Feasibility and Evaluation of Surgical Simulation with Developed Crisis Scenarios: A Comparison of Performance by Vascular Surgery Training Paradigms

OBJECTIVES: Surgical simulation is an integral component of training and has become increasingly vital in the evaluation and assessment of surgical trainees. Simulation proficiency determination has been traditionally based on accuracy and time to completion of various simulated tasks, but we were interested in assessing clinical judgment during a simulated crisis scenario. This study assessed the feasibility of creating a crisis simulator station for vascular surgery and evaluated the performance of vascular surgery integrated residents (0+5) and vascular surgery fellows (5+2) during a technical testing with an integrated crisis scenario. METHODS: A Modified Delphi method was used to create vascular surgery crisis simulation stations containing a clinical scenario in conjunction with either an open or endovascular simulator. Senior level vascular surgery trainees from both integrated residencies (0+5) and traditional vascular surgery fellowships (5+2) were then evaluated on two simulation stations: 1) Elective carotid endarterectomy (CEA) where the crisis is a postoperative stroke and 2) Endovascular aneurysm repair (EVAR) for a ruptured abdominal aortic aneurysm (rAAA). Each simulation had a crisis scenario incorporated into the procedure. Assessment was completed using a performance assessment tool containing a Likert scale. Total score was calculated as a percentage. Scores were also sub-divided in the following four categories: Situation Recognition and Decision-making, Procedural Flow, Technical Skills, and Interpretation and Use of Imaging Skills. Student\u27s t-test was used for analysis. RESULTS: 40 senior-level trainees were evaluated (27 fellows and 13 integrated residents) completing 80 simulations. The CEA crisis simulation yielded similar results between both groups (0+5 vs. 5+2, p = 1.00). The 0+5 residents in vascular surgery were graded to be more proficient in the EVAR for rAAA crisis simulation and demonstrated significant differences in Total Score (p = 0.04), Procedural Flow (p=0.03), and Interpretation and Use of Imaging Skills (p = 0.02). CONCLUSIONS: The creation of crisis-based simulation for trainees in vascular surgery is feasible and actionable. Integrated 0+5 residents performed similarly to 5+2 fellows on an open carotid endarterectomy (CEA) crisis simulation, but 0+5 residents scored significantly higher compared to traditional 5+2 fellows in an endovascular rAAA crisis simulation. Crisis simulation may offer better educational experiences and improved value compared to routine simulation. Further studies using different procedural models and clinical scenarios are needed to assess the validity of crisis simulation in vascular surgery and to better understand the performance disparities found between these training paradigms

Supraclavicular decompression for neurogenic thoracic outlet syndrome in adolescent and adult populations

ObjectiveThis study was conducted to better define clinical results and understand factors determining responsiveness to surgical treatment for neurogenic thoracic outlet syndrome (NTOS) in adolescent and adult populations.MethodsA retrospective review was conducted for 189 patients with disabling NTOS who underwent primary supraclavicular decompression (scalenectomy, brachial plexus neurolysis and first rib resection, with or without pectoralis minor tenotomy) from April 2008 to December 2010. Clinical characteristics were compared between 35 adolescent patients (aged <21 years) and 154 adults (aged >21 years). Functional outcome measures were assessed before surgery and at 3- and 6-month follow-up using a composite NTOS Index combining the Disabilities of the Arm, Shoulder and Hand (DASH) survey, the Cervical-Brachial Symptom Questionnaire (CBSQ), and a 10-point visual analog scale (VAS) for pain.ResultsAdolescent and adult patients were not significantly different with respect to sex (overall 72.5% female), side affected (58.7% right, 60.3% dominant limb), bony anomalies (23.3%), previous injury (55.6%), coexisting pain disorders (11.1%), and positive responses to scalene muscle anesthetic blocks (95.6%). Compared with adults, adolescent patients had a significantly (P < .05) lower incidence of depression (11.4% vs 41.6%), motor vehicle injury (5.7% vs 20.1%), previous operations (11.4% vs 29.9%), preoperative use of opiate medications (17.1% vs 44.8%), and symptom duration >2 years (24.2% vs 50.0%). Mean preoperative NTOS Index (scale 0-100) was significantly lower in adolescent vs adult patients (46.5 ± 3.6 vs 58.5 ± 1.7; P = .009), and hospital length of stay was 4.4 ± 0.2 vs 4.9 ± 0.1 days (P = .03), but the rate of postoperative complications was no different (overall, 4.2%). Although both groups exhibited significant improvement in functional outcome measures at 3 and 6 months, adolescent patients had significantly lower NTOS Index (10.4 ± 3.1 vs 39.3 ± 3.3; P < .001) and use of opiate medications (11.4% vs 47.4%; P < .001) compared with adults.ConclusionsAdolescents undergoing supraclavicular decompression for NTOS had more favorable preoperative characteristics and enhanced 3-month and 6-month functional outcomes than adults. Further study is needed to delineate the age-dependent and independent factors that promote optimal surgical outcomes for NTOS

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations