Outcomes of Premature Infants With Type C Esophageal Atresia.

BACKGROUND: To review the outcomes of premature patients with type C esophageal atresia (EA). METHODS: In this retrospective cohort study, charts of patients of type C EA patients were reviewed from 1992 to 2022. Outcomes of premature patients were compared to term patients. Preterm patients were analyzed to compare outcomes of infants with very low birth weights (VLBW) to patients >1,500 g as well as primary versus delayed anastomosis. RESULTS: Among 192 type C EA, 67 were premature. Median and interquartile range (IQR) gestational age and birth weight of preterm patients were 34 [33-36] weeks and 1965 [1740-2290] g. Delayed anastomosis was performed in 12 (18%) preterm vs. 3 (2%) term patients (p = 0.0003). Short-term postoperative outcomes were similar between preterm and term patients, except for recurrent fistula (16% vs. 6%, p = 0.01). Prematurity was associated with an increased need for long-term enteral tube feeding (56% vs. 10%, p = 0.0001) and parenteral nutrition (10 days vs. 0 days, p = 0.0004). The length of stay was 3 times longer when patients were premature (50 days vs. 17 days, p = 0.002). Delayed surgery in preterm patients was associated with post-operative leaks, strictures, recurrent fistula, prolonged enteral tube feeding, and gastrostomy insertion. Patients with very low birth weight (VLBW) were compared to other preterm patients and showed no difference in terms of rate of delayed surgery, and post-operative outcomes. CONCLUSION: Despite increased prematurity-related comorbidities and low birth weight, premature infants with type C EA/TEF have similar post-operative outcomes to term patients though recurrent fistula was more frequent with prematurity. TYPE OF STUDY: Retrospective cohort study. LEVEL OF EVIDENCE: III.

The Vagus Nerve Regulates Immunometabolic Homeostasis in the Ovine Fetus near Term: The Impact on Terminal Ileum.

BACKGROUND: Glucosensing elements are widely distributed throughout the body and relay information about circulating glucose levels to the brain via the vagus nerve. However, while anatomical wiring has been established, little is known about the physiological role of the vagus nerve in glucosensing. The contribution of the vagus nerve to inflammation in the fetus is poorly understood. Increased glucose levels and inflammation act synergistically when causing organ injury, but their interplay remains incompletely understood. We hypothesized that vagotomy (Vx) will trigger a rise in systemic glucose levels and this will be enhanced during systemic and organ-specific inflammation. Efferent vagus nerve stimulation (VNS) should reverse this phenotype. METHODS: Near-term fetal sheep (n = 57) were surgically prepared using vascular catheters and ECG electrodes as the control and treatment groups (lipopolysaccharide (LPS), Vx + LPS, Vx + LPS + selective efferent VNS). The experiment was started 72 h postoperatively to allow for post-surgical recovery. Inflammation was induced with LPS bolus intravenously (LPS group, 400 ng/fetus/day for 2 days; n = 23). For the Vx + LPS group (n = 11), a bilateral cervical vagotomy was performed during surgery; of these n = 5 received double the LPS dose, LPS800. The Vx + LPS + efferent VNS group (n = 8) received cervical VNS probes bilaterally distal from Vx in eight animals. Efferent VNS was administered for 20 min on days 1 and 2 +/10 min around the LPS bolus. Fetal arterial blood samples were drawn on each postoperative day of recovery (-72 h, -48 h, and -24 h) as well as at the baseline and seven selected time points (3-54 h) to profile inflammation (ELISA IL-6, pg/mL), insulin (ELISA), blood gas, and metabolism (glucose). At 54 h post-LPS, a necropsy was performed, and the terminal ileum macrophages' CD11c (M1 phenotype) immunofluorescence was quantified to detect inflammation. The results are reported for p < 0.05 and for Spearman R2 > 0.1. The results are presented as the median (IQR). RESULTS: Across the treatment groups, blood gas and cardiovascular changes indicated mild septicemia. At 3 h in the LPS group, IL-6 peaked. That peak was decreased in the Vx + LPS400 group and doubled in the Vx + LPS800 group. The efferent VNS sped up the reduction in the inflammatory response profile over 54 h. The M1 macrophage activity was increased in the LPS and Vx + LPS800 groups only. The glucose and insulin concentrations in the Vx + LPS group were, respectively, 1.3-fold (throughout the experiment) and 2.3-fold higher vs. control (at 3 h). The efferent VNS normalized the glucose concentrations. CONCLUSIONS: The complete withdrawal of vagal innervation resulted in a 72-h delayed onset of a sustained increase in glucose for at least 54 h and intermittent hyperinsulinemia. Under the conditions of moderate fetal inflammation, this was related to higher levels of gut inflammation. The efferent VNS reduced the systemic inflammatory response as well as restored both the concentrations of glucose and the degree of terminal ileum inflammation, but not the insulin concentrations. Supporting our hypothesis, these findings revealed a novel regulatory, hormetic, role of the vagus nerve in the immunometabolic response to endotoxin in near-term fetuses.

