bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of microstructure and mechanical properties of Ti-based metal-matrix composites during high-pressure torsion
Authors: Ozerov M S , Klimova M V , Shigoleva E A , Vershinina T N , Ivanisenko Yu V , Stepanov N D , Zherebtsov S V
Published: November 2019

The microstructure and microhardness evolution of a Ti/TiB and Ti-15(wt.%)Mo/TiB metal-matrix composites (MMC) during high-pressure torsion (HPT) at 400 °C was studied. The composites were fabricated by spark plasma sintering of either hcp α-Ti with 10 wt.% of TiB2 or Ti with 13.5 wt.% of Mo (resulted in a bcc β-Ti matrix) and of 10 wt.% TiB2 powders mixtures at 1000 or 1200 °C, respectively. An increase in the dislocation density, a considerable decrease in the grain size in both hcp or bcc Ti matrix, and shortening of TiB whiskers were observed in the microstructures of the composites during HPT. After five revolutions, a nanostructure with a (sub) grain size of ~30 or ~55 nm was produced in Ti or Ti-15Mo matrix, respectively. The microhardness increased with strain from 452 HV in the initial state to 520 HV after 5 revolutions for Ti/TiB MMC and from 575 to 730 HV for Ti-15Mo/TiB MMC. The contributions of various hardening mechanisms to the composites were evaluated.
Anodic plasma electrolytic saturation of the Ti6Al4V alloy with nitrogen and oxygen
Authors: Kusmanov S A , Tambovskiy I V , Korableva S S , Belkin P N
Published: November 2019

The structure of the Ti6Al4V alloy, its microhardness, surface roughness, and wear and corrosion resistance after anodic plasma electrolytic saturation with nitrogen and oxidation of the surface were investigated. It was shown that an electrolyte containing ammonia and ammonium chloride provided the saturation of the alloy with nitrogen and oxygen and the formation of TiO2 with rutile structure and a nitrogen solid solution in the alloy. The treatment at 750 °C during 5 min results in an increase in microhardness up to 790 HV and a decrease in surface roughness by 1.4-fold owing to the anode dissolution of titanium. The dry friction coefficient of the samples after treatment at 700 °C can be 3.5-fold reduced through sliding with a speed of 0.144 and a load of 105 N. These regimes allow diminishing the wear rate of samples of titanium alloy after their wear testing by 2 orders of magnitude. Corrosion resistance in Ringer’s solution does not deteriorate after treatment at a low temperature, when an oxide layer forms on the surface.
Abnormal grain growth in a double-sided friction-stir welded Al-Mg-Si alloy
Authors: Vysotskiy I , Malopheyev S , Mironov S , Kaibyshev R
Published: November 2019

In this work, a standard T6 tempering (involving solution annealing followed by artificial aging) was employed to a fine-grained Al-Mg-Si alloy produced by double-sided friction-stir welding (FSW). The material was found to exhibit abnormal grain growth, thus demonstrating a relatively low thermal stability. The kinetics of abnormal grain growth in the joint was studied.
Friction-stir welding of Al-Mg-Mn-Zr sheets by using a hemispherical tool
Authors: Vysotskiy I , Malopheyev S , Mironov S , Kaibyshev R
Published: November 2019

A new design of the welding tool for friction-stir welding (FSW) was proposed. The main idea was in using of a hemispherical tool probe. Such a tool is very simple (and cost-effective) in fabrication and provides excellent mixing of the material during FSW, thus avoiding welding defects. In this work, the feasibility of this tool for joining of Al-Mg-Mn-Zr alloy and its effect on the microstructure and mechanical properties of the produced welds were studied.
Strengthening mechanisms of ultrafine grained copper alloys
Authors: Morozova A , Mishnev R , Belyakov A , Kaibyshev R
Published: November 2019

Cu-Cr-Zr alloys are characterized by an excellent combination of strength and electrical conductivity and are applied as structural materials in various electrical/electronic devices. The microstructure design of Cu-Cr-Zr alloys, the effect of thermomechanical treatment based on severe plastic deformation, and physical mechanisms providing high strength and electrical conductivity are investigated. The main structure-property relations in Cu-Cr-Zr alloys are considered. The dissolution of the dispersed particles during severe plastic deformation and an increase in the dislocation density, as well as the effect of heat treatment after deformation on the mechanical and electrical properties are discussed.
Strength and electrical conductivity of UFG Cu-Fe alloys subjected to HPT
Authors: Nesterov K M , Islamgaliev R K
Published: November 2019

This paper investigates the strength and specific conductivity of UFG Cu-Fe alloys processed by high-pressure torsion (HPT). The effect of an ultrafine-grained structure and further heat treatment on the increase of microhardness and specific conductivity is examined. The results of the structural study of the UFG samples by electron back-scatter diffraction (EBSD) are presented.
Effect of the UFG structure on the fatigue properties of ferritic/martensitic steel
Authors: Nikitina M A , Islamgaliev R K , Ganeev A V , Sitdikov V D , Zhernakov V S
Published: November 2019

This paper presents the results of investigation of the effect of an ultrafine-grained structure on the fatigue properties of ferritic/martensitic steel. Special attention is paid to the study of structural changes after fatigue tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study the features of fatigue fracture and microstructural evolution, depending on the distance from the fracture surface. Using X-ray diffraction, we determined the lattice parameter, coherent scattering region, dislocation density, the volume fraction and size of carbide particles. The paper discusses the effect of the ultrafine-grained structure, as well as the volume fraction and size of carbides on the mechanism of fracture during fatigue tests.
Features of a severe plastic deformation method for threaded steel reinforcing bars used in construction
Authors: Raab A G , Raab G I
Published: November 2019

