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Background Right ventricle (RV) to pulmonary artery (PA) shunts have become the shunt of choice at many centers for use during the Norwood procedure for single ventricle palliation. Some centers have begun to use cryopreserved femoral or saphenous venous homografts as an alternative to polytetrafluoroethylene (PTFE) for shunt construction. The immunogenicity of these homografts is unknown, and potential allosensitization could have significant implications on transplant candidacy. Methods All patients undergoing Glenn procedure at our center between 2013 and 2020 were screened. Patients who initially underwent Norwood procedure with either PTFE or venous homograft RV-PA shunt and had available pre-Glenn serum were included in the study. The primary outcome of interest was panel reactive antibody (PRA) level at the time of Glenn surgery. Results Thirty-six patients met inclusion criteria (N = 28 PTFE, N = 8 homograft). Patients in the homograft group had significantly higher median PRA levels at the time of Glenn surgery (0% [IQR 0-18] PTFE vs 94% [IQR 74-100] homograft, P = .003). There were no other differences between the two groups. Conclusions Despite potential improvements in PA architecture, the use of venous homografts for RV-PA shunt construction at the time of Norwood procedure is associated with significantly elevated PRA level at the time of Glenn surgery. Centers should carefully consider the use of currently available venous homografts given the high percentage of these patients who may require future transplantation.

Antihydrogen atoms, H―, are now routinely created and can be stored for long enough to allow comparison with ordinary matter. A major goal of these efforts is to test potential physics beyond the Standard Model. This will require further developments in the experiments including the accumulation of more antihydrogen atoms and their storage over longer times. The latter is limited by the unavoidable presence of normal hydrogen molecules. Interactions of H― with H2 lead to the destruction of the hard-won antimatter. Little is known about these interactions but quantitative information will be crucial in guiding experimental developments. Physically realistic modelling of rearrangement scattering of “heavy” antimatter particles (antiprotons, p―, and antihydrogen atoms) by normal matter molecules, such as H2 + H―→ Pn + Ps + H (where Pn represents protonium and Ps positronium), requires the development of new theoretical and computational methodologies. R-matrix theory offers a strong prospect for tackling such problems having proved itself in atomic, molecular and optical physics. It divides the problem into a computationally demanding but energy-independent inner region and simpler energy-dependent outer regions. We propose to adapt the new RmatReact ultracold chemistry approach for the more complex molecular matter-antimatter problems. Here, developments required for the inner region, the boundary and outer regions are outlined. We also report some preliminary bound-state calculations on the {p,p,p―} system and a study of the required mixed coordinate systems for the general effective 3-body case and their transformations at the R-matrix boundary surfaces.

A recently discovered, enhanced Ge diffusion mechanism along the oxidizing interface of Si/SiGe nanostructures has enabled the formation of single-crystal Si nanowires and quantum dots embedded in a defect-free, single-crystal SiGe matrix. Here, we report oxidation studies of Si/SiGe nanofins aimed at gaining a better understanding of this novel diffusion mechanism. A superlattice of alternating Si/Si

Superior vena cava oxygen saturation (SVC O 2 ) monitoring is well described for early detection of hemodynamic deterioration after neonatal cardiac surgery but inferior vena cava vein oxygen saturation (IVC O 2 ) monitoring data are limited.Retrospective cohort study of 118 neonates with congenital heart disease (52 single ventricle) from February 2008 to January 2014.Pediatric cardiac ICU.Neonates (30 d) with concurrent admission IVC O 2 and SVC O 2 measurements after cardiac surgery with cardiopulmonary bypass.None.The primary aim was to correlate admission IVC O 2 and SVC O 2 . Secondary aims included: correlate flank or cerebral near-infrared spectroscopy with IVC O 2 and SVC O 2 , respectively, and exploratory analysis to evaluate associations between oximetry data and a composite adverse outcome defined as any of the following: increasing serum lactate or vasoactive support at 2 hours post-admission, cardiac arrest, or mortality. Admission IVC O 2 and SVC O 2 correlated ( r = 0.54; p0.001). However, IVC O 2 measurements were significantly lower than paired SVC O 2 (mean difference, -6%; 95% CI, -8% to -4%; p0.001) with wide variability in sample agreement. Logistic regression showed that each 12% decrease in IVC O 2 was associated with a 12-fold greater odds of the composite adverse outcome (odds ratio [OR], 12; 95% CI, 3.9-34; p0.001). We failed to find an association between SVC O 2 and increased odds of the composite adverse outcome (OR, 1.8; 95% CI, 0.99-3.3; p = 0.053). In an exploratory analysis, the area under the receiver operating curve for IVC O 2 and SVC O 2 , and the composite adverse outcome, was 0.85 (95% CI, 0.77-0.92) and 0.63 (95% CI, 0.52-0.73), respectively. Admission IVC O 2 had strong correlation with concurrent flank near-infrared spectroscopy value ( r = 0.74; p0.001). SVC O 2 had a weak association with cerebral near-infrared spectroscopy ( r = 0.22; p = 0.02).In postoperative neonates, admission IVC O 2 and SVC O 2 correlate. Lower admission IVC O 2 may identify a cohort of postsurgical neonates at risk for low cardiac output and associated morbidity.

Recent data have demonstrated that overall mortality and adverse events are not significantly different for primary repair (PR) and staged repair (SR) approaches to management of neonates with symptomatic tetralogy of Fallot (sTOF). Cost data can be used to compare the relative value (cost for similar outcomes) of these approaches and are a potentially more sensitive measure of morbidity.This study sought to compare the economic costs associated with PR and SR in neonates with sTOF.Data from a multicenter retrospective cohort study of neonates with sTOF were merged with administrative data to compare total costs and cost per day alive over the first 18 months of life in a propensity score-adjusted analysis. A secondary analysis evaluated differences in department-level costs.In total, 324 subjects from 6 centers from January 2011 to November 2017 were studied (40% PR). The 18-month cumulative mortality (P = 0.18), procedural complications (P = 0.10), hospital complications (P = 0.94), and reinterventions (P = 0.22) did not differ between PR and SR. Total 18-month costs for PR (median $179,494 [IQR: $121,760-$310,721]) were less than for SR (median: $222,799 [IQR: $167,581-$327,113]) (P 0.001). Cost per day alive (P = 0.005) and department-level costs were also all lower for PR. In propensity score-adjusted analyses, PR was associated with lower total cost (cost ratio: 0.73; P 0.001) and lower department-level costs.In this multicenter study of neonates with sTOF, PR was associated with lower costs. Given similar overall mortality between treatment strategies, this finding suggests that PR provides superior value.

Background Utilization of extracorporeal membrane oxygenation (ECMO) support in the post-cardiotomy setting is vital to successful perioperative outcomes following pediatric cardiac surgery. Specific analysis of protocolized management strategies and staff preparedness is imperative to optimizing institutional ECMO outcomes. Methods All patients requiring post-cardiotomy ECMO support at a single institution from 2013 to 2019 were retrospectively reviewed. In 2015, several modifications were made to the ECMO support paradigm that addressed deficiencies in equipment, critical care protocols, and staff preparedness. Cases were stratified according to era of ECMO support; patients supported prior to paradigm change from 2013 to 2015 (Group EARLY, n = 20), and patients supported following the implementation of systematic modifications from 2016 to 2019 (Group LATE, n = 26). The primary outcomes of interest were survival to decannulation and hospital discharge. Results Median age at cannulation was 24.5 days (IQR 7-96) and median duration of support was 4 days (IQR 2-8). Overall survival to decannulation was 78.3% (65% EARLY vs. 88.5% LATE, P = .08) and overall survival to hospital discharge was 58.7% (35% EARLY vs. 76.9% LATE, P = .004). Conclusion Systematic modifications to ECMO support strategy and staff preparation are associated with a significant increase in perioperative survival for pediatric patients requiring post-cardiotomy ECMO support.

We report the development of a process/device simulation platform to model superconductor electronics. The process simulator leverages the back-end modeling capabilities of Florida object-oriented process/device/reliability simulator (FLOOXS) and builds on the existing models to simulate processes specific to Josephson junction (JJ) fabrication. The device simulator uses the process generated models and computes the normal-state electrical properties of a Nb/Al-AlO/Nb JJ. It is used to predict key operational figures of merit and how they vary with changes in process models. By integrating the process and device simulation tools, this research aims to offer an environment for the simulation of JJ circuits.

By modeling the propagation of a seed layer with various crystal orientations, this study explores the influence of process variations on grain formation with the help of a physics-based process simulator. Grain boundaries allow easy diffusion of foreign atoms through the lattice, which causes Al to move inside the Nb bottom electrode layer and more interestingly, O to penetrate through the Al layer during oxidation and create a barrier with non-uniform thickness. In addition to thickness variations, the grain structure exhibited by Nb and Al can cause significant suppression of supercurrent at the boundaries depending on the degree of lattice mismatch, impurity deposition, etc. This work details the process simulation of grain boundary formation and aims to provide geometrical models that may be used in the simulation of device performance to account for process-induced variations.

We describe the hybrid Norwood as first-stage palliation for a patient with hypoplastic left heart syndrome, right aortic arch, right descending aorta, bilateral ductus arteriosus, and left innominate artery arising from the left ductus.

Right ventricular outflow tract (RVOT) obstruction is present in a variety of congenital heart disease states including tetralogy of Fallot, pulmonary atresia/stenosis and other conotruncal abnormalities etc. After surgical repair, these patients develop RVOT residual abnormalities of pulmonic stenosis and/or insufficiency of their native outflow tract or right ventricle to pulmonary artery conduit. There are also sequelae of other surgeries like the Ross operation for aortic valve disease that lead to right ventricle to pulmonary artery conduit dysfunction. Surgical pulmonic valve replacement (SPVR) has been the mainstay for these patients and is considered standard of care. Transcatheter pulmonic valve implantation (TPVI) was first reported in 2000 and has made strides as a comparable alternative to SPVR, being approved in the United States in 2010. We provide a comprehensive review in this space–indications for TPVI, detailed procedural facets and up-to-date review of the literature regarding outcomes of TPVI. TPVI has been shown to have favorable medium-term outcomes free of re-interventions especially after the adoption of the practice of pre-stenting the RVOT. Procedural mortality and complications are uncommon. With more experience, recognition of risk of dreaded outcomes like coronary compression has improved. Also, conduit rupture is increasingly being managed with transcatheter tools. Questions over endocarditis risk still prevail in the TPVI population. Head-to-head comparisons to SPVR are still limited but available data suggests equivalence. We also discuss newer valve technologies that have limited data currently and may have more applicability for treatment of native dysfunctional RVOT substrates.

