54%), macroscopic impression (13%), and radiology (2%). Duhamel PT is performed by 52%, Soave by 31%, and Swenson by 17%. Overall, 31% would perform a J-pouch. Conclusions Most aspects of HD management lack consensus with wide variations in obtaining a diagnosis. Transanal Soave PT is the most common technique in standard segment HD. Guidelines should be developed to avoid such variability in management and to facilitate research studies.

Increased uptake of dietary retinoids at the maternal-fetal barrier in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: The retinol signaling pathway is disrupted in congenital diaphragmatic hernia (CDH). Since there is no fetal retinol synthesis, maternal retinol has to cross the placenta. Nitrofen interferes with the retinol-binding protein (RBP) transfer pathway in CDH. However, in RBP knockout mice, retinol has been shown to be present. In this model, increased uptake of maternal dietary retinyl ester (RE) bounded in low-dense-lipoprotein (LDL) through low-density-lipoprotein-receptor 1 (LRP1) and increased activity of RE hydrolysis by lipoprotein-lipase (LPL) have been found. The aim of this study was to investigate the RE transfer pathway in the nitrofen CDH model. METHODS: Pregnant rats were treated with nitrofen or vehicle on gestational day (D9) and sacrificed on D21. Immunohistochemistry was performed to evaluate LRP1 and LPL protein expression. Serum LDL levels were measured by ELISA. Pulmonary and serum retinoid levels were measured using HPLC. RESULTS: Markedly increased trophoblastic and pulmonary LRP1 and LPL immunoreactivity were observed in CDH compared to controls. Significantly increased serum LDL and RE levels were observed in CDH compared to controls. CONCLUSIONS: The increased uptake of dietary retinoids at the maternal-fetal barrier in the nitrofen CDH model suggests that the RE transfer pathway may be the main source of retinol in this model.

Nitrofen increases total retinol levels in placenta during lung morphogenesis in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: It has been shown that pulmonary retinol level is decreased during lung morphogenesis in the nitrofen-induced PH in congenital diaphragmatic hernia (CDH). Placenta has a major role in the retinol homeostasis in fetal life. Since there is no fetal retinol synthesis, maternal retinol has to cross the placenta. Placenta is the main fetal retinol store where retinol is stored in retinyl-ester formation. Trophoblasts have to produce its own retinol-binding protein (RBP) for retinol transport from placenta to fetus. Recently, we demonstrated that trophoblastic RBP expression is decreased in the nitrofen model of CDH. The aim of this study was to investigate the retinol transfer from mother to the placenta in nitrofen model of CDH. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal placenta harvested on D21 and divided into two groups: control (n = 11) and nitrofen with CDH (n = 11). Retinoid levels in placenta were measured using HPLC. Immunohistochemistry was performed to evaluate trophoblastic expression of main RSP genes. RESULTS: Total retinol levels in the placenta were significantly increased in CDH placenta compared to control placenta. The retinyl-ester levels were significantly increased in CDH placenta compared to control placenta. Markedly, decreased immunoreactivity of retinoid signaling pathway was observed in trophoblast cells in CDH compared to control placenta. CONCLUSIONS: Increased placental retinol levels show that retinol is transferred from mother to placenta and stored in the placenta in nitrofen model of CDH during lung morphogenesis. Nitrofen may disturb the mobilization of retinol from placenta to fetal circulation causing PH in CDH.

Variants of Hirschsprung disease.

Variants of Hirschsprung disease are conditions that clinically resemble Hirschsprung disease, despite the presence of ganglion cells in rectal suction biopsies. The characterization and differentiation of various entities are mainly based on histologic, immunohistochemical, and electron microscopy findings of biopsies from patients with functional intestinal obstruction. Intestinal neuronal dysplasia is histologically characterized by hyperganglionosis, giant ganglia, and ectopic ganglion cells. In most intestinal neuronal dysplasia cases, conservative treatments such as laxatives and enema are sufficient. Some patients may require internal sphincter myectomy. Patients with the diagnosis of isolated hypoganglionosis show decreased numbers of nerve cells, decreased plexus area, as well as increased distance between ganglia in rectal biopsies, and resection of the affected segment has been the treatment of choice. The diagnosis of internal anal sphincter achalasia is based on abnormal rectal manometry findings, whereas rectal suction biopsies display presence of ganglion cells as well as normal acetylcholinesterase activity. Internal anal sphincter achalasia is either treated by internal sphincter myectomy or botulinum toxin injection. Megacystis microcolon intestinal hypoperistalsis is a rare condition, and the most severe form of functional intestinal obstruction in the newborn. Megacystis microcolon intestinal hypoperistalsis is characterized by massive abdominal distension caused by a largely dilated nonobstructed bladder, microcolon, and decreased or absent intestinal peristalsis. Although the outcome has improved in recent years, survivors have to be either maintained by total parenteral nutrition or have undergone multivisceral transplant. This review article summarizes the current knowledge of the aforementioned entities of variant HD.

