Simple Arch Research Articles

Transcarotid artery revascularization outperforms transfemoral carotid artery stenting regardless of aortic arch type or degree of atherosclerosis

ObjectiveThe Centers for Medicare and Medicaid Services now approve reimbursement for transfemoral carotid artery stenting (TFCAS) in the treatment of standard-risk patients with carotid artery occlusive disease. TFCAS in patients with complex aortic arch anatomy is known to be challenging with worse outcomes. Transcarotid artery revascularization (TCAR) could be a preferable alternative in these patients owing to avoiding the aortic arch and using flow reversal during stent deployment. We aim to compare the outcomes of TCAR vs TFCAS across all aortic arch types and degrees of arch atherosclerosis. MethodsAll patients undergoing carotid artery stenting between September 2016 and October 2023 were identified in the Vascular Quality Initiative database. Patients were stratified into four groups: Group A (mild atherosclerosis and type I/II arch), Group B (mild atherosclerosis and type III arch), Group C (moderate/severe atherosclerosis and type I/II arch), and Group D (moderate/severe atherosclerosis and type III arch). The primary outcome was in-hospital composite stroke or death. Analysis of variance and χ2 tests analyzed differences for baseline characteristics. Logistic regression models were adjusted for potential confounders, and backward stepwise selection was implemented to identify significant variables for inclusion in the final models. Kaplan-Meier survival estimates, log rank test, and multivariable Cox regression models analyzed hazard ratios for 1-year mortality. ResultsA total of 20,114 patients were included (Group A: 12,980 [64.53%]; Group B: 1175 [5.84%]; Group C: 5124 [25.47%]; and Group D: 835 [4.15%]). TCAR was more commonly performed across the four groups (72.21%, 67.06%, 74.94%, and 69.22%; P < .001). Compared with patients with mild arch atherosclerosis, patients with advanced arch atherosclerosis in Group C and Group D were more likely to be female, hypertensive, smokers, and have chronic kidney disease. Patients with type III arch in Group B and Group D were more likely to present with stroke preoperatively. On multivariable analysis, TCAR had less than one-half the risk of stroke/death and 1-year mortality compared with TFCAS in the patients with the mildest atherosclerosis and simple arch anatomy (Group A) (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.31-0.61; P < .001; hazard ratio, 0.42; 95% CI, 0.32-0.57; P < .001). Group B patients with similar atherosclerosis but more complex arch anatomy had 70% lower odds of stroke/death with TCAR compared with TFCAS (OR, 0.30; 95% CI, 0.12-0.75; P = .01). Similar findings were also evident in patients with more severe atherosclerosis and simple arch anatomy (OR, 0.66; 95% CI, 0.44-0.97; P = .037). There was no significant difference in odds of stroke/death in patients with advanced arch atherosclerosis and complex arch (Group D) (OR, 0.91; 95% CI, 0.39-2.16; P = .834). ConclusionsTCAR is safer than TFCAS in patients with simple and advanced arch anatomy. This could be related to the efficiency of flow reversal vs distal embolic protection. The current Centers for Medicare and Medicaid Services decision will likely increase stroke and death outcomes of carotid stenting nationally if multidisciplinary approach and appropriate patient selection are not implemented.

Correlation of palatal anatomic characteristics with dermatoglyphic heterogeneity in different growth patterns

The study aimed to explore the correlation between dermatoglyphic patterns and quantitative palatal anatomic variables in individuals with different growth patterns. A cross-sectional study was conducted involving 126 healthy patients aged 17-25 years. Participants were divided into three groups based on growth patterns: average, vertical, and horizontal. Dermatoglyphic patterns were recorded using an optical fingerprint sensor, and palatal characteristics were measured using digital software. Palatal characteristics, including intercanine width, intermolar width, and palatal depth, were measured using digital software. The results were statistically analyzed. Significant differences were observed in ridge counts among the three growth patterns. The average growth pattern showed lower ridge counts compared to the vertical and horizontal growth patterns. Dermatoglyphic patterns, such as double loops and tented arches, were significantly higher in the horizontal growth pattern. Weak correlations were found between certain dermatoglyphic patterns and palatal characteristics, with simple arch patterns showing a negative correlation with inter-canine width and symmetrical whorl patterns showing a positive correlation with palatal depth. Loop patterns, spiral patterns, double loop patterns, symmetrical whorl, and simple arch patterns were significant predictors of growth patterns. This study revealed distinct dermatoglyphic patterns and ridge counts among individuals with different growth patterns. Weak correlations were observed between dermatoglyphic patterns and palatal characteristics. However, the predictive value of dermatoglyphics for skeletal malocclusion requires further investigation. Understanding the relationships between dermatoglyphic patterns and craniofacial growth can provide valuable insights into genetic and developmental factors affecting dental and orthodontic conditions.

