European Pediatric Surgeons' Association Survey on Timing of Inguinal Hernia Repair in Premature Infants.

AIM: This article evaluates the practice patterns of European Pediatric Surgeons' Association (EUPSA) members regarding the timing of inguinal hernia (IH) repair in premature infants. METHODS: Online survey containing 29 questions distributed to EUPSA members during January 2023. RESULTS: A total of 180 responds were received. Overall, IH repair prior to discharge was favored by 60% of respondents when there was a history of incarceration and 56% when there was not. In the case of very/extremely premature infants (< 32 weeks) with no history of incarceration, fewer (43%) respondents postpone the surgery until after discharge. The majority of respondents cited the risk of incarceration as the reason for advocating surgery prior to discharge, whereas a reduced risk of apnea was the most cited reason for respondents who prefer delayed surgery. Open approach under general anesthesia was favored by 54% of respondents, with 27% of them preferring open approach with spinal anesthesia. Laparoscopic surgery for premature infants is used in 11% while 7% of them preferred in all premature infants including extremely/very premature ones. Contralateral side evaluation was never done by 40% of respondents and 29% only performed it only during laparoscopic repair. The majority of respondents (77%) indicated that they have an overnight stay policy for premature infants < 45 weeks of gestation. CONCLUSION: There is variation in the practice patterns of pediatric surgeons in the treatment of IH in premature infants. Due to the concern for the high risk of incarceration, IH repair before discharge was the most prevalent practice. Lower risk of postoperative apnea was cited as the most common reason for delaying surgery. Randomized studies are required to establish the optimal timing for IH repair in premature infants.

Neonatal Intestinal Segmental Volvulus: What Are the Differences with Midgut Volvulus?

OBJECTIVE: Intestinal volvulus in the neonate is a surgical emergency caused by either midgut volvulus (MV) with intestinal malrotation or less commonly, by segmental volvulus (SV) without intestinal malrotation. The aim of our study was to investigate if MV and SV can be differentiated by clinical course, intraoperative findings, and postoperative outcomes. METHODS: Using a defined search strategy, two investigators independently identified all studies comparing MV and SV in neonates. PRISMA guidelines were followed, and a meta-analysis was performed using RevMan 5.3. RESULTS: Of 1,026 abstracts screened, 104 full-text articles were analyzed, and 3 comparative studies were selected (112 patients). There were no differences in gestational age (37 vs. 36 weeks), birth weight (2,989 vs. 2,712 g), and age at presentation (6.9 vs. 3.8 days). SV was more commonly associated with abnormal findings on fetal ultrasound (US; 65 vs. 11.6%; p < 0.00001). Preoperatively, SV was more commonly associated with abdominal distension (32 vs. 77%; p < 0.05), whereas MV with a whirlpool sign on ultrasound (57 vs. 3%; p < 0.01). Bilious vomiting had similar incidence in both (88 ± 4% vs. 50 ± 5%). Intraoperatively, SV had a higher incidence of intestinal atresia (2 vs. 19%; p < 0.05) and need for bowel resection (13 vs. 91%; p < 0.00001). There were no differences in postoperative complications (13% MV vs. 14% SV), short bowel syndrome (15% MV vs. 0% SV; data available only from one study), and mortality (12% MV vs. 2% SV). CONCLUSION: Our study highlights the paucity of studies on SV in neonates. Nonetheless, our meta-analysis clearly indicates that SV is an entity on its own with distinct clinical features and intraoperative findings that are different from MV. SV should be considered as one of the differential diagnoses in all term and preterm babies with bilious vomiting after MV was ruled out-especially if abnormal fetal US and abdominal distension is present.

Fetal lung regeneration using stem cell-derived extracellular vesicles: A new frontier for pulmonary hypoplasia secondary to congenital diaphragmatic hernia.

