23 research outputs found

    Thoracoamniotic shunt placement for a right-sided congenital diaphragmatic hernia complicated by hydrops

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    AbstractMortality associated with congenital diaphragmatic hernia (CDH) is high, and the role of prenatal management continues to evolve. We report a case of a right-sided CDH complicated by fetal hydrops successfully managed with thoracoamniotic shunt placement. Subsequent ultrasounds indicated resolution of hydrops. Despite preterm premature rupture of membrane and preterm delivery at 32 3/7 weeks gestation, the infant survived to hospital discharge at 2.5 months of life. This is the first case of a hydropic right-sided CDH successfully treated with a thoracoamniotic shunt

    Fundamental differences between SPH and grid methods

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    We have carried out a hydrodynamical code comparison study of interacting multiphase fluids. The two commonly used techniques of grid and smoothed particle hydrodynamics (SPH) show striking differences in their ability to model processes that are fundamentally important across many areas of astrophysics. Whilst Eulerian grid based methods are able to resolve and treat important dynamical instabilities, such as Kelvin-Helmholtz or Rayleigh-Taylor, these processes are poorly or not at all resolved by existing SPH techniques. We show that the reason for this is that SPH, at least in its standard implementation, introduces spurious pressure forces on particles in regions where there are steep density gradients. This results in a boundary gap of the size of the SPH smoothing kernel over which information is not transferred.Comment: 15 pages, 13 figures, to be submitted to MNRAS. For high-resolution figures, please see http://www-theorie.physik.unizh.ch/~agertz

    Fundamental differences between SPH and grid methods

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    We have carried out a comparison study of hydrodynamical codes by investigating their performance in modelling interacting multiphase fluids. The two commonly used techniques of grid and smoothed particle hydrodynamics (SPH) show striking differences in their ability to model processes that are fundamentally important across many areas of astrophysics. Whilst Eulerian grid based methods are able to resolve and treat important dynamical instabilities, such as Kelvin-Helmholtz or Rayleigh-Taylor, these processes are poorly or not at all resolved by existing SPH techniques. We show that the reason for this is that SPH, at least in its standard implementation, introduces spurious pressure forces on particles in regions where there are steep density gradients. This results in a boundary gap of the size of an SPH smoothing kernel radius over which interactions are severely dampe

    Implantable Ultralow Pulmonary Pressure Monitoring System for Fetal Surgery

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    Congenital pulmonary hypoplasia is a devastating condition affecting fetal and newborn pulmonary physiology, resulting in great morbidity and mortality. The fetal lung develops in a fluid-filled environment. In this work, we describe a novel, implantable pressure sensing and recording device which we use to study the pressures present in the fetal pulmonary tree throughout gestation. The system achieves 0.18 cm H2O resolution and can record for twenty one days continuously at 256 Hz. Sample tracings of in vivo fetal lamb recordings are shown

    Left Heart Structures in Human Neonates with Congenital Diaphragmatic Hernia and the Effect of Fetal Endoscopic Tracheal Occlusion

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    Background: Small left heart structures are observed in fetuses with left-sided congenital diaphragmatic hernia (CDH). Fetoscopic tracheal occlusion (FETO) in mid-gestation promotes lung growth in fetuses with CDH, however cardiac effects of FETO are poorly described. We studied the effects of FETO on cardiac structure size at birth, hypothesizing that left heart structures would be larger in neonates who had undergone fetal intervention. Methods/Results: We performed retrospective measurements of atrioventricular and semilunar valve and pulmonary artery diameters, ventricular lengths, left ventricular end-diastolic volume indexed (LVEDVi) to body surface area. 35 patients were studied (9 FETO, 26 controls). All fetuses had liver herniation and a lung-to-head ratio <1 at fetal presentation. At birth the intervention group had larger LVEDVi (16.8 vs. 12.76 ml/m(2), p < 0.05), LV length Z-score (-2.05 vs. -4, p < 0.01), LV:RV length ratio (1.43 vs. 1.04, p <0.05), LPA diameter Z-score (+1.71 vs. -1.04, p < 0.05), and better growth of aortic valve (-2.18 FETO, -3.3 controls, p <0.01). There was a trend toward higher LV output in the FETO group. Conclusions: Left heart structures and LPA were larger postnatally in patients with CDH who underwent FETO than in those who did not. Hemo-dynamic alterations are introduced with tracheal occlusion that are associated with alterations in ventricular loading and may influence growth. (C) 2013 S. Karger AG, BaselFed Univ São Paulo UNIFESP, Dept Obstet, Div Fetal Cardiol, São Paulo, BrazilUniv Calif San Francisco, Benioff Childrens Hosp, Dept Pediat, Div Cardiol, San Francisco, CA 94143 USAUniv Calif San Francisco, Benioff Childrens Hosp, Div Neonatol, San Francisco, CA 94143 USAUniv Calif San Francisco, Fetal Treatment Ctr, Dept Surg, San Francisco, CA 94143 USAUniv Calif San Francisco, Div Pediat Surg, San Francisco, CA 94143 USAFed Univ São Paulo UNIFESP, Dept Obstet, Div Fetal Cardiol, São Paulo, BrazilWeb of Scienc

    Can congenital pulmonary airway malformation be distinguished from Type I pleuropulmonary blastoma based on clinical and radiological features?