Pediatric Aerodigestive Medicine: Advancing Collaborative Care for Children With Oropharyngeal Dysphagia.

OBJECTIVES: Aerodigestive disorders encompass various pathological conditions affecting the lungs, upper airway, and gastrointestinal tract in children. While advanced care has primarily occurred in specialty centers, many children first present to general pediatric gastroenterologists with aerodigestive symptoms necessitating awareness of these conditions. At the 2021 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the aerodigestive Special Interest Group held a full-day symposium entitled, Pediatric Aerodigestive Medicine: Advancing Collaborative Care of Children with Aerodigestive Disorders. The symposium aimed to underline the significance of a multidisciplinary approach to achieve better outcomes for these complex patients. METHODS: The symposium brought together leading experts to highlight the growing aerodigestive field, promote new scientific and therapeutic strategies, share the structure and benefits of a multidisciplinary approach in diagnosing common and rare aerodigestive disorders, and foster multidisciplinary discussion of complex cases while highlighting the range of therapeutic and diagnostic options. In this article, we showcase the diagnostic and therapeutic approach to oropharyngeal dysphagia (OPD), one of the most common aerodigestive conditions, emphasizing the role of a collaborative model. CONCLUSIONS: The aerodigestive field has made significant progress and continues to grow due to a unique multidisciplinary, collaborative model of care for these conditions. Despite diagnostic and therapeutic challenges, the multidisciplinary approach has enabled and greatly improved efficient, high-quality, and evidence-based care for patients, including those with OPD.

The International Network on Oesophageal Atresia (INoEA) consensus guidelines on the transition of patients with oesophageal atresia-tracheoesophageal fistula.

Oesophageal atresia-tracheoesophageal fistula (EA-TEF) is a common congenital digestive disease. Patients with EA-TEF face gastrointestinal, surgical, respiratory, otolaryngological, nutritional, psychological and quality of life issues in childhood, adolescence and adulthood. Although consensus guidelines exist for the management of gastrointestinal, nutritional, surgical and respiratory problems in childhood, a systematic approach to the care of these patients in adolescence, during transition to adulthood and in adulthood is currently lacking. The Transition Working Group of the International Network on Oesophageal Atresia (INoEA) was charged with the task of developing uniform evidence-based guidelines for the management of complications through the transition from adolescence into adulthood. Forty-two questions addressing the diagnosis, treatment and prognosis of gastrointestinal, surgical, respiratory, otolaryngological, nutritional, psychological and quality of life complications that patients with EA-TEF face during adolescence and after the transition to adulthood were formulated. A systematic literature search was performed based on which recommendations were made. All recommendations were discussed and finalized during consensus meetings, and the group members voted on each recommendation. Expert opinion was used when no randomized controlled trials were available to support the recommendation. The list of the 42 statements, all based on expert opinion, was voted on and agreed upon.

Faecal calprotectin: Marker of intestinal inflammatory process in anorexia nervosa? A preliminary study.

PURPOSE: Anorexia Nervosa (AN) is a serious and potentially lethal mental disorder characterised by a deliberate quest to reduce one's weight. It can have multiple physical and psychological consequences. The clinical presentation of AN can include gastrointestinal symptoms, however, the pathophysiology of these symptoms in the context of AN remains uncertain. It is hypothesised that patients with AN may have an increase in intestinal permeability, which could lead to an increase in faecal calprotectin (fCP), a marker of intestinal inflammation. No relation between AN and elevation of fCP has been previously described in literature. METHODS: Eight patients hospitalised for AN have a dosage of fCP. RESULTS: Calprotectine was found to be elevated in 50% of cases, with or without any underlying comorbid gastrointestinal disease. Only the duration of illness tended to be associated with the increase in fCP suggesting a greater alteration as a function related to the time of denutrition. CONCLUSION: Although these findings provide insights in the potential pathophysiology of gastrointestinal symptoms in AN, further studies that evaluate the factors associated with elevated fCP in patients with AN are needed.

Indocyanine green fluorescence angiography in pediatric intestinal resections: A first prospective mixed methods clinical trial.

BACKGROUND: The aim of this study was to establish the feasibility and safety of the use of indocyanine green technology during pediatric intestinal resections. While indocyanine green fluorescence angiography (ICG-FA) has been advocated as an imaging technique to assess bowel perfusion in adults, few studies have evaluated this technology in a pediatric context. METHODS: A prospective clinical trial was conducted. Patients 16 years old or younger undergoing a surgery potentially requiring an intestinal resection were eligible. Patients received a standardized intravenous injection of indocyanine green and intestinal perfusion was evaluated. The study endpoints included safety, impact on bowel resection and feasibility and acceptance of ICG-FA in this population. RESULTS: From May 2020 to March 2021, 30 consecutive patients were included in this trial. Final analysis was done on 28 patients with a median age of 15.00 [6.36,85.00] weeks and weight of 5.58 [3.64,11.70] kg at surgery. Adequate fluorescence was achieved in less than one minute for all cases with an average dose of 0.14 mg/kg. No adverse event related to indocyanine green occurred. ICG-FA versus standard assessment of potential resection sites differed in 62% (95% IC 0.41-0.82) of our cases. Qualitative analysis demonstrated that 95% of the surgical team agreed that ICG-FA was safe. CONCLUSIONS: The use of ICG-FA is feasible and safe for pediatric intestinal resections. Introduction of ICG-FA was simple and acceptance rates were high within the surgical team. This fluorescence imaging may be a valuable imaging technology for intestinal resections in pediatric surgery.

iPSCs derived from esophageal atresia patients reveal SOX2 dysregulation at the anterior foregut stage.

A series of well-regulated cellular and molecular events result in the compartmentalization of the anterior foregut into the esophagus and trachea. Disruption of the compartmentalization process leads to esophageal atresia/tracheoesophageal fistula (EA/TEF). The cause of EA/TEF remains largely unknown. Therefore, to mimic the early development of the esophagus and trachea, we differentiated induced pluripotent stem cells (iPSCs) from EA/TEF patients, and iPSCs and embryonic stem cells from healthy individuals into mature three-dimensional esophageal organoids. CXCR4, SOX17 and GATA4 expression was similar in both patient-derived and healthy endodermal cells. The expression of the key transcription factor SOX2 was significantly lower in the patient-derived anterior foregut. We also observed an abnormal expression of NKX2.1 (or NKX2-1) in the patient-derived mature esophageal organoids. At the anterior foregut stage, RNA sequencing revealed the critical genes GSTM1 and RAB37 to be significantly lower in the patient-derived anterior foregut. We therefore hypothesize that a transient dysregulation of SOX2 and the abnormal expression of NKX2.1 in patient-derived cells could be responsible for the abnormal foregut compartmentalization.

Early diagnosis and successful long-term management of a rare, severe lysosomal acid lipase deficiency/Wolman disease patient: Infancy to age five.

Background: This report describes a unique case of long-term survival of a young girl who was diagnosed with severe, rapidly progressive lysosomal acid lipase deficiency (LAL-D; historically "Wolman disease") at three months of age and began receiving therapeutic interventions at four months of age. This disease involves rapidly progressive multisystemic impairments and limited survival (6-12 months) without treatment. Methods: Case report taking into account clinical aspects and patient management including a semi-structured interview with the main family caregiver. Results: Presentation at two months of age: severe malnutrition and chronic diarrhea; hypoalbuminemia; low iron, vitamin A, and vitamin D levels; high triglyceride levels; profound anemia; thrombocytopenia; adrenal calcifications; and mild hepatosplenomegaly. Enzyme replacement therapy (ERT) with sebelipase alfa, parenteral nutrition, and a low-fat diet began at age four months. The patient has received sebelipase alfa for >5 years with good tolerability and is thriving, with a body mass index of 16.35 kg/m2 (80th percentile) despite a stature delay (height <3rd percentile), and mild developmental delay. Optimal medical management requires that family caregivers and health professionals have the knowledge and skills to provide appropriate care and supports multidisciplinary teams through transfer of knowledge to all stakeholders. Effective coordination of services and activities related to child health and development, including navigation of administrative and financial barriers, is also imperative. Conclusions: Formerly fatal in untreated infants, severe LAL-D, when diagnosed early, can be promptly and effectively treated by combining sebelipase alfa ERT, modified diet, involvement of family caregivers, and multidisciplinary team collaboration.

Erratum: Identification and validation of candidate risk genes in endocytic vesicular trafficking associated with esophageal atresia and tracheoesophageal fistulas.

[This corrects the article DOI: 10.1016/j.xhgg.2022.100107.].

Management of Gastroesophageal Reflux Disease in Esophageal Atresia Patients: A Cross-Sectional Survey amongst International Clinicians.

OBJECTIVES: After surgical repair, up to 70% of esophageal atresia (EA) patients suffer from gastroesophageal reflux disease (GERD). The ESPGHAN/NASPGHAN guidelines on management of gastrointestinal complications in EA patients were published in 2016. Yet, the implementation of recommendations on GERD management remains poor.We aimed to assess GERD management in EA patients in more detail, to identify management inconsistencies, gaps in current knowledge, and future directions for research. METHODS: A digital questionnaire on GERD management in EA patients was sent to all members of the ESPGHAN EA working group and members of the International network of esophageal atresia (INoEA). RESULTS: Forty responses were received. Thirty-five (87.5%) clinicians routinely prescribed acid suppressive therapy for 1-24 (median 12) months. A fundoplication was considered by 90.0% of clinicians in case of refractory GERD with persistent symptoms despite maximal acid suppressive therapy and in 92.5% of clinicians in case of GERD with presence of esophagitis on EGD. Half of clinicians referred patients with recurrent strictures or dependence on transpyloric feeds. Up to 25.0% of clinicians also referred all long-gap EA patients for fundoplication, those with long-term need of acid suppressants, recurrent chest infections and feedings difficulties. CONCLUSIONS: Respondents' opinions on the optimal duration for routine acid suppressive therapy and indications for fundoplication in EA patients varied widely. To improve evidence-based care for EA patients, future prospective multicenter outcome studies should compare different diagnostic and treatment regimes for GERD in patients with EA. Complications of therapy should be one of the main outcome measures in such trials.

Pediatric Intestinal Pseudo-Obstruction: Progress and Challenges.

Background: Chronic intestinal pseudo-obstruction is a rare disorder and represents the most severe form of gastrointestinal dysmotility with significant morbidity and mortality. Emerging research shows considerable differences between the adult and pediatric population with intestinal pseudo-obstruction and the term Pediatric Intestinal Pseudo-Obstruction (PIPO) was recently proposed. Purpose: The aim of this article is to provide pediatric gastroenterologists and pediatricians with an up to date review of the etiology and underlining pathophysiology, clinical features, diagnostic and management approaches currently available for PIPO and to discuss future perspectives for the diagnosis and management of this rare disease.

Identification and validation of candidate risk genes in endocytic vesicular trafficking associated with esophageal atresia and tracheoesophageal fistulas.

Esophageal atresias/tracheoesophageal fistulas (EA/TEF) are rare congenital anomalies caused by aberrant development of the foregut. Previous studies indicate that rare or de novo genetic variants significantly contribute to EA/TEF risk, and most individuals with EA/TEF do not have pathogenic genetic variants in established risk genes. To identify the genetic contributions to EA/TEF, we performed whole genome sequencing of 185 trios (probands and parents) with EA/TEF, including 59 isolated and 126 complex cases with additional congenital anomalies and/or neurodevelopmental disorders. There was a significant burden of protein-altering de novo coding variants in complex cases (p = 3.3 × 10-4), especially in genes that are intolerant of loss-of-function variants in the population. We performed simulation analysis of pathway enrichment based on background mutation rate and identified a number of pathways related to endocytosis and intracellular trafficking that as a group have a significant burden of protein-altering de novo variants. We assessed 18 variants for disease causality using CRISPR-Cas9 mutagenesis in Xenopus and confirmed 13 with tracheoesophageal phenotypes. Our results implicate disruption of endosome-mediated epithelial remodeling as a potential mechanism of foregut developmental defects. Our results suggest significant genetic heterogeneity of EA/TEF and may have implications for the mechanisms of other rare congenital anomalies.

Generation of three induced pluripotent stem cells lines from patients with esophageal atresia/tracheoesophageal fistula type C.

Esophageal atresia/tracheoesophageal fistula (EA/TEF) is the most common congenital anomaly of the upper gastrointestinal tract affecting 1 in 3,000 which could stem from a developmental anomaly of the foregut. The cause is not fully understood. We generated three iPSC cell lines using peripheral blood mononuclear cells (PBMCs) from EA/TEF type C patients. Pluripotency and trilineage differentiation capacity of these three iPSC cell lines were confirmed by gene and protein expression profiles and the differentiation ability into the three germ layers. The generated disease-specific cell lines could serve as a tool to investigate the mechanisms of EA/TEF and acquired associated diseases.

Effect of transanastomotic feeding tubes on anastomotic strictures in patients with esophageal atresia and tracheoesophageal fistula: The Quebec experience.

PURPOSE: Recent studies have identified transanastomotic tubes (TATs) as a risk factor for the development of anastomotic strictures after repair of esophageal atresia with tracheoesophageal fistula (EATEF). We further investigated these findings in a multicenter study. METHODS: We conducted a retrospective cohort study at three university-affiliated hospitals in the province of Quebec. All patients with types C and D EATEF who underwent primary repair between January 1993 and August 2018 were included. Anastomotic stricture was defined as clinical symptoms of stricture with confirmation on esophagram or endoscopy. Multivariate logistic regression and the Wilcoxon Rank-Sum test were used to evaluate the primary outcome of stricture within one year of surgery and secondary outcome of duration of postoperative total parenteral nutrition (TPN). RESULTS: 244 patients were included, of which 234 (96%) were type C and 10 (4%) were type D. The anastomotic stricture rate at 1 year was 30%. TATs were utilized in 61% of patients. Thirty-six percent of patients with TATs developed a stricture within one year, as compared to 19% of patients without TATs (p = 0.005). TATs were associated with stricture on univariate analysis (OR 2.49, p = 0.004, 95% CI: 1.37-4.69). On multivariate analysis, after adjusting for gestational age, birth weight, leak, long gap, anastomotic tension, and daily acid suppression, patients with TATs had 2.72 times higher odds of developing a stricture as compared to patients without TATs (p = 0.006, 95% CI: 1.35-5.74). The median duration of TPN was 9 days in both groups (p = 0.139, IQR 6-14 in patients with TATs versus IQR 7-16 in patients without). CONCLUSION: Transanastomotic tubes are associated with a significantly higher risk of postoperative stricture following repair of esophageal atresia with tracheoesophageal fistula and do not shorten the duration of total parenteral nutrition. LEVEL OF EVIDENCE: III.

Functional Luminal Imaging Probe in the Management of Pediatric Esophageal Disorders.

BACKGROUND: Functional luminal imaging probe (FLIP) measures pressure-geometry relationships of digestive luminal space. When used in esophageal disorders, it provides several luminal parameters that help better understand the pathophysiology. Data about the potential utility of FLIP in pediatrics are scarce and there is no standardized use in children. We aim to describe the use of FLIP in our center, its safety, feasibility, and clinical impact in esophageal disorders in children. METHODS: Consecutive FLIP recordings performed at the Centre Hospitalier Universitaire-Sainte-Justine, Montréal, Canada between February 2018 and January 2021 were extracted. A chart review was conducted for demographics and medical history. Symptomatology after the procedure was evaluated with validated dysphagia scores. KEY RESULTS: Nineteen patients were included (11 girls, median age 16 years, range 3.2-19.6) with achalasia (n = 5), post-Heller's myotomy dysphagia (n = 3), esophagogastric junction outflow obstruction (n = 3), congenital esophageal stenosis (n = 2); post-esophageal atresia repair stricture (n = 3), and post-fundoplication dysphagia (n = 3). There was no significant correlation between integrated relaxation pressure measured with high resolution manometry and distensibility index (DI). The use of FLIP made it possible to differentiate between dysphagia related to an esophageal obstruction (DI < 2.8 mm2/mmHg) and dysphagia without major motility disorder (DI > 2.8 mm2/mmHg) that guided the indication for dilation. FLIP led to a change in management in 47% of the patients. Forty-seven percent of the patients were symptom free at the time of the evaluation. CONCLUSIONS INFERENCES: FLIP provides key esophageal luminal values and therefore can play an important role in pediatric esophageal disorders management.

Characterization of the Transition Zone in Short Segment Hirschsprung Disease Using Calretinin Immunostaining.

Introduction: The detailed expression pattern of calretinin immunohistochemistry in the transition zone (TZ) of Hirschsprung disease (HSCR) has not yet been reported. This study aims to examine the value of calretinin immunohistochemistry for more accurately determining the distal and proximal border of the TZ in short segment HSCR. Methods: Specimens of pull-through surgery from 51 patients with short form of HSCR were analyzed on two longitudinal strips using hematoxylin and eosin (H&E) staining and calretinin immunohistochemistry. Results: In all but two patients, the first appearance of calretinin expression was seen on mucosal nerve fibers before the appearance of any ganglion cells, indicating the distal border of the TZ. The maximum distance between the distal border of the TZ and the proximal border of the TZ, defined by ganglion cells in a normal density on H&E stained sections, a strong calretinin expression on mucosal nerve fibers and in >80% of submucosal and myenteric ganglion cells, with no nerve hypertrophy and absence of ganglionitis was 60 mm. Conclusion: The distal border of the TZ is characterized by calretinin positive intramucosal neurites in nearly all of short form of HSCR and not by calretinin expression on ganglion cells.

The Use of Indocyanine Green Fluorescence Angiography in Pediatric Surgery: A Systematic Review and Narrative Analysis.