Prenatal retinoic acid upregulates connexin 43 (Cx43) gene expression in pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia rat model.

PURPOSE: Connexin 43 (Cx43), a major gap junction protein, is necessary for alveologenesis and plays an important role in the differentiation of type II to type I alveolar epithelial cells. Knockout mice of Cx43 display severe pulmonary hypoplasia (PH). Prenatal administration of retinoic acid (RA) is known to stimulate alveologenesis in nitrofen-induced PH. Recent studies revealed that retinoids upregulate Cx43 expression. We hypothesized that gene expression of Cx43 is downregulated during alveologenesis and that administration of RA upregulates Cx43 expression in the nitrofen-induced PH. METHODS: Pregnant rats were exposed to olive oil or nitrofen on day 9 (D9) of gestation. Retinoic acid was given intraperitoneally on D18, D19, and D20. Fetal lungs were harvested on D18 and D21 and divided into control, nitrofen, control+RA (D21), and nitrofen+RA (D21). The Cx43 expression levels were determined using reverse transcription polymerase chain reaction and immunohistochemistry. RESULTS: On D18 and D21, Cx43 relative messenger RNA expression levels were significantly downregulated in nitrofen compared with those in the control group. On D21, expression levels of Cx43 were significantly upregulated in nitrofen+RA and control+RA compared with those in nitrofen group. Immunohistochemical studies confirmed these results. CONCLUSION: Downregulation of Cx43 expression may interfere with normal alveologenesis. Upregulation of Cx43 pulmonary gene expression after RA treatment may promote lung growth by stimulating alveologenesis in nitrofen-induced PH.

Does the length of the history influence the outcome of pneumatic reduction of intussusception in children?

PURPOSE: Intussusception is the most common cause of acute abdomen in infants and preschool children. Nonoperative reduction using air enema is an established treatment in children with intussusception. The aim of this study was to determine whether length of the history influences the outcome of pneumatic reduction of intussusception in children? METHODS: The medical records of 256 consecutive children with intussusception between July 1998 and June 2010, who underwent air enema reduction regardless of the length of the history were reviewed. In all 256 patients, intussusception was confirmed by ultrasound before proceeding to air enema. RESULTS: The length of history ranged from 2 to 240 h with median time of 18.5 h. The median age in 256 patients was 7 months (range 1 day to 12 years). The presenting clinical features included irritability/abdominal pain (77%), vomiting (80%), bleeding per rectum (36%) and palpable abdominal mass (50%). Air enema reduction was successful in 234 (91.5%) of the 256 patients. In 22 (8.5%) patients, air enema failed to reduce the intussusception and 3 (1.1%) of these patients had colonic perforation during the procedure. All 22 patients required surgery. The duration of symptoms did not influence the outcome of pneumatic reduction. 37 (14%) patients developed recurrence after successful pneumatic reduction of intussusception, with 58% presenting within 48 h of the initial procedure. CONCLUSION: Our data suggest that pneumatic reduction should be first-line treatment in all children with intussusception regardless of the length of the history.

Prenatal treatment with retinoic acid activates parathyroid hormone-related protein signaling in the nitrofen-induced hypoplastic lung.

