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Background This study aimed to evaluate our outcomes and complication rate following placement of self-expanding esophageal stents in children for the management of refractory esophageal strictures and comparing these to the existing literature. Methods Outcomes following placement of stents in consecutive patients under 18 years at a single center from 2003 to 2018 were reviewed. A PRISMA-guided systematic review was conducted identifying studies with 5 or more children evaluating self-expanding stents published from 1975 to 2018. Endpoints for both the retrospective and systematic reviews were the requirement for further intervention and stent-associated complications. Results 25 patients received 65 stents. There were 12 caustic injury-related strictures (48%), 9 anastomotic strictures (36%), and 4 esophagitis-related strictures (16%). Four patients were lost to follow-up. 19/21 patients (90%) required further intervention, and 8/21 (38%) had esophageal replacement. Nine studies, all case series, were included in the systematic review. 97 patients received 160 stents for esophageal strictures and/or perforation. 36 out of 69 patients (52%) with strictures required no further treatment post-stenting, and 22/29 (76%) of esophageal perforations closed with stenting. Conclusions Esophageal stents may have a role as a bridge to definitive surgery and for the management of esophageal leaks, but complete stricture resolution post-stenting is unlikely. Type of Study Treatment Study (Case Series with no Comparison Group) Level of Evidence Level IV

Background CDH UK is a registered charity governed by a volunteer committee and providing informal support to patients, families and healthcare workers affected directly or indirectly with congenital diaphragmatic hernia (CDH) internationally. This is the first patient-led survey undertaken by CDH UK aiming for highlighting the feeding problems and their impact on the daily life of CDH survivors. Methods Answers from CDH survivors were collected through an online questionnaire (SurveyMonkey®) undertaken by CDH UK. The questionnaire contained questions about their feeding problems and support they were receiving for it. Main results Overall, 151 patients answered some parts of the survey and 102 patients completed the questionnaire. Overall, 116 (76.8%) responders reported suffering from any type of feeding issue. Gastric acid reflux (GER) and growth retardation were the commonest symptoms experienced by 97 (91.5%) and 72 (62.2%) responders, respectively. Only 18 (17.0%) responders have received any written information on feeding or details of patient/parent support. Eighty (75.5%) responders are satisfied with the level of support they are receiving, but 78 (76.4%) answered that the whole experience associated with the disease has been very or extremely stressful. Conclusions CDH survivors frequently have various issues with feeding, which may not be adequately supported or discussed clinically. It is desirable to assist the patients to reliable resources of long-term support, including multidisciplinary team (MDT) approach.

This study describes functional and health-related quality of life (HRQoL) outcomes in patients with Hirschsprung’s disease (HSCR) with associated learning disability or neurodevelopmental delay (LD), completing a core outcome set for HSCR. This was a cross-sectional study from a tertiary pediatric surgery center. Patients treated between 1977 and 2013 were prospectively contacted to complete an outcomes survey. Children under 12 and older patients with LD were assisted to complete these by a proxy. Bowel and urologic function were assessed (Rintala’s BFS and modified DanPSS) along with HRQoL (PedsQL/GIQLI/SF-36). Thirty-two patients with LD were compared to 186 patients with normal cognition. Patients with LD had 76% survival over the follow-up period, compared to 99% in the remainder of the cohort. Poor functional outcomes were common in the patients with LD, considerably higher than cognitively normal patients: with weekly issues withholding stool, soiling and fecal accidents in over half of patients surveyed (44–60%), and urinary incontinence in 46%. Use of permanent stoma was significantly higher (22% vs. 4%; p = 0.001). HRQoL was worse in domains of physical functioning in adults and children but not for social or emotional domains in adults. Subgroup analysis of patients with Down syndrome suggested similar functional results but better QoL. Multivariate analysis demonstrated a dramatically higher incidence of poor continence outcomes in patients with LD (adjusted OR 9.6 [4.0–23]).Conclusions: We provide LD-specific outcomes showing inferior function but similar HRQoL to other patients with HSCR, this is much needed in the counselling of families of these children. What is Known:• Hirschsprung’s disease is commonly associated with syndromes or other anomalies with resultant cognitive impairments.• The outcomes for these patients specifically have been poorly described in the literature. What is New:• Objective functional and quality of life surveys demonstrate significant differences from patients without cognitive impairment.• Patients with learning disability Patients with associated LD were almost ten times more likely to have an associated poor functional outcome, with very little impact on proxy-reported quality of life.

Aim To evaluate the practice patterns of the European Pediatric Surgeons' Association (EUPSA) members regarding the management of primary spontaneous pneumothorax (PSP) in children. Methods An online survey was distributed to all members of EUPSA. Results In total, 131 members from 44 countries participated in the survey. Interventional approach (78%) is the most common choice of treatment in the first episode, and most commonly, chest tube insertion (71%) is performed. In the case of a respiratory stable patient, 60% of the responders insert chest tubes if the pneumothorax is more than 2 cm. While 49% of surgeons prefer surgical intervention in the second episode, 42% still prefer chest tube insertion. Main indications for surgical treatment were the presence of bullae more than 2 cm (77%), and recurrent pneumothorax (76%). Eighty-four percent of surgeons prefer thoracoscopy and perform excision of bullae with safe margins (91%). To prevent recurrences, 54% of surgeons perform surgical pleurodesis with pleural abrasion (55%) and partial pleurectomy (22%). The responders who perform thoracoscopy use more surgical pleurodesis and prefer shorter chest tube duration than the surgeons performing open surgery (p Conclusion Most of the responders prefer chest tube insertion in the management of first episode of PSP and perform surgical treatment in the second episode in case of underlying bullae more than 2 cm and recurrent pneumothorax. The surgeons performing thoracoscopy use more surgical pleurodesis and prefer shorter chest tube duration than the responders performing open surgery. The development of evidence-based guidelines may help standardize care and improve outcomes in children with PSP.

Paper 2 of the paediatric regenerative medicine Series focuses on recent advances in postnatal approaches. New gene, cell, and niche-based technologies and their combinations allow structural and functional reconstitution and simulation of complex postnatal cell, tissue, and organ hierarchies. Organoid and tissue engineering advances provide human disease models and novel treatments for both rare paediatric diseases and common diseases affecting all ages, such as COVID-19. Preclinical studies for gastrointestinal disorders are directed towards oesophageal replacement, short bowel syndrome, enteric neuropathy, biliary atresia, and chronic end-stage liver failure. For respiratory diseases, beside the first human tracheal replacement, more complex tissue engineering represents a promising solution to generate transplantable lungs. Genitourinary tissue replacement and expansion usually involve application of biocompatible scaffolds seeded with patient-derived cells. Gene and cell therapy approaches seem appropriate for rare paediatric diseases of the musculoskeletal system such as spinal muscular dystrophy, whereas congenital diseases of complex organs, such as the heart, continue to challenge new frontiers of regenerative medicine.