Purpose: Indocyanine green fluorescence angiography (ICG-FA) is a validated non-invasive imaging technique used to assess tissue vascularization and guide intraoperative decisions in many surgical fields including plastic surgery, neurosurgery, and general surgery. While this technology is well-established in adult surgery, it remains sparsely used in pediatric surgery. Our aim was to systematically review and provide an overview of all available evidence on the perioperative use of indocyanine green fluorescence angiography in pediatric surgical patients. Methods: We conducted a systematic review with narrative synthesis in conformity with the PRISMA guidelines using PubMed, Medline, All EBM Reviews, EMBASE, PsycINFO, and CINAHL COMPLETE databases to identify articles describing the perioperative use of ICG-FA in pediatric patients. Two independent authors screened all included articles for eligibility and inclusion criteria. We extracted data on study design, demographics, surgical indications, indocyanine green dose, and perioperative outcomes. We developed a risk of bias assessment tool to evaluate the methodological quality of included studies. Results: Of 1,031 articles retrieved, a total of 64 articles published between 2003 and 2020 were included reporting on 664 pediatric patients. Most articles were case reports and case series (n = 36; 56%). No adverse events related to ICG-FA were reported in the included articles. Risk of bias was high. We did not conduct a meta-analysis given the heterogeneous nature of the populations, interventions, and outcome measures. A narrative synthesis is presented. Conclusion: Indocyanine green fluorescence angiography is a safe imaging technology and its use is increasing rapidly in pediatric surgical specialties. However, the quality of evidence supporting this trend currently appears low. Case-control and randomized trials are needed to determine the adequate pediatric dose and to confirm the potential benefits of ICG-FA in pediatric surgical patients. Systematic Review Registration: This study was registered on Prospero a priori, identifier: CRD42020151981.

Clinician Knowledge of Societal Guidelines on Management of Gastrointestinal Complications in Esophageal Atresia.

OBJECTIVES: The aim of this study was to assess whether clinicians approached the management of children with esophageal atresia (EA) in accordance with the 2016 European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)/North American Society of Paediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) guidelines on the management of gastrointestinal and nutritional complications in this cohort. METHODS: We invited expert physicians and surgeons closely involved in the care of children with EA (members of the International network on esophageal atresia [INoEA], ESPGHAN EA working group, French national EA registry, European pediatric surgical association (EUPSA), and European rare disease reference network [ERNICA]) to participate in an anonymous online survey containing 15 multiple choice questions concerning the management of gastrointestinal and nutritional complications in children with EA. Questions were based on the management of gastroesophageal reflux disease (GERD) dysphagia, cyanotic spells, feeding and nutrition, anastamotic strictures, and transition to adult care as detailed in the 2016 guidelines. RESULTS: Median concordance with ESPGHAN/NASPHAN EA Guidelines was 69% (16-100%, SD 16%) across all responders. Areas of greatest concordance were in the fields of surveillance endoscopy and medical management of GERD. Areas for potential educational opportunities include: the differential diagnosis and appropriate investigation of dysphagia and the diagnostic evaluation of extraesophageal symptoms. CONCLUSIONS: This survey highlights the importance of improving the understanding and adherence to the EA guidelines amongst clinicians involved in the care of these patients.

Male-biased aganglionic megacolon in the TashT mouse model of Hirschsprung disease involves upregulation of p53 protein activity and Ddx3y gene expression.