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    BACKGROUND: The management of congenital cystic lung lesions is controversial. Arguments for routine resection during infancy include the possibility of the lesion being Type I pleuropulmonary blastoma (PPB) rather than a cystic congenital pulmonary airway malformation (CPAM). We aimed to identify clinical and radiological features that might distinguish between CPAM and PPB and to develop a diagnostic algorithm based on these features. METHODS: All recorded cases of Type I PPB were retrieved from the International PPB Registry and compared with an institutional cohort of children undergoing resection of CPAM (2002–2013) that was noted at some stage to be at least partially cystic. Regression models were created to identify variables that might differentiate CPAM from PPB. Odds ratio (OR) and positive predictive value (PPV) were calculated for each variable and a decision algorithm developed. RESULTS: In 112 cases of Type I PPB and 103 of CPAM, factors favoring a diagnosis of CPAM included prenatal detection (OR 89.4), systemic feeding vessel (OR 61.7), asymptomatic (OR 8.0), and hyperinflated lung (OR 6.6). Factors favoring a diagnosis of PPB included bilateral or multisegment involvement (OR 2.4). A decision algorithm that helps to identify lesions requiring resection and those which can be safely observed is presented. CONCLUSION: Clinical and radiological features can help to differentiate between CPAM and PPB. Our algorithm allows identification of children at higher risk of PPB in whom we would recommend resection and those at low risk in whom continued close observation is safe

    Clinical, Biologic, and Prognostic Differences on the Basis of Primary Tumor Site in Neuroblastoma: A Report From the International Neuroblastoma Risk Group Project

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    Purpose Neuroblastoma (NB) is a heterogeneous tumor arising from sympathetic tissues. The impact of primary tumor site in influencing the heterogeneity of NB remains unclear. Patients and Methods Children younger than age 21 years diagnosed with NB or ganglioneuroblastoma between 1990 and 2002 and with known primary site were identified from the International Neuroblastoma Risk Group database. Data were compared between sites with respect to clinical and biologic features, as well as event-free survival (EFS) and overall survival (OS). Results Among 8,369 children, 47% had adrenal tumors. All evaluated clinical and biologic variables differed statistically between primary sites. The features that were > 10% discrepant between sites were stage 4 disease, MYCN amplification, elevated ferritin, elevated lactate dehydrogenase, and segmental chromosomal aberrations, all of which were more frequent in adrenal versus nonadrenal tumors (P < .001). Adrenal tumors were more likely than nonadrenal tumors (adjusted odds ratio, 2.09; 95% CI, 1.67 to 2.63; P < .001) and thoracic tumors were less likely than nonthoracic tumors (adjusted odds ratio, 0.20; 95% CI, 0.11 to 0.39; P < .001) to have MYCN amplification after controlling for age, stage, and histologic grade. EFS and OS differed significantly according to the primary site (P < .001 for both comparisons). After controlling for age, MYCN status, and stage, patients with adrenal tumors had higher risk for events (hazard ratio, 1.13 compared with nonadrenal tumors; 95% CI, 1.03 to 1.23; P = .008), and patients with thoracic tumors had lower risk for events (HR, 0.79 compared with nonthoracic; 95% CI, 0.67 to 0.92; P = .003). Conclusion Clinical and biologic features show important differences by NB primary site, with adrenal and thoracic sites associated with inferior and superior survival, respectively. Future studies will need to investigate the biologic origin of these differences. (C) 2014 by American Society of Clinical Oncolog

    Antenatal maternally-administered phosphodiesterase type 5 inhibitors normalize eNOS expression in the fetal lamb model of congenital diaphragmatic hernia

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    PURPOSE: Pulmonary hypertension (pHTN), a main determinant of survival in congenital diaphragmatic hernia (CDH), results from in utero vascular remodeling. Phosphodiesterase type 5 (PDE5) inhibitors have never been used antenatally to treat pHTN. The purpose of this study is to determine if antenatal PDE5 inhibitors can prevent pHTN in the fetal lamb model of CDH. METHODS: CDH were created in pregnant ewes. Postoperatively, pregnant ewes received oral placebo or tadalafil, a PDE5 inhibitor, until delivery. Near term gestation, lambs underwent resuscitations, and lung tissue was snap frozen for protein analysis. RESULTS: Mean cGMP levels were 0.53±0.11 in placebo-treated fetal lambs and 1.73±0.21 in tadalafil-treated fetal lambs (p=0.002). Normalized expression of eNOS was 82±12% in Normal-Placebo, 61±5% in CDH-Placebo, 116±6% in Normal-Tadalafil, and 86±8% in CDH-Tadalafil lambs. Normalized expression of β-sGC was 105±15% in Normal-Placebo, 82±3% in CDH-Placebo, 158±16% in Normal-Tadalafil, and 86±8% in CDH-Tadalafil lambs. Endothelial NOS and β-sGC were significantly decreased in CDH (p = 0.0007 and 0.01 for eNOS and β-sGC, respectively), and tadalafil significantly increased eNOS expression (p = 0.0002). CONCLUSIONS: PDE5 inhibitors can cross the placental barrier. β-sGC and eNOS are downregulated in fetal lambs with CDH. Antenatal PDE5 inhibitors normalize eNOS and may prevent in utero vascular remodeling in CDH
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