Enhancing the mechanical properties of products by developing new technologically advanced SPD methods, as the most efficient for strengthening of materials due to deep refinement of the initial structure, is an urgent task. For this purpose, a method was developed for the continuous forming of threaded rods with the required properties, using successive operations of rolling and transverse shear. The produced rods with a threaded profile can be used in construction as reinforcing bars for the reinforcement of concrete structures. The studies were conducted using mathematical modeling and physical experiments. We analyzed the stress-strain state of the produced billets. In one processing cycle, the strength of the initial billet from low-carbon steel 10 was raised from 350 to 530-550 MPa and simultaneously a threaded profile was formed. The obtained parameters comply with the Russian state standard GOST for steel reinforcing bars of the A500 class used in construction.
Effect of the processing parameters of the hot rolling of a stainless austenitic steel on the processes of structural and phase transformation
Authors: Raab G I , Semenov V I , La P , Dobatkin S V
Published: November 2019

We studied the mechanism of structure formation of the stainless austenitic steel with the composition 0.09%C, 17.5%Cr, 11.6%Ni, 0.5%Ti (a close analogue of the AISI 304 steel) during hot deformation by rolling at a temperature of 900 °C, strain rates of 0.5-5 s−1 and strains of about 10-60%. It was demonstrated that with increasing strain the fraction of polygonized volumes grows, and inside them the fraction of equiaxed subgrains grows.
Effect of cold rolling on the structure and properties of the UFG Cu-0.5wt%Cr alloy
Authors: Sarkeeva E A , Raab G I , Wei W , Alexandrov I V
Published: November 2019

The results of studying the microstructure, mechanical and electrical properties of the UFG alloy Cu-0.5wt.% Cr, obtained by equal-channel angular pressing (ECAP), followed by cold rolling and subjected to aging, are presented. It was found that, as a result, the average size of the fragmented structure is 160 nm. The results showed that the tensile strength increases with increasing degree of deformation. The maximum strength value of 605 MPa was achieved after a combination of 8 ECAP passes followed by rolling by 95%, while ductility was reduced to 13%. The number of ECAP passes and subsequent rolling practically do not affect the electrical conductivity and is 34-39% of IACS.
Mechanical behavior at elevated temperatures of the ultrafine-grained titanium alloy VT8M-1 processed by rotary swaging
Authors: Stotskiy A G , Yakovleva T V , Modina Yu M , Polyakov A V , Ramazanov I A , Semenova I P
Published: November 2019

This paper investigates the mechanical properties at elevated operation temperatures of the Ti alloy VT8M-1(Ti-5.3Al-4.0Mo-1.2Zr-1.3Sn-0.2Si) in the coarse-grained (CG) and ultrafine-grained (UFG) states. The duplex UFG structure was produced by rotary swaging at a temperature of 750 °C. The UFG state was studied in terms of thermal stability during annealing at temperatures 500, 550, 600, 700 °C for a period of 1 hour. It was demonstrated that the recrystallization processes in the UFG structure start after annealing at 550 °C and above. We performed tensile mechanical tests at such temperatures. In a range of 300-450 °C, the ultimate tensile strength of the UFG alloy was stably above that of the CG alloy. Mechanical tests at 500 and 550 °C revealed a more significant decrease in the ultimate tensile strength of the UFG alloy as compared to the CG alloy, conditioned by the intensification of the recovery and recrystallization processes at these temperatures.
Optimisation of laser assisted forming conditions for improved formability of aerospace materials
Authors: Yakushina E , McArthur M , Canavan M
Published: November 2019

ISF technology was gradually considered as a manufacturing technology for fabricating sheet metal parts for both commercial and military aircraft. However, many challenges remain with respect to improving the consistency of the process, such as part thinning and springback. This is especially critical for two phase titanium alloy Ti-6AL-4V which has limited formability at room temperature. Therefore, understanding the correlation of laser system parameters and material properties is a key aspect for successful ISF of non-fractured Ti-6AL-4V. The laser heating is modelled to find the relationships between laser power, beam radius, scan speed, and the resultant temperature. The analysis shows that the temperature from laser heating increases with an increase in power, decreases significantly with an increase in beam radius, and decreases slightly with an increase in scan speed.
Study on the extrusion load during equal channel angular pressing
Authors: Zhang D T , Tong Y X , Li L , Zheng Y F
Published: November 2019

The equal channel angular pressing or extrusion technique, ECAP/ECAE, is a severe plastic deformation process employed to produce bulk ultra-fine grained materials. In this work, the extrusion load for performing the ECAP process is studied. The resistance includes deformation resistance and frictional resistance during ECAP processing. Base on the slip line method, upper bound solution and finite element analysis, the formula of extrusion load is proposed. The calculated results of extrusion load are in a good agreement with the experimentally measured curves. According to the formula, the influencing factors on the extrusion load are the length of the samples, friction coefficient, geometric parameters of die, yield strength and work hardening coefficient of the materials.
Analytical Fresnel laws for curved dielectric interfaces
Authors: Luhn Sebastian , Hentschel Martina
Published: November 2019

Fresnel laws and the corresponding Fresnel reflection and transmission coefficients provide the quantitative information of the amount of reflected and transmitted (refracted) light in dependence on its angle of incidence. They are at the core of ray optics at planar interfaces. However, the well-known Fresnel formulae do not hold at curved interfaces and deviations are appreciable when the radius of curvature becomes of the order of several wavelengths of the incident light. This is of particular importance for optical microcavities that play a significant role in many modern research fields. Their convexly curved interfaces modify Fresnel’s law in a characteristic manner. Most notably, the onset of total internal reflection is shifted to angles larger than critical incidence (Martina and Henning 2002 Phys. Rev. E 65 045603). Here, we derive analytical Fresnel formulae for the opposite type of interface curvature, namely concavely curved refractive index boundaries, that have not been available so far. The accessibility of curvature-dependent Fresnel coefficients facilitates the analytical, ray-optics based description of light in complex mesoscopic optical structures that will be important in future nano- and microphotonic applications.
Basic-hydrophobic sites are localized in conserved positions inside and outside of PH domains and affect localization ofDictyosteliummyosin 1s
Authors: Brzeska Hanna , Gonzalez Jesus , Korn Edward D. , Titus Margaret A.
Published: November 2019

Comparison of the highly dynamic localizations of Dictyostelium myosin 1s reveals significant differences between their localizations in macropinocytic protrusions and in actin waves. The short basic-hydrophobic sites lie in conserved positions and are the important determinants of myosin 1s localization.
On So-Called Novel and Regular Metonymies
Authors: Brdar Mario
Published: November 2019

Two issues pertaining to the use of metonymy that plays a central role in Slabakova et al. (2016) are mentioned in the very title of their study—novel metonymy and regular metonymy. In this article I draw attention to some problems with the identification of these as well as with the assumption that these are opposites of each other.
A survey and systematic assessment of computational methods for drug response prediction
Authors: Chen Jinyu , Zhang Louxin
Published: November 2019

Drug response prediction arises from both basic and clinical research of personalized therapy, as well as drug discovery for cancers. With gene expression profiles and other omics data being available for over 1000 cancer cell lines and tissues, different machine learning approaches have been applied to drug response prediction. These methods appear in a body of literature and have been evaluated on different datasets with only one or two accuracy metrics. We systematically assess 17 representative methods for drug response prediction, which have been developed in the past 5 years, on four large public datasets in nine metrics. This study provides insights and lessons for future research into drug response prediction.
Neural Transcription Correlates of Multimodal Cortical Phenotypes during Development
Authors: Pecheva Diliana , Lee Annie , Poh Joann S , Chong Yap-Seng , Shek Lynette P , Gluckman Peter D , Meaney Michael J , Fortier Marielle V , Qiu Anqi
Published: November 2019

During development, cellular events such as cell proliferation, migration, and synaptogenesis determine the structural organization of the brain. These processes are driven in part by spatiotemporally regulated gene expression. We investigated how the genetic signatures of specific neural cell types shape cortical organization of the human brain throughout infancy and childhood. Using a transcriptional atlas and in vivo magnetic resonance imaging (MRI) data, we demonstrated time-dependent associations between the expression levels of neuronal and glial genes and cortical macro- and microstructure. Neonatal cortical phenotypes were associated with prenatal glial but not neuronal gene expression. These associations reflect cell migration and proliferation during fetal development. Childhood cortical phenotypes were associated with neuronal and astrocyte gene expression related to synaptic signaling processes, reflecting the refinement of cortical connections. These findings indicate that sequential developmental stages contribute to distinct MRI measures at different time points. This helps to bridge the gap between the genetic mechanisms driving cellular changes and widely used neuroimaging techniques.
Uric acid and left ventricular hypertrophy: another relationship in hemodialysis patients
Authors: Selim Gjulsen , Stojceva-Taneva Olivera , Tozija Liljana , Zafirova-Ivanovska Beti , Spasovski Goce , Gerasimovska Vesna , Petronijevic Zvezdana , Trajceska Lada , Dzekova-Vidimliski Pavlina , Gjorgjievski Nikola , Pavleska-Kuzmanovska Svetlana , Kabova Angela , Georgievska-Ismail Ljubica
Published: November 2019

Background

The impact of serum uric acid (UA) on morbidity and mortality in hemodialysis (HD) patients is quite controversial in relation to the general population. The aim of this study was to evaluate the association of serum UA with both mortality and left ventricular hypertrophy (LVH) in HD patients.

Methods

This longitudinal study enrolled 225 prevalent HD patients who were classified into three groups according to their follow-up-averaged UA (FA-UA) levels: low FA-UA (FA-UA <400 µmol/L), intermediate/reference FA-UA (FA-UA between 400 and 450 µmol/L) and high FA-UA (FA-UA >450 µmol/L). Echocardiography was performed on a nondialysis day and the presence of LVH was defined based on a left ventricular mass index (LVMI) >131 and >100 g/m2 for men and women, respectively. The patients were followed during a 60-month period.

Results

The mean FA-UA level was 425 ± 59 µmol/L (range 294–620). There was a consistent association of higher FA-UA with better nutritional status (higher body mass index, normalized protein catabolic rate, creatinine, albumin and phosphorus), higher hemoglobin, but lower C-reactive protein and LVMI. During the 5-year follow-up, 81 patients died (36%) and the main causes of death were cardiovascular (CV) related (70%). When compared with the reference group, the hazard ratio for all-cause mortality was 1.75 [95% confidence interval (CI) 1.02–2.98; P = 0.041] in the low FA-UA group, but there was no significant association with the high FA-UA group. In contrast, FA-UA did not show an association with CV mortality neither with the lower nor with the high FA-UA group. The unadjusted odds ratio (OR) of LVH risk in the low FA-UA compared with the reference FA-UA group was 3.11 (95% CI 1.38–7.05; P = 0.006), and after adjustment for age, gender, diabetes and CV disease, ORs for LVH persisted significantly only in the low FA-UA group [OR 2.82 (95% CI 1.16–6.88,); P = 0.002].

