Local and systemic responses to SARS-CoV-2 infection in children and adults.

It is not fully understood why COVID-19 is typically milder in children1-3. Here, to examine the differences between children and adults in their response to SARS-CoV-2 infection, we analysed paediatric and adult patients with COVID-19 as well as healthy control individuals (total n = 93) using single-cell multi-omic profiling of matched nasal, tracheal, bronchial and blood samples. In the airways of healthy paediatric individuals, we observed cells that were already in an interferon-activated state, which after SARS-CoV-2 infection was further induced especially in airway immune cells. We postulate that higher paediatric innate interferon responses restrict viral replication and disease progression. The systemic response in children was characterized by increases in naive lymphocytes and a depletion of natural killer cells, whereas, in adults, cytotoxic T cells and interferon-stimulated subpopulations were significantly increased. We provide evidence that dendritic cells initiate interferon signalling in early infection, and identify epithelial cell states associated with COVID-19 and age. Our matching nasal and blood data show a strong interferon response in the airways with the induction of systemic interferon-stimulated populations, which were substantially reduced in paediatric patients. Together, we provide several mechanisms that explain the milder clinical syndrome observed in children.

Adaptable haemodynamic endothelial cells for organogenesis and tumorigenesis.

Endothelial cells adopt tissue-specific characteristics to instruct organ development and regeneration1,2. This adaptability is lost in cultured adult endothelial cells, which do not vascularize tissues in an organotypic manner. Here, we show that transient reactivation of the embryonic-restricted ETS variant transcription factor 2 (ETV2)3 in mature human endothelial cells cultured in a serum-free three-dimensional matrix composed of a mixture of laminin, entactin and type-IV collagen (LEC matrix) 'resets' these endothelial cells to adaptable, vasculogenic cells, which form perfusable and plastic vascular plexi. Through chromatin remodelling, ETV2 induces tubulogenic pathways, including the activation of RAP1, which promotes the formation of durable lumens4,5. In three-dimensional matrices-which do not have the constraints of bioprinted scaffolds-the 'reset' vascular endothelial cells (R-VECs) self-assemble into stable, multilayered and branching vascular networks within scalable microfluidic chambers, which are capable of transporting human blood. In vivo, R-VECs implanted subcutaneously in mice self-organize into durable pericyte-coated vessels that functionally anastomose to the host circulation and exhibit long-lasting patterning, with no evidence of malformations or angiomas. R-VECs directly interact with cells within three-dimensional co-cultured organoids, removing the need for the restrictive synthetic semipermeable membranes that are required for organ-on-chip systems, therefore providing a physiological platform for vascularization, which we call 'Organ-On-VascularNet'. R-VECs enable perfusion of glucose-responsive insulin-secreting human pancreatic islets, vascularize decellularized rat intestines and arborize healthy or cancerous human colon organoids. Using single-cell RNA sequencing and epigenetic profiling, we demonstrate that R-VECs establish an adaptive vascular niche that differentially adjusts and conforms to organoids and tumoroids in a tissue-specific manner. Our Organ-On-VascularNet model will permit metabolic, immunological and physiochemical studies and screens to decipher the crosstalk between organotypic endothelial cells and parenchymal cells for identification of determinants of endothelial cell heterogeneity, and could lead to advances in therapeutic organ repair and tumour targeting.

Human enteric nervous system progenitor transplantation improves functional responses in Hirschsprung disease patient-derived tissue.

OBJECTIVE: Hirschsprung disease (HSCR) is a severe congenital disorder affecting 1:5000 live births. HSCR results from the failure of enteric nervous system (ENS) progenitors to fully colonise the gastrointestinal tract during embryonic development. This leads to aganglionosis in the distal bowel, resulting in disrupted motor activity and impaired peristalsis. Currently, the only viable treatment option is surgical resection of the aganglionic bowel. However, patients frequently suffer debilitating, lifelong symptoms, with multiple surgical procedures often necessary. Hence, alternative treatment options are crucial. An attractive strategy involves the transplantation of ENS progenitors generated from human pluripotent stem cells (hPSCs). DESIGN: ENS progenitors were generated from hPSCs using an accelerated protocol and characterised, in detail, through a combination of single-cell RNA sequencing, protein expression analysis and calcium imaging. We tested ENS progenitors' capacity to integrate and affect functional responses in HSCR colon, after ex vivo transplantation to organotypically cultured patient-derived colonic tissue, using organ bath contractility. RESULTS: We found that our protocol consistently gives rise to high yields of a cell population exhibiting transcriptional and functional hallmarks of early ENS progenitors. Following transplantation, hPSC-derived ENS progenitors integrate, migrate and form neurons/glia within explanted human HSCR colon samples. Importantly, the transplanted HSCR tissue displayed significantly increased basal contractile activity and increased responses to electrical stimulation compared with control tissue. CONCLUSION: Our findings demonstrate, for the first time, the potential of hPSC-derived ENS progenitors to repopulate and increase functional responses in human HSCR patient colonic tissue.