PURPOSE: Prenatal treatment with retinoic acid (RA) has been reported to stimulate alveologenesis in hypoplastic lungs (HL) in the nitrofen model of congenital diaphragmatic hernia (CDH). Parathyroid hormone-related protein (PTHrP) promotes alveolar maturation by stimulating surfactant production, regulated by PTHrP receptor (PTHrP-R). PTHrP knockout and PTHrP-R null mice both exhibit pulmonary hypoplasia. We have recently reported that nitrofen inhibits PTHrP signaling in the nitrofen-induced HL. Because both PTHrP and PTHrP-R genes have RA-inducible element, we hypothesized that prenatal administration of RA upregulates pulmonary gene expression of PTHrP and PTHrP-R in the nitrofen-induced HL. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). RA was given on days D18, D19 and D20. Fetal lungs were obtained on D21 and divided into four groups: control, control + RA, nitrofen, nitrofen + RA. RT-PCR and Immunohistochemistry were performed to investigate the pulmonary PTHrP and PTHrP-R gene and protein expression in each group, respectively. RESULTS: The pulmonary gene expression levels of PTHrP and PTHrP-R were significantly increased in nitrofen + RA group compared to nitrofen group (p < 0.05). Immunoreactivity of PTHrP and PTHrP-R was also remarkably increased in nitrofen + RA group compared to nitrofen group. CONCLUSIONS: Upregulation of PTHrP and PTHrP-R genes after prenatal treatment with RA in the nitrofen-induced HL suggests that RA may have a therapeutic potential in reverting lung hypoplasia in CDH, by stimulating surfactant production and alveolar maturation.

Altered regulation of retinoic acid synthesis in nitrofen-induced hypoplastic lung.

Retinoids are a group of molecules derived from vitamin A, which play an important role in lung development. Within the cell, retinol can either be oxidized to retinal or esterified to retinyl esters by lecithin : retinol acyltransferase (LRAT) for storage. Retinal is then oxidized to an active metabolite of vitamin A, retinoic acid (RA) by retinal dehydrogenase (RALDH). RA is the active metabolite of vitamin A. Cyp26 (a1,b1, and c1), which is a member of the cytochrome P450 family, acts by reducing the activity of RA. Cyp26 type b1 is the predominant subtype expressed in the murine lung. Several studies have suggested that nitrofen may interfere with the retinoid pathway resulting in congenital diaphragmatic hernia (CDH) and pulmonary hypoplasia. Recently, it was reported that nitrofen may act by inhibiting RALDH2. The aim of this study was to examine the pulmonary expression of Cyp26b1, LRAT, and RALDH2, the key enzymes involved in the synthesis of RA, in order to understand the mechanisms underlying pulmonary hypoplasia in the nitrofen CDH model. Pregnant rats were exposed to either olive oil or 100 mg of nitrofen on day 9 of gestation (D9). Fetal lungs were harvested at D15, D17, D19, and D21. D17, D19, and D21 lungs were divided into three groups: control, nitrofen without CDH and nitrofen with CDH, whereas D15 lungs were divided into only two groups; control and nitrofen as the diaphragm is not fully formed yet at this stage. Real- time PCR was performed to evaluate the relative level of Cyp26b1, LRAT, and RALDH2 expression in the lung. Relative levels of Cyp26b1 mRNA were significantly decreased in the lungs of nitrofen with CDH (D17;0.19 +/- 0.09, D19;0.70 +/- 0.20, D21;0.40 +/- 0.36) and nitrofen without CDH (D17;0.14 +/- 0.06, D19;0.54 +/- 0.42, D21;0.51 +/- 0.56) compared to controls (D17;0.35 +/- 0.16, D19;1.15 +/- 0.48, D21;1.28 +/- 0.78) (P < 0.05). LRAT expression was also significantly decreased in nitrofen with CDH (D17; 19.3 +/- 7.8, D19; 4.3 +/- 1.1, D21; 3.3 +/- 1.6) and nitrofen without CDH (D17; 21.2 +/- 11.1, D19; 4.5 +/- 3.6, D21; 4.1 +/- 1.6) compared to controls (D17; 153.7 +/- 29.8, D19; 26.8 +/- 16.8 D21; 10.1 +/- 3.8) (P < 0.05). There was no significant difference in the relative levels of Cyp26b1 and LRAT between nitrofen with CDH and nitrofen without CDH. There were no significant differences in RALDH2 expression among the groups at any stages. Down-regulation of Cryp26b1 and LRAT demonstrates that RA content is decreased in nitrofen induced hypoplastic lungs compared to controls. The finding that RALDH2 expression in the hypoplastic lung is not altered suggests that nitrofen may act by interfering with the retinoid metabolism during the early stage of the retinoid signaling pathway.