Conclusions

Low serum UA is a mortality risk factor and is associated with LVH in HD patients. These results are in contrast with the association of UA in the general population and should be the subject of further research.
Artificial Intelligence Surpassing Human Intelligence: Factual or Hoax
Authors: Khanam Sana , Tanweer Safdar , Khalid Syed
Published: November 2019

Artificial intelligence is one of the most trending topics in the field of Computer Science which aims to make machines and computers ‘smart’. There are multiple diverse technical and specialized research associated with it. Due to the accelerating rate of technological changes, artificial intelligence has taken over a lot of human jobs and is giving excellent results that are more efficient and effective, than humans. However, a lot of time there has been a concern about the following: will artificial intelligence surpass human intelligence in the near future? Are computers’ ever accelerating abilities to outpace human jobs and skills a matter of concern? The different views and myths on the subject have made it even a more than just a topic of discussion.

 

In this research paper, we will study the existing facts and literature to understand the true definitions of artificial intelligence (AI) and human intelligence (HI) by classifying each of its types separately and analyzing the extent of their full capabilities. Later, we will discuss the possibilities if AI eventually can replace human jobs in the market. Finally, we will synthesize and summarize results and findings of why artificial intelligence cannot surpass human intelligence completely in the future.
P5 FEASIBILITY AND EFFICACY OF INDOCYANINE GREEN ANGIOGRAPHY DURING ESOPHAGECTOMY: A SYSTEMATIC REVIEW
Authors: Elke Van Daele , Hanne Vanommeslaeghe , Yves Van Nieuwenhove , Wim Ceelen , Christian Vanhove , Bart P Braeckman , Anne Hoorens , Jurgen Van Limmen , Oswald Varin , Dirk Van de Putte , Wouter Willaert , Piet Pattyn
Published: November 2019

Aim

The aim of this review was to evaluate feasibility and effectiveness of Indocyanine green fluorescence angiography (ICGA) as an assessment tool for gastric tube (GT) perfusion during the construction of the esophago-gastric anastomosis, and as a predictor of anastomotic leakage (AL). Moreover, attention was given to attempts made to quantify this method in esophageal surgery.

Background & Methods

After an esophagectomy, a GT is most commonly used to restore continuity of the upper gastrointestinal tract. Esophago-gastric anastomoses are known for their complications such as AL, associated with high morbidity and mortality. Graft perfusion is an important predictor for anastomotic integrity. Tissue perfusion assessment is currently based on subjective parameters as tissue color and vessel pulsations. Near infrared fluorescent (NIRF) imaging is an emerging medical imaging modality, requiring penetrating NIR light that excites a NIRF agent within the tissue, generating fluorescence that can then be captured by adapted cameras. Indocyanine green Angiography (ICGA) is such a NIRF imaging technique which can be used as a method to visualize anastomotic perfusion. For this review, 2 reviewers independently searched Pubmed and Embase for studies evaluating intraoperative ICGA perfusion assessment of the GT. Feasibility, complications, intraoperative surgical changes based on ICGA findings, quantification attempts, anatomical data and the impact of ICGA on postoperative anastomotic complications were documented and further analyzed.

Results

Nineteen studies were included for qualitative analyses. All described ICGA as a safe and easy method for gastric graft perfusion assessment. AL occurred in 13.8% of the entire cohort, 10% in the ICG guided group and 20.6% in the control group (p<.001). AL in the well-perfused group was 6.3% vs. 20.5% in the control group without ICGA (p< .001). The group with an altered surgical plan based on the ICG image had similar AL rates as the well perfused group (6.5% vs. 6.3%) and significantly less than the poorly perfused group (47.8%) (p<.001), suggesting that the technique is able to identify and alter a potential bad outcome.

Conclusion

the present review suggest that ICGA is a safe and easy method for GT perfusion assessment. Differences in AL rate between the well perfused and poor perfused anastomotic sites suggest that a good fluorescent signal is a predictor of good outcome.
O102 FINDING FACTORS ASSOCIATED WITH SAFE IMPLEMENTATION OF IVOR LEWIS TOTALLY MINIMALLY INVASIVE ESOPHAGECTOMY
Authors:   On behalf of the esophagectomy learning curve collaborative group, Claassen Linda , van Workum Frans , Rovers Maroeska M , Hannink Gerjon , Rosman Camiel
Published: November 2019

Aim

To define factors associated with more efficient learning after implementation of Ivor Lewis totally minimally invasive esophagectomy (TMIE).

Background and Methods

It is unknown which factors are associated with more efficient learning after implementation of Ivor Lewis TMIE. Prospectively collected data of 15 European expert centers are retrospectively analyzed. Consecutive patients undergoing Ivor Lewis TMIE are included. The primary outcome is anastomotic leakage and the secondary outcome is textbook outcome (TBO). The pre-defined level of acceptance for anastomotic leakage is set at 8% with a 5% margin. Trends in outcome parameters are plotted using weighted moving average to define when the pre-defined level of acceptance is reached. Outcome trends are compared between groups of hospitals for the following factors: hospital volume, surgeon experience, overall TMIE experience, expert clinic visit, Ivor Lewis TMIE course followed and Ivor Lewis TMIE proctor supervision during implementation.