Synchronisation of apical constriction and cell cycle progression is a conserved behaviour of pseudostratified neuroepithelia informed by their tissue geometry.

Neuroepithelial cells balance tissue growth requirement with the morphogenetic imperative of closing the neural tube. They apically constrict to generate mechanical forces which elevate the neural folds, but are thought to apically dilate during mitosis. However, we previously reported that mitotic neuroepithelial cells in the mouse posterior neuropore have smaller apical surfaces than non-mitotic cells. Here, we document progressive apical enrichment of non-muscle myosin-II in mitotic, but not non-mitotic, neuroepithelial cells with smaller apical areas. Live-imaging of the chick posterior neuropore confirms apical constriction synchronised with mitosis, reaching maximal constriction by anaphase, before division and re-dilation. Mitotic apical constriction amplitude is significantly greater than interphase constrictions. To investigate conservation in humans, we characterised early stages of iPSC differentiation through dual SMAD-inhibition to robustly produce pseudostratified neuroepithelia with apically enriched actomyosin. These cultured neuroepithelial cells achieve an equivalent apical area to those in mouse embryos. iPSC-derived neuroepithelial cells have large apical areas in G2 which constrict in M phase and retain this constriction in G1/S. Given that this differentiation method produces anterior neural identities, we studied the anterior neuroepithelium of the elevating mouse mid-brain neural tube. Instead of constricting, mid-brain mitotic neuroepithelial cells have larger apical areas than interphase cells. Tissue geometry differs between the apically convex early midbrain and flat posterior neuropore. Culturing human neuroepithelia on equivalently convex surfaces prevents mitotic apical constriction. Thus, neuroepithelial cells undergo high-amplitude apical constriction synchronised with cell cycle progression but the timing of their constriction if influenced by tissue geometry.

Self-reported respiratory and gastrointestinal outcomes in children with isolated congenital diaphragmatic hernia: A prospective multicentre study.

OBJECTIVE: To evaluate medium-term self-reported respiratory and gastrointestinal (GI) outcomes in children with congenital diaphragmatic hernia (CDH). DESIGN: Self-reported respiratory and GI outcomes correlated with prenatal severity indicators. SETTING: Prospective study at three fetal medicine units. POPULATION: Families of children prenatally diagnosed with isolated, left-sided CDH surviving for >1 year. METHODS: Families received validated questionnaires for GI outcomes (Infant Gastroesophageal Reflux Questionnaire Revised, I-GERQ-R, for infants aged <2 years, or Paediatric Gastro-oesophageal Symptom and Quality of Life Questionnaire, PGSQ, for children aged aged 2-8 years or >9 years) and respiratory outcomes (preschool respiratory outcome questionnaire, for children aged ≤5 years, or the International Study of Asthma and Allergies in Childhood asthma questionnaire, for children aged 6-8 years or ≥9 years). Prenatal data collected from the medical records included lung size (percentage observed/expected lung-to-head ratio, O/E LHR %), liver position, fetal endoluminal tracheal occlusion (FETO) gestational age (GA) at delivery, and perinatal data included birthweight, location, patch repair and respiratory support. MAIN OUTCOME MEASURES: The GI and respiratory scores were correlated with O/E LHR using linear and logistic regression models. Univariate analysis was used to evaluate associations with perinatal variables. RESULTS: We obtained 142 responses from 342 families (representing a response rate of 45%). The baseline characteristics of participants and non-participants were comparable. No correlations between perinatal variables and respiratory or GI scores were identified. Children aged ≤5 years with lower O/E LHR values reported higher respiratory scores (P = 0.0175); this finding was not reported in older children. Overall, the children who underwent FETO (n = 51) had GI (P = 0.290) and respiratory (P = 0.052) scores that were comparable with those of children who were expectantly managed. CONCLUSIONS: Families and children with prenatally diagnosed CDH reported fewer respiratory symptoms with increasing age. There was no correlation between O/E LHR or the use of FETO and self-reported outcomes.