Tissue engineering is an interdisciplinary field that combines stem cells and matrices to form functional constructs that can be used to repair damaged tissues or regenerate whole organs. Tissue stem cells can be expanded and functionally differentiated to form 'mini-organs' resembling native tissue architecture and function. The choice of the scaffold is also pivotal to successful tissue reconstruction. Scaffolds may be broadly classified into synthetic or biological depending upon the purpose of the engineered organ. Bioengineered intestinal grafts represent a potential source of transplantable tissue for patients with intestinal failure, a condition resulting from extensive anatomical and functional loss of small intestine and therefore digestive and absorptive capacity. Prior strategies in intestinal bioengineering have predominantly used either murine or pluripotent cells and synthetic or decellularized rodent scaffolds, thus limiting their translation. Microscale models of human intestinal epithelium on shaped hydrogels and synthetic scaffolds are more physiological, but their regenerative potential is limited by scale. Here we present a protocol for bioengineering human intestinal grafts using patient-derived materials in a bioreactor culture system. This includes the isolation, expansion and biobanking of patient-derived intestinal organoids and fibroblasts, the generation of decellularized human intestinal scaffolds from native human tissue and providing a system for recellularization to form transplantable grafts. The duration of this protocol is 12 weeks, and it can be completed by scientists with prior experience of organoid culture. The resulting engineered mucosal grafts comprise physiological intestinal epithelium, matrix and surrounding niche, offering a valuable tool for both regenerative medicine and the study of human gastrointestinal diseases.

Anomalies in tracheo-esophageal development result in a spectrum of congenital malformations ranging from, most commonly, esophageal atresia with or without trachea-esophageal fistula (EA+/-TEF) to esophageal web, duplication, stricture, tracheomalacia and tracheal agenesis. Despite the relative frequency of EA, however, the underlying etiology remains unknown and is likely due to a combination of genetic, epigenetic and environmental factors. In recent years, animal models have dramatically increased our understanding of the molecular and morphological processes involved in normal esophageal development during the key stages of anterior-posterior regionalization, dorsal-ventral patterning and morphogenic separation. Moreover, the use of animal models in conjunction with increasingly advanced techniques such as genomic sequencing, sophisticated live imaging studies and organoid models have more recently cast light on potential mechanisms involved in EA pathogenesis. This article aims to unravel some of the mysteries behind the anatomy and embryology of EA whilst providing insights into future directions for research. ispartof: Semin Pediatr Surg vol:31 issue:6 pages:151231- ispartof: location:United States status: published

Tissue architecture is a driving force for morphogenetic processes during development as well as for several physiological and regenerative responses. Far from being a passive static environment, tissue architecture is highly dynamic. Hydrogel technology reproduces in vitro geometrical and mechanical constrains that control the three-dimensional self-organization of (3D) organoids and organ-like cultures. This control is restricted to the initial culture conditions and cannot be adapted to the dynamic morphological changes of complex 3D cultures during their developmental trajectory. Here, we developed a method that overcomes this spatiotemporal limit. Using 2P crosslinking approach, high resolution 3D hydrogel structures can be fabricated within pre-existing hydrogel with spatiotemporal (four-dimensional, 4D) control relative to ex-vivo organotypic or organoid culture. This hydrogel-in-hydrogel bioprinting approach enables to continuously instruct the self-organization of the evolving 3D organ-like cultures.

Tissue engineering (TE) aims to generate bioengineered constructs which can offer a surgical treatment for many conditions involving tissue or organ loss. Construct generation must be guided by suitable assessment tools. However, most current tools (e.g. histology) are destructive, which restricts evaluation to a single-2D anatomical plane, and has no potential for assessing constructs prior to or following their implantation. An alternative can be provided by laboratory-based x-ray phase contrast computed tomography (PC-CT), which enables the extraction of 3D density maps of an organ's anatomy. In this work, we developed a semi-automated image processing pipeline dedicated to the analysis of PC-CT slices of oesophageal constructs. Visual and quantitative (density and morphological) information is extracted on a volumetric basis, enabling a comprehensive evaluation of the regenerated constructs. We believe the presented tools can enable the successful regeneration of patient-specific oesophagus, and bring comparable benefit to a wide range of TE applications. STATEMENT OF SIGNIFICANCE: Phase contrast computed tomography (PC-CT) is an imaging modality which generates high resolution volumetric density maps of biological tissue. In this work, we demonstrate the use of PC-CT as a new tool for guiding the progression of an oesophageal tissue engineering (TE) protocol. Specifically, we developed a semi-automated image-processing pipeline which analyses the oesophageal PC-CT slices, extracting visual and quantitative (density and morphological) information. This information was proven key for performing a comprehensive evaluation of the regenerated constructs, and cannot be obtained through existing assessment tools primarily due to their destructive nature (e.g. histology). This work paves the way for using PC-CT in a wide range of TE applications which can be pivotal for unlocking the potential of this field.

BackgroundChildren undergoing surgery, and their parents, are at risk of developing post-traumatic stress reactions. We systematically reviewed the literature to understand the prevalence of this issue, as well as potential risk factors.MethodsWe conducted a systematic review and meta-analysis, using PubMed, PsycInfo, Web of Science and Google Scholar, with searches conducted in February 2021. Papers were included if they measured post-traumatic stress in children and/or parents following paediatric surgery, and were excluded if they did not use a validated measure of post-traumatic stress. Data was extracted from published reports.FindingsOur search yielded a total of 1,672 papers, of which 16 of met our inclusion criteria. In meta-analysis, pooled studies of children estimated an overall prevalence of 16% meeting criteria for post-traumatic stress disorder post-surgery (N= 187, 95% CI : 5-31%, I2= 80%). After pooling studies of parents, overall prevalence was estimated at 23% (N= 1444, 95% CI 16-31%, I2= 91%). Risk factors reported within studies included length of stay, level of social support and parental mental health.InterpretationThere is consistent evidence of traumatic stress following surgery in childhood which warrants further investigation. Those delivering surgical care to children would benefit from a raised awareness of the potential for post-traumatic stress in their patients and their families, including offering screening and support.FundingWe did not seek or receive any funding for this study.

Necrotizing enterocolitis (NEC) is a devastating neonatal disease characterized by acute intestinal injury. Intestinal stem cell (ISC) renewal is required for gut regeneration in response to acute injury. The Wnt/β-catenin pathway is essential for intestinal renewal and ISC maintenance. We found that ISC expression, Wnt activity and intestinal regeneration were all decreased in both mice with experimental NEC and in infants with acute active NEC. Moreover, intestinal organoids derived from NEC-injured intestine of both mice and humans failed to maintain proliferation and presented more differentiation. Administration of Wnt7b reversed these changes and promoted growth of intestinal organoids. Additionally, administration of exogenous Wnt7b rescued intestinal injury, restored ISC, and reestablished intestinal epithelial homeostasis in mice with NEC. Our findings demonstrate that during NEC, Wnt/β-catenin signaling is decreased, ISC activity is impaired, and intestinal regeneration is defective. Administration of Wnt resulted in the maintenance of intestinal epithelial homeostasis and avoidance of NEC intestinal injury. ispartof: Cell Death & Disease vol:10 issue:10 ispartof: location:England status: published

