Portal vein thrombosis (PVT) is a frequent complication of cirrhosis. Benefit, safety, and duration of anticoagulant treatment in this setting are controversial issues. The aim of this study was to ...analyze the course of PVT in a large cohort of cirrhotic patients undergoing or not anticoagulation therapy.
The data of 182 patients who presented between January 2008 and March 2016 with cirrhosis and PVT with at least 3 months of follow-up after the first PVT detection were analyzed. Eighty-one patients received anticoagulants and 101 were untreated per physician discretion.
The extension of the thrombosis decreased by >50% in 46 (56.8%, with complete recanalization in 31/46) patients under anticoagulation and in 26 (25.7%) untreated patients. Of the 46 patients who underwent recanalization, 17 (36%) suffered recurrent thrombosis after stopping anticoagulation therapy. Kaplan-Meier analysis showed a higher survival rate in the treated group (p = 0.010). At multivariate analysis, anticoagulation was an independent factor associated with longer survival (HR:0.30, CI:0.10-0.91, p = 0.014). The Child-Turcotte-Pugh classes B/C negatively influenced survival (hazard ratio, (HR):3.09, confidence interval (CI):1.14-8.36, p = 0.027 for Child-Turcotte-Pugh B and HR:9.27, CI:2.67-32.23, p < 0.001 for Child-Turcotte-Pugh C). Bleeding complications occurred in 22 (21.8%) untreated and 16 (19.7%) treated patients, but in only four cases was it judged to be related to the anticoagulant treatment. No death was reported as a consequence of the bleeding events.
Anticoagulant treatment is a safe and effective treatment leading to partial or complete recanalization of the portal venous system in 56.8% of cases, improving the survival of patients with cirrhosis and PVT. Discontinuation of the therapy is associated with a high rate of PVT recurrence.
Summary Transarterial chemoembolization (TACE) is considered the gold standard for treating intermediate-stage hepatocellular carcinoma (HCC). However, intermediate-stage HCC includes a heterogeneous ...population of patients with varying tumour burdens, liver function (Child-Pugh A or B) and disease aetiology. This suggests that not all patients with intermediate-stage HCC will derive similar benefit from TACE, and that some patients may benefit from other treatment options. Results of an extensive literature review into the treatment of unresectable HCC with TACE were combined with our own clinical experience to identify factors that may predict survival after TACE. We also report contraindications to TACE and propose a treatment algorithm for the repetition of TACE. In addition, we have constructed a number of expert opinions that may be used as a guide to help physicians make treatment decisions for their patients with intermediate-stage HCC. The data included in the literature review related almost exclusively to conventional TACE, rather than to TACE with drug-eluting beads. Therefore, the findings and conclusions of the literature review are only applicable to the treatment of HCC with conventional TACE. Treating physicians may want to consider other treatment options for patients with intermediate-stage HCC who are not suitable for or do not respond to TACE. By distinguishing those patients who represent good candidates for TACE from those where little or no benefit might be expected, it may be possible to make better use of current treatment options and improve outcomes for patients.
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•Analytical method to predict the thermal behavior of multi-source multi-layer compound systems.•Reduction of total component resistance is obtained through optimal apportionment of layer ...thicknesses.•Anisotropic materials allow limited substrate thickness, but at an expected high cost.•For single-source systems, the objective function reduces to the minimum total resistance of the compound system.•For multi-source systems, the objective function aims at minimizing the peak temperature on top surface.
This work investigates the effect of the anisotropy on the heat transfer properties of layered composite materials with discrete heat sources, that are used in the power electronics of hybrid-electric propulsion systems. An analytical method, based on closed-form expressions structured on Fourier expansion series, is proposed for the solution of the Laplace’s steady-state anisotropic heat equation. The physical presence of electrical components is replaced by externally applied power sources. The method provides an accurate prediction of the temperature distribution and of the heat transfer across perfect layer-to-layer adhesion or finite conductance interfaces; its use is therefore encouraged for the optimization of composite substrates. Code verification has been employed on test cases for which the analytical solution was available.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•We describe the development of a 3-phase single-fluid algebraic VoF solver supporting phase-change.•Capture the interface between coexisting miscible phases is crucial to model fuel cavitation.•We ...introduce a novel benchmark case to verify the conservation of the phase-fraction equations in presence of phase-change.•The proposed solver enables prediction of swirl cavitation and hydraulic flip regime in fuel-injectors.
The development of a single-fluid solver supporting phase-change and able to capture the evolution of three fluids, two of which are miscible, into the sharp interface capturing Volume of Fluid (VOF) approximation, is presented. The transport of each phase-fraction is solved independently by a flux-corrected transport method to ensure the boundedness of the void fraction over the domain. The closure of the system of equations is achieved by a cavitation model, that handles the phase change between the liquid and the fuel vapor and it also accounts for the interaction with the non-condensable gases. Boundedness and conservativeness of the solver in the transport of the volume fraction are verified on two numerical benchmarks: a two-dimensional bubble rising in a liquid column and a cavitating/condensing liquid column. Finally, numerical predictions from large-eddy simulations are compared against experimental results available from literature; in particular, validation against high-speed camera visualizations and Laser Doppler Velocimetry (LDV) measurements of cavitating microscopic in-nozzle flows in a fuel injector is reported.
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In the last 12 - 18 months nearly all ultrasound manufacturers have arrived to implement ultrasound shear wave elastography modality in their equipment for the assessment of chronic liver disease; ...the few remaining players are expected to follow in 2016.When all manufacturers rush to a new technology at the same time, it is evident that the clinical demand for this information is of utmost value. Around 1990, there was similar demand for color Doppler ultrasound; high demand for contrast-enhanced ultrasonography was evident at the beginning of this century, and around 2010 demand increased for strain elastography. However, some issues regarding the new shear wave ultrasound technologies must be noted to avoid misuse of the resulting information for clinical decisions. As new articles are expected to appear in 2016 reporting the findings of the new technologies from various companies, we felt that the beginning of this year was the right time to present an appraisal of these issues. We likewise expect that in the meantime EFSUMB will release a new update of the existing guidelines 1 2.The first ultrasound elastography method became available 13 years ago in the form of transient elastography with Fibroscan(®) 3. It was the first technique providing non-invasive quantitive information about the stiffness of the liver and hence regarding the amount of fibrosis in chronic liver disease 3. The innovation was enormous, since a non-invasive modality was finally available to provide findings otherwise achievable only by liver biopsy. In fact, prior to ultrasound elastography, a combination of conventional and Doppler ultrasound parameters were utilized to inform the physician about the presence of cirrhosis and portal hypertension 4. However, skilled operators were required, reproducibility and diagnostic accuracy were suboptimal, and it was not possible to differentiate the pre-cirrhotic stages of fibrosis. All these limitations were substantially improved by transient elastography, performed with Fibroscan(®), a technology dedicated exclusively to liver elastography. Since then, more than 1300 articles dealing with transient elastography have been listed in PubMed, some describing results with more than 10,000 patients 5. The technique has been tested in nearly all liver disease etiologies, with histology as the reference standard. Meta-analysis of data, available in many etiologies 6, showed good performance and reproducibility as well as some situations limiting reliability 5. Thresholds for the different fibrosis stages (F0 to F4) have been provided by many large-scale studies utilizing histology as the reference standard 7. Transient elastography tracks the velocity of shear waves generated by the gentle hit of a piston on the skin, with the resulting compression wave traveling in the liver along its longitudinal axis. The measurement is made in a 4 cm long section of the liver, thus able to average slightly inhomogeneous fibrotic deposition.In 2008 a new modality became available, Acoustic Radiation Force Impulse (ARFI) quantification, and classified by EFSUMB 1 as point shear wave elastography (pSWE), since the speed of the shear wave (perpendicular to the longitudinal axis) is measured in a small region (a "point", few millimeters) at a freely-choosen depth within 8 cm from the skin. This technology was the first to be implemented in a conventional ultrasound scanner by Siemens(®) 8. Several articles have been published regarding this technology, most with the best reference standards 9, some including findings on more than 1000 hepatitis C patients 10 or reporting meta-analysis of data 11. Although the correlation between Siemens pSWE and transient elastography appeared high 12 13, the calculated thresholds for the different fibrosis stages and the stiffness ranges between the two techniques are not superimposable.Interestingly, pSWE appears to provide greater applicability than transient elastography for measuring both liver 13 and spleen stiffness, which is a new application of elastography 14, of interest for the prediction of the degree of portal hypertension 15 16.Nowadays other companies have started producing equipment with pSWE technology, but only very few articles have been published so far, for instance describing the use of Philips(®) equipment, which was the second to provide pSWE. These articles show preliminary good results also in comparison with TE 17 18. Not enough evidence is currently available in the literature about the elastographic performance of the products most recently introduced to the market. Furthermore, with some products the shear wave velocities generated by a single ultrasound acoustic push pulse can be measured in a bidimensional area (a box in the range of 2 - 3 cm per side) rather than in a single small point, producing a so-called bidimensional 2D-SWE 1. The stiffness is depicted in color within the area and refreshing of the measurement occurs every 1 - 2 seconds. Once the best image is acquired, the operator chooses a Region Of Interest (ROI) within the color box, where the mean stiffness is then calculated. 2D-SWE can be performed as a "one shot" technique or as a semi-"real-time" technique for a few seconds (at about 1 frame per second) in order to obtain a stable elastogram. With either technique, there should be no motion/breathing during image acquisition. A bidimensional averaged area should overcome the limitation of pSWE to inadvertently investigate small regions of greater or lesser stiffness than average. A shear wave quality indicator could be useful to provide real-time feedback and optimize placement of the sampling ROIs, a technology recently presented by Toshiba(®), but which is still awaiting validation in the literature.Supersonic Imagine by Aixplorer(®) which works with a different modality of insonation and video analysis compared to the the previously-mentioned three techniques (i. e., transient elastography, pSWE and 2D-SWE), leading to a bidimensional assessment of liver stiffness in real time up to 5 Hz and in larger regions; thus this technique is also termed real-time 2 D SWE. It has been available on the market for a few years 19 20, and many articles have been published showing stiffness values quite similar to those of Fibroscan(®) 21; likewise, defined thresholds based on histological findings have appeared in several articles 19 20 21.After this brief summary of the technological state of the art we would like to mention the following critical issues that we believe every user should note prior to providing liver stiffness reports. · The thresholds obtained from the "oldest" techniques for the various fibrosis stages based on hundreds of patients with histology as reference standard cannot be straightforwardly applied to the new ultrasound elastography techniques, even if based on the same principle (e. g. pSWE). In fact, the different manufacturers apply proprietary patented calculation modes, which might result in slightly to moderately different values. It should be kept in mind that the range for intermediate fibrosis stages (F1 to F3) is quite narrow, in the order of 2 - 3 kilopascal (over a total range spanning 2 to 75 kPa with Fibroscan), so that slightly different differences in outputs could shift the assessment of patients from one stage to another. Comparative studies using phantoms and healthy volunteers, as well as patients, are eagerly awaited. In fact, the equipment might not produce linear correlations of measurements at different degrees of severity of fibrosis. As a theoretical example, some equipment might well correlate in their values with an older technique, such as transient elastography, at low levels of liver fibrosis, but not as well in cases of more advanced fibrosis or vice versa. Consequentely, when elastography data are included in a report, the equipment utilized for the measurement should be clearly specified, and conclusions about the fibrosis stage should be withheld if an insufficient number of comparative studies with solid reference standards are available for that specific equipment.. · Future studies using histology as a reference might be biased in comparison to previous studies, since nowadays fewer patients with chronic hepatitis C or hepatitis B undergo biopsy. In fact, due to wide availability of effective drugs as well as the use of established elastography methods for patients with viral hepatitis, most cases submitted to biopsy today have uncertain etiology or inconsistent and inconclusive clinical data. Therefore, extrapolated thresholds from such inhomogeneous populations applied to more ordinary patients with viral hepatitis might become problematic in the future, although no better solution is currently anticipated. This situation might lead to the adoption of a standard validated elastographic method as reference, but this has to be agreed-upon at an international level.. · Ultrasound elastography embedded in conventional scanners usually allows the choice of where to place the ROI within the color stiffness box and whether to confirm or exclude each single measurement when determining the final value. Thus, the operator has a greater potential to influence the final findings than with Fibroscan®, where these choices are not available. This has to be kept in mind to avoid the possibility that an operator could, even inadvertently, tend to confirm an assumption about that specific patient or to confirm the patient's expectations.. · Quality criteria for the new technologies following transient elastography are absent (depending on the manufacturer) or have not been satisfactorily defined, so that the information potentially inserted in a report cannot currently be judged for its reliability by the clinician.. (ABSTRACT TRUNCATED)
Background & Aims Aim of the study was to assess the clinical impact of conventional transarterial chemoembolization (cTACE) repeated “on demand” on HCC outcome. Outcome measures were: response rate ...to first and repeated cTACE, recurrence rates and overall survival. Methods The outcome of 151 consecutive HCC patients submitted to a first cTACE from January 2004 to December 2005 was retrospectively analyzed. Results Complete radiological response (CR) was observed in 72/151 (48%), 34/60 (52%) and 12/22 (55%) patients after first, second and third cTACE, respectively. Recurrence rates at 6 and 12 months were 37% and 61% after the first cTACE, and 40% and 59% after the second cTACE, respectively. Patients not achieving CR or with a recurrence after CR not treated with curative therapies were 94 and 84 after first and second cTACE, respectively. Of these, 60/94 (64%) and 22/84 (26%) were submitted to a second and third cTACE, respectively. Median overall survival was 32.0 months but 25.0 months excluding transplanted patients. Factors at the time of first cTACE associated with overall shorter survival at multivariate analysis were higher bilirubin, higher AFP and not achieving CR. Conclusions CR and recurrence rates after first and second cTACE were similar. About 64% of patients were submitted to second cTACE, while only few patients (26%) were submitted to third cTACE using an “on demand” policy. These figures may be also useful for planning trials for the evaluation of the efficacy of repeated TACE vs . TACE combined with adjuvant treatments or vs . systemic treatments.
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Conventional criteria for liver transplantation for patients with hepatocellular carcinoma are single HCC ≤ 5 cm or less than or equal to three HCCs ≤ 3 cm. We prospectively evaluated the possibility ...of slightly extending these criteria in a down‐staging protocol, which included patients initially outside conventional criteria: single HCC 5–6 cm or two HCCs ≤ 5 cm or less than six HCCs ≤ 4 cm and sum diameter ≤ 12 cm, but within Milan criteria in the active tumors after the down‐staging procedures. The outcome of patients down‐staged was compared to that of Milan criteria after liver transplantation and since the first evaluation according to an intention‐to‐treat principle. From 2003 to 2006, 177 patients with HCC were considered for transplantation: the transplantation rate was comparable between the Milan and down‐staging groups: 88/129 cases (68%) versus 32/48 cases (67%), respectively. At a median follow‐up of 2.5 years after transplantation, the 1 and 3 years' disease‐free survival rates were comparable: 80% and 71% in the Milan group versus 78% and 71% in the down‐staging. The actuarial intention‐to‐treat survival was 27/48 patients (56.3%) in the down‐staging and 81/129 cases (62.8%) in the Milan group, p = n.s. The proposed down‐staging criteria provide a comparable outcome to the conventional criteria.
This study of a new down‐staging protocol for patients with HCC moderately beyond the Milan criteria on waiting list for liver transplantation shows that both the intention‐to‐treat analysis and the post‐operative outcome were comparable between down‐staging and conventional criteria group. See also editorial by Lo in this issue on page 2485.
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BFBNIB, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Summary
Background
Gadoxetic acid (Gd‐EOB‐DTPA) is a ‘hepatocyte‐specific’ contrast agent for magnetic resonance (MR) in both the vascular and the hepatobiliary phases.
Aim
To evaluate the ...contribution of the hepatobiliary phase of Gd‐EOB‐DTPA MR in the diagnosis of small hepatocellular carcinoma (HCC) in cirrhotic patients under surveillance.
Methods
Between 2008 and 2011, 48 consecutive small (10–30 mm) liver nodules were detected in 33 patients, who prospectively underwent contrast‐enhanced ultrasound (CEUS), Gd‐EOB‐DTPA‐enhanced MR and helical‐computed tomography (CT) in a blind study. The diagnosis of HCC was established according to AASLD 2005 criteria.
Results
Of the 48 nodules, 38 (79%) were diagnosed as HCC, 24 (63%) of them based on AASLD non‐invasive criteria, 11 diagnosed at histology and 3 during follow‐up. The typical vascular pattern (arterial hypervascularisation and venous/late washout) was detected in 30 (79%) HCC nodules by MR, in 22 (58%) by CT and in 17 (45%) by CEUS. Hypointensity during the MR hepatobiliary phase was observed in all HCC nodules and in 3 nonmalignant nodules (sensitivity 100%, specificity 70%, positive predictive value 93%, negative predictive value 100%, positive likelihood ratio 3.33, negative likelihood ratio 0). Eight (21%) of the 38 HCC nodules, 7 of which lacked the typical vascular features at any of the imaging modalities, showed washout in the portal/venous phase and hypointensity in the hepatobiliary phase at MRI, while this pattern was not detected in any nonmalignant lesion.
Conclusions
Gadoxetic acid magnetic resonance may enhance the sensitivity of the non‐invasive diagnosis of small hepatocellular carcinoma nodules in cirrhotic patients under surveillance. Double hypointensity in the portal/venous and hepatobiliary phases could be considered a new magnetic resonance pattern, highly suggestive of hypovascular hepatocellular carcinoma.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The technical part of these Guidelines and Recommendations, produced under the auspices of EFSUMB, provides an introduction to the physical principles and technology on which all forms of ...current commercially available ultrasound elastography are based. A difference in shear modulus is the common underlying physical mechanism that provides tissue contrast in all elastograms. The relationship between the alternative technologies is considered in terms of the method used to take advantage of this. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided on optimisation of scanning technique, image display, image interpretation and some of the known image artefacts.
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