Exteriorization of the uterus reduces fetoscopic cannula-induced stress and strain: A finite element model analysis.

OBJECTIVE: To estimate stresses and strains in the uterine wall and fetal membranes with single/multi-port fetoscopy, simulating either a percutaneous access or via exteriorized uterus. STUDY DESIGN: Finite element models based on anatomical dimensions, material properties and boundary conditions were created to simulate stresses, strains and displacements on the uterine wall and fetal membranes during simulated fetal surgery either via exteriorized uterus or percutaneous approach, and with one or three cannulas. Clinically, we measured the anatomical layer thickness and cannula entry point displacement in patients undergoing single port percutaneous fetoscopy. RESULTS: Simulations demonstrate that single port percutaneous fetoscopy increases stress on the fetal membranes (+105%, 128 to 262 kPa) and uterine wall (+115%, 0.89 to 1.9 kPa) compared to exteriorized uterine access. Using three ports increases stress by 110% (148 to 312 kPa) on membranes and 113% (1.08 to 2.3 kPa) on uterine wall. Finite Element Method showed 0.75 cm uterine entry point displacement from the cutaneous entry, while clinical measurements demonstrated displacement of more than double (1.69 ± 0.58 cm), suggesting modeled measurements may be underestimations. CONCLUSION: The stresses and strains on the fetal membranes and uterus are double as high when entering percutaneously than via an exteriorized uterus. Based on what can be clinically measured, this may be an underestimation.

Barrier-Forming Potential of Epithelial Cells from the Exstrophic Bladder.

Bladder exstrophy (BEX) is a rare developmental abnormality resulting in an open, exposed bladder plate. Although normal bladder urothelium is a mitotically quiescent barrier epithelium, histologic studies of BEX epithelia report squamous and proliferative changes that can persist beyond surgical closure. The current study examined whether patient-derived BEX epithelial cells in vitro were capable of generating a barrier-forming epithelium under permissive conditions. Epithelial cells isolated from 11 BEX samples, classified histologically as transitional (n = 6) or squamous (n = 5), were propagated in vitro. In conditions conducive to differentiated tight barrier formation by normal human urothelial cell cultures, 8 of 11 BEX lines developed transepithelial electrical resistances of more than 1000 Ω.cm2, with 3 squamous lines failing to generate tight barriers. An inverse relationship was found between expression of squamous KRT14 transcript and barrier development. Transcriptional drivers of urothelial differentiation PPARG, GATA3, and FOXA1 showed reduced expression in squamous BEX cultures. These findings implicate developmental interruption of urothelial transcriptional programming in the spectrum of transitional to squamous epithelial phenotypes found in BEX. Assessment of BEX epithelial phenotype may inform management and treatment strategies, for which distinction between reversible versus intractably squamous epithelium could identify patients at risk of medical complications or those who are most appropriate for reconstructive tissue engineering strategies.

Congenital diaphragmatic hernia subtypes: Comparing birth prevalence, occurrence by maternal age, and mortality in a national birth cohort.