The poor outcomes of babies with congenital diaphragmatic hernia (CDH) are directly related to pulmonary hypoplasia, a condition characterized by impaired lung development. Although the pathogenesis of pulmonary hypoplasia is not fully elucidated, there is now evidence that CDH patients have missing or dysregulated microRNAs (miRNAs) that regulate lung development. A prenatal therapy that supplements these missing/dysregulated miRNAs could be a strategy to rescue normal lung development. Extracellular vesicles (EVs), also known as exosomes when of small dimensions, are lipid-bound nanoparticles that can transfer their heterogeneous cargo (proteins, lipids, small RNAs) to target cells to induce biological responses. Herein, we review all studies that show evidence for stem cell-derived EVs as a regenerative therapy to rescue normal development in CDH fetal lungs. Particularly, we report studies showing that administration of EVs derived from amniotic fluid stem cells (AFSC-EVs) to models of pulmonary hypoplasia promotes fetal lung growth and maturation via transfer of miRNAs that are known to regulate lung developmental processes. We also describe that stem cell-derived EVs exert effects on vascular remodeling, thus possibly preventing postnatal pulmonary hypertension. Finally, we discuss future perspectives and challenges to translate this promising stem cell EV-based therapy to clinical practice.

The Role of Exosomes in the Treatment, Prevention, Diagnosis, and Pathogenesis of COVID-19.

The novel coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), continues to be a major health concern. In search for novel treatment strategies against COVID-19, exosomes have attracted the attention of scientists and pharmaceutical companies worldwide. Exosomes are small extracellular vesicles, secreted by all types of cells, and considered as key mediators of intercellular communication and stem-cell paracrine signaling. Herein, we reviewed the most recent literature about the role of exosomes as potential agents for treatment, prevention, diagnosis, and pathogenesis of COVID-19. Several studies and ongoing clinical trials have been investigating the anti-inflammatory, immunomodulatory, and reparative effects of exosomes derived from mesenchymal stem/stromal cells for COVID-19-related acute lung injury. Other studies reported that exosomes play a key role in convalescent plasma therapy for COVID-19, and that they could be of use for the treatment of COVID-19 Kawasaki's-like multisystem inflammatory syndrome and as drug delivery nanocarriers for antiviral therapy. Harnessing some advantageous aspects of exosome biology, such as their endogenous origin, capability of crossing biological barriers, high stability in circulation, and low toxicity and immunogenicity, several companies have been testing exosome-based vaccines against SARS-CoV-2. As they carry cargos that mimic the status of parent cells, exosomes can be isolated from a variety of sources, including plasma, and employed as biomarkers of COVID-19. Lastly, there is growing evidence supporting the role of exosomes in COVID-19 infection, spread, reactivation, and reinfection. The lessons learned using exosomes for COVID-19 will help determine their efficacy and applicability in other clinical conditions.

Activation of Wnt signaling by amniotic fluid stem cell-derived extracellular vesicles attenuates intestinal injury in experimental necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) is a devastating intestinal disease primarily affecting preterm neonates and causing high morbidity, high mortality, and huge costs for the family and society. The treatment and the outcome of the disease have not changed in recent decades. Emerging evidence has shown that stimulating the Wnt/ß-catenin pathway and enhancing intestinal regeneration are beneficial in experimental NEC, and that they could potentially be used as a novel treatment. Amniotic fluid stem cells (AFSC) and AFSC-derived extracellular vesicles (EV) can be used to improve intestinal injury in experimental NEC. However, the mechanisms by which they affect the Wnt/ß-catenin pathway and intestinal regeneration are unknown. In our current study, we demonstrated that AFSC and EV attenuate NEC intestinal injury by activating the Wnt signaling pathway. AFSC and EV stimulate intestinal recovery from NEC by increasing cellular proliferation, reducing inflammation and ultimately regenerating a normal intestinal epithelium. EV administration has a rescuing effect on intestinal injury when given during NEC induction; however, it failed to prevent injury when given prior to NEC induction. AFSC-derived EV administration is thus a potential emergent novel treatment strategy for NEC.

First national survey on opioids prescribing practices of Canadian pediatric surgeons.

PURPOSE: Prescription opioid misuse has become a public health concern globally. In Canada, little is known about the national prescription patterns in children. The purpose of the present study was to evaluate the opioid prescribing practices of pediatric surgeons in Canada. METHODS: Following ethical approval, an electronic questionnaire was administered to all pediatric surgeons currently practicing in Canada. Questions included surgeon practice information, patterns of opioid prescription at discharge based on the type of surgery, type of opioid prescribed, and availability of training for surgeons/families. RESULTS: Fifty-eight questionnaires were completed (response rate: 84%) by surgeons from 8 out of 8 Canadian provinces with pediatric surgery coverage. 33% of responders prescribed opioids (most commonly morphine) for day surgeries and 73% of Pediatric Surgeons prescribed opioids for major surgeries. Most responders (84%) declared that at their institution there was no formal training for residents/fellows in pain control and opioid prescribing. Similarly, 57% reported no education for families about opioids at discharge. CONCLUSION: This first national survey on opioid prescribing practices across Canada reveals that opioids were prescribed to pediatric patients following a broad range of minor and major surgical procedures. Moreover, there seems to be a lack of education for surgeons and families about opioid use. TYPE OF STUDY: Descriptive, cross-sectional, practice survey. LEVEL OF EVIDENCE: Level 5.