Background To determine whether parenteral plus enteral glutamine supplementation influences microbial invasion in surgical infants who require parenteral nutrition (PN). Methods An prospective double-blind randomized controlled trial studying surgical infants receiving PN for at least 5 days for congenital or acquired intestinal anomalies (2009-2012) was used. Infants were randomized to receive either glutamine supplementation (parenteral plus enteral; total 400 mg/kg/d) or isonitrogenous control. The primary end point was microbial invasion evaluated after 5 days of supplementation and defined as: (i) positive conventional blood culture, (ii) evidence of microbial DNA in blood (polymerase chain reaction), (iii) plasma endotoxin level ≥50 pg/mL, or (iv) plasma level of lipopolysaccharide binding protein ≥50 ng/mL. Data are given as median (range) and compared by logistic regression. Results Sixty infants were randomized and reached the primary end point. Twenty-five patients had intestinal obstruction, 19 had abdominal wall defects, and 13 had necrotizing enterocolitis. Thirty-six infants showed evidence of microbial invasion during the study, and 17 of these were not detected by conventional blood culture. There was no significant difference between the 2 groups in the primary outcome; evidence of microbial invasion after 5 days was found in 9/31 (control group) and 8/29 (glutamine group) (odds ratio 0.83 [0.24-2.86; P = 0.77]). Conclusion More than half of surgical infants requiring PN showed evidence of microbial invasion. Approximately half of this was not detectable by conventional blood cultures. Parenteral plus enteral glutamine supplementation had no effect on incidence of microbial invasion.

In utero transplantation (IUT) of hematopoietic stem cells (HSC) has been proposed as a strategy for the prenatal treatment of congenital hematological diseases. However, levels of long-term hematopoietic engraftment achieved in experimental IUT to date are sub-therapeutic, likely due to host fetal HSC out-competing their bone-marrow (BM) derived donor equivalents for space in the hematopoietic compartment. In the present study we demonstrate that amniotic fluid stem cells (AFSC; c-Kit+/Lin-) have hematopoietic characteristics and, thanks to their fetal origin, favourable proliferation kinetics in vitro and in vivo, which are maintained when the cells are expanded. IUT of autologous/congenic freshly-isolated or cultured AFSC resulted in stable mutli-lineage hematopoietic engraftment, far higher to that achieved with BM-HSC. Intravascular IUT of allogenic AFSC was not successful as recently reported after intraperitoneal IUT. Herein we demonstrated that this likely due to a failure of timely homing of donor cells to the host fetal thymus resulted in lack of tolerance induction and rejection. This study reveals that intravascular IUT leads to a remarkable hematopoietic engraftment of AFSC in the setting of autologous/congenic IUT, and confirms the requirement for induction of central tolerance for allogenic IUT to be successful. Autologous, gene engineered and in-vitro expanded AFSC could be used as a stem cell/gene therapy platform for the in utero treatment of inherited disorders of hematopoiesis. SIGNIFICANCE STATEMENT: Amniotic fluid stem cells can be expanded without losing their hematopoietic characteristics In utero transplantation of allogenic AFSC results in adaptive immune response and donor cell rejection, due to failure of timely homing of donor cells to the host fetal thymus and lack of central tolerance induction. Autologous/congenic amniotic fluid stem cells can be transplanted in utero and result in stable, multi-lineage, long-term hematopoietic engraftment that is significantly higher to that achieved with bone marrow-derived cells and could be therapeutic in many inherited disorders of hematopoiesis. © AlphaMed Press 2019.

BACKGROUND: Endoscopic ultrasound is seldom available at paediatric centres; therefore drainage of pancreatic pseudocysts in children has traditionally been achieved by surgery. OBJECTIVE: This study assessed the feasibility and safety of performing image-guided internal drainage of pancreatic pseudocysts with a flanged self-expanding covered nitinol pancreatic pseudocyst drainage stent. MATERIALS AND METHODS: We conducted a retrospective case note review of children undergoing image-guided cystogastrostomy at two paediatric hospitals. Percutaneous access to the stomach was achieved via an existing gastrostomy tract or image-guided formation of a new tract. Under combined ultrasound, fluoroscopic or cone-beam CT guidance the pancreatic pseudocysts were punctured through the posterior wall of the stomach. A self-expanding covered nitinol stent was deployed to create a cystogastrostomy opening. RESULTS: Image-guided cystogastrostomy was performed in 6 children (4 male; median age 6 years, range 46 months to 15 years; median weight 18 kg, range 13.8-47 kg). Two children had prior failed attempts at surgical or endoscopic drainage. Median maximum cyst diameter was 11.5 cm (range 4.7-15.5 cm) pre-procedure. Technical success was 100%. There were no complications. There was complete pseudocyst resolution in five children and a small (2.1-cm) residual pseudocyst in one. Pseudocyst-related symptoms resolved in all children. CONCLUSION: Pancreatic pseudocyst drainage can be successfully performed in children by image-guided placement of a cystogastrostomy stent. In this cohort of six children there were no complications. ispartof: Pediatric Radiology vol:49 issue:13 pages:1816-1822 ispartof: location:Germany status: published

BACKGROUND: Traditionally, ultrasound (US)-guided bowel mass biopsies are avoided in favour of endoscopic or surgical biopsies. However, endoscopy cannot easily reach lesions between the duodenojejunal flexure and the terminal ileum and lesions not involving the mucosa may not be accessible via an endoscopic route. OBJECTIVE: The aim of this study was to report our technique and to assess the diagnostic accuracy and safety of US-guided biopsy of bowel masses in children. MATERIALS AND METHODS: We conducted a 14-year retrospective review of US-guided bowel mass biopsies at a single paediatric hospital. RESULTS: Twenty US-guided bowel mass biopsies were performed in 19 patients (median age: 6 years and 6 months, range: 22 months-17 years, median weight: 22 kg, range: 10.2-48.4 kg). For 14 biopsies, there was no other lesion that could potentially be biopsied. A percutaneous coaxial technique was used for 19 biopsies and a transanal non-coaxial biopsy was performed in 1. A median of 9 (range: 2-15) cores of tissue was obtained at each biopsy. The technical success rate and adequacy of diagnostic yield were 100%. The most common diagnosis was lymphoma, which occurred in 16 biopsies. Three biopsies contained mucosa. There was one complication out of 20 biopsies (5%, 95% confidence interval 0-15%): a self-limiting, post biopsy pyrexia. Nineteen procedures were accompanied by a bone marrow aspirate and/or trephine within 2 weeks of the bowel biopsy, only one of which was diagnostic. CONCLUSION: US-guided bowel mass biopsy can be performed safely in children, with a high diagnostic yield and low complication rate. ispartof: Pediatric Radiology vol:49 issue:13 pages:1809-1815 ispartof: location:Germany status: published

Background The current methodologies for the identification of therapeutic targets for inflammatory bowel disease (IBD) are limited to conventional 2-dimensional (2D) cell cultures and animal models. The use of 3D decellularized human intestinal scaffolds obtained from surgically resected intestine and engineered with human intestinal cells may provide a major advancement in the development of innovative intestinal disease models. The aim of the present study was to design and validate a decellularization protocol for the production of acellular 3D extracellular matrix (ECM) scaffolds from the human duodenum. Methods Scaffolds were characterized by verifying the preservation of the ECM protein composition and 3D architecture of the native intestine and were employed for tissue engineering with primary human intestinal myofibroblasts for up to 14 days. Results Engrafted cells showed the ability to grow and remodel the surrounding ECM. mRNA expression of key genes involved in ECM turnover was significantly different when comparing primary human intestinal myofibroblasts cultured in 3D scaffolds with those cultured in standard 2D cultures on plastic dishes. Moreover, incubation with key profibrogenic growth factors such as TGFβ1 and PDGF-BB resulted in markedly different effects in standard 2D vs 3D cultures, further emphasizing the importance of using 3D cell cultures. Conclusions These results confirm the feasibility of 3D culture of human intestinal myofibroblasts in intestinal ECM scaffolds as an innovative platform for disease modeling, biomarker discovery, and drug testing in intestinal fibrosis.