UPPER CRETACEOUS-OLIGOCENE TETHYAN AGGLUTINATED BENTHIC FORAMINIFERAL SPECIES OF THE GENUS ARENOBULIMINA

The agglutinated test of the genus Arenobulimina has trochospirally enrolled, four or more chambers per whorl, aperture interiomarginal with a simple arch or loop, which has a comprising various species. Seven small Upper Cretaceous-Oligocene benthic foraminiferal species of this agglutinated genus Arenobulimina are common in some Tethyan localities: North Atlantic (USA, Trinidad, Labrador Sea), Europe (Spain, France, Germany, Czech, Poland, Sweden), Northeast Africa (Egypt), and Southwest Asia (Palestine, UAE). These species are: Upper Cretaceous A. americana Cushman, Late Maastrichtian A. beitjebrinensis Anan and A. jerusalemensis Anan, Upper Cretaceous-Paleocene A. truncata (Reuss), Paleocene Arenobulimina aegyptiaca (Said &amp; Kenawy) and Paleocene-Eocene A. dorbignyi (Reuss). One Early Eocene – Early-Oligocene species Arenobulimina kaminskii is believed here to be new species.

Earthquake Response of Arch Dams including Hydrodynamic effect using ABAQUS

A simple arch dam [1] is analyzed to find responses due to an earthquake, including the hydrodynamic effect of the reservoir water. The simple arch shape dam was modeled as a monolith structure, assuming the linear behavior of dam concrete. The arch dam is modeled with finite elements. The hydrodynamic effect is considered as an added mass of water adhered to the dam’s upstream surface [2]. Natural frequencies and mode shapes are computed for the dam without water and the dam with water. Time history analysis of the dam is performed for the Kern County earthquake (1952), Taft component 111 acceleration time history. The added mass of water is calculated according to the Kuo 1982 [2] research paper. Various results containing Cantilever stresses, arch stresses, and deflections are shown and plotted. Analyses are performed with the help of the Abaqus Software.

Green-in-green biohybrids as transient biotriboelectric nanogenerators

Green self-powered devices based on biodegradable materials have attracted widespread attention. Here, we propose the construction of the transient biotriboelectric nanogenerator (TENG) using green-in-green bionanocompoites. The green-in-green nanocomposites, cellulose nanocrystal (CNC)/polyhydroxybutyrate (PHB), are prepared with a high-pressure molding method. The CNC promotes the degradation and enhances the dielectric constant of CNC/PHB. It further allows for the significant improvement of the triboelectric output of CNC/PHB-based TENG. The voltage output and current output of CNC/PHB-based TENG are 5.7 and 12.5 times higher than those of pristine PHB-based TENG, respectively. Also, the bio-TENG exhibits admirable signal stability in over 20000 cycles. Despite the high hardness of CNC/PHB, a soft but simple-structured arch sensor is successfully assembled using CNC/PHB-based TENG. It can attain the precise real-time monitoring of various human motions. This study may provide new insights into the design/fabrication of green functional materials, and initiate the next wave of innovations in eco-friendly self-powered devices.