Results

This study included 1718 patients. Hospitals with a volume >50 cases per year reached the pre-defined level of acceptance for anastomotic leakage at case 114, hospitals with a volume <50 cases did not reach the pre-defined level of acceptance. Hospitals with surgeon experience >10 years and <10 years reached the pre-defined level of acceptance at case 112 and 135, respectively. Hospitals with overall TMIE experience >50 cases and <50 cases reached the pre-defined level of acceptance at case 45 and 112, respectively. Visiting an expert clinic, followed a TMIE course, or implementation under a proctor’s supervision did not contribute to reaching the level of acceptance earlier.

Conclusion

Learning curves are shorter and the level of acceptance is reached earlier if Ivor Lewis TMIE is implemented in a high-volume hospital, if the procedure is implemented in a hospital with a surgeon with >10 years of experience, or if the surgeon has experience in other types of TMIE of >50 cases. These findings can inform surgeons and can contribute to formulate evidence-based training programs.
P103 A HAND-SEWN INTRATHORACIC ANASTOMOSIS IN ROBOT-ASSISTED MINIMALLY INVASIVE ESOPHAGECTOMY (RAMIE): A DETAILED DESCRIPTION OF TECHNIQUE AND OUTCOMES
Authors: de Groot E M , Kingma B F , van Hillegersberg R , Ruurda J P
Published: November 2019

Aim

The aim of this study was to describe a technique that was developed and refined to construct a hand-sewn intrathoracic anastomosis during robot-assisted minimally invasive esophagectomy (RAMIE).

Background & Methods

Whilst some case series have reported promising results of a hand-sewn intrathoracic anastomosis during RAMIE, the exact techniques were often not described in detail. Therefore, the current single-center retrospective study was designed to provide a detailed and reproducible technical description of a hand-sewn, intrathoracic anastomosis that was developed and refined for patients who underwent RAMIE in a high volume center for esophageal cancer surgery (2016-2018). Video recordings were reviewed to evaluate technical details regarding the anastomosis, including number of sutures and distances between the anastomosis and the longitudinal staple line or gastric conduit tip. Technical details and distances were extracted and measured by using video analysis software. Moving average analyses were performed to evaluate whether the anastomotic leakage rate changed over the consecutive cases.

Results

A total of 68 patients were included in the study. For creation of the anastomosis, the gastric conduit was opened on a median distance of 19 millimeters (range 0-66) from the gastric conduit tip. After initially performing end-to-end anastomoses, a switch was made to an end-to-side anastomosis for the majority of 55 patients (81%). A median total of 27 sews (range 20-38) were required to close the anastomosis. In the last 22 patients of the cohort (32%), 4 tension release stitches were placed after circular suturing of the anastomosis. A re-inforcing omental wrap was positioned around the anastomosis in 64 patients (94%). The moving average curve for anastomotic leakage started at a rate of 40% (cases 1-10) and ended at 10% (cases 59-68).

Conclusion

This is the first study to report technical features and outcomes of a hand-sewn intrathoracic anastomosis during RAMIE in detail. Although an acceptable anastomotic leakage rate was observed in the final inclusion phase, a hand-sewn intrathoracic anastomosis during RAMIE may carry a substantial learning curve.
P104 SELECTIVE LYMPHATIC EMBOLIZATION TO MANAGE SEVERE POSTOPERATIVE LYMPHATIC LEAK
Authors: Gustav Linder , Pär Gerwins , Magnus Sundbom , Jakob Hedberg
Published: November 2019

Aim

To describe methods and clinical outcomes in a cohort of patients at Uppsala University Hospital who underwent selective lymphatic embolization due to severe lymphatic leak.

Background & Methods

Surgery for malignant disease with extensive lymph node dissection in the abdomen or thorax can be complicated by postoperative lymphatic leak. This is a relatively rare condition, associated with great morbidity and can be difficult to treat. Selective embolization of leaking lymphatic vessels is a recently introduced method for management of thoracic and abdominal lymphatic leaks.

Patients that had undergone treatment with selective embolization for severe lymphatic leaks were studied retrospectively. Lymphatic leaks were diagnosed with dynamic contrast enhanced magnetic resonance imaging (MRI)-lymphangiography and/or nodal lymphangiography utilizing Lipiodol. Selective embolization of leaking lymphatic vessels was performed in local anesthesia through transabdominal access, selective catheterization of lymphatic vessels with microcatheters, followed by occlusion of the vessel with coils and glue. Alternatively the leaking lymphatic vessel was occluded by injection of Lipiodol or Fibrovein via an adjacent lymph node. Data was analyzed with descriptive statistics.

Results

The study comprised 14 patients with severe postoperative lymphatic leak (six following transthoracic esophageal resection and eight following abdominal resections). Prior to intervention the average daily lymph output was 2092 ml and average serum albumin was 19 g/l (range 7-27). Median time from primary surgery to selective embolization was 73 days indicating that conservative treatment had previously been tried and failed. Selective embolization was successful in 93% (n=13) and in nine patients the lymphatic leak ceased instantly. A few patients needed more than one embolization procedure.

Median time in hospital care after embolization was two days. No procedure-related complications occurred and only one patient later needed open surgery due to persisting lymphatic leakage.

Conclusion

Selective lymphatic embolization appears to be a safe and effective method with potential to preclude open surgery in patients with persistent severe postoperative lymphatic leak. The procedure can be performed under local anesthesia but demands a highly skilled and dedicated interventional radiologist. The most detailed imaging to facilitate the procedure was achieved through dynamic contrast enhanced MRI-lymphangiography.
P105 MIRNA483-3P AND MIRNA221 DYSREGULATION AND CORRELATION WITH SURVIVAL IN ESOPHAGEAL ADENOCARCINOMA (EAC)
Authors: Isidori F , Bozzarelli I , Lugaresi M , Malvi D , Mastracci L , Hoefnagel S J M , Räsänen J , Söderström H , Raulli G , D’Errico A , Fiocca R , Seri M , Krishnadath K K , Bonora E , Mattioli S ,   EACSGE
Published: November 2019

Aim

Our study aimed to characterize miR-221 and 483-3p dysregulation and to correlate their expression with clinical outcomes in patients submitted in first instance to surgical therapy (naïve patients) for esophageal adenocarcinoma (EAC).

Background & Methods

MicroRNA (miRNAs) are small, noncoding RNAs that play important roles in several biological processes by fine-tuning gene expression1. In a cohort of well-characterized EAC, we analyzed the expression of miRNAs. RNA was extracted from formalin-embedded (FFPE) surgical specimens of normal gastric tissues and EACs, classified according to BIM/GIM classification (BIM=Barrett’s intestinal metaplasia, GIM=Gastric intestinal metaplasia): 43 BIM-/GIM-, 32 BIM+/GIM-, 2 BIM+/GIM+, 9 BIM-/GIM+). Expression of 754 human miRNAs was profiled in 8 cases with TaqMan MicroRNA Array card A1.1/B3.0. miR-221 and 483-3p validation was performed with single TaqMan probes on all 85 FFPE samples. miR-221 and miR-483-3p were also analyzed in a cohort of 39 fresh-frozen biopsies (29 EAC and 10 normal esophageal tissues). In 3 EAC cell-lines (OE-19, OE-33, FLO-1)2 we tested the expression of miR-221 and miR-483-3p3 and of two major targets (PTEN and SMAD4, respectively). Correlations between miRNAs and clinical outcomes were calculated using Kruskal-Wallis, Mann-Whitney, t-Student’s and Kaplan-Meier tests.

Results

miR-221 and 483-3p resulted upregulated from the MicroRNA Array card analysis. This increase was confirmed in two independent cohorts (FFPE-cohort: miR-483-3p p=0.0065; fresh-frozen-cohort: miR-483-3p p<0.0001, miR-221 p=0.0062). Statistical analysis showed an upregulation of both miRNAs, in particular miR-483-3p (p<0.0001), in BIM-/GIM-, compared to BIM+/GIM-. miR-221 and 483-3p up- regulation correlated with reduced cancer-specific survival in FFPE samples (miR-483-3p p=0.053, miR-221 p=0.001). We demonstrated a significantly increase for miR-483-3p (p=0.01) with a trend toward reduction of SMAD4 expression in FLO-1 compared to other cell-lines.

Conclusions

We identified an up-regulation of miR-221 and miR-483-3p, which might contribute to cancer progression. In the most aggressive cell line, FLO-1, we observed an increased expression of miR-483-3p, with SMAD4 reduction. Further studies are warranted to elucidate in depth the role of miR-221 and miR-

483-3p in EAC.
P107 PREDICTION OF A POSITIVE CIRCUMFERENTIAL RESECTION MARGIN IN ADENOCARCINOMA OF THE ESOPHAGUS
Authors: William R C Knight , Connie Yip , Audrey Jacques , Nyree Griffin , Janine Zylstra , Wahyu Wulaningsih , Mieke Van Hemelrijck , Nick Maisey , DrAndrew Gaya , Cara R Baker , Mark Kelly , James A Gossage , Jesper Largergren , David Landau , Vicky Goh , Andrew R Davies
Published: November 2019

Aim

To determine if a positive circumferential resection margin (CRM) can be predicted in patients with esophageal adenocarcinoma undergoing neo-adjuvant chemotherapy prior to surgery

Methods

223 patients were included in this study. Multivariable analyses of clinico-pathological and computed tomography (CT) imaging predictors were performed to evaluate the likelihood of a positive CRM at initial staging and following neoadjuvant chemotherapy, with prediction models constructed. Area under curve (AUC) with 95% confidence interval (CI) from 1000 bootstrapping was assessed.

Results

Advanced clinical T-stage (T3-4) (odds ratio, OR 2.93 95%CI 1.03-9.48) and poor tumor differentiation (OR 2.84, 95%CI 1.39-6.01) were independently associated with an increased risk of a positive CRM. Non response to chemotherapy as estimated by CT independently corresponded with an increased risk of CRM positivity (OR 3.38 95% CI 1.43-8.50). Additional CT evidence of local invasion/pleural thickening and higher CT tumor volume (14cm3) improved the performance of a prediction model, including all above parameters; with AUC (c-index) of 0.76 (0.68-0.83).

Conclusion

Combining advanced clinical T-stage, poor tumor differentiation, CT non-response to chemotherapy, higher CT tumor volume and local invasion may be helpful in selecting patients for intensification of neo-adjuvant treatment prior to resection.
P109 GEOGRAPHICAL DIFFERENCES IN RESECTION RATES ASSOCIATED WITH SURVIVAL IN SWEDEN-IS SURGERY UNDERUSED?
Authors: Gustav Linder , Christine Jestin , Mats Lindblad , Jakob Hedberg
Published: November 2019

Aim

To investigate associations between resection rates and survival in esophageal and gastroesophageal junctional cancer.