Background Congenital hyperinsulinism is a rare disease and patients not responding to medical treatment need near-total or partial pancreatectomy, dependent on whether they have diffuse or focal hyperinsulinism, respectively. While laparoscopic technique for distal and for total pancreatectomy has been developed, minimally invasive resection of the pancreatic neck with pancreatico-jejunostomy has not been reported in children before. Case summary A 2-year old boy suffered from congenital hyperinsulinism, which was refractory to high-dose medical treatment. The nuclear-medicine scan revealed a focal lesion of the pancreatic neck, hence partial pancreatectomy was indicated. On laparoscopy, a slightly prominent tissue mass was apparent in the area of the pancreatic neck. We proceeded with laparoscopic mobilisation of the pancreas from the underlying splenic vessels and resected the pancreatic neck and adjacent parts of the body and the head. After macroscopic resection of the mass, the patient's intraoperative blood glucose levels increased to a point where insulin had to be substituted. To drain the pancreatic tail, we formed an end-to-side anastomosis in the proximal Jejunum and brought the open end to the pancreatic tail and performed a laparoscopic pancreatico-jejunostomy. The patient tolerated the procedure well and had no remaining signs or symptoms of hyperinsulinism. Conclusion This is the first report of a laparoscopic middle-segmental pancreatic resection with laparoscopic assisted Roux-en-Y pancreatico-jejunostomy in a child. For benign pancreatic lesions proximal to the body and tail, the described minimally invasive technique should be considered.

BACKGROUND: Conditions leading to reduced gastric volume are difficult to manage and are associated to poor quality-of-life. Stomach augmentation using a tissue-engineered stomach is a potential solution to restore adequate physiology and food reservoir. Aim of this study was to evaluate the decellularisation of whole rat stomach using a detergent-enzymatic protocol. METHODS: Stomachs harvested from rats were decellularised through luminal and vascular cannulation using 24-h detergent-enzymatic treatment and completely characterized by appropriate staining, DNA and Extracellular matrix -component quantifications. RESULTS: The detergent-enzymatic protocol allows a complete decellularisation of the gastric tissue, with a complete removal of the DNA with two cycles as confirmed by both quantifications and histological analysis. Extracellular matrix components, collagen, fibronectin, laminin and elastin, were optimally preserved by the treatment, while glycosaminoglycans were reduced. CONCLUSION: Gastric tissue can be efficiently decellularised. Scaffolds retained original structure and important components that could enhance integration with other tissues for in vivo transplant. The use of naturally derived material could be potentially considered for the treatment of both congenital and acquired conditions. ispartof: PEDIATRIC SURGERY INTERNATIONAL vol:35 issue:1 pages:21-27 ispartof: location:ITALY, Taormina status: published

Aim of the study Divided colostomy (DC) has been recommended in anorectal malformations (ARMs) with previously reported advantages of decreasing overflow into the distal limb and urinary tract infections (UTIs). Skin bridge loop colostomy (LC) is a technically easier alternative without an increase in these complications. We report our institutional experience of LC in ARM. Methods Retrospective study (Institution-approved Clinical Audit) reviewing the clinical records of all patients with ARM undergoing stoma formation in a single UK tertiary pediatric surgical center (2000–2015). Data collected included type of ARM, associated anomalies, type and level of colostomy, time to stoma closure, complications and UTIs. Results One hundred and eighty-two (95 female) patients underwent colostomy formation for ARM. The vast majority (171/ 94%) underwent LC; 9 (5%) had a divided colostomy (DC) and 2 (1%) had no available data. The spectrum of defects in girls included rectovestibular (62/65%), rectovaginal (4/4%) and cloaca (29/31%). In boys, 71 (82%) had a fistula to the urinary tract and 16 (18%) presented with a perineal fistula. Urological abnormalities coexisted in 87 (47.8%) patients. Thirty five (21%) patients developed UTIs. Among the 19 girls who developed UTI, 8 had rectovestibular fistula and 11 had cloaca. Of the 16 boys who developed UTI, 14 had a fistula to the urinary tract and 11 had an independent urological abnormality. The mean time from stoma formation to stoma closure was 10 (3–52) months. Complications were reported in 22 (12%) LCs. Fifteen patients (9%) developed a stoma prolapse following LC with 10 (6%) requiring surgical revision. Conclusions This is the largest reported series of outcomes following LC for ARM. LC is easier to perform and to close, requiring minimal surgical access, with comparable complications and outcomes to those published for DC. Type of study Retrospective comparative study. Level of evidence III.

Spinal muscular atrophy (SMA) is a single gene disorder affecting motor function in uterus. Amniotic fluid is an alternative source of stem cell to ameliorate SMA. Therefore, this study aims to examine the therapeutic potential of Human amniotic fluid stem cell (hAFSC) for SMA. Our SMA model mice were generated by deletion of exon 7 of Smn gene and knock-in of human SMN2. A total of 16 SMA model mice were injected with 1 × 105 hAFSC in uterus, and the other 16 mice served as the negative control. Motor function was analyzed by three behavioral tests. Engraftment of hAFSC in organs were assessed by flow cytometry and RNA scope. Frequency of myocytes, neurons and innervated receptors were estimated by staining. With hAFSC transplantation, 15 fetuses survived (93.75% survival) and showed better performance in all motor function tests. Higher engraftment frequency were observed in muscle and liver. Besides, the muscle with hAFSC transplantation expressed much laminin α and PAX-7. Significantly higher frequency of myocytes, neurons and innervated receptors were observed. In our study, hAFSC engrafted on neuromuscular organs and improved cellular and behavioral outcomes of SMA model mice. This fetal therapy could preserve the time window and treat in the uterus.