Application of topology optimization method for the gothic greenhouse design

Purpose This research presents a design method for designing greenhouse structures based on topology optimization. Moreover, the structural design of a gothic greenhouse is proposed in which its structural strength has been improved by using this proposed method. In this method, the design of the structure is done mathematically; therefore, in the design process, more attention can be focused on the constraint space and boundary conditions. It was also shown how the static reliability and fatigue coefficients will change as a result of the design of the greenhouse structure with this method. Another purpose of this study is to find the weakest part of the greenhouse structure against lateral winds and other general loads on the greenhouse structure. Design/methodology/approach In the proposed method, the outer surface and the allowable volume as a constraint domain were considered. The desired loads can be located on the constraint domain. The topology optimization was used to minimize the mass and structural compliance as the objective function. The obtained volume was modified for simplifying the construction. The changes in the shape of the greenhouse structure were investigated by choosing three different penalty numbers for the topology optimization algorithm. The final design of the proposed structure was performed based on the total simultaneous critical loads on the structure. The results of the proposed method were compared in the order of different volume fractions. This showed that the volume fraction approach can significantly reduce the weight of the structure while maintaining its strength and stability. Findings Topology optimization results showed different strut and chords composition because of the changes in maximum mass limit and volume fraction. The results showed that the fatigue was more hazardous, and it decreased the strength of structure nearly three times more than a static analysis. Further, it was noticed that how the penalty numbers can affect topology optimization results. An optimal design based on topology optimization results was presented to improve the proposed greenhouse design against destruction and demolition. Furthermore, this study shows the most sensitive part of the greenhouse against the standard loads of wind, snow, and crop. Originality/value The obtained designs were compared with a conventional arch greenhouse, and then the structural performances were shown based on standard loads. The results showed that in designing the proposed structure, the optimized changes increased the structure strength against the standard loads compared to a simple arch greenhouse. Moreover, the stress safety factor and fatigue safety factor because of different designs of this structure were also compared with each other.

Abstract 11778: Comparison of Prenatal Diagnosis Rates and Cardiac Morphometry in Fetal Coarctation by Ultimate Surgical Repair Type

Background: Fetal diagnosis of coarctation of aorta is challenging, with limited data examining prenatal detection rates in patients requiring simple vs. extensive arch reconstruction. This study aims to evaluate prenatal detection rate s and fetal cardiac morphometric differences in neonates requiring simple vs. complex coarctation repair. Methods: Pre- and postnatal records of neonates with isolated coarctation repair from the Society of Thoracic Surgeons database from Jan 2010 - Dec 2020 at our center were reviewed. Patients were classified as requiring discrete (Group 1) or extended arch repair (Group 2). Fetal echocardiograms were measured by a single observer blinded to repair type. Results: Of 228 neonates requiring repair, 67 (29%) had a prenatal diagnosis. The proportion with prenatal diagnosis was not different in group 1 (28%) vs. group 2 (32%) (χ2 = 0.45, p = 0.5). At the first fetal echo (median gestational age (GA) of 21.9 wks in group 1 vs 23.6 wks in group 2, p = 0.2), there were no differences between groups when comparing right ventricular (RV) and left ventricular (LV) dimensions, valvular dimensions, or aortic arch dimensions. At the final fetal echo (median GA of 33.7 wks in both groups, p = 0.6), there were statistical differences between group 1 and 2 in RV geometry with ratio of RV minor to major axis (0.72 vs 0.83, p = 0.03) and ratio of LV to RV minor axis (0.68 vs 0.59, p = 0.02), ascending aorta Z score (-2.6 vs -3.4, p = 0.03), distal arch Z score (-3.9 vs -4.6, p = 0.048), and ratio of isthmus to distal arch dimension (0.88 vs 1.02, p = 0.045) (Figure). Conclusion: The rate of prenatal diagnosis in fetuses requiring neonatal coarctation repair remains low, regardless of ultimate surgical repair type. Fetuses ultimately requiring extensive arch repair have smaller aortic sizes, and greater RV/LV size disproportion in the third trimester. This data may be useful in counseling families with regard to postnatal surgical management in fetuses with suspected coarctation.

Detection of Dental Caries' and Dermatoglyphics' Association with Relative Enamel Thickness Using CBCT Images in Saudi Subpopulation: A Novel Approach.

Background Dental caries is the localized destruction of dental hard tissues (enamel and dentine). Decayed, Missing, and Filled Teeth (DMFT) index is the most commonly used dental caries index. Thickness of the outermost part of the tooth called the enamel is determined by the rate of deposition of enamel proteins. Relative enamel thickness (RET) gives a measure of enamel thickness with respect to dentine. Dental caries is influenced by a genetically determined factor called dermatoglyphics (DG). As the genes responsible for RET and DG lie on the same chromosome and develop during the same time of intrauterine life, it is biologically plausible to correlate RET and DG. Aims This study consists of two primary aims: (1) to assess RET using cone beam computed tomography images and correlate it with caries and (2) to correlate RET with DG. Materials and Methods 148 dental subjects were assessed for DMFT caries score and were categorized as Group 1 with DMFT = 0 and Group 2 with DMFT ≥ 1. Following this, their DG pattern was recorded digitally. The CBCT images of these subjects were assessed for RET, and the data were analyzed statistically. Results Mean RET in our sample population is 18.45 (SD 3.79) while mean DMFT is 5.34 (SD 5.13). Mean RET in Group 1 subjects was 19.82 (SD 4.05) while that in the Group 2 was 17.68 (SD 3.43). RET and DMFT showed a statistically significant negative correlation (p = 0.007). The “Single Loop” DG characteristic showed a statistically significant difference between males and females (p = 0.031). The “Simple Arch” type of DG was positively correlated with RET. Conclusion This is the first in vivo study to assess RET using CBCT images and correlate with DMFT and DG. RET is inversely related to DMFT while directly proportional to the “Simple arch” DG pattern. Males and females differed in their “Single Loop” DG characteristic.