Background:Multicentre research databases can provide insights into healthcare processes to improve outcomes and make practice recommendations for novel approaches. Effective audits can establish a framework for reporting research efforts, ensuring accurate reporting, and spearheading quality improvement. Although a variety of data auditing models and standards exist, barriers to effective auditing including costs, regulatory requirements, travel, and design complexity must be considered.Materials and methods:The Congenital Cardiac Research Collaborative conducted a virtual data training initiative and remote source data verification audit on a retrospective multicentre dataset. CCRC investigators across nine institutions were trained to extract and enter data into a robust dataset on patients with tetralogy of Fallot who required neonatal intervention. Centres provided de-identified source files for a randomised 10% patient sample audit. Key auditing variables, discrepancy types, and severity levels were analysed across two study groups, primary repair and staged repair.Results:Of the total 572 study patients, data from 58 patients (31 staged repairs and 27 primary repairs) were source data verified. Amongst the 1790 variables audited, 45 discrepancies were discovered, resulting in an overall accuracy rate of 97.5%. High accuracy rates were consistent across all CCRC institutions ranging from 94.6% to 99.4% and were reported for both minor (1.5%) and major discrepancies type classifications (1.1%).Conclusion:Findings indicate that implementing a virtual multicentre training initiative and remote source data verification audit can identify data quality concerns and produce a reliable, high-quality dataset. Remote auditing capacity is especially important during the current COVID-19 pandemic.

Dopant profiles near the semiconductor–oxide interface are critical for microelectronic device performance. As the incorporation of Si1−xGex into transistors continues to increase, it is necessary to understand the behavior of dopants in Si1−xGex. In this paper, the diffusion and electrical activation of phosphorus within a strained, single-crystal Si0.7Ge0.3 layer on Si during oxidation are reported. Both layers were uniformly doped, in situ, with an average phosphorus concentration of 4 × 1019 atoms/cm3. After high-temperature oxidation, secondary ion mass spectrometry measurements revealed that the bulk of the phosphorus diffuses out of only the SiGe layer and segregates at the oxidizing SiGe–SiO2 interface. Hall effect measurements corroborate the observed phosphorus loss and show that the phosphorus diffusing to the oxidizing interface is electrically inactive. Through density functional theory (DFT) calculations, it is shown that phosphorus interstitials prefer sites near the SiGe–SiO2 interface. Finally, based on a combination of experimental data and DFT calculations, we propose that the phosphorus atoms are displaced from their lattice sites by Ge interstitials that are generated during SiGe oxidation. The phosphorus atoms then migrate toward the SiGe–SiO2 interface through a novel mechanism of hopping between Ge sites as P–Ge split interstitials. Once they reach the interface, they are electrically inactive, potentially in the form of interstitial clusters or as part of the reconstructed interface or oxide.

In this study, the response to a heavy-ion strike and the resulting single effect burnout on beta-Ga2O3 Schottky diodes with biased field rings is investigated via TCAD. The model used to simulate the device under high-reverse bias is validated using experimental current-voltage (I-V) curves. A field ring configuration for the device demonstrates an improved charge removal after simulated heavy-ion strikes. If the time scale for charge removal is faster than single event burnout, this can be an effective mechanism for reducing the effect of single ion strikes. This study explores various configurations of the termination structure and shows the impact of different design parameters in terms of a transient response after the ion strike.

Some packaging technologies of electronic devices introduce compressive biaxial stress and variable vertical stress. In unipolar MOS devices, stress variations typically only linearly affect drain current via carrier mobility. Collector currents of bipolar devices are additionally affected by variations in intrinsic carrier concentration. This leads to increased variability of key device parameters in the compressive stress regime. Reducing package-induced compressive stress, or inducing tensile stress, should improve device variability due to local stress variations.

Transcatheter aortic valve replacement (TAVR) offers well established benefit for adults with severe aortic stenosis, although applications in the pediatric population remain limited. We describe a case of a 15-year-old male with complex congenital heart disease presenting with cardiogenic shock in the setting of mixed severe aortic stenosis (AS) and severe aortic insufficiency (AI). Self-expanding TAVR was performed via suprasternal approach with robust clinical improvement. At one month follow up, he had resolution of clinical heart failure with improvement in ejection fraction and no symptoms of valvulopathy. To our knowledge, there have been no described cases of suprasternal TAVR in a pediatric patient.

Background:Recurrent laryngeal nerve injury leading to vocal cord paralysis is a known complication of cardiothoracic surgery. Its occurrence during interventional catheterisation procedures has been documented in case reports, but there have been no studies to determine an incidence.Objective:To establish the incidence of left recurrent laryngeal nerve injury leading to vocal cord paralysis after left pulmonary artery stenting, patent ductus arteriosus device closure and the combination of the procedures either consecutively or simultaneously.Methods:Members of the Congenital Cardiovascular Interventional Study Consortium were asked to perform a retrospective analysis to identify cases of recurrent laryngeal nerve injury after the aforementioned procedures. Twelve institutions participated in the analysis. They also contributed the total number of each procedure performed at their respective institutions for statistical purposes.Results:Of the 1337 patients who underwent left pulmonary artery stent placement, six patients (0.45%) had confirmed vocal cord paralysis. 4001 patients underwent patent ductus arteriosus device closure, and two patients (0.05%) developed left vocal cord paralysis. Patients who underwent both left pulmonary artery stent placement and patent ductus arteriosus device closure had the highest incidence of vocal cord paralysis which occurred in 4 of the 26 patients (15.4%). Overall, 92% of affected patients in our study population had resolution of symptoms.Conclusion:Recurrent laryngeal nerve injury is a rare complication of left pulmonary artery stent placement or patent ductus arteriosus device closure. However, the incidence is highest in patients undergoing both procedures either consecutively or simultaneously. Additional research is necessary to determine contributing factors that might reduce the risk of recurrent laryngeal nerve injury.

TAVR is increasingly becoming a common treatment for severe symptomatic aortic stenosis. Although there has been marked reduction in intra-procedural complications with evolution in the TAVR technology, these complications remain a challenge. We present a unique case of paravalvular leak (PVL) and iatrogenic ventricular septal defect as a result of closing attempts of PVL. We aim to highlight our procedural approach to percutaneously repair the aforementioned complications using our heart team approach for decision making.

Percutaneous coronary intervention (PCI) is an uncommon procedure in the pediatric population, and the use of intravascular ultrasound (IVUS) to guide stent optimization in this setting is not well described. We present a case of a 22-month old female who developed left main coronary stenosis following surgical correction of anomalous left coronary artery from the pulmonary artery (ALCAPA). PCI was pursued, and with the use of IVUS, stent placement was determined to be optimal. Given the limited data on the use of IVUS in PCI for children, we discuss the unique applications of IVUS, drug-eluting stents, and future clinical concerns following management of post-surgical stenosis following ALCAPA repair. 〈Learning objective: Percutaneous coronary intervention is a rare procedure in the pediatric population, and the use of intravascular ultrasound to optimize stent placement is not well described in this setting. Intravascular ultrasound may allow for more precise stent placement and may be useful during acute and long-term management of pediatric patients undergoing percutaneous coronary intervention.〉.

An 80-year-old male with severe, complex mitral regurgitation (MR) after recent transcatheter aortic valve replacement presented in heart failure for percutaneous mitral valve repair and possible tricuspid valve repair. Transesopheageal echocardiography (TEE) demonstrated mixed Carpentier Types 1 and 2 components with annular dilation, two leaflet perforations, and excessive leaflet motion (P2 flail). There were three distinct MR jets appreciated reflecting a central coaptation defect and two posterior mitral valve leaflet perforations emanating from a cystic dilatation. Under TEE guidance transseptal puncture and percutaneous edge-to-edge mitral valve repair was performed with a MitraClip XTR device (Abbott, IL). A 10 mm Amplatzer Muscular VSD Occluder (Abbott, Abbott Park, IL) was deployed to close one of the perforations on the posterior leaflet with a significant reduction in MR severity. Attempts at crossing the remaining defect were unsuccessful and the procedure was concluded. The patient recovered uneventfully and transthoracic echocardiography on postoperative day (POD) 1 and again on POD 34 demonstrated normal systolic dominance on pulmonary venous Doppler interrogation, mild to moderate MR, and a mean transvalvular gradient of 5 mmHg. Both devices appeared firmly attached and stable. This is the first documented use of a VSD occluder device in this clinical scenario. Management of complex MR with an approach combining edge-to-edge repair for a central coaptation defect and leaflet flail with codeployment of a VSD occluder device to address a perforated leaflet is feasible and can achieve durable results.

OBJECTIVE To determine whether the presence of a standardized feeding protocol improves outcomes in a subset of neonates undergoing cardiac surgery. DESIGN Retrospective cohort study. SETTING Cardiovascular ICU at a freestanding academic children's hospital. PATIENTS Neonates with a diagnosis of d-transposition of the great arteries undergoing arterial switch operation from January 2007 to June 2017. INTERVENTIONS Initiation of perioperative feeding protocols. MEASUREMENTS AND MAIN RESULTS Patients were evaluated before and after implementation of standardized perioperative feeding protocols in neonates with d-transposition of the great arteries undergoing arterial switch operation. Low-risk patients born after initiation of nurse-driven protocols were compared with a similar historical group. Data obtained included time to achievement of feeding goals, with primary outcome being weight gain at hospital discharge. Other measures analyzed included duration of mechanical ventilation and postoperative hospital length of stay. Overall, 33 patients in the protocol group were compared with 44 patients in the historical group. No significant baseline differences existed between the two cohorts. The protocol group achieved improved feeding outcomes in nearly all measured categories, including introduction to enteral feeds preoperatively (91% vs 59%; p < 0.01) and earlier attainment of postoperative full enteral feeds of 120 mL/kg/d (2 vs 5 d; p < 0.01). Protocol patients had significantly improved weight gain at the time of discharge (60 vs 1 g; p < 0.01), while achieving shorter postoperative length of stay (10.1 vs 12.6 d; p = 0.04). CONCLUSIONS An aggressive, but safe, perioperative feeding protocol implemented in a homogenous low-risk neonatal cardiac surgical population improves feeding outcomes, including increased weight gain, as well as decreased postoperative length of stay. Consideration for perioperative feeding protocol implementation and further study should be given.