While a substantial proportion of adults infected with SARS-CoV-2 progress to develop severe disease, children rarely manifest respiratory complications. Therefore, understanding differences in the local and systemic response to SARS-CoV-2 infection between children and adults may provide important clues about the pathogenesis of SARS-CoV-2 infection. To address this, we first generated a healthy reference multi-omics single cell data set from children (n=30) in whom we have profiled triple matched samples: nasal and tracheal brushings and PBMCs, where we track the developmental changes for 42 airway and 31 blood cell populations from infancy, through childhood to adolescence. This has revealed the presence of naive B and T lymphocytes in neonates and infants with a unique gene expression signature bearing hallmarks of innate immunity. We then contrast the healthy reference with equivalent data from severe paediatric and adult COVID-19 patients (total n=27), from the same three types of samples: upper and lower airways and blood. We found striking differences: children with COVID-19 as opposed to adults had a higher proportion of innate lymphoid and non-clonally expanded naive T cells in peripheral blood, and a limited interferon-response signature. In the airway epithelium, we found the highest viral load in goblet and ciliated cells and describe a novel inflammatory epithelial cell population. These cells represent a transitional regenerative state between secretory and ciliated cells; they were found in healthy children and were enriched in paediatric and adult COVID-19 patients. Epithelial cells display an antiviral and neutrophil-recruiting gene signature that is weaker in severe paediatricversusadult COVID-19. Our matched blood and airway samples allowed us to study the spatial dynamics of infection. Lastly, we provide a user-friendly interface for this data1as a highly granular reference for the study of immune responses in airways and blood in children.

Background Congenital diaphragmatic hernia (CDH) is, depending of the severity, a birth defect associated with significant mortality and morbidity. Prenatal screening by ultrasound may detect this condition and comprehensive assessment of severity is possible, allowing for in utero referral to an experienced centre for planned delivery. In an effort to improve outcomes, prenatal interventions to stimulate lung development were proposed. Along the same lines, new postnatal management strategies are being developed. In order to enable proper comparison of novel perinatal interventions as well as outcomes, a set of uniform and relevant outcome measures is required. Core outcome sets (COS) are agreed, clearly defined sets of outcomes to be measured in a standardised manner and reported consistently. Herein we aim to describe the methodology we will use to define a COS for perinatal and neonatal outcomes of foetuses and newborns with congenital diaphragmatic hernia and to draft a dissemination and implementation plan. Methods We will use the methodology described in the Core Outcome Measures in Effectiveness Trials (COMET) Initiative Handbook. An international steering group will be created to guide the development of the COS. We are systematically reviewing the literature to identify all potential relevant pre- and neonatal outcomes previously used in studies on perinatal interventions for CDH. We will build a consensus on these core outcomes in a stakeholder group using the Delphi method. After completion, a stakeholder meeting will decide on a final COS, using a modified Nominal Group Technique. Thereafter, we will review potential definitions and measurements of these outcomes, and again a consensus meeting will be organised, to finalise the COS before dissemination. Discussion We have started a procedure to develop a COS for studies on perinatal interventions for congenital diaphragmatic hernia, with the purpose of improving the quality of research, guide clinical practice and improve patient care and eventual use in future clinical trials, systematic reviews and clinical practice guidelines. Trial registration We prospectively registered this study in the International Prospective Register of Systematic Reviews (PROSPERO) (registration number: CRD42019124399) and The Core Outcome Measures in Effectiveness Trials (COMET) Initiative (registration number:1296).

Purpose Thoracoscopic OA/TOF repair was first described in 1999. Currently, less than 10% of surgeons routinely employ minimally access surgery. Our primary aim was to review our immediate-, early- and long-term outcomes with this technique compared with the open approach. Methods A retrospective review of all patients undergoing primary OA/TOF (Type C) repair at our institution from 2009 was conducted. Outcome measures included length of surgery, conversion rate from thoracoscopy, early complications such as anastomotic leak and post-operative complications such as anastomotic strictures needing dilatations. Fisher’s exact and Kruskal–Wallis tests were used for statistical analysis. Results 95 patients in total underwent OA/TOF repair during the study period of which 61 (64%) were completed via an open approach. 34 were attempted thoracoscopically of which 11 (33%) were converted. There was only one clinically significant anastomotic leak in our series that took place in the thoracoscopic group. We identified a significantly higher stricture rate in our thoracoscopic cohort (72%) versus open surgery (43%, P Conclusion In our experience, the clinically significant leak rate for both open and thoracoscopic repair as well as recurrent fistula is much lower than has been reported in the literature. We do not routinely perform contrast studies and are, thus, reporting clinically significant leaks only. The use of post-operative neck flexion, ventilation and paralysis is likely to be protective towards a leak. Thoracoscopic OA/TOF repair is associated with a higher stricture rate compared with open surgery; however, these strictures respond to a similar number of dilatations and are no more refractory. Larger, multicentre studies may be useful to investigate these finding further.

Purpose Knowledge of gastric epithelial homeostasis remains incomplete, lacking human-specific models for study. This study establishes a protocol for deriving gastric epithelial organoids from paediatric gastric biopsies, providing a platform for modelling disease and developing translational therapies. Methods Full-thickness surgical samples and endoscopic mucosal biopsies were obtained from six patients. Gastric glands were isolated by a chemical chelation protocol and then plated in 3D culture in Matrigel® droplets in chemically defined medium. After formation, organoids were passaged by single cell dissociation or manual disaggregation. Cell composition and epithelial polarity of organoids were assessed by bright field microscopy and immunofluorescence analysis, comparing them to native paediatric gastric tissue. Results Gastric glands were successfully isolated from all six patients who were aged 4 months to 16 years. Gastric glands from all patients sealed to form spherical gastric organoids. These organoids could be passaged by manual disaggregation or single cell dissociation, remaining proliferative up to 1 year in culture. Organoids retained normal epithelial cell polarity, with the apical surface orientated towards the central lumen. Organoids expressed markers of mature gastric epithelial cell types, except for parietal cells. Conclusion Gastric organoids can be reliably generated from paediatric biopsies and are a representative in vitro model for studying gastric epithelium.

COVID-19 typically manifests as a respiratory illness, but several clinical reports have described gastrointestinal symptoms. This is particularly true in children in whom gastrointestinal symptoms are frequent and viral shedding outlasts viral clearance from the respiratory system. These observations raise the question of whether the virus can replicate within the stomach. Here we generate gastric organoids from fetal, pediatric, and adult biopsies as in vitro models of SARS-CoV-2 infection. To facilitate infection, we induce reverse polarity in the gastric organoids. We find that the pediatric and late fetal gastric organoids are susceptible to infection with SARS-CoV-2, while viral replication is significantly lower in undifferentiated organoids of early fetal and adult origin. We demonstrate that adult gastric organoids are more susceptible to infection following differentiation. We perform transcriptomic analysis to reveal a moderate innate antiviral response and a lack of differentially expressed genes belonging to the interferon family. Collectively, we show that the virus can efficiently infect the gastric epithelium, suggesting that the stomach might have an active role in fecal-oral SARS-CoV-2 transmission., Several clinical reports have described gastrointestinal symptoms for COVID-19, though whether the virus can replicate within the stomach remains unclear. Here the authors generate gastric organoids from human biopsies and show that the virus can efficiently infect gastric epithelium, suggesting that the stomach might have an active role in fecal-oral transmission.

The National Heart, Lung, and Blood Institute of the National Institutes of Health, together with the Longfonds BREATH consortium, convened a working group to review the field of lung regeneration and suggest avenues for future research. The meeting took place on May 22, 2019, at the American Thoracic Society 2019 conference in Dallas, Texas, United States, and brought together investigators studying lung development, adult stem-cell biology, induced pluripotent stem cells, biomaterials, and respiratory disease. The purpose of the working group was 1) to examine the present status of basic science approaches to tackling lung disease and promoting lung regeneration in patients and 2) to determine priorities for future research in the field.

Background: While pregnant women have been identified as a potentially at-risk group concerning COVID-19 infection, little is known regarding the susceptibility of the fetus to infection. Co-expression of ACE2 and TMPRSS2 has been identified as a pre-requisite for infection, and expression across different tissues is known to vary between children and adults. However, the expression of these proteins in the fetus is unknown. Methods: We performed a retrospective analysis of single cell data repositories. This data was then validated at both gene and protein level by performing qRT-PCR and two-colour immunohistochemistry on a library of second-trimester human fetal tissues. Findings: TMPRSS2 is present at both gene and protein level in the predominantly epithelial fetal tissues analysed. ACE2 is present at significant levels, only in the fetal intestine and kidney and is not expressed in the fetal lung. The placenta is also negative for the two proteins both during development and at term. Interpretation: This dataset indicates that the lungs are unlikely to be a viable route of SARS-CoV2 fetal infection. The fetal kidney, despite presenting both the proteins required for the infection, is anatomically protected from the exposure to the virus. However, the GI tract is likely to be susceptible to infection due to its high co-expression of both proteins, as well as its exposure to potentially infected amniotic fluid. Funding Information: This work was made possible by an MRC / UKRI COVID-19 Rapid response initiative grant (MR/V028480/1). Declaration of Interests: The authors declare no conflicts of interest related to this work or its developments. DC is founder, shareholder, and consultant of Next Generation Diagnostic SRL. Ethics Approval Statement: Human fetal tissues were obtained with consent through the Human Developmental Biology Resource (HDBR; REC 18/LO/0822 – IRAS 244325; Project ID 2000478). Placental samples were obtained at delivery of an uncomplicated, full-term pregnancy (median 39 weeks PCW [Range 38+1 -39+4] for 6 patients recruited through the EVERREST Prospective Study as normal controls (National Research Ethics reference 13/LO/1254), NCT02097667 registered 31st October 2013[10].

PurposeThe COVID-19 pandemic has resulted in a global health crisis of unparalleled magnitude. The direct risk to the health of children is low. However, disease-containment measures have society-wide impacts. This study explored the pandemic experiences of parents of children with oesophageal atresia/tracheo-oesophageal fistula (OA/TOF) in the UK.DesignA phenomenological approach underpinned use of an asynchronous online forum method, in collaboration with a patient support group. Data were evaluated using thematic analysis.ResultsThe online forum ran between 7 November and 18 December 2020 with 109 participants.Pandemic experiences were divided into themes relating to healthcare and disease containment. Participants described positive experiences with remote healthcare but identified limitations. Delays and cancellations led to escalation of care to an emergency level, slower developmental progress and feelings of being abandoned by services. Inpatient care was perceived as safe but caring alone was emotionally and practically challenging. Disease containment themes revealed anxiety regarding health risks, ‘collateral’ damage to well-being because of isolation, and an impact on finances and employment. Parents described a transition from worry about direct health risks to concern about the impact of isolation on socialisation and development. A process of risk–benefit analysis led some to transition to a more ‘normal life’, while others continued to isolate. Benefits to their child’s health from isolation were reported.ConclusionsParents’ experiences of caring for a child with OA/TOF during the pandemic were varied. Rapid adoption of telehealth has demonstrated the enormous potential of remote healthcare delivery but requires refinement to meet the needs of the individual. Future pandemic planning should aim to retain community healthcare services to avoid escalation of care to an emergency, manage chronic and developmental concerns, and support parental well-being. Accurate and consistent disease-specific information is highly valued by parents. Third sector organisations are ideally positioned to support this.

Hydrogels are biomaterials that, thanks to their unique hydrophilic and biomimetic characteristics, are used to support cell growth and attachment and promote tissue regeneration. The use of decellularized extracellular matrix (dECM) from different tissues or organs significantly demonstrated to be far superior to other types of hydrogel since it recapitulates the native tissue’s ECM composition and bioactivity. Different muscle injuries and malformations require the application of patches or fillers to replenish the defect and boost tissue regeneration. Herein, we develop, produce, and characterize a porcine diaphragmatic dECM-derived hydrogel for diaphragmatic applications. We obtain a tissue-specific biomaterial able to mimic the complex structure of skeletal muscle ECM, we characterize hydrogel properties in terms of biomechanical properties, biocompatibility, and adaptability for in vivo applications. Lastly, we demonstrate that dECM-derived hydrogel obtained from porcine diaphragms can represent a useful biological product for diaphragmatic muscle defect repair when used as relevant acellular stand-alone patch.

Decellularized skeletal muscle (dSkM) constructs have received much attention in recent years due to the versatility of their applications in vitro. In search of adequate in vitro models of the skeletal muscle tissue, the dSkM offers great advantages in terms of the preservation of native-tissue complexity, including three-dimensional organization, the presence of residual signaling molecules within the construct, and their myogenic and neurotrophic abilities. Here, we attempted to develop a 3D model of neuromuscular tissue. To do so, we repopulated rat dSkM with human primary myogenic cells along with murine fibroblasts and we coupled them with organotypic rat spinal cord samples. Such culture conditions not only maintained multiple cell type viability in a long-term experimental setup, but also resulted in functionally active construct capable of contraction. In addition, we have developed a customized culture system which enabled easy access, imaging, and analysis of in vitro engineered co-cultures. This work demonstrates the ability of dSkM to support the development of a contractile 3D in vitro model of neuromuscular tissue fit for long-term experimental evaluations.

Fetal lung underdevelopment, also known as pulmonary hypoplasia, is characterized by decreased lung growth and maturation. The most common birth defect found in babies with pulmonary hypoplasia is congenital diaphragmatic hernia (CDH). Despite research and clinical advances, babies with CDH still have high morbidity and mortality rates, which are directly related to the severity of lung underdevelopment. To date, there is no effective treatment that promotes fetal lung growth and maturation. Here, we describe a stem cell-based approach in rodents that enhances fetal lung development via the administration of extracellular vesicles (EVs) derived from amniotic fluid stem cells (AFSCs). Using fetal rodent models of pulmonary hypoplasia (primary epithelial cells, organoids, explants, and in vivo), we demonstrated that AFSC-EV administration promoted branching morphogenesis and alveolarization, rescued tissue homeostasis, and stimulated epithelial cell and fibroblast differentiation. We confirmed this regenerative ability in in vitro models of lung injury using human material, where human AFSC-EVs obtained following good manufacturing practices restored pulmonary epithelial homeostasis. Investigating EV mechanism of action, we found that AFSC-EV beneficial effects were exerted via the release of RNA cargo. MicroRNAs regulating the expression of genes involved in lung development, such as the miR17-92 cluster and its paralogs, were highly enriched in AFSC-EVs and were increased in AFSC-EV-treated primary lung epithelial cells compared to untreated cells. Our findings suggest that AFSC-EVs hold regenerative ability for underdeveloped fetal lungs, demonstrating potential for therapeutic application in patients with pulmonary hypoplasia.