BACKGROUND: Population-based administrative data have rarely been used to compare the birth prevalence, risk factors for occurrence, and mortality of congenital diaphragmatic hernia (CDH) subtypes. OBJECTIVES: We used a national birth cohort to identify CDH subtypes and compared their birth prevalence, relationship with maternal age after accounting for sociodemographic factors, and 1-year mortality rates. METHODS: Linked hospital admission and death records were used to identify isolated and complex CDH cases (involving additional anomalies) among singleton livebirths in England between 2002 and 2018. The prevalence of each CDH subtype per 10,000 livebirths was estimated overall and by infant, birth and maternal characteristics. The relationship between maternal age and each subtype relative to no CDH was examined using multivariable log-binomial regression to estimate risk ratios (RRs). One-year mortality rates were examined using Kaplan-Meier curves and the hazard ratio (HR) of complex versus isolated CDH was calculated using Cox regression. RESULTS: Among 9.5 million livebirths, we identified 1285 with isolated CDH and 1150 with complex CDH. The overall prevalence of isolated and complex CDH was 1.4 (95% confidence interval [CI] 1.3, 1.4) and 1.2 (95% CI 1.1, 1.3) per 10,000 livebirths, respectively. Only complex CDH was associated with maternal age. Compared with maternal age 25-34 years, complex CDH risk was elevated for maternal age < 20 years (RR 1.31, 95% CI 1.00, 1.72). Risk was highest for maternal age ≥ 40 years (RR 1.61, 95% CI 1.21, 2.15) although accounting for chromosomal anomalies attenuated the risk (RR 1.39, 95% CI 1.00, 1.92). The 1-year mortality rate for complex CDH (33.1%, 95% CI 30.5, 35.9) was slightly higher than for isolated CDH (29.7%, 95% CI 27.3, 32.3) (HR 1.10, 95% CI 0.96, 1.27). CONCLUSIONS: Mechanisms of occurrence differed between and within CDH subtypes and 1-year mortality of complex CDH was slightly higher than for isolated CDH.

Multi-disciplinary Insights from the First European Forum on Visceral Myopathy 2022 Meeting.

Visceral myopathy is a rare, life-threatening disease linked to identified genetic mutations in 60% of cases. Mostly due to the dearth of knowledge regarding its pathogenesis, effective treatments are lacking. The disease is most commonly diagnosed in children with recurrent or persistent disabling episodes of functional intestinal obstruction, which can be life threatening, often requiring long-term parenteral or specialized enteral nutritional support. Although these interventions are undisputedly life-saving as they allow affected individuals to avoid malnutrition and related complications, they also seriously compromise their quality of life and can carry the risk of sepsis and thrombosis. Animal models for visceral myopathy, which could be crucial for advancing the scientific knowledge of this condition, are scarce. Clearly, a collaborative network is needed to develop research plans to clarify genotype-phenotype correlations and unravel molecular mechanisms to provide targeted therapeutic strategies. This paper represents a summary report of the first 'European Forum on Visceral Myopathy'. This forum was attended by an international interdisciplinary working group that met to better understand visceral myopathy and foster interaction among scientists actively involved in the field and clinicians who specialize in care of people with visceral myopathy.

Local host response of commercially available dural patches for fetal repair of spina bifida aperta in rabbit model.

OBJECTIVE: Fetal surgery for spina bifida aperta (SBA) by open hysterotomy typically repairs anatomical native tissue in layers. Increasingly, fetoscopic repair is performed using a dural patch followed by skin closure. We studied the host response to selected commercially available patches currently being used in a fetal rabbit model for spina bifida repair. METHODS: SBA was surgically induced at 23-24 days of gestation (term = 31 days). Fetal rabbits were assigned to unrepaired (SBA group), or immediate repair with Duragen™ or Durepair™. Non-operated littermates served as normal controls. At term, spinal cords underwent immunohistochemical staining including Nissl and glial fibrillary acidic protein. We hypothesized that spinal cord coverage with a dural patch and skin closure would preserve motor neuron density within the non-inferiority limit of 201.65 cells/mm2 and reduce inflammation compared to unrepaired SBA fetuses. RESULTS: Motor neuron density assessed by Nissl staining was conserved both by Duragen (n = 6, 89.5; 95% CI -158.3 to -20.6) and Durepair (n = 6, 37.0; 95% CI -132.6 to -58.5), whereas density of GFAP-positive cells to quantify inflammation was lower than in unrepaired SBA-fetuses (SBA 2366.0 ± 669.7 cells/mm2 vs. Duragen 1274.0 ± 157.2 cells/mm2 ; p = 0.0002, Durepair 1069.0 ± 270.7 cells/mm2 ; p < 0.0001). CONCLUSIONS: Covering the rabbit spinal cord with either Duragen or Durepair followed by skin closure preserves motor neuron density and reduces the inflammatory response.

Regenerative medicine: current research and perspective in pediatric surgery.

