The Incidence of Venous Thromboembolism in Children Following Colorectal Resection for Inflammatory Bowel Disease: A Multi-Center Study

Background/Purpose Children with inflammatory bowel disease (IBD) have increased risk for venous thromboembolism (VTE). We sought to determine incidence and risk factors for postoperative VTE in a multicenter cohort of pediatric patients undergoing colorectal resection for IBD. Methods Retrospective review of children ≤18 years who underwent colorectal resection for IBD from 2010 to 2016 was performed at four children's hospitals. Primary outcome was VTE that occurred between surgery and last follow-up. Factors associated with VTE were determined using univariable and multivariable analyses. Results Two hundred seventy-six patients were included with median age 15 years [13,17]. Forty-two children (15%) received perioperative VTE chemoprophylaxis, and 88 (32%) received mechanical prophylaxis. DVT occurred in 12 patients (4.3%) at a median of 14 days postoperatively [8,147]. Most were portomesenteric (n = 9, 75%) with the remaining catheter-associated DVTs in extremities (n = 3, 25%). There was no association with chemoprophylaxis (p > 0.99). On Cox regression, emergent procedure [HR 18.8, 95%CI: 3.18–111], perioperative plasma transfusion [HR 25.1, 95%CI: 2.4–259], and postoperative infectious complication [HR 10.5, 95%CI: 2.63–41.8] remained predictive of DVT. Conclusion Less than 5% of pediatric IBD patients developed postoperative VTE. Chemoprophylaxis was not protective but rarely used. Patients with risk factors identified in this study should be monitored or given prophylaxis for VTE

Appendectomy versus non-operative treatment for acute uncomplicated appendicitis in children: Study protocol for a multicentre, open-label, non-inferiority, randomised controlled trial

Background Appendectomy is considered the gold standard treatment for acute appendicitis. Recently the need for surgery has been challenged in both adults and children. In children there is growing clinician, patient and parental interest in non-operative treatment of acute appendicitis with antibiotics as opposed to surgery. To date no multicentre randomised controlled trials that are appropriately powered to determine efficacy of nonoperative treatment (antibiotics) for acute appendicitis in children compared with surgery (appendectomy) have been performed. Methods Multicentre, international, randomised controlled trial with a non-inferiority design. Children (age 5–16 years) with a clinical and/or radiological diagnosis of acute uncomplicated appendicitis will be randomised (1:1 ratio) to receive either laparoscopic appendectomy or treatment with intravenous (minimum 12 hours) followed by oral antibiotics (total course 10 days). Allocation to groups will be stratified by gender, duration of symptoms (≫ or \u3c48 hours) and centre. Children in both treatment groups will follow a standardised treatment pathway. Primary outcome is treatment failure defined as additional intervention related to appendicitis requiring general anaesthesia within 1 year of randomisation (including recurrent appendicitis) or negative appendectomy. Important secondary outcomes will be reported and a cost-effectiveness analysis will be performed. The primary outcome will be analysed on a non-inferiority basis using a 20% non-inferiority margin. Planned sample size is 978 children. Discussion The APPY trial will be the first multicentre randomised trial comparing non-operative treatment with appendectomy for acute uncomplicated appendicitis in children. The results of this trial have the potential to revolutionise the treatment of this common gastrointestinal emergency. The randomised design will limit the effect of bias on outcomes seen in other studies. Trial registration number clinicaltrials.gov:NCT02687464. Registered on Jan 13th 2016

Infants with esophageal atresia and right aortic arch: Characteristics and outcomes from the Midwest Pediatric Surgery Consortium

Purpose Right sided aortic arch (RAA) is a rare anatomic finding in infants with esophageal atresia with or without tracheoesophageal fistula (EA/TEF). In the presence of RAA, significant controversy exists regarding optimal side for thoracotomy in repair of the EA/TEF. The purpose of this study was to characterize the incidence, demographics, surgical approach, and outcomes of patients with RAA and EA/TEF. Methods A multi-institutional, IRB approved, retrospective cohort study of infants with EA/TEF treated at 11 children's hospitals in the United States over a 5-year period (2009 to 2014) was performed. All patients had a minimum of one-year follow-up. Results In a cohort of 396 infants with esophageal atresia, 20 (5%) had RAA, with 18 having EA with a distal TEF and 2 with pure EA. Compared to infants with left sided arch (LAA), RAA infants had a lower median birth weight, (1.96 kg (IQR 1.54–2.65) vs. 2.57 kg (2.00–3.03), p = 0.01), earlier gestational age (34.5 weeks (IQR 32–37) vs. 37 weeks (35–39), p = 0.01), and a higher incidence of congenital heart disease (90% vs. 32%, p  0.29). Conclusion RAA in infants with EA/TEF is rare with an incidence of 5%. Compared to infants with EA/TEF and LAA, infants with EA/TEF and RAA are more severely ill with lower birth weight and higher rates of prematurity and complex congenital heart disease. In neonates with RAA, surgical repair of the EA/TEF is technically feasible via thoracotomy from either chest. A higher incidence of anastomotic strictures may occur with a right-sided approach