Drug screening and disease modelling for skeletal muscle related pathologies would strongly benefit from the integration of myogenic cells derived from human pluripotent stem cells within miniaturized cell culture devices, such as microfluidic platform. Here, we identified the optimal culture conditions that allow direct differentiation of human pluripotent stem cells in myogenic cells within microfluidic devices. Myogenic cells are efficiently derived from both human embryonic (hESC) or induced pluripotent stem cells (hiPSC) in eleven days by combining small molecules and non-integrating modified mRNA (mmRNA) encoding for the master myogenic transcription factor MYOD. Our work opens new perspective for the development of patient-specific platforms in which a one-step myogenic differentiation could be used to generate skeletal muscle on-a-chip.

BackgroundType III spinal muscular atrophy (SMA) is a single gene disorder affecting motor function in uterus. Several types of stem cells were utilized to ameliorate SMA based on its capability of regeneration and differentiation. Amniotic fluid is an alternative source of stem cells and is safely sampled without ethical issues. Human amniotic fluid stem cell (hAFSC) shared common surface markers of mesenchymal stem cell. Therefore, this study aims to examine the therapeutic potential of hAFSC for SMA. MethodsOur SMA model mice were generated by deletion of exon 7 of Smn gene and knock-in of human SMN2. A total of 16 SMA model mice were injected with 1x105 hAFSC in uterus, and the other 16 mice served as the negative control. Motor function was analyzed by Rotarod maintenance test, tilting test and grasping test every two months. Twelve months after transplantation, all organs were extracted for post-mortem analysis. Engraftment of hAFSC in organs were assessed by flow cytometry and RNA scope. To observe the function of neuromuscular junction, frequency of myocytes, neurons and innervated receptors were estimated by H&E, methylene blue and immunocytochemistry staining. ResultsWith hAFSC transplantation, 15 fetuses from 5 dams survived (15 of 16, 93.75% survival) and showed better performance in all three motor function tests. Higher engraftment frequency in organs were observed in muscle and liver after hAFSC transplantation. Besides, the muscle of SMA mice with hAFSC transplantation expressed much laminin α and PAX-7. Significantly higher frequency of myocytes, neurons and innervated receptors were observed after hAFSC transplantation. ConclusionsIn our study, hAFSC engrafted on neuromuscular organs and improved cellular and behavioral outcomes of SMA model mice. This fetal therapy could preserve the time window and treat in the uterus to avoid irreversible damage.

This book offers a contemporary overview of the subject in general, as well as detailed information about core subjects. Structured to assist problem-solving and diagnosis, the handbook contains detailed clinical features on all aspects of neonatal and general paediatric surgical conditions and is a patient guide for GPs, paediatricians, and general and specialist paediatric surgeons. The contents have been designed to align with the MRCS and FRCS (Paediatrics) postgraduate exams, and the European Union of Medical Specialists (UEMS) European exam in paediatric surgery. With a focus on knowledge needed in clinical practice, the book also provides supporting background, and science is included to strengthen understanding.

Several paediatric gastrointestinal diseases result in life-shortening organ failure. For many of these conditions, current therapeutic options are suboptimal and may not offer a cure. Regenerative medicine is an inter-disciplinary field involving biologists, engineers, and clinicians that aims to produce cell and tissue-based therapies to overcome organ failure. Exciting advances in stem cell biology, materials science, and bioengineering bring engineered gastrointestinal cell and tissue therapies to the verge of clinical trial. In this review, we summarise the requirements for bioengineered therapies, the possible sources of the various cellular and non-cellular components, and the progress towards clinical translation of oesophageal and intestinal tissue engineering to date.

The larynx, trachea and bronchi have separate embryological development and as such a variety of congenital anomalies are possible. In addition, improvements in neonatal intensive care have led to increased numbers of children with secondary airway pathology. Our preference is for conservative or endoscopic management for the majority of cases, but severely stenotic or defective airways may require immediate or open correction in the neonatal period.

Congenital diaphragmatic hernia (CDH) is characterized by a defect in the muscle dividing the thoracic and abdominal cavities. This leads to herniation of the abdominal organs into the thorax and a disturbance of lung development. Two-thirds of cases are identified by prenatal ultrasound in the second trimester, which should prompt referral to a tertiary center for prognosis assessment and counseling by a multidisciplinary team familiar with this condition. In this review, we summarize evidence on prenatal diagnosis and postnatal management of CDH. There is a focus on information that should be provided to expecting parents during prenatal counseling.

OBJECTIVE: We performed a systematic review to summarize the efficacy and safety of in utero stem cells application in preclinical models with myelomeningocele (MMC). METHODS: The study was registered with PROSPERO (CRD42019160399). We searched MEDLINE, Embase, Web of Science, Scopus and CENTRAL for publications articles on stem cell therapy in animal fetuses with MMC until May 2020. Publication quality was assessed by the SYRCLE's tool. Meta-analyses were pooled if studies were done in the same animal model providing similar type of stem cell used and outcome measurements. Narrative synthesis was performed for studies that could not be pooled. RESULTS: Nineteen and seven studies were included in narrative and quantitative syntheses, respectively. Most used mesenchymal stem cells (MSCs) and primarily involved ovine and rodent models. Both intra-amniotic injection of allogeneic amniotic fluid (AF)-MSCs in rat MMC model and the application of human placental (P)-MSCs to the spinal cord during fetal surgery in MMC ovine model did not compromise fetal survival rates at term (rat model, relative risk [RR] 1.03, 95% CI 0.92-1.16; ovine model, RR 0.94, 95% CI 0.78-1.13). A single intra-amniotic injection of allogeneic AF-MSCs into rat MMC model was associated with a higher rate of complete defect coverage compared to saline injection (RR 16.35, 95% CI 3.27-81.79). The incorporation of human P-MSCs as a therapeutic adjunct to fetal surgery in the ovine MMC model significantly improved sheep locomotor rating scale after birth (mean difference 5.18, 95% CI 3.36-6.99). CONCLUSIONS: Stem cell application during prenatal period in preclinical animal models is safe and effective. ispartof: PRENATAL DIAGNOSIS vol:41 issue:3 pages:283-300 ispartof: location:England status: published