There are no large reports of comparative outcomes of transcatheter pulmonic valve implantation (TPVI) and surgical pulmonic valve replacement (SPVR). Prospective studies are unlikely to be feasible in the future also. Thus, we utilized a large adult inpatient database to compare the two with respect to temporal trends, in hospital outcomes and costs. Data from the National Inpatient Sample database from 2003 to 2014 was analyzed to extract patients who underwent TPVI and SPVR using unique ICD 9-CM codes. In-hospital outcomes and charges were then analyzed. All charges were converted to 2018 dollars and a loss of wages analysis was performed using the Bureau of Labor Statistics published median weekly wages. A total of 8,449 and 555 SPVR and TPVI discharges were identified. 5.8% SPVR procedures were done in rural setting versus 1.8% of TPVI. Complications including in-hospital mortality (2.3 vs 0.9%; p = 0.02) were higher in SPVR group. Length of stay was significantly shorter for the TPVI group (1 vs 5 days; p0.001), which also contributed to lower loss of wages ($1028.57 vs $6042.86; p0.001) with similar hospital charges. In conclusion, volumes of both TPVI and SPVR are increasing across adult hospitals in the United States, reflecting an overall increase in the adult congenital heart disease population. TPVI offers improved short-term outcomes and decreased loss of wages through shorter recovery time in this real-world database analysis.

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005-2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score - 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p 0.001) were more common in RVOTI. Significant center differences were noted (p 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63-1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93-4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36-3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI.

Background: Stenting of the patent ductus arteriosus (PDA) is an established palliative option for infants with ductal-dependent pulmonary blood flow. Following initial palliation, reintervention on the PDA stent is common, but risk factors have not been characterized. Methods: Infants with ductal-dependent pulmonary blood flow palliated with PDA stent between 2008 and 2015 were reviewed within the Congenital Cardiac Research Collaborative. Rates and risk factors for reintervention were analyzed. Results: Among 105 infants who underwent successful PDA stenting, 41 patients (39%) underwent a total of 53 reinterventions on the PDA stent, with all but one occurring within 6 months of the initial intervention. Stent redilation constituted the majority of reintervention (n=35; 66%) followed by additional stent placement (n=11; 21%) and surgical shunt placement (n=7; 13%). The majority of reintervention was nonurgent, and there were no deaths during the reintervention procedure. All but one reintervention occurred within 6 months of the initial procedure. On univariate analysis, risk factors for reintervention included anticipated single-ventricle physiology, lack of prior balloon pulmonary valvuloplasty, use of drug-eluting stent, and increased ductal tortuosity. Conclusions: In infants with ductal-dependent pulmonary blood flow palliated with PDA stent implantation, reintervention is common, can be performed safely, and is associated with both anatomic/procedural factors and anticipated final physiology.

Introduction: Absent ductus arteriosus (ADA) is a poorly described feature associated with tetralogy of Fallot (TOF). We compare characteristics and outcomes of neonates with symptomatic TOF (sTOF) with ADA to those with a ductus arteriosus (DA). Hypothesis: We hypothesized: neonates with sTOF and ADA would have similar outcomes to those born with a DA, and a small portion of the ADA cohort would have critically-deficient pulmonary blood flow (CDPBF). Methods: Consecutive neonates with sTOF who underwent intervention during the neonatal period from 2005—2017 were identified from the Congenital Cardiac Research Collaborative. Those with DA on echocardiogram performed on the first day of life or on fetal echocardiogram were identified and compared to those with ADA. ADA neonates who required ECMO or intervention to augment PBF on the first day of life were defined as having CDPBF. Patient characteristics and outcomes were compared between DA and ADA groups. Results: Among 519 neonates, 460 (89%) had a DA and 59 (11%) had ADA. ADA neonates were more likely to carry a genetic or syndromic diagnosis, had smaller branch PA sizes, and were more likely to receive a transannular patch compared to those with a DA. Despite this, reintervention rates were similar (data not shown), and there was only a small difference in mortality that did not reach statistical significance. Of ADA neonates, 7/59 (12%) had CDPBF. Compared to ADA neonates without CDPBF, those with CDPBF had lower baseline oxygen saturation (58 vs 87%, p=0.031) and smaller pulmonary valve (PV) annular z-score (-2.9 vs -2.5, p=0.015) with similar reintervention rates and mortality. Conclusion: ADA is relatively common in sTOF. Despite higher rates of comorbidities, mid-term reintervention rates and mortality are similar to those with DA. CDPBF is a rare, high-risk feature of infants with sTOF and ADA. Smaller PV size may be a marker of CDPBF. Future work should focus on prenatal factors to identify fetuses with TOF, ADA and CDPBF.

To evaluate early growth following primary or staged repair of neonatal symptomatic tetralogy of Fallot (sTOF).We performed a retrospective, multicenter cohort study of consecutive infants with sTOF who underwent initial intervention at age ≤30 days, from 2005 to 2017. Management strategies were either primary repair or staged repair (ie, initial palliation followed by complete repair). The primary outcome was change in weight-for-age z-score (ΔWAZ) from the initial intervention to age 6 ± 2 months. Secondary outcomes included method and mode of feeding, feeding-related medications, and feeding-related readmissions. Propensity score adjustment was used to account for baseline differences between groups. A secondary analysis was performed comparing patients stratified by the presence of adequate growth (6-month ΔWAZ -0.5) or inadequate growth (6-month ΔWAZ ≤ -0.5), independent of treatment strategy.The study cohort included 143 primary repair subjects and 240 staged repair subjects. Prematurity was more common in the staged repair group. After adjustment, median ΔWAZ did not differ between treatment groups over the first 6 months of life (primary: -0.43 [IQR, -1.17 to 0.50]; staged: -0.31 [IQR, -1.31 to 0.71]; P = .55). For the entire cohort, ΔWAZ was negative (-0.36; IQR, -1.21 to 0.63). There were no between-group differences in the secondary outcomes. Secondary analysis revealed that the subjects with adequate growth were more likely to be orally fed at initial hospital discharge (P = .04).In neonates with sTOF, growth trajectory over the first 6 months of life was substandard, irrespective of treatment strategy. Those patients with adequate growth were more likely to be discharged from the index procedure on oral feeds.