The role of sonography in differentiating congenital intrinsic duodenal anomalies from midgut malrotation: emphasizing the new signs of duodenal and gastric wall thickening and hyperechogenicity.

BACKGROUND: The clinical and plain radiographic differentiation of congenital intrinsic duodenal anomalies (atresia, web, stenosis) from intestinal malrotation is not always clear. Although sonography has been documented as an important diagnostic tool in the differentiation of these two entities, its role is still not widely appreciated and it is still not universally utilized in this clinical setting. OBJECTIVE: To assess the usefulness of sonographic features of the duodenal and gastric wall in the differentiation of congenital intrinsic duodenal anomalies from midgut malrotation in a large series of neonates and to compare them with other features on abdominal radiographs, ultrasound and upper gastrointestinal series. MATERIALS AND METHODS: Using the surgical database at our tertiary pediatric hospital, we identified neonates who had surgically proven congenital intrinsic duodenal anomalies or malrotation over a period of 15 years (2000-2015). We reviewed imaging findings in both groups of neonates (blinded to the final diagnosis) with attention to the echogenicity and thickness of the wall of the duodenum and stomach, the relationship between the superior mesenteric artery and vein, the position of the third portion of the duodenum and the presence of the whirlpool sign. Findings were compared between the groups using the unpaired t-test and Fisher exact test. RESULTS: We included 107 neonates in the study, 40 with a congenital intrinsic duodenal anomaly, 49 with malrotation (36 with volvulus) and 18 with a combination of both. Duodenal and gastric wall thickening and hyperechogenicity were significantly more common in the group with a congenital intrinsic duodenal anomaly compared to those with malrotation (P<0.0001). Conversely, an abnormal relationship between the superior mesenteric artery and vein, abnormal position of the third part of the duodenum, and the whirlpool sign were significantly more common in neonates with malrotation than in those with congenital intrinsic duodenal anomalies (P<0.0001). CONCLUSION: Duodenal or gastric wall thickening, and increased wall echogenicity are helpful sonographic features in the differentiation of congenital intrinsic duodenal anomalies from malrotation. Evaluation of the duodenal and gastric wall should thus be added to the features routinely assessed on ultrasound examinations in the clinical setting of suspected duodenal obstruction in the neonate.

Impaired Wnt/ß-catenin pathway leads to dysfunction of intestinal regeneration during necrotizing enterocolitis.

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/ß-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/ß-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.

Experimental necrotizing enterocolitis induces neuroinflammation in the neonatal brain.

BACKGROUND: Necrotizing enterocolitis (NEC) is an inflammatory gastrointestinal disease primarily affecting preterm neonates. Neonates with NEC suffer from a degree of neurodevelopmental delay that is not explained by prematurity alone. There is a need to understand the pathogenesis of neurodevelopmental delay in NEC. In this study, we assessed the macroscopic and microscopic changes that occur to brain cell populations in specific brain regions in a neonatal mouse model of NEC. Moreover, we investigated the role of intestinal inflammation as part of the mechanism responsible for the changes observed in the brain of pups with NEC. METHODS: Brains of mice were assessed for gross morphology and cerebral cortex thickness (using histology). Markers for mature neurons, oligodendrocytes, neural progenitor cells, microglia, and astrocytes were used to quantify their cell populations in different regions of the brain. Levels of cell apoptosis in the brain were measured by Western blotting and immunohistochemistry. Endoplasmic reticulum (ER) stress markers and levels of pro-inflammatory cytokines (in the ileum and brain) were measured by RT-qPCR and Western blotting. A Pearson test was used to correlate the levels of cytokines (ELISA) in the brain and ileum and to correlate activated microglia and astrocyte populations to the severity of NEC. RESULTS: NEC pups had smaller brain weights, higher brain-to-body weight ratios, and thinner cortices compared to control pups. NEC pups had increased levels of apoptosis and ER stress. In addition, NEC was associated with a reduction in the number of neurons, oligodendrocytes, and neural progenitors in specific regions of the brain. Levels of pro-inflammatory cytokines and the density of activated microglia and astrocytes were increased in the brain and positively correlated with the increase in the levels pro-inflammatory cytokines in the gut and the severity of NEC damage respectively. CONCLUSIONS: NEC is associated with severe changes in brain morphology, a pro-inflammatory response in the brain that alters cell homeostasis and density of brain cell populations in specific cerebral regions. We show that the severity of neuroinflammation is associated with the severity of NEC. Our findings suggest that early intervention during NEC may reduce the chance of acute neuroinflammation and cerebral damage.