Liver fibrosis is driven by progressive accumulation of extracellular matrix (ECM), coupled with chronic inflammation. Recent evidence shows that ECM changes in liver disease directly and indirectly modulate the immune system. Since traditional cell culture models often lack immune cell and ECM components, bioengineered models of liver disease using decellularised tissues present an appealing alternative. Here, we describe the generation of a bioengineered model which incorporates the dynamic culture of circulating immune cells with decellularised human liver scaffolds, supported in a custom-made bioreactor to explore interactions between the immune system and liver ECM proteins at different stages of fibrosis. Liver ECM-scaffolds were generated bydecellularisingliver tissue with/without underlying disease from human liver tissue samples from partial hepatectomy, or by perfusion decellularisation of whole rat liver using established protocols. PBMCs isolated from healthy donor whole-blood were first cultured in the bioreactor under semi-continuous perfusion at high (4.22 Pa) or low shear stress (0.34 Pa) and compared to static conditions. Longitudinal profiling of PBMC phenotype was determined byFACs. ECM-scaffold were then perfused with PBMCs and cultured for 5 days. Immune-perfused tissues were stained for PBMC surface markers (T, B, NK cells and macrophages) to identify cell homing. We designed a custom-made bioreactor which can house 6 decellularised human liver scaffolds and which supports dynamic culture of PBMCs. We found that shear stress impacts PBMC viability and that PBMCs are better supported under low shear stress conditions. PBMC phenotype profiling byFACs show no significant changes in proportion of T cells between static and dynamic culture, while an increase in proportion ofTregsand a decrease in proportion of NK cells were detected in dynamic culture. Perfusion of PBMCs in decellularised scaffolds without fibrosis show homing of cells in different areas of the scaffold at all time points, with CD3+ T cells representing 50% of cells and with small clusters of macrophages, monocytes and B cells at 3 days of culture. Dynamic perfusion improved cell density and homing in decellularised liver scaffolds compared to static conditions. Our bioengineered system supports dynamic co-culture of PBMCs and decellularised scaffolds, with varying grades of fibrosis, allowing us to explore the interactions between the ECM and immune cells in liver disease in a dynamic perfusion system. A better understanding of ECM-immune interactions will aid our understanding of the driving factors behind fibrosis and could highlight new disease progression biomarkers and therapeutic targets to treat disease.

Incomplete lung development, also known as pulmonary hypoplasia, is a recognized cause of neonatal death and poor outcome for survivors. To date, there is no effective treatment that promotes fetal lung growth and maturation. Herein, we describe a novel stem cell-based approach that enhances fetal lung development via the administration of extracellular vesicles (EVs) derived from amniotic fluid stem cells (AFSCs). In experimental models of pulmonary hypoplasia, administration of AFSC-EVs promoted lung branching morphogenesis and alveolarization, and stimulated pulmonary epithelial cell and fibroblast differentiation. This regenerative ability was confirmed in two models of injured human lung cells, where human AFSC-EVs obtained following good manufacturing practices restored pulmonary epithelial homeostasis. AFSC-EV beneficial effects were exerted via the release of RNA cargo, primarily miRNAs, that regulate the expression of genes involved in fetal lung development. Our findings suggest that AFSC-EVs hold regenerative ability for underdeveloped fetal lungs, demonstrating potential for therapeutic application.One Sentence SummaryFetal lung regeneration via administration of extracellular vesicles derived from amniotic fluid stem cells

Introduction Many aspects of the management of esophageal atresia (EA) and tracheoesophageal fistula (TEF) are controversial and the evidence for decision making is limited. Members of the European Reference Network for Rare Inherited Congenital Anomalies (ERNICA) conducted a consensus conference on the surgical management of EA/TEF based on expert opinions referring to the latest literature. Materials and Methods Nineteen ERNICA representatives from nine European countries participated in the conference. The conference was prepared by item generation, item prioritization by online survey, formulation of a final list containing the domains diagnostics, preoperative, operative, and postoperative management, and literature review. The 2-day conference was held in Berlin in October 2018. Anonymous voting was conducted via an internet-based system. Consensus was defined when 75% of the votes scored 6 to 9. Results Fifty-two items were generated with 116 relevant articles of which five studies (4.3%) were assigned as level-1evidence. Complete consensus (100%) was achieved on 20 items (38%), such as TEF closure by transfixing suture, esophageal anastomosis by interrupted sutures, and initiation of feeding 24 hours postoperatively. Consensus ≥75% was achieved on 37 items (71%), such as routine insertion of transanastomotic tube or maximum duration of thoracoscopy of 3 hours. Thirteen items (25%) were controversial (range of scores, 1–9). Eight of these (62%) did not reach consensus. Conclusion Participants of the conference reached significant consensus on the management of patients with EA/TEF. The consensus may facilitate standardization and development of generally accepted guidelines. The conference methodology may serve as a blueprint for further conferences on the management of congenital malformations in pediatric surgery.

Introduction Evidence supporting best practice for long-gap esophageal atresia is limited. The European Reference Network for Rare Inherited Congenital Anomalies (ERNICA) organized a consensus conference on the management of patients with long-gap esophageal atresia based on expert opinion referring to the latest literature aiming to provide clear and uniform statements in this respect. Materials and Methods Twenty-four ERNICA representatives from nine European countries participated. The conference was prepared by item generation, item prioritization by online survey, formulation of a final list containing items on perioperative, surgical, and long-term management, and literature review. The 2-day conference was held in Berlin in November 2019. Anonymous voting was conducted via an internet-based system using a 1 to 9 scale. Consensus was defined as ≥75% of those voting scoring 6 to 9. Results Ninety-seven items were generated. Complete consensus (100%) was achieved on 56 items (58%), e.g., avoidance of a cervical esophagostomy, promotion of sham feeding, details of delayed anastomosis, thoracoscopic pouch mobilization and placement of traction sutures as novel technique, replacement techniques, and follow-up. Consensus ≥75% was achieved on 90 items (93%), e.g., definition of long gap, routine pyloroplasty in gastric transposition, and avoidance of preoperative bougienage to enable delayed anastomosis. Nineteen items (20%), e.g., methods of gap measurement were discussed controversially (range 1–9). Conclusion This is the first consensus conference on the perioperative, surgical, and long-term management of patients with long-gap esophageal atresia. Substantial statements regarding esophageal reconstruction or replacement and follow-up were formulated which may contribute to improve patient care.

Summary Explosion of gene therapy approaches for treating rare monogenic and common liver disorders created an urgent need for disease models able to replicate human liver cellular environment. Available models lack 3D liver structure or are unable to survive in long-term culture. We aimed to generate and test a 3D culture system that allows long-term maintenance of human liver cell characteristics. The in vitro whole-organ “Bioreactor grown Artificial Liver Model” (BALM) employs a custom-designed bioreactor for long-term 3D culture of human induced pluripotent stem cells-derived hepatocyte-like cells (hiHEPs) in a mouse decellularized liver scaffold. Adeno-associated viral (AAV) and lentiviral (LV) vectors were introduced by intravascular injection. Substantial AAV and LV transgene expression in the BALM-grown hiHEPs was detected. Measurement of secreted proteins in the media allowed non-invasive monitoring of the system. We demonstrated that humanized whole-organ BALM is a valuable tool to generate pre-clinical data for investigational medicinal products., Graphical Abstract, Highlights • Generation of a perfused humanized in vitro whole liver bioreactor model: BALM • BALM improves maturation and long-term survival of human iPS-derived hepatocytes • BALM allows viral transduction of human iHEPs through its vasculature • BALM provides a tool for gene therapy testing of human iHEPs, Clinical Genetics; Bioengineering; Tissue Engineering