Percutaneous pericardiocentesis remains a challenging and potentially dangerous procedure, particularly in small, critically ill patients. We present outcomes of the PLANE (pericardiocentesis using long-axis in-plane real-time echocardiography) technique for pediatric pericardiocentesis compared with a standard echocardiography (ECHO) guidance cohort. This was a retrospective chart review of all children undergoing percutaneous pericardiocentesis from March 2013 to February 2021 at a single center. A total of 78 procedures were performed, 52 utilizing PLANE technique and 26 utilizing standard ECHO-guidance technique. There was 100% technical success rate with only one minor complication for the entire cohort. Procedures were evenly split between the bedside intensive care unit and cardiac catheterization laboratory. PLANE technique was utilized in significantly younger (1.4 vs. 8.4 years, p = 0.008) and smaller (11.1 vs. 31.8 kg, p = 0.007) patients, as well as in most patients deemed high risk (postoperative

In this work we present a finite element quasi-Fermi implementation of a generalized first principles strain model for silicon. Strain effects in silicon are often modeled with separate mobility, bandgap, density of states, piezo-Hall, temperature, and doping models. The current work encompasses these effects by utilizing first principles and the finite element quasi-Fermi method to write a conductivity tensor with the appropriate carrier relationships.

We present a review of the published experimental and simulation radiation damage results in Ga2O3. All of the polytypes of Ga2O3 are expected to show similar radiation resistance as GaN and SiC, considering their average bond strengths. However, this is not enough to explain the orders of magnitude difference of the relative resistance to radiation damage of these materials compared to GaAs and dynamic annealing of defects is much more effective in Ga2O3. It is important to examine the effect of all types of radiation, given that Ga2O3 devices will potentially be deployed both in space and terrestrial applications. Octahedral gallium monovacancies are the main defects produced under most radiation conditions because of the larger cross-section for interaction compared to oxygen vacancies. Proton irradiation introduces two main paramagnetic defects in Ga2O3, which are stable at room temperature. Charge carrier removal can be explained by Fermi-level pinning far from the conduction band minimum due to gallium interstitials (Ga i ), vacancies (VGa), and antisites (GaO). One of the most important parameters to establish is the carrier removal rate for each type of radiation, since this directly impacts the current in devices such as transistors or rectifiers. When compared to the displacement damage predicted by the Stopping and Range of Ions in Matter(SRIM) code, the carrier removal rates are generally much lower and take into account the electrical nature of the defects created. With few experimental or simulation studies on single event effects (SEE) in Ga2O3, it is apparent that while other wide bandgap semiconductors like SiC and GaN are robust against displacement damage and total ionizing dose, they display significant vulnerability to single event effects at high Linear Energy Transfer (LET) and at much lower biases than expected. We have analyzed the transient response of β-Ga2O3 rectifiers to heavy-ion strikes via TCAD simulations. Using field metal rings improves the breakdown voltage and biasing those rings can help control the breakdown voltage. Such biased rings help in the removal of the charge deposited by the ion strike.

Dysphagia and vocal cord dysfunction are frequent complications after congenital heart surgery. Both are risk factors for aspiration, which can lead to pneumonia, progressive lung disease, and respiratory arrest. A protocol was implemented to promote early detection of aspiration in a high-risk cohort of patients. Retrospective data were collected on all patients under 120 days old who underwent the Norwood procedure, aortic arch repair, Blalock-Taussig shunt placement, or cervical cannulation for extracorporeal membrane oxygenation from 10/2012 to 05/2016 at a single institution. Patients underwent an assessment of symptoms, fiberoptic endoscopic evaluation of swallowing (FEES), and modified barium swallow (MBS) study in the postoperative period prior to initiating oral feeds. Patients with and without aspiration were compared. Of the 96 patients included in the study, one-third (33%) of patients had evidence of vocal cord dysfunction by FEES and just over half (51%) had evidence of aspiration by FEES or MBS. Most (73%) of the patients with aspiration were asymptomatic and a majority (53%) of patients with aspiration had normal vocal cord function. Aspiration is common after congenital heart surgery, and an assessment of vocal cord or swallow function in isolation may lead to underdiagnosis. A comprehensive protocol including MBS and FEES is necessary for the early detection of vocal cord dysfunction and aspiration and may prevent adverse outcomes in high-risk postoperative patients.

Ga2O3 is a candidate for power electronics due to its large bandgap, controllable doping and availability of large inexpensive substrates. These include power conditioning systems, pulsed power for avionics and electric ships, solid-state drivers for heavy electric motors and advanced power management and control electronics. There are already cases where the performance exceeds the theoretical values for SiC. Existing Si, SiC (vertical devices), and GaN (lateral devices) enjoy advantages in terms of process maturity, especially for Si, where devices such as super-junctions surpass the unipolar "limit". Continued development of low defect substrates, optimized epi growth and improved device design and processing methods for Ga2O3 are required to push the experimental results closer to their theoretical values. The actual experimental value of VB is well below the theoretical predictions. Thermal management is a key issue in Ga2O3 power devices and initial studies have appeared on both the experimental and theoretical fronts.

It has been hypothesized that the variation of the critical currents in Nb/Al-AlO$_x$/Nb junctions is due to, among other effects, the presence of grain boundaries in the system. Motivated by this, we examine the effect of grain boundaries on the critical current of a Josephson junction. We assume that the hopping amplitudes are dependent on the interatomic distance, and derive a physically realistic model of distance-dependent hopping amplitudes. We find that the presence of a grain boundary and associated disorder is responsible for a very large drop in the critical current relative to a clean system. We also find that when a tunnel barrier is present, grain boundaries cause substantial variations in the critical currents due to the disordered hoppings near the tunnel barrier. We discuss the applicability of these results to Josephson junctions presently intended for use in superconducting electronics applications., Comment: 10 pages, 11 figures, published version, includes minor changes

Introduction: Neonates with tetralogy of Fallot and pulmonary atresia (TOF/PA) with pulmonary blood flow supplied by the ductus arteriosus require early intervention. This may be accomplished by: initial palliation (IP) followed by complete repair (CR) or initial primary repair (PR). The optimal approach for patients with TOF/PA has not been established. Methods: Neonates with TOF/PA who underwent IP or PR from 2005-17 were retrospectively reviewed from the Congenital Catheterization Research Collaborative. The primary outcome was mortality. Outcomes were compared as IP vs PR and IP+CR vs PR. Secondary outcomes included hospital and procedural complications and are listed in table 1. Propensity scoring was used to adjust for baseline differences between strategies. Results: Of 282 neonates with TOF/PA, 106 underwent PR and 176 underwent IP (144 surgical, 32 transcatheter). Prior to initial intervention, IP patients had higher rates of mechanical ventilation (83.9% vs 72.2%, p=0.023) and DiGeorge syndrome (14.77% vs 4.72%, p=0.009). Mortality was greater in the IP cohort (HR 2.7, 95% CI 1.02 - 7.1, p = 0.046), with no mortality in the PR cohort after 6 months post-repair. After adjustment, differences in survival were no longer significant (HR 1.4, 95% CI 0.7 - 3.1, p=0.39). Both cohorts had similar mechanical ventilation duration and inotrope use as well as procedural and hospital complications. Intensive care and hospital length of stay, cardiac bypass (CPB) and anesthesia time favored PR when compared to IP+CR (p= Conclusions: In neonates with TOF/PA, the IP approach is more often utilized in higher-risk patients. Accounting for this difference, IP and PR strategies have similar adjusted survival rates. Perioperative morbidities and lower risk for reintervention generally favor PR.

Introduction: Symptomatic neonates with tetralogy of Fallot (sTOF) and hypoplastic branch pulmonary arteries (hPA) are at high risk. Management strategies include staged repair (SR) - initial palliation (IP) followed by later complete repair (CR) - or primary repair (PR). A balanced comparison of these approaches is needed in the sTOF neonate with hPA. Methods: Consecutive neonates with sTOF and hPA - defined as one hPA z-score Results: The cohort comprised 188 neonates including 121 SR (IP: 29 transcatheter; 54 surgery) and 67 PR patients. Presence of pulmonary atresia, lower gestational age and birthweight were more common in the SR cohort. Median right and left hPA z-scores were -2.19 (IQR -2.65, -1.92) and -2.33 (-2.84, -1.99), respectively. There were significant differences in treatment strategy across centers (p Conclusions: In this multicenter comparison of SR or PR for management of neonates with sTOF and hPA, after PSA, no difference in mortality was found. Neonatal morbidities largely favored the SR group, but cumulative morbidities and reintervention favored the PR group. Further study is needed to determine late impact of these early advantages to SR.

We report a successful pediatric bridge to transplant following application of the ProTekDuo Cannula to provide right ventricular support in a 12-year-old child with biventricular cardiomyopathy and on left ventricular assist device support. We are unaware of any other reports of pediatric use of this device in the medical literature.

Introduction Children who have been supported with extracorporeal membrane oxygenation (ECMO) require follow-up including neurodevelopmental screening and audiological assessment. Hearing screening or audiometry is also included within the Extracorporeal Life Support Organization (ELSO) recommendations for the care of children post-ECMO. Methods A retrospective survey was sent to families of children who were supported on ECMO run between 2008 and 2017 in a large paediatric ECMO centre. The aim of this questionnaire was to enquire about their experiences, follow up and any hearing or neuro-developmental difficulties their children had experienced. Families were also asked if their children had undergone hearing screening after hospital discharge. The central and local notes (if available) of these children were reviewed to look for evidence of audiological assessment. Results 146 surveys were sent out with 64 families responding representing a 43.8% return rate. Thirty four of the families who responded (53%) report their children had hearing screening after ECMO. Seven families (11%) expressed concern about their children’s hearing. There was evidence of hearing screening in the medical notes of only 28% responders (18 children). Most of these were not planned assessments due to the history of ECMO. The children undergoing hearing screening were referred due to concerns such as speech delay and recurrent ear infections. Forty four percent of children (8/18) had documented hearing screening because of their previous ECMO run. Conclusions Over half of children who have had an ECMO run were reported by their parents to have had hearing screening completed though there was only documentation of the results in 28% of those where it was said to be undertaken. In the cases of documented audiological assessment, 56% of these were due to concerns raised out with routine post-ECMO assessment. It is important to raise awareness of the hearing screening requirement in children after ECMO and look at implementing a robust system to ensure this takes place. The responsibility for ensuring this takes place should lie with the ECMO centre.

Neonates with tetralogy of Fallot and symptomatic cyanosis (sTOF) require early intervention.This study sought to perform a balanced multicenter comparison of staged repair (SR) (initial palliation [IP] and subsequent complete repair [CR]) versus primary repair (PR) treatment strategies.Consecutive neonates with sTOF who underwent IP or PR at ≤30 days of age from 2005 to 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was death. Secondary outcomes included component (IP, CR, PR) and cumulative (SR): hospital and intensive care unit lengths of stay; durations of cardiopulmonary bypass, anesthesia, ventilation, and inotrope use; and complication and reintervention rates. Outcomes were compared using propensity score adjustment.The cohort consisted of 342 patients who underwent SR (IP: surgical, n = 256; transcatheter, n = 86) and 230 patients who underwent PR. Pre-procedural ventilation, prematurity, DiGeorge syndrome, and pulmonary atresia were more common in the SR group (p ≤0.01). The observed risk of death was not different between the groups (10.2% vs 7.4%; p = 0.25) at median 4.3 years. After adjustment, the hazard of death remained similar between groups (hazard ratio: 0.82; 95% confidence interval: 0.49 to 1.38; p = 0.456), but it favored SR during early follow-up (4 months; p = 0.041). Secondary outcomes favored the SR group in component analysis, whereas they largely favored PR in cumulative analysis. Reintervention risk was higher in the SR group (p = 0.002).In this multicenter comparison of SR or PR for management of neonates with sTOF, adjusted for patient-related factors, early mortality and neonatal morbidity were lower in the SR group, but cumulative morbidity and reinterventions favored the PR group, findings suggesting potential benefits to each strategy.

To compare management strategies for neonates2.5 kg with tetralogy of Fallot and symptomatic cyanosis who either undergo staged repair (SR) (initial palliation followed by later complete repair) or primary repair (PR).Consecutive neonates with tetralogy of Fallot and symptomatic cyanosis weighing2.5 kg at initial intervention and between 2005 and 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Primary outcome was mortality and secondary outcomes included component (eg, initial palliation, complete repair, or primary repair) and cumulative (SR: initial palliation followed by later complete repair) hospital and intensive care unit lengths of stay, durations of ventilation, inotrope use, cardiopulmonary bypass time, procedural complications, and reintervention. Outcomes were compared with propensity score adjustments with PR as the reference group.The cohort included 76 SR (initial palliation: 53 surgical and 23 transcatheter) and 44 PR patients. The observed risk of overall mortality was similar between SR and PR groups (15.8% vs 18.2%: P = .735). The adjusted hazard of mortality remained similar between groups overall (hazard ratio, 0.59; 95% confidence interval, 0.26-1.36; P = .214), as well as during short-term (4 months: hazard ratio, 0.37; 95% confidence interval, 0.13-1.09; P = .071) and midterm (4 months: hazard ratio, 1.32; 95% confidence interval, 0.30-5.79; P = .717) follow-up. Reintervention in the first 18 months was common in both groups (53.2% vs 48.4%; hazard ratio, 1.69; 95% confidence interval, 0.96-2.28; P = .072). Adjusted procedural complications and neonatal morbidity burden were overall lower in the SR group. Cumulative secondary outcome burdens largely favored the PR group.In this study comparing SR and PR treatment strategies for neonates with tetralogy of Fallot and symptomatic cyanosis and weight2.5 kg, mortality and reintervention burden was high and independent of treatment strategy. Other potential advantages were observed with each approach.

There are continuing rapid developments in vertical geometry Ga2O3 for high voltage switching applications. Ga2O3 is emerging as a viable candidate for certain classes of power electronics with capabilities beyond existing technologies due to its large bandgap, controllable doping and the availability of large diameter, relatively inexpensive substrates. These include power conditioning systems, including pulsed power for avionics and electric ships, solid-state drivers for heavy electric motors and advanced power management and control electronics. There are already cases where the performance exceeds the theoretical values for SiC. Existing Si, SiC (vertical devices), and heteroepitaxial GaN (lateral devices) enjoy tremendous advantages in terms of process maturity, an advantage that is especially true for Si, where the ability to precisely process the material has resulted in devices such as super-junctions that surpass the unipolar “limit”. Continued development of low defect substrates, optimized epi growth and surface treatments and improved device design and processing methods for Ga2O3 are still required to push the experimental results closer to their theoretical values. Even 3 μm epi layers with doping concentration of 1016 cm-3 should have a theoretical breakdown voltage of ~1800V. The actual experimental value of VB is currently well below the theoretical predictions. Thermal management is a key issue in Ga2O3 power devices for practical high current devices and initial studies have appeared on both the experimental and theoretical fronts. We summarize progress in edge termination design, temperature measurement using thermoreflectance-based thermography to measure the thermal rise and decay of the active diodes, failure under forward bias and development of large current (up to 130A) arrays.