First Population-Based Report of Infants with Congenital Diaphragmatic Hernia: 30-Day Outcomes from the American College of Surgeons National Quality Improvement Program.

AIM: The American College of Surgeons has developed a registry, the National Quality Improvement Program Pediatric (NSQIP-P), that provides participating centers with high-quality surgical outcome data for children. Herein, we aimed to analyze for the first time the short-term outcomes of live-born infants with congenital diaphragmatic hernia (CDH) registered on this large North American database. METHODS: During 2015 to 2016, up to 101 participating centers uploaded 95 perioperative data points on the NSQIP-P database for patients that underwent surgical repair of CDH. The demographics, peri-, and post-operative data (up to 30 days following surgical repair) of infants with CDH were reviewed. Binary logistic regression was performed to test associations between risk factors and mortality. MAIN RESULTS: There were 432 (61% male) infants, who underwent CDH surgical repair during the study period. The prematurity rate (gestational age < 37 weeks) was 17%. The majority of infants (82%) had cardiac risk factors identified (72% were reported as major/severe). Extracorporeal membrane oxygenation (ECMO) was employed in 13% of patients prior to surgery. The majority of infants (83%) were ventilated preoperatively, and 34% received inotropes. Median age at surgery was 5 (0-74) days. CDH repair was attempted via thoracoscopy in 18% (n = 79) infants, but with a high rate of conversion to open surgery (n = 32, 41%). The postoperative 30-day mortality rate was 9%. At binary logistic regression, major cardiac risk factors (odds ratio [OR], 1.7 [0.9-3.2], p = 0.095), Appearance, Pulse, Grimace, Activity, and Respiration at 1 minute (OR, 0.7 per unit [0.5-0.8], p < 0.005), and birth weight (OR, 0.5 per kg [0.2-1.0], p < 0.05) were retained in the final model as significantly associated with mortality. CONCLUSION: This is the first report on CDH outcomes from the NSQIP-P database. Utilization of ECMO was low compared with single-center studies from North America. The early postoperative mortality rate of babies with CDH considered suitable for surgery remains high.

Open Versus Laparoscopic Approach for Morgagni's Hernia in Infants and Children: A Systematic Review and Meta-Analysis.

INTRODUCTION: The laparoscopic repair of Morgagni's hernia (MH) has been reported to be safe and feasible. However, it is still unclear whether laparoscopy is superior to open surgery in repairing MH. MATERIALS AND METHODS: Using a defined search strategy, three investigators independently identified all comparative studies reporting data on open and laparoscopic MH repair in patients <18 years of age. Case reports and opinion articles were excluded. Meta-analysis was conducted according to PRISMA guidelines and using RevMan 5.3. Data are expressed as mean ± SD. RESULTS: Systematic review - Of 774 titles/abstracts screened, 51 full-text articles were analyzed. Three studies were included (92 patients), with 53 (58%) open approaches and 39 (42%) laparoscopy. Meta-analysis - The length of surgery was shorter in laparoscopy (50.5 ± 17.0 min) than in open procedure (90.0 ± 15.0 min; P < .00001). Laparoscopy shortened the length of hospital stay (2.1 ± 1.4 days) versus open surgery (4.5 ± 2.1 days; P < .00001). There was no difference with regards to complications (laparoscopy: 8.8% ± 5.5%, open: 9.4% ± 1.6%; P = .087) and recurrences (laparoscopy: 2.9% ± 5.0%, open: 5.7% ± 1.8%; P = .84). DISCUSSION: Comparative studies indicate that laparoscopic MH repair can be performed in infants and children. Laparoscopy is associated with shortened length of surgery and hospital stay in comparison to open procedure. Prospective randomized studies would be needed to confirm present data.

A critical review of recent clinical practice guidelines on management of cryptorchidism.

BACKGROUND/PURPOSE: Limited efforts have been made in assessing the qualities of clinical practice guidelines (CPGs) on cryptorchidism (UDT). This appraisal aims to determine the quality of recent CPGs on the management of UDT. METHODS: After systematic literature search, all English-based CPGs providing recommendations for the management of UDT from 2012 to 2017 were reviewed. Using the AGREE II (Appraisal of Guidelines and Research Evaluation) instrument, eligible CPGs were independently appraised by 5 reviewers. Domain scores were calculated and summarized. Intraclass coefficient (ICC) was used to assess for interrater reliability. RESULTS: Five CPGs from Agency for Healthcare Research and Quality (AHRQ), American Urological Association (AUA), British Association of Pediatric Surgeons/British Association of Urologic Surgeons (BAPS/BAUS), Canadian Urological Association (CUA), and European Association of Urology/European Society for Pediatric Urology (EAU/ESPU) were assessed. There was a solid agreement (ICC: 0.749) among the 5 reviewers (p<0.001). Most recommendations for diagnostic and treatment approaches were consistent across CPGs. For most guidelines, the domains of 'clarity of presentation,' 'scope and purpose,' 'stakeholder involvement,' and 'rigor of development' were high, while 'applicability' was low. CONCLUSION: Most guidelines on UDT score high in the AGREE II domains and have consistent recommendations. To improve the 'applicability' domain, future guidelines should improve on aspects that facilitate implementation of the recommendations. TYPE OF STUDY: Systematic review. LEVEL OF EVIDENCE: V (based on the lowest level of evidence utilized by the assessed guidelines).

Intraoperative acidosis and hypercapnia during thoracoscopic repair of congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula.

BACKGROUND: Intraoperative hypercapnia and acidosis have been associated with thoracoscopic repair of both congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula. AIM: The aim of the present study was to investigate whether thoracoscopic repair of congenital diaphragmatic hernia or esophageal atresia/tracheoesophageal fistula was associated with acidosis and hypercapnia in a large group of neonates, and to analyze the effects of acidosis and hypercapnia on early postoperative outcomes. METHODS: We reviewed the charts of neonates who underwent open or thoracoscopic congenital diaphragmatic hernia or esophageal atresia/tracheoesophageal fistula repair (2004-2014). Patients with available intraoperative arterial gas values were included. Data (PaCO2 : mm Hg) were compared using paired/unpaired tests and are reported as difference [95% confidence interval]. RESULTS: Congenital diaphragmatic hernia: 187 neonates underwent open (n=153) or thoracoscopic (n=34) repair. Intraoperative arterial gas values were recorded in 96 open and in 23 thoracoscopic operations. Both groups had similar preoperative pH and PaCO2 , and developed intraoperative acidosis (open -0.08 [-0.11, -0.05] P<.001, thoracoscopic -0.14 [-0.24, -0.04] P=.01) and hypercapnia (open: 7.8 [3.2, 12.4], P=.002; thoracoscopic: 20.2 [-2.5, 43, P=.07). Intraoperatively, neonates undergoing thoracoscopic repair developed lower pH than those having open surgery (-0.06 [-0.01, -0.10] P=.018), but maintained similar levels of PaCO2 (-4.0 [-9.0, 4.4] P=.39). Esophageal atresia/tracheoesophageal fistula: 205 neonates underwent open (n=180) or thoracoscopic (n=25) repair. Intraoperative arterial gas values were recorded in 62 open and in 14 thoracoscopic operations. Both groups had similar preoperative pH and PaCO2 , and developed intraoperative acidosis (open: -0.09 [-0.14, -0.04], P<.001; thoracoscopic: 0.21 [-0.28, -0.14], P<.001) and hypercapnia (open: 9.2 [2.6, 15.7] P=.008; thoracoscopic: 15.2 [1.6, 28.7], P=.03). Intraoperatively, neonates undergoing thoracoscopic repair developed lower pH than those having open surgery (difference 0.08 [0.01, 0.15], P=.02) but maintained similar levels of PaCO2 (difference -1 [-9, 3], P=.35). CONCLUSION: Neonates undergoing operative repair of congenital diaphragmatic hernia and esophageal atresia/tracheoesophageal fistula develop intraoperative acidosis and hypercapnia, regardless of the approach used. However, this phenomenon is more severe during thoracoscopic repair. Novel modalities to reduce intraoperative gas derangements, particularly during thoracoscopic repair, need to be established.