The field of regenerative medicine, encompassing several disciplines including stem cell biology and tissue engineering, continues to advance with the accumulating research on cell manipulation technologies, gene therapy and new materials. Recent progress in preclinical and clinical studies may transcend the boundaries of regenerative medicine from laboratory research towards clinical reality. However, for the ultimate goal to construct bioengineered transplantable organs, a number of issues still need to be addressed. In particular, engineering of elaborate tissues and organs requires a fine combination of different relevant aspects; not only the repopulation of multiple cell phenotypes in an appropriate distribution but also the adjustment of the host environmental factors such as vascularisation, innervation and immunomodulation. The aim of this review article is to provide an overview of the recent discoveries and development in stem cells and tissue engineering, which are inseparably interconnected. The current status of research on tissue stem cells and bioengineering, and the possibilities for application in specific organs relevant to paediatric surgery have been specifically focused and outlined.

Generation of human gastric assembloids from primary fetal organoids.

PURPOSE: Understanding human gastric epithelium homeostasis remains partial, motivating the exploration of innovative in vitro models. Recent literature showcases the potential of fetal stem cell-derived organoids in developmental and disease modelling and translational therapies. To scale the complexity of the model, we propose to generate assembloids, aiming to increase gastric maturation to provide new structural and functional insights. METHODS: Human fetal gastric organoids (fGOs) were expanded in 3D Matrigel cultures. Confluent organoid cultures were released from the Matrigel dome and resuspended in a collagen I hydrogel. Subsequently, the organoid mixture was seeded in a ring shape within a 24-well plate and allowed to gelate. The structure was lifted in the medium and cultured in floating conditions, allowing for organoid self-assembling into a gastric assembloid. After 10 days of maturation, the assembloids were characterized by immunostaining and RT-PCR, comparing different fetal developmental stages. RESULTS: Successful generation of human fetal gastric assembloids (fGAs) was achieved using spontaneous self-aggregation within the collagen I hydrogel. Immunostaining analysis of early and late fGAs showed the establishment of apico-basal cell polarity, secretion of gastric mucins, and the presence of chromogranin A in both samples. Transcriptional markers analysis revealed distinct disparities in markers associated with mature cell types between late and early fetal stages. CONCLUSIONS: fGOs can reliably be generated from human fetal samples. This pioneering assembloid approach paves the way for advancing our comprehension of human gastric epithelium homeostasis and its perturbation, offering a better in vitro platform for the study of gastric epithelial development and therapeutic translation.

Minimal access surgery for congenital diaphragmatic hernia: surgical tricks to facilitate anchoring the patches to the ribs.

OBJECTIVE: Minimal Access Surgery (MAS) for Congenital Diaphragmatic Hernia (CDH) repair is well described, yet only a minority of surgeons report this as their preferred operative approach. Some surgeons find it particularly difficult to repair the defect using MAS and convert to laparotomy when a patch is required. We present in this study our institutional experience in using an easy and relatively cheap methodology to anchor the patch around the ribs using Endo Close™. This device has an application in MAS for tissue approximation using percutaneous suturing. METHODS AND TECHNIQUE: We retrospectively reviewed our database for patients undergoing MAS repair of CDH between 2009 and 2021. Outcome measures included length of surgery and recurrence rates after patch repair. Endo Close™ was used in all patients who required patch repair. We declare no conflict of interest and to not having received any funding from Medtronic (UK). The technique is as follows: (1) The edges of the diaphragm are delineated by dissection. When primary suture repair of the diaphragmatic hernia was unfeasible without tension, a patch was used. (2) The patch is anchored in place by two corner stitches at the medial and lateral borders. (3) The posterior border of the patch is fixed to the diaphragmatic edge by running or interrupted stitches. (4) For securing the anterior border, a non-absorbable suture is passed through the anterior chest wall and the patch border is taken with intracorporeal instruments. (5) Without making another stab incision, the Endo Close™ is tunnelled subcutaneously through the anterior chest wall. (6) The suture end is pulled through the Endo Close™ and the knot is tied around the rib. This procedure can be performed as many times as required to secure the patch. RESULTS: 58 patients underwent MAS surgery for repair of CDH between 2009 and 2021. 48 (82%) presented with a left defect. 34 (58%) had a patch repair. The length of patch repair surgery for CDH ranged from 100-343 min (median 197). There was only one patient (3%) in the patch repair cohort that had a recurrent hernia, diagnosed 12 months after the initial surgery. CONCLUSIONS: In our experience, MAS repair of CDH is feasible. We adopted a low threshold in using a patch to achieve a tension-free repair. We believe that the Endo Close™ is a cheap and safe method to help securing the patch around the ribs.

Thoracoscopic vs open repair of congenital diaphragmatic hernia after extracorporeal membrane oxygenation: a comparison of intra-operative data.

PURPOSE: ECMO is an escalation treatment for hypoxic respiratory failure in patients with CDH. Open repair has been advocated after ECMO indicating that physiological changes associated to thoracoscopic repair were not well tolerated. METHODS: We have performed a retrospective review of all patients who underwent ECMO prior CDH repair over a 7 year period (2015-2021). Outcome measures were intra-operative Ph, PCO2, PO2 and FiO2 at 30 min, 1 h 30 min, and 2 h 30 min of surgery, operative time and recurrence rate. Data are shown in median (range). RESULTS: Eleven patients required ECMO prior CDH repair. Six of eleven (55%) were done thoracoscopically (Group A) and five of eleven (45%) via laparotomy (Group B). Two of six (33%) patients (Group A) were converted to a laparotomy, one of six (16%) patient developed a recurrence, and there was no recurrence in Group B. Two of five (40%) patients died within the first 60 days of life, whilst there was no death in Group A. Intra-operative values are shown below. CONCLUSION: Whilst this is a preliminary report of a limited number of patients, there is no obvious difference of intra-operative blood gas parameters during surgical repair in patients after ECMO. Thoracoscopic CDH repair may be considered in patients after ECMO.

Ultrasonographic features associated with previous torsion and the impact of surgery in managing neonatal ovarian cysts: a 20-year single-centre retrospective study.

PURPOSE: To identify markers of previous ovarian torsion and outline the outcomes according to US appearance and operative management. METHODS: A retrospective single-centre review of neonatal ovarian cysts from January 2000 to January 2020. Data on postnatal cyst size and sonographic features and operative treatment were co-related with outcomes of ovarian loss and histology. RESULTS: 77 females were included with 22 simple and 56 complex cysts, one patient had bilateral cysts. 9/22 (41%) simple cysts regressed spontaneously in a median of 13 weeks (8-17). Complex cysts regressed spontaneously less frequently, 7/56(12%, P = 0.01), in 13 weeks (7-39). 38/56 (68%) complex and 12/22 (55%) simple cysts were treated operatively. 21/22 (95%) ovaries with initially simple cyst were salvaged compared to 20/56(36%) with initially complex cyst (P < 0.001). A fluid-debris level in 23/26 complex cysts was most associated with ovarian loss (P = 0.0006). Presence of viable ovarian stromal tissue was seen in 8/20 (40%) excised specimens during ovarian sparing procedures and in 5/30 (17%) oophorectomies for necrotic appearing ovaries. CONCLUSIONS: Fluid-debris level on US is significantly associated with ovarian loss likely due to previous torsion. Simple cysts are viable and often regress spontaneously. The finding of viable ovarian stromal tissue in resected specimens supports attempting ovarian preservation wherever possible.

Laparoscopic inguinal hernia repair (LIHR): the benefit of the double stitch in the largest single-center experience.

AIM: To review our experience of laparoscopic inguinal hernia repair (LIHR) regarding complication rates, the practice of closing the asymptomatic patent processes vaginalis (PPV), and comparison of complication rates between pre-term (< 37 week gestation) and term infants. METHODS: Retrospective review of LIHR performed between 2009 and 2021. Repair was performed by intracorporal single or double purse string/purse string + Z-stitch using a non-absorbable suture. Data were analyzed using Chi-squared/Mann-Whitney and are quoted as median (range). RESULTS: 1855 inguinal rings were closed in 1195 patients (943 (79%) male). 1378 rings (74%) were symptomatic. 492 (41%) patients were pre-term. Corrected gestational age at surgery was 55 weeks (31 weeks-14.6 years) and weight 5.9 kg (1-65.5). Closure of contralateral PPV was higher in the premature group (210/397 [53%] vs. 265/613 [43%] p = 0.003). There were 23 recurrences in 20 patients, of whom 10 had been born prematurely. The only factor significantly associated with a lower recurrence was use of a second stitch (p = 0.011). CONCLUSION: This is the largest single-center reported series of LIHR. LIHR is safe at any age, the risk of recurrence is low, and can be corrected by re-laparoscopy. Use of a Z-stitch or second purse string is associated with a significantly lower rate of recurrence.

Stomach engineering: region-specific characterization of the decellularized porcine stomach.

PURPOSE: Patients affected by microgastria, severe gastroesophageal reflux, or those who have undergone subtotal gastrectomy, have commonly described reporting dumping syndromes or other symptoms that seriously impair the quality of their life. Gastric tissue engineering may offer an alternative approach to treating these pathologies. Decellularization protocols have great potential to generate novel biomaterials for large gastric defect repair. There is an urgency to define more reliable protocols to foster clinical applications of tissue-engineered decellularized gastric grafts. METHODS: In this work, we investigated the biochemical and mechanical properties of decellularized porcine stomach tissue compared to its native counterpart. Histological and immunofluorescence analyses were performed to screen the quality of decellularized samples. Quantitative analysis was also performed to assess extracellular matrix composition. At last, we investigated the mechanical properties and cytocompatibility of the decellularized tissue compared to the native. RESULTS: The optimized decellularization protocol produced efficient cell removal, highlighted in the absence of native cellular nuclei. Decellularized scaffolds preserved collagen and elastin contents, with partial loss of sulfated glycosaminoglycans. Decellularized gastric tissue revealed increased elastic modulus and strain at break during mechanical tensile tests, while ultimate tensile strength was significantly reduced. HepG2 cells were seeded on the ECM, revealing matrix cytocompatibility and the ability to support cell proliferation. CONCLUSION: Our work reports the successful generation of acellular porcine gastric tissue able to support cell viability and proliferation of human cells.

What should we tell parents? Congenital diaphragmatic hernia.

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.

Pulmonary hypertension in congenital diaphragmatic hernia: Antenatal prediction and impact on neonatal mortality.

OBJECTIVE: To determine the prevalence of pulmonary hypertension (PAH) in left-sided congenital diaphragmatic hernia (CDH); how we could predict it; and how PAH contributed to the model for mortality prediction. STUDY DESIGN: Retrospective analysis in three European centers. The primary outcome was the presence of PAH on postnatal day (d) 1, 7, and at discharge. Studied predictors of PAH were: observed/expected-lung/head-ratio (o/e LHR), liver-herniation, fetoscopic endoluminal tracheal occlusion (FETO), and gestational age (GA) at delivery. The combined effect of pre- and postnatal variables on mortality was modeled by Cox regression. RESULTS: Of the 197 neonates, 56 (28.4%) died. At d1, 67.5% (133/197) had PAH and 61.9% (101/163) by d7. Overall, 6.4% (9/141) had PAH at discharge. At d1, o/e LHR (odds ratio (OR) 0.96) and FETO (OR 2.99) independently correlated to PAH (areas under the curve [AUC]: 0.74). At d7, PAH significantly correlated only with the use of FETO (OR 3.9; AUC: 0.65). None were significant for PAH at discharge. Combining the occurrence of PAH with antenatal biomarkers improved mortality prediction (p = 0.02), in a model including o/e LHR (HR: 0.94), FETO (HR: 0.35), liver herniation (HR: 16.78), and PAH (HR: 15.95). CONCLUSIONS: Antenatal prediction of PAH was only moderate. The postnatal occurrence of PAH further increases the risk of death. Whereas this may be used to counsel parents in the postnatal period, our study demonstrates there is a need to find more accurate antenatal predictors for PAH.

Antenatal management of congenital diaphragmatic hernia: What's next ?

Congenital diaphragmatic hernia can be diagnosed in the prenatal period and its severity can be measured by fetal imaging. There is now level I evidence that, in selected cases, Fetoscopic Endoluminal Tracheal Occlusion with a balloon increases survival to discharge from the neonatal unit as well as the risk for prematurity. Both effects are dependent on the time point of tracheal occlusion. Fetoscopic Endoluminal Tracheal Occlusion may also lead to iatrogenic death when the balloon cannot be timely retrieved. The implementation of the findings from our clinical studies, may also vary based on local conditions. These may be different in terms of available skill set, access to fetal therapy, as well as outcome based on local neonatal management. We encourage prior benchmarking of local outcomes with optimal postnatal management, based on large enough numbers and using identical criteria as in the recent trials. We propose to work further on prenatal prediction methods, and the improvement of fetal intervention. In this manuscript, we describe a research agenda from a fetal medicine perspective. This research should be in parallel with innovation in neonatal and pediatric (surgical) management of this condition.