Background & Methods

Surgical resection is the mainstay of curative treatment for cancer in the esophagus and the gastroesophageal junction. Merely about one third of these patients undergo resectional surgery although proportions vary. We set out to study differences in resection rates by county and their influence, if any, on survival.

A national cohort of patients with esophageal- and gastroesophageal junctional cancer, diagnosed 2006-2015, was set up by cross linking several national registries. The annual resection rate of each geographical county was calculated and divided into three groups (low, middle and high). Survival was analyzed with a Cox proportional hazards model including resection rate, sex, age, year of diagnosis, clinical TNM status, relevant comorbidities, neoadjuvant treatment as well as proportion intended curative oncological treatment.

Results

6532 patients were diagnosed during the study period whereof 1733 (26.3 %) underwent open or endoscopic resectional surgery. 860 (49.6%) patients received neoadjuvant treatment. In the studied decade, rates ranged from 21% to 33% in the 21 counties. Overall mean survival after diagnosis was 8.1, 9.9 and 12.1 months in the low, middle and high-resection rate groups respectively. In the multivariate Cox analysis, higher resection rate was associated with improved survival (HR 0.87, 95% CI 0.84-0.90, p<0.001).

Conclusion

In this national population-based cohort study, patients undergoing treatment in counties with higher resection rates had an associated improved survival. Local underuse of the surgical modality cannot be excluded.
P111 ROBOTIC-ASSISTED REPAIR OF IATROGENIC LEFT BRONCHUS PERFORATION DURING RAMIE – A CASE REPORT
Authors: Mann C , Lang H , Grimminger P P
Published: November 2019

Background

Iatrogenic bronchial injury during an esophageal surgery is a severe complication. Hence, immediate treatment is necessary to avoid further pulmonary complications and death. We present a case of an intraoperative bronchial injury caused by a bronchial tube cuff during a full robotic-assisted Ivor-Lewis esophagectomy (RAMIE).

Case report

A 64-year old patient with adenocarcinoma of the distal esophagus was planned for a RAMIE after completing neoadjuvant radiochemotherapy. Before beginning the thoracic phase, the anesthesist reported an airway leakage during the ventilation. During the transthoracic robotic assisted esophagectomy a perforation of the left main bronchus caused by the cuff of the double-lumen tube was found. Due to the diameter of the defect (1/2 inch) direct suturing was not possible. Therefore, we used a stalked pericardial patch to robotically oversew the perforation. The precise agility using the robotic DaVinci system was very useful treating this perforation minimally- invasively during the RAMIE without conversion. The rest of the surgery including the gastric pull-up and intrathoracic anastomosis was carried out without further complication.

The patient had a normal postoperative course and showed no signs of any pulmonary restrictions or any other morbidity. The patient was discharged fully enteralised and in good conditions at the 9th postoperative day. The histopathological stage was ypT3, N2(4/21), L0, V0, Pn0, R0 (stage IIIB in 7th UICC).

Conclusion

This case report points out the great possibilities of robotic surgery dealing with unexpected complications during complex operations. Robot-assisted complex suturing is a great advantage in robot-assisted minimally invasive surgery, especially during sewing a pericardium-flap onto the left bronchus perforation during an esophagectomy.
P115 TRANSITION FROM OESOPHAGECTOMY TO ENDOSCOPIC THERAPY FOR EARLY OESOPHAGEAL CANCER – A SINGLE CENTRE EXPERIENCE OF 251 CONSECUTIVE CASES
Authors: Reyhani A , J.M Dunn , Zylstra J , Santaolalla A , Gimson E , Baker C , Kelly M , Van Hemelrijck M , Zeki S S , Gossage J , Davies A
Published: November 2019

Aim

To compare Oesophagectomy and Endoscopic mucosal resection (EMR) short and long term outcomes of patients treated for early oesophageal cancer over a transition period in a single institution.

Background and Methods

Introduction of Endoscopic eradication therapy (EET) techniques in 2012 provided an alternative to oesophagectomy for high grade dysplasia (HGD) and early cancer. Historically the gold-standard treatment had been oesophagectomy, which is associated with significant post-operative morbidity and prolonged recovery, but offers a high chance of cure with additional benefit of regional lymphadenectomy. A single centre, contemporaneously maintained database of consecutive patients diagnosed with early oesophageal cancer and treated at a tertiary referral centre during 2000-2018 was analysed. Patients were discussed at MDT; histology was confirmed by 2 expert pathologists. Oesophagectomy was not preceded by neoadjuvant chemotherapy. Primary outcomes are overall and disease specific survival, secondary outcomes including hospital stay, complications and overall cost.

Results

113 patients underwent oesophagectomy and 138 underwent EMR +/- further EET. Mean age for oesophagectomy 64.6 vs. EMR 71.6 years (p=<.0001). Mean follow up for oesophagectomy was 5.6 vs 2.4 years after EET. The proportion of T1 tumours was (HGD 25% vs 39%, T1a 17% vs 34%, T1b 43% vs 16%, p<0.001), poor differentiation (23% vs 5%, p<0.001), lymphovascular invasion (19% vs 4%, p<0.001) and Inpatient hospital stay (median 14 vs 1.5 days EMR; p=<.0001) was significantly higher in oesophagectomy group. In-hospital and 30 day mortality was 0%. Surgical group suffered more complications (Clavien-dindo ≥ 3) 26% vs. EMR 1%, p=<.0001. Cancer recurrence after oesophagectomy was 18% (local 4%, systemic 9%, mixed 5%) vs. 5% following EET (local). Overall survival showed no difference between both groups (HR 1.157 95%CI 0.62-2.16). Stage matched survival in HGD; T1a and T1b sub-groups didn´t significantly differ.