Inhibition of corticotropin-releasing hormone receptor 1 and activation of receptor 2 protect against colonic injury and promote epithelium repair.

Maternal separation (MS) in neonates can lead to intestinal injury. MS in neonatal mice disrupts mucosal morphology, induces colonic inflammation and increases trans-cellular permeability. Several studies indicate that intestinal epithelial stem cells are capable of initiating gut repair in a variety of injury models but have not been reported in MS. The pathophysiology of MS-induced gut injury and subsequent repair remains unclear, but communication between the brain and gut contribute to MS-induced colonic injury. Corticotropin-releasing hormone (CRH) is one of the mediators involved in the brain-gut axis response to MS-induced damage. We investigated the roles of the CRH receptors, CRHR1 and CRHR2, in MS-induced intestinal injury and subsequent repair. To distinguish their specific roles in mucosal injury, we selectively blocked CRHR1 and CRHR2 with pharmacological antagonists. Our results show that in response to MS, CRHR1 mediates gut injury by promoting intestinal inflammation, increasing gut permeability, altering intestinal morphology, and modulating the intestinal microbiota. In contrast, CRHR2 activates intestinal stem cells and is important for gut repair. Thus, selectively blocking CRHR1 and promoting CRHR2 activity could prevent the development of intestinal injuries and enhance repair in the neonatal period when there is increased risk of intestinal injury such as necrotizing enterocolitis.

Pentalogy of Cantrell: Is Echocardiography Sufficient in the Neonatal Period?

Pentalogy of Cantrell is a rare syndrome that is characterized by varying degrees of midline wall defects and congenital cardiac anomalies. A left ventricular diverticulum (LVD) is defined as partial ectopia cordis, can be part of the pentalogy of Cantrell, and can put the patient at risk of severe complications. Early diagnosis and ligation/resection of the LVD is important to prevent complications. We report on a case of pentalogy of Cantrell, in which a LVD was diagnosed only at 2 months of age despite preceding pre- and postnatal echocardiography. We conclude that in the suspicion of pentalogy of Cantrell, either complete or incomplete, cardiac magnetic resonance imaging should be performed, when possible, to avoid the potential complication of a herniating ventricular diverticulum.

Intestinal epithelial injury induced by maternal separation is protected by hydrogen sulfide.

PURPOSE: Oxidative stress has been implicated in the pathogenesis of various neonatal diseases involving the intestine. Hydrogen sulfide (H2S) has been shown to protect against oxidative stress. We hypothesized that administration of sodium hydrosulfide (NaHS), an H2S donor, to neonatal mice can decrease the intestinal epithelial injury associated with maternal separation (MS). METHODS: C57BL/6 mice received either intraperitoneal phosphate buffered saline (PBS; n=10) or NaHS (1mg/kg/day; n=10), followed by MS for 3h daily between postnatal day P5 and P9. Control neonatal mice were untreated and were not exposed to MS (n=10). Proximal colon was harvested and analyzed for crypt length, goblet cell number per crypt, oxidative stress and inflammation. Groups were compared using one-way ANOVA with Bonferroni post-test. RESULTS: Compared to controls, MS+PBS mice had shorter crypt lengths, fewer goblet cells per crypt, reduced glutathione peroxidase activity, increased expression of thiobarbituric acid reactive substances and inducible nitric oxide synthase mRNA, as well as increased IL-6, TNFα and myeloperoxidase. Administration of NaHS significantly counteracted these negative effects of MS. CONCLUSIONS: H2S protects the colon from the epithelial damage, oxidative stress and inflammation caused by maternal separation. This study provides insights on the pathogenesis of neonatal bowel diseases and indicates the potential for a pharmacological intervention to rescue the colonic epithelium. LEVEL OF EVIDENCE: n/a - animal and laboratory study.

Endoplasmic reticulum stress is involved in the colonic epithelium damage induced by maternal separation.