Hirschsprung disease (HSCR) is a complex genetic disorder of neural crest development resulting in incomplete formation of the enteric nervous system (ENS). This life-threatening neurocristopathy affects 1/5000 live births, with a currently unexplained male-biased ratio. To address this lack of knowledge, we took advantage of the TashT mutant mouse line, which is the only HSCR model to display a robust male bias. Our prior work revealed that the TashT insertional mutation perturbs a Chr.10 silencer-enriched non-coding region, leading to transcriptional dysregulation of hundreds of genes in neural crest-derived ENS progenitors of both sexes. Here, through sex-stratified transcriptome analyses and targeted overexpression in ENS progenitors, we show that male-biased ENS malformation in TashT embryos is not due to upregulation of Sry-the murine ortholog of a candidate gene for the HSCR male bias in humans-but instead involves upregulation of another Y-linked gene, Ddx3y. This discovery might be clinically relevant since we further found that the DDX3Y protein is also expressed in the ENS of a subset of male HSCR patients. Mechanistically, other data including chromosome conformation captured-based assays and CRISPR/Cas9-mediated deletions suggest that Ddx3y upregulation in male TashT ENS progenitors is due to increased transactivation by p53, which appears especially active in these cells yet without triggering apoptosis. Accordingly, in utero treatment of TashT embryos with the p53 inhibitor pifithrin-α decreased Ddx3y expression and abolished the otherwise more severe ENS defect in TashT males. Our data thus highlight novel pathogenic roles for p53 and DDX3Y during ENS formation in mice, a finding that might help to explain the intriguing male bias of HSCR in humans.

Glial Cell-Derived Neurotrophic Factor Induces Enteric Neurogenesis and Improves Colon Structure and Function in Mouse Models of Hirschsprung Disease.

BACKGROUND & AIMS: Hirschsprung disease (HSCR) is a life-threatening birth defect in which the distal colon is devoid of enteric neural ganglia. HSCR is treated by surgical removal of aganglionic bowel, but many children continue to have severe problems after surgery. We studied whether administration of glial cell derived neurotrophic factor (GDNF) induces enteric nervous system regeneration in mouse models of HSCR. METHODS: We performed studies with four mouse models of HSCR: Holstein (HolTg/Tg, a model for trisomy 21-associated HSCR), TashT (TashTTg/Tg, a model for male-biased HSCR), Piebald-lethal (Ednrbs-l//s-l, a model for EDNRB mutation-associated HSCR), and Ret9/- (with aganglionosis induced by mycophenolate). Mice were given rectal enemas containing GDNF or saline (control) from postnatal days 4 through 8. We measured survival times of mice, and colon tissues were analyzed by histology, immunofluorescence, and immunoblots. Neural ganglia regeneration and structure, bowel motility, epithelial permeability, muscle thickness, and neutrophil infiltration were studied in colon tissues and in mice. Stool samples were collected, and microbiomes were analyzed by 16S rRNA gene sequencing. Time-lapse imaging and genetic cell-lineage tracing were used to identify a source of GDNF-targeted neural progenitors. Human aganglionic colon explants from children with HSCR were cultured with GDNF and evaluated for neurogenesis. RESULTS: GDNF significantly prolonged mean survival times of HolTg/Tg mice, Ednrbs-l//s-l mice, and male TashTTg/Tg mice, compared with control mice, but not Ret9/- mice (which had mycophenolate toxicity). Mice given GDNF developed neurons and glia in distal bowel tissues that were aganglionic in control mice, had a significant increase in colon motility, and had significant decreases in epithelial permeability, muscle thickness, and neutrophil density. We observed dysbiosis in fecal samples from HolTg/Tg mice compared with feces from wild-type mice; fecal microbiomes of mice given GDNF were similar to those of wild-type mice except for Bacteroides. Exogenous luminal GDNF penetrated aganglionic colon epithelium of HolTg/Tg mice, inducing production of endogenous GDNF, and new enteric neurons and glia appeared to arise from Schwann cells within extrinsic nerves. GDNF application to cultured explants of human aganglionic bowel induced proliferation of Schwann cells and formation of new neurons. CONCLUSIONS: GDNF prolonged survival, induced enteric neurogenesis, and improved colon structure and function in 3 mouse models of HSCR. Application of GDNF to cultured explants of aganglionic bowel from children with HSCR induced proliferation of Schwann cells and formation of new neurons. GDNF might be developed for treatment of HSCR.