The Nexus of Sophisticated Digital Assets with Economic Policy Uncertainty: A Survey of Empirical Findings and an Empirical Investigation

This paper sets out to explore the nexus between economic policy uncertainty (EPU) and digital currencies. An integrated survey takes place based on eleven primary studies. Furthermore, an econometric analysis is conducted by the threshold ARCH, simple asymmetric ARCH and non-linear ARCH specifications covering the bull and the bear markets as well as the highly volatile period up to the present. Threshold ARCH is found to provide the best fit for estimations. Outcomes reveal that Bitcoin is strongly connected with EPU while Ethereum and Litecoin are not but are strongly linked with Bitcoin performance. Moreover, weak negative effects of the VIX on both cryptocurrencies are detected while oil exerts weak positive impacts on Ethereum. Overall, Ethereum and Litecoin could serve for diversifiers against Bitcoin or hedgers against traditional assets during highly stressed periods with the advantage of not being affected by economic policy uncertainty news.

Complexity of Aortic Arch Anatomy Affects the Outcomes of Transcarotid Artery Revascularization Versus Transfemoral Carotid Artery Stenting

Transcarotid artery revascularization (TCAR) has been shown to have half the rates of transient ischemic attack (TIA), stroke, and death compared with transfemoral carotid artery stenting (TFCAS). Successful outcomes of TFCAS require careful patient selection. The aim of this study was to determine the outcomes of TFCAS versus TCAR in both simple (type I) and complex (type II and III) aortic arches. A retrospective cohort study was performed comparing the outcomes of patients undergoing TFCAS versus TCAR with simple and complex aortic arches using the Vascular Quality Initiative registry from August 2011 to May 2019. The primary outcome was a composite of in-hospital TIA/stroke/death. About 6,108 carotid artery interventions were analyzed, including 3,536 (57.9%) patients with type I, 2,013 (33.0%) with type II, and 559 (9.2%) with type III aortic arch. In 3,535 patients with a simple arch, 1,917 underwent TFCAS and 1,619 had TCAR. Mean age was 70.6 (±9.5) years, and 2,382 (67.4%) patients were males. The primary outcome of postoperative TIA/stroke/death was seen significantly less frequently in those undergoing TCAR compared with TFCAS in simple arches (odds ratio [OR], 0.63; 95% confidence interval [95% CI], 0.43-0.94; P=0.0236). Although the individual outcome of death occurred less often in TCAR (P=0.0025), there was no difference in the occurrence of in-hospital stroke (P=0.8836) or TIA (P=0.4608). On multivariable analysis, TCAR was associated with improved outcomes (P=0.0062). A worse outcome was associated with increasing age (P<0.001), a prior stroke (P<0.0001), and increasing number of stents (P=0.0483). In 2,572 patients with a complex arch, 1,416 underwent TFCAS and 1,156 had TCAR. Mean age was 73.0 (±9.1) years, and 1,655 (64.4%) were males. In complex arch anatomy, the primary outcome of in-hospital TIA/stroke/death was seen significantly less frequently in TCAR compared with TFCAS (OR, 0.49; 95% CI, 0.31-0.77; P=0.0022). Again noted was a significant difference in death, with better outcomes in TCAR (P=0.0133). Although the occurrence of in-hospital TIA was no different between the 2 approaches (P=0.6158), there were significantly fewer strokes in those treated with TCAR (P=0.0132). TCAR (P=0.0146) was associated with improved outcomes. A worse outcome was seen with advancing age (P=0.0003), prior strokes (P=0.01), and a left-sided lesion (P=0.0176). TCAR has improved outcomes of TIA/stroke/death compared with TFCAS in both simple and complex aortic arch anatomy. In simple aortic arches, there is no difference in neurologic outcomes between both approaches. In complex arch anatomy, TCAR has fewer strokes.

Rampant Arch and Its Optimum Geometrical Generation

Gothic art was developed in western Europe from the second half of the 12th century to the end of the 15th century. The most characteristic Gothic building is the cathedral. Gothic architecture uses well-carved stone ashlars, and its essential elements include the arch. The thrust is transferred by means of external arches (flying buttresses) to external buttresses that end in pinnacles, which accentuates the verticality. The evolution of the flying buttresses should not only be considered as an aesthetic consideration, but also from a constructive point of view as an element of transmission of forces or loads. Thus, one evolves from a beam-type buttress to a simple arch, and finally to a rampant arch. In this work, we study the geometry of the rampant arch to determine which is the optimum from the constructive point of view. The optimum rampant arch obtained is the one with the common tangent to the two arches parallel to the slope line. A computer program was created to determine this optimal rampant arch by means of a numerical or graphical input. It was applied to several well-known and representative cases of Gothic art in France (church of Saint Urbain de Troyes) and Spain (Cathedral of Palma de Mallorca), establishing if they were designs of optimal rampant arches or not.

Three-dimensional palatal anatomic characteristics' correlation with dermatoglyphic heterogeneity in Angle malocclusions.

To assess correlation of dermatoglyphic (DG) pattern with quantitative palatal anatomic parameters measured using three-dimensional (3D) scanning of dental casts and to explore the possibility of utilizing these to predict future occurrence of malocclusion. Pretreatment casts of 477 Saudi Arabian patients were divided into Class I, II, and III malocclusion groups. Fingerprints were recorded for all hand digits using a digital biometric device. Maxillary arch analysis was accomplished including intercanine, intermolar distance, palatal height, and palatal area. The results were statistically analyzed. The mean surface area of the palate was highest in Class II malocclusion. The DG pattern was not significantly associated with the type of malocclusion, except in the instance of the double loop characteristic (P = .05). There was a strong correlation, however, between DG characteristics like simple arch, loop, and double loop and palatal dimensions (intercanine, intermolar distance, and palatal height). Heterogeneity of DG pattern could be reliably used to predict palatal dimensions. Logistic regression revealed that only tented arch, symmetrical, spiral DG patterns and palatal area were significant but weak predictors of Angle malocclusion (P < .05). A novel correlation of DG pattern with 3D palatal anatomic characteristics was assessed in different Angle malocclusion classes. Few of the DG characteristics and palatal dimensions showed significant correlations. However, only some of these were significant predictors of Angle malocclusion.

Flow and clog in a silo with oscillating exit.

When grains flow out of a silo, flow rate W increases with exit size D. If D is too small, an arch may form and the flow may be blocked at the exit. To recover from clogging, the arch has to be destroyed. Here we construct a two-dimensional silo with movable exit and study the effects of exit oscillation (with amplitude A and frequency f) on flow rate, clogging, and unclogging of grains through the exit. We find that, if exit oscillates, W remains finite even when D (measured in unit of grain diameter) is only slightly larger than one. Surprisingly, while W increases with oscillation strength Γ≡4π^{2}Af^{2} as expected at small D, W decreases with Γ when D≥5 due to induced random motion of the grains at the exit. When D is small and oscillation speed v≡2πAf is slow, temporary clogging events cause the grains to flow intermittently. In this regime, W depends only on v-a feature consistent to a simple arch breaking mechanism, and the phase boundary of intermittent flow in the D-v plane is consistent to either a power law: D∝v^{-7} or an exponential form: D∝e^{-D/0.55}. Furthermore, the flow time statistic is Poissonian whereas the recovery time statistic follows a power-law distribution.