Conclusion

In a large consecutive series of patients treated during a transition period, overall survival was similar in both groups. Surgery was associated with prolonged recovery and significant post-operative morbidity. EMR should be available for HGD and early cancer patients as gold standard of care although patients with adverse prognostic features may still benefit from oesophagectomy.
P116 A PILOT STUDY ON ENERGY INTAKE AND TOTAL ENERGY EXPENDITURE, USING A MULTI SENSOR DEVICE, IN OESOPHAGEAL CANCER PATIENTS DURING THE ENTIRE COURSE OF MODERN MULTIMODALITY TREATMENT
Authors: Ericson Jessica , Lundell Lars , Nilsson Magnus , Lindblad Mats , Klevebro Fredrik , Rouvelas Ioannis
Published: November 2019

Aim

The objective of the present pilot study was to address the feasibility and practical use of SenseWear Armband Mini® (SWA) as a possible valid method offering longitudinal, comprehensive and complete assessment of energy balance in oesophageal cancer patients submitted to modern multimodality therapy.

Background and methods

Assessment of malnutrition and its consequences are pivotal in the curative management of patients with oesophageal cancer. Twenty patients were recruited at diagnosis of oesophageal cancer, all amenable for curative treatment. The baseline measurement took place before start of neoadjuvant treatment and at three additional measurement periods: after the completion of neoadjuvant treatment, and at three and six months postoperatively. The patients carried the SWA for three consecutive days at each measurement period, allowing the measurement of free-living total energy expenditure (TEE) and physical activity level (PAL). Alongside, a three-day food diary was recorded, permitted the calculation of energy and protein intake. The body weigth was measured at all four occasions.

Results

Body weight steadily decreased during the preoperative phase. However, the greatest weight loss was observed during the first 3 months after surgery (mean=5.6 kg), where after it stabilised. The median energy intake of 1982 kcal (range: 910-3455) at baseline increased to 2210 kcal (range: 1718-3355, p=0.009) after the completion of the neoadjuvant treatment. At 3 months after oesophagectomy energy intake decreased to 1749 kcal (range: 1024-2707, p=0.101) and regained baseline levels first at 6 months postoperatively. The same trend was observed regarding protein intake. The TEE was 2262 kcal (range: 1595-3150) at baseline with no change after preoperative oncological treatment. A significant reduction in energy expenditure to 1975 kcal (range 1396-2336, p=0.005) was recorded at 3 months post oesophagectomy, which remained unchanged at six months after surgery.

Conclusion

There are significant obstacles in recording complete, comprehensive and repetitive data on energy balance during the entire course of modern multimodality treatment of oesophageal cancer patients.

With the objective to achieve and maintain positive energy balance focus must be on the patients’ energy intake already at the time of diagnosis, throughout the neoadjuvant therapy phase but particularly during the first 3 postoperative months.
P118 LOSS OF SMAD4 EXPRESSION IN ESOPHAGEAL ADENOCARCINOMA (EAC) IS CORRELATED TO POOR SURVIVAL
Authors: Mastracci L , Isidori F , Bozzarelli I , Lugaresi M , Malvi D , Hoefnagel S , Rasanen J , Soderstrom H , D'Errico A , Fiocca R , Seri M , Krishnadath K , Bonora E , Mattioli S
Published: November 2019

Aim

Our study is aimed to evaluate the impact of SMAD4 expression on the clinical outcome of therapy for esophageal adenocarcinoma (EAC).

Background & Methods

Esophageal adenocarcinoma is characterized by a high genetic heterogeneity and a low survival rate, despite the adoption of aggressive therapies. We evaluated the expression of SMAD4, a tumor suppressor gene frequently mutated in cancer. by immunohistochemistry in 67 formalin-embedded (FFPE) EAC surgical specimens (patients were primarily treated with surgical resection-naïve cases), 34 of which were analyzed for SMAD4 gene by Next Generation Sequencing (NGS) with a dedicated target panel. Loss of SMAD4 protein was defined by a complete loss of expression in least 30% of cancer cells. Survival curves were determined using Kaplan–Meier methods.

Results

Loss of SMAD4 immunoreactivity was found in 33 out of 67 EAC cases (49.3%). Among a subset of 34 cases assessed in NGS, SMAD4 mutations were found in 3 cases (8.8%), all associated with protein loss. Loss of SMAD4 expression was also found in several cases with no mutations in SMAD4 gene (17/34, 50%). Loss of SMAD4 immunoreactivity was associated with poor overall survival (p=0.013) and higher risk of recurrence (p=0.001).

Conclusion

Loss of SMAD4 expression was a recurrent event in EAC, linked with genetic mutations in few cases, whereas in the majority of cases it might be related to epigenetic mechanisms, such as promoter hypermethylation. SMAD4 loss was strongly associated with recurrence and poor survival in patients, suggesting SMAD4 expression as potential prognostic biomarker in EAC. Further studies are required to develop strategic therapeutic options directly targeting SMAD4 and/or its regulators.