BACKGROUND: Maternal separation (MS) leads to intestinal barrier dysfunction in neonatal mice. Endoplasmic reticulum (ER) stress is associated with apoptosis and pro-inflammatory response induction. We hypothesized that MS induced gut damage is associated with ER stress and that administration of an ER stress inhibitor protects gut damage. METHODS: C57BL/6 mice received intraperitoneal PBS (n=10) or Salubrinal (1mg/kg/day, n=10). MS was performed soon after treatment for 3h daily between P5 and P9. Ten untreated neonatal mice served as control. The colon was harvested on P9 and analyzed for ER stress markers (BiP, CHOP), apoptosis (CC3), goblet cell number per crypt and crypt length (Alcian blue, hematoxylin/eosin), and transcellular permeability (Ussing chamber). Groups were compared using one-way ANOVA with Bonferroni post-test. RESULTS: Compared to controls, MS mice had higher relative protein expression of ER stress and apoptosis markers (p<0.05) and reduced goblet cell number per crypt and crypt length (p<0.001). In comparison to PBS mice, Salubrinal treated mice had higher goblet cell number (p<0.05), crypt length (p<0.001), and lower transcellular permeability (p<0.05). CONCLUSIONS: Maternal separation induces ER stress and causes colon damage, but ER stress inhibitor protects morphology and permeability. This provides insights on bowel pathogenesis and potential novel treatments for diseases such as necrotizing enterocolitis.

Intestinal epithelial cell injury is rescued by hydrogen sulfide.

BACKGROUND/PURPOSE: Oxidative stress is implicated in the pathogenesis of necrotizing enterocolitis (NEC). Hydrogen sulfide (H2S) has been reported to have a protective function against oxidative stress in the gut. We hypothesize that administration of H2S can help decrease intestinal epithelial cell injury in vitro. METHODS: Intestinal epithelial cells (IEC-18) were treated with 200µM hydrogen peroxide (H2O2) for 21h. At 21h sodium hydrosulfide (NaHS), an H2S donor, was administered as a rescue treatment at two different concentrations: 0.1mM and 0.2mM. At 24h, cell viability was measured using a colorimetric assay (MTT). Oxidative stress was studied by glutathione peroxidase (GPx) activity and thiobarbituric acid reactive substances (TBARS). IL-6 and TNFα levels were tested to study inflammation. Data were presented as mean±SD and compared using one-way ANOVA with Bonferroni post-test. RESULTS: Compared to control, H2O2-treated IEC-18 had reduced viability (p<0.01), lower GPx activity (p<0.01), higher TBARS levels (p<0.01), and increased IL6 and TNFα (p<0.001). Compared to H2O2-treated IEC-18, treatment with 0.2mM NaHS rescued viability (p<0.01), increased GPx activity (p<0.05), and reduced TBARS (p<0.01), IL6 and TNFα (p<0.001). CONCLUSIONS: H2S successfully rescues epithelial cell damage induced by oxidative stress in vitro. This indicates that H2S could be a potential pharmacological intervention in conditions like NEC.

A spectrum of intestinal injury models in neonatal mice.

PURPOSE: To compare the degree of necrotizing enterocolitis (NEC)-like damage under different stress conditions in neonatal mice. METHODS: 5-day-old C57BL/6 mice were assigned to: (A) breastfed and no stress factors; (B) breastfed+maternal separation (3 h daily); (C) breastfed+hypoxia+lipopolysaccharide (LPS-4 mg/kg/day); (D) hyperosmolar formula+hypoxia+LPS. Mice were killed at 9 days of life. Ileum and colon were stained for hematoxylin/eosin and blindly assessed. A scoring ≥2 was considered NEC. Data were compared using one-way ANOVA and reported as median (range). RESULTS: Ileum-Mucosal injury was mild in group B (0.0-1). Hypoxia+LPS induced greater injury in group C (1.6, 1-2.5; p < 0.0001 to B) and D (2, 0.5-3.5; p < 0.0001 to B). There were no differences between group C and D (p = n.s.). There were no cases of NEC in group A or B, whereas NEC was present in 36 % group C and 68 % group D mice. Colon-a similar degree of mucosal injury was observed among group B (2, 1-3), C (1.7, 0-3) and D (1.5, 1-3; p = n.s.). NEC was present in 75 % of group B, 50 % of group C and 86 % of group D. CONCLUSION: These models establish a spectrum of intestinal injury and are useful to investigate the variability of neonatal intestinal diseases, such as NEC.

The Value of Surveys in Pediatric Surgery.

Surveys are an important research tool to evaluate the practice patterns of physicians. In the medical literature, practice surveys are increasingly used in specialties, such as pediatric surgery, characterized by the lack of sufficient evidence-based literature due to the rarity of the conditions treated. To maintain a level that yields to a meaningful scientific contribution the design, data collection and analysis of the survey have to be rigorous. Herein, we describe the general principles of survey methodology, we report the benefits and limitations of this statistical method, and we discuss the value of surveys in pediatric surgery.