16.09: Influence of arch bridge skewness

ABSTRACTThis article performs a parameter study on a detailed finite element model of a simple arch bridge consisting of a single arch. The objective is to investigate the influence of different hanger arrangements, dimensions and finally a variation of the angle of skewness between the arch axis and longitudinal bridge deck axis. The influence on the stresses, forces and bending moments in the bridge deck girders, hangers and arch is examined. Finally, a buckling analysis is performed on all different models and the change in critical buckling load is discussed.The displacements in the bridge deck stay the same for small angles of skewness. Starting from an angle of ± 13°, the position of maximum deflection in the bridge deck shifts towards the ends of the bridge deck instead of being situated staying in the middle. This can be explained by the influence of the wind load acting on the arch structure and the direction of the horizontal resultants of the hanger forces. This can cause partial relaxation, thus ensuring a small uplift at the longitudinal girders of the bridge deck. This is also the cause for the higher displacements in the arch. The torsion effect in the arch results in a counter clockwise rotation of the arch. When performing a buckling analysis on the changing angle of skewness, it is found that this initially has only a small impact on the critical load factor.

Surgical Methods of Zygomaticomaxillary Complex Fracture.

BackgroundZygoma is a major buttress of the midfacial skeleton, which is frequently injured because of its prominent location. Zygoma fractures are classified according to Knight and North based on the direction of anatomic displacement and the pattern created by the fracture. In zygomaticomaxillary complex (ZMC) fracture many incisions (lateral eyebrow, lateral upper blepharoplasty, transconjunctival, subciliary, subtarsal, intraoral, direct percutaneous approach) are useful. We reviewed various approaches for the treatment of ZMC fractures and discussed about incisions and fixation methods.MethodsA retrospective review was conducted of patients with ZMC fracture at a single institution from January 2005 to December 2014. Patients with single zygomatic arch fracture were excluded.ResultsThe identified 694 patients who were admitted for zygomatic fractures from which 192 patients with simple arch fractures were excluded. The remaining 502 patients consisted of 439 males and 63 females, and total 532 zygomatic bone was operated. Orbital fracture was the most common associated fracture. According to the Knight and North classification the most frequent fracture was Group IV. Most fractures were fixated at two points (73%).ConclusionWe reviewed our cases over 10 years according to fracture type and fixation methods. In conclusion, minimal incision, familiar approach and fixation methods of the surgeon are recommended.

Missing mean does no harm to volatility!

Many empirical studies of financial volatility within the GARCH framework tend to exclude terms in the mean equation that are often proved to be statistically significant. We analyze analytically how omission of various mean terms affects the value of the ARCH parameter in the simple ARCH(1) model. We focus on the following terms missing from the mean equation when they are in fact present: a constant, a seasonal dummy, an autoregressive term, and a time-varying risk premium. We track how the relative distortion in the value of the ARCH parameter depends on amount of misspecification, and calibrate it to actual daily and monthly returns. It turns out that the effect on the variance equation of missing elements in the mean equation tends to be quite benign.

A Study on Dynamic Performance of Concrete Filled Steel Tube Arch Bridges

With the span of CFST (Concrete Filled Steel Tube) arch bridges getting much longer, the dynamic performance of them is becoming more and more advanced. In order to evaluate the structure of CFST arch bridges in a comprehensive way, it is necessary to take the dynamic performance of this kind of bridges into consideration. Methods of doing the dynamic analysis can be divided into two kinds: one is traditional theoretical analytical method, which is only suitable for simple arch bridge models; the other is FEM (Finite Element Methods), which is able to simulate the real structure and lead to more precise results. This paper attempts to study the calculation theory of free vibration characteristic of arch bridges through theoretical analytical method, and then it will do an empirical study on the dynamic performance of a CFST arch bridge by FEM to test the conclusion of theoretical study.

EComment. Rare combination of aortic anomalies

We have read with great interest the article by Gandolfo et al., in which they shared their strategy for one-stage repair in a patient with Charge syndrome, an aberrant left brachiocephalic artery and coarctation of the aorta in the right aortic arch. It is a well-structured case report study. Recently, we had a similar patient with a right-sided hypoplastic aortic arch, aberrant left subclavian artery, Kommerell's diverticulum and a retroaortic course of the innominate vein. Our patient was 1.5-year old girl referred to our clinic for surgical correction of hypoplasia of the aortic arch. She was diagnosed with PHACE (posterior fossa malformations, haemangiomas, arterial anomalies, cardiac defects, eye abnormalities) syndrome after birth. She had no history of dysphagia or dyspnoea. After the incidental finding of a heart murmur, transthoracic echocardiography (TTE) was performed. The pressure gradient measured in the descending aorta was only 60 mmHg. No additional cardiac abnormalities were found. Cardiac catheterization showed a right-sided aortic arch with an aberrant left subclavian artery. The entire aortic arch was hypoplastic. Moreover, it was shown that the left subclavian artery had aberrant course originating from a region distal to the left common carotid artery with diverticulum of Kommerell in its ostium. To better understand the morphology, a computed tomography scan was performed and in addition to those anomalies, retroaortic course of the left innominate vein was identified. Preoperative findings were consistent with intraoperative observations. PHACE syndrome is an uncommon association between large infantile haemangiomas, usually of the face, and structural abnormalities of the brain, cerebral vasculature, eyes, and/or aorta [1]. The association of coarctation of the aorta/hypoplasia of aortic arch and right-sided aortic arch is uncommon in non-syndromic patients [2]. An anomalous course of the innominate vein is rare. Right-sided aortic arch may have been with retroaortic course of innominate vein and more than 80% of the patients with anomalous left innominate vein have obstruction of the right ventricular outflow tract (RVOT), commonly tetralogy of Fallot (TOF) with or without pulmonary atresia [3, 4]. However, as in our case, combination of right-sided aortic arch with hypoplasia, aberrant left subclavian artery and retroaortic course of innominate vein without RVOT obstruction has not been published yet. In contrast to simple aortic coarctation or aortic arch interruption observed in non-syndromic patients, aortic anomalies found in the context of PHACE and other syndromes, such as Charge syndrome may represent a distinctive morphological entity with unusually complex and unpredictable anatomic involvement. For that reason, accurate interpretation of the anomaly as well as the related anatomical structures is crucial, especially in patients with syndromes. Conflict of interest: none declared

Analysis of early results of 43 children with aortic arch lesion after operation

Objective To analyze the clinical data of aortic arch lesions after operation in order to provide better operation and decrease the mortality and shorten the duration of intensive care unit(ICU) treatment. Methods Forty-three children with aortic arch lesions including 26 male and 17 female in Fuwai Angiocardiopathy Hospital between Jan.and Sep.2012 were enrolled.The ages ranged from 29 days to 10 years old with the median age of 6 months and the weight ranged from 3.2 kg to 38.0 kg with the median weight of 6.0 kg.Nine cases were simple aortic arch lesions, while 34 cases were associated with 2 or more complex cardiac anomalies.The cases were divided into groups according to the age and residence time in ICU. Results The median duration of mechanical ventilation was 23 hours and the median duration of residence time in ICU was 3 days.There were 3 postoperative deaths.Infants younger than 6 months needed more time of mechanical ventilation and longer ICU stay than children older than 6 months.The single factor analysis revealed that young age, low weight, combined with complex cardiac anomalies, and long time of cardiopulmonary bypass and mechanical ventilation were risk factors of prolonged stay in ICU.Postoperative complications occurred in 15 cases: 12 cases had the pulmonary infection, 5 cases had systemic capillary leak syndrome, 2 cases had tracheal stenosis, and 2 cases had low cardiac output syndrome.Extracorporeal membrane oxygenation support and cardiopulmonary resuscitation were guarantees of successful operation of low cardiac output syndrome. Conclusions Outcomes of repair of aortic arch lesion were good, so timely operation should be preformed for aortic arch lesions infants with asso-ciated cardiac anomalies, but there is risk of operation and infants need longer duration of ICU stay and tend to have more postoperative complications.The preliminary experiences suggested that it would be better for the children older than 6 months with aortic arch lesion to undertake operation as they tend to have less postoperative complications. Key words: Congenital heart disease; Aortic arch lesion; Coarctation of aorta; Interrupted aortic arch; Posto-perative complication; Risk factor

Backtesting Value-at-Risk Using Forecasts for Multiple Horizons, a Comment on the Forecast Rationality Tests of A.J. Patton and A. Timmermann

textabstractPatton and Timmermann (2011, 'Forecast Rationality Tests Based on Multi-Horizon Bounds', Journal of Business & Economic Statistics, forthcoming) propose a set of useful tests for forecast rationality or optimality under squared error loss, including an easily implemented test based on a regression that only involves (long-horizon and short-horizon) forecasts and no observations on the target variable. We propose an extension, a simulation-based procedure that takes into account the presence of errors in parameter estimates. This procedure can also be applied in the field of 'backtesting' models for Value-at-Risk. Applications to simple AR and ARCH time series models show that its power in detecting certain misspecifications is larger than the power of well-known tests for correct Unconditional Coverage and Conditional Coverage.