Changing the Paradigm for Management of Pediatric Primary Spontaneous Pneumothorax: A Simple Aspiration Test Predicts Need for Operation

Purpose Chest tube (CT) management for pediatric primary spontaneous pneumothorax (PSP) is associated with long hospital stays and high recurrence rates. To streamline management, we explored simple aspiration as a test to predict need for surgery. Methods A multi-institution, prospective pilot study of patients with first presentation for PSP at 9 children’s hospitals was performed. Aspiration was performed through a pigtail catheter, followed by 6 h observation with CT clamped. If pneumothorax recurred during observation, the aspiration test failed and subsequent management was per surgeon discretion. Results Thirty-three patients were managed with simple aspiration. Aspiration was successful in 16 of 33 (48%), while 17 (52%) failed the aspiration test and required hospitalization. Twelve who failed aspiration underwent CT management, of which 10 (83%) failed CT management owing to either persistent air leak requiring VATS or subsequent PSP recurrence. Recurrence rate was significantly greater in the group that failed aspiration compared to the group that passed aspiration [10/12 (83%) vs 7/16 (44%), respectively, P = 0.028]. Conclusion Simple aspiration test upon presentation with PSP predicts chest tube failure with 83% positive predictive value. We recommend changing the PSP management algorithm to include an initial simple aspiration test, and if that fails, proceed directly to VATS

Receiver development for BICEP Array, a next-generation CMB polarimeter at the South Pole

A detection of curl-type (B-mode) polarization of the primary CMB would be direct evidence for the inflationary paradigm of the origin of the Universe. The Bicep/Keck Array (BK) program targets the degree angular scales, where the power from primordial B-mode polarization is expected to peak, with ever-increasing sensitivity and has published the most stringent constraints on inflation to date. Bicep Array (BA) is the Stage-3 instrument of the BK program and will comprise four Bicep3-class receivers observing at 30/40, 95, 150 and 220/270 GHz with a combined 32,000+ detectors; such wide frequency coverage is necessary for control of the Galactic foregrounds, which also produce degree-scale B-mode signal. The 30/40 GHz receiver is designed to constrain the synchrotron foreground and has begun observing at the South Pole in early 2020. By the end of a 3-year observing campaign, the full Bicep Array instrument is projected to reach σr between 0.002 and 0.004, depending on foreground complexity and degree of removal of B-modes due to gravitational lensing (delensing). This paper presents an overview of the design, measured on-sky performance and calibration of the first BA receiver. We also give a preview of the added complexity in the time-domain multiplexed readout of the 7,776-detector 150 GHz receiver

Discovery and Characterization of Novel Vascular and Hematopoietic Genes Downstream of Etsrp in Zebrafish

The transcription factor Etsrp is required for vasculogenesis and primitive myelopoiesis in zebrafish. When ectopically expressed, etsrp is sufficient to induce the expression of many vascular and myeloid genes in zebrafish. The mammalian homolog of etsrp, ER71/Etv2, is also essential for vascular and hematopoietic development. To identify genes downstream of etsrp, gain-of-function experiments were performed for etsrp in zebrafish embryos followed by transcription profile analysis by microarray. Subsequent in vivo expression studies resulted in the identification of fourteen genes with blood and/or vascular expression, six of these being completely novel. Regulation of these genes by etsrp was confirmed by ectopic induction in etsrp overexpressing embryos and decreased expression in etsrp deficient embryos. Additional functional analysis of two newly discovered genes, hapln1b and sh3gl3, demonstrates their importance in embryonic vascular development. The results described here identify a group of genes downstream of etsrp likely to be critical for vascular and/or myeloid development

CMB-S4: Forecasting Constraints on Primordial Gravitational Waves

CMB-S4---the next-generation ground-based cosmic microwave background (CMB) experiment---is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semi-analytic projection tool, targeted explicitly towards optimizing constraints on the tensor-to-scalar ratio, $r$, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2--3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments given a desired scientific goal. To form a closed-loop process, we couple this semi-analytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for $r > 0.003$ at greater than $5\sigma$, or, in the absence of a detection, of reaching an upper limit of $r < 0.001$ at $95\%$ CL.Comment: 24 pages, 8 figures, 9 tables, submitted to ApJ. arXiv admin note: text overlap with arXiv:1907.0447

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements