bluuebunny/crossref_metadata_2025 huggingface dataset:
Consecutive diagnosis of nanosecond pulsed discharge in a coaxial electrode configuration using a quadruple emICCD camera system
Authors: Liu Zhengyan , Hirakawa Yoichi , Yamamoto Kazuto , Ryu Terumasa , Li Jie , Jiang Nan , Namihira Takao , Wang Douyan
Published: September 2024

Understanding the rapid dynamics of the primary streamer is crucial for comprehending the nanosecond pulsed discharge process. To reveal the fast primary streamer process, this study introduces a newly developed quadruple emICCD camera system capable of capturing a sequence of four discharge images in single pulse, coupled with self-customized software for data analysis. A nanosecond pulse power with its FWHM of 10.5 ns was applied to a coaxial reactor, focusing on the dynamics of the primary streamer. Our research clarifies the spatiotemporal variations of the primary streamer’s properties and examines their relation with inner electrode diameter (i.d. 0.2–2.0 mm). Results showed that in a pulse-powered coaxial electrode, there are three stages in the primary streamer process and that i.d. serves as an important factor influencing the formation and propagation of streamers. Interestingly, we found that streamer head velocity, streamer width, and streamer area for individual streamers remain constant prior to streamer channels reaching the outer electrode. Furthermore, we also observed an initial increase followed by a decrease in both streamer head velocity and streamer width with increasing i.d values. This study sheds light on the fundamental properties of the primary streamer during nanosecond pulsed discharge, contributing valuable insights for future plasma applications.
Kagome materials AV3Sb5 (A = K,Rb,Cs): pairing symmetry and pressure-tuning studies
Authors: Zhou Yuwei , Ye Ge , Luo Shuaishuai , Song Yu , Lu Xin , Yuan Huiqiu
Published: September 2024

The vanadium-based kagome metals AV3Sb5 (A = K, Rb, and Cs) host a superconducting ground state that coexists with an unconventional charge density wave (CDW). The CDW state exhibits experimental signatures of chirality, electronic nematicity, and time-reversal-symmetry-breaking, raising the questions whether the superconductivity (SC) in AV3Sb5 may also be unconventional, how SC interplays with CDW, and how the two orders evolve upon tuning. This article reviews studies of the superconducting pairing symmetry, and the tuning of SC and CDW in the AV3Sb5 compounds. Various experimental techniques consistently find that CsV3Sb5 exhibits nodeless SC, which remains robust regardless whether the CDW is present. Under hydrostatic pressure, SC in AV3Sb5 becomes enhanced as the CDW is gradually suppressed, revealing a competition between the two orders. In CsV3Sb5, a new CDW state emerges under pressure that competes more strongly with SC relative to the CDW at ambient pressure, and results in two superconducting domes that coexist with CDW. After the CDW in AV3Sb5 is fully suppressed with hydrostatic pressure, a further increase in pressure leads to a nonmonotonic evolution of the superconducting transition temperature driven by lattice modulations. Thickness is shown to be a powerful tuning parameter in AV3Sb5 thin flakes, revealing the evolution of CDW and SC upon dimensional reduction, and can be combined with hydrostatic pressure to shed light on the interplay between SC and CDW. Based on results reviewed in this article, we discuss outstanding issues to be addressed in the AV3Sb5 systems.
Coherent electron phase-space manipulation by combined elastic and inelastic light-electron scattering
Authors: Kempers S T , van Elk I J M , van Leeuwen K A H , Luiten O J
Published: September 2024

Photon-Induced Near-field Electron Microscopy (PINEM), Kapitza–Dirac (KD) gratings, and ponderomotive phase plates are examples of techniques in which the wave function of an electron in free space is manipulated using light fields: free electron quantum optics (FEQO). These effects are usually treated in separate theoretical frameworks. In this paper we present a unified, two-pronged framework that can be used to describe and numerically evaluate the performance of a number of FEQO-based electron-optical elements. The first part is a combination of existing analytical treatments of light-electron scattering, based on solving a relativistically corrected Schrödinger equation. The theoretical overview covers both second-order contributions to PINEM and the Kapitza–Dirac effect. The second, novel element of the approach is based on electron wavefront reconstruction by evaluating the quantum mechanical phase along a bundle of classical electron trajectories. The quasi-classical (but fully relativistic) approach lends itself to simulating a wide variety of FEQO devices, including the examples mentioned. We apply both approaches to a few specific experimental configurations: mirror-based first-order PINEM, second-order PINEM in very high laser intensity, and Kapitza–Dirac diffraction. The results show excellent agreement between the analytical results and the quasi-classical simulations. Finally, we propose a setup that combines KD and PINEM to allow for simultaneous coherent energy and transverse momentum shaping of an electron beam, and present simulation results thereof.
Relation between photoionisation cross sections and attosecond time delays
Authors: Ji Jia-Bao , Kheifets Anatoli S , Han Meng , Ueda Kiyoshi , Jakob Wörner Hans
Published: September 2024

Determination and interpretation of Wigner-like photoionisation delays is one of the most active fields of attosecond science. Previous results have suggested that large photoionisation delays are associated with structured continua, but a quantitative relation between photoionisation cross sections and time delays has been missing. Here, we derive a Kramers–Kronig-like relation between these quantities and demonstrate its validity for (anti)resonances. This new concept defines a topological analysis, which rationalises the sign of photoionisation delays and thereby sheds new light on a long-standing controversy regarding the sign of the photoionisation delay near the Ar 3s Cooper minimum. Our work bridges traditional photoionisation spectroscopy with attosecond chronoscopy and offers new methods for analysing and interpreting photoionisation delays.
Inferring galaxy cluster masses from cosmic microwave background lensing with neural simulation based inference
Authors: Baxter Eric J. , Pandey Shivam
Published: September 2024

Gravitational lensing by massive galaxy clusters distorts the observed cosmic microwave background (CMB) on arcminute scales, and these distortions carry information about cluster masses. Standard approaches to extracting cluster mass constraints from the CMB cluster lensing signal are either sub-optimal, ignore important physical or observational effects, are computationally intractable, or require additional work to turn the lensing measurements into constraints on cluster masses. We apply simulation based inference (SBI) using neural likelihood models to the problem. We show that in circumstances where the exact likelihood can be computed, the SBI constraints on cluster masses are in agreement with the exact likelihood, demonstrating that the SBI constraints are close to optimal. In scenarios where the exact likelihood cannot be feasibly computed, SBI still recovers unbiased estimates of individual cluster masses and combined constraints from multiple clusters. SBI will be a powerful tool for constraining the masses of galaxy clusters detected by future cosmic surveys. Code to run the analyses presented here will be made publicly available.
Inflating in perturbative LVS: global embedding and robustness
Authors: Bera Swagata , Chakraborty Dibya , Leontaris George K. , Shukla Pramod
Published: September 2024

The perturbative LARGE volume scenario (LVS) is a promising moduli stabilisation scheme in which the overall volume modulus of the compactifying Calabi-Yau (CY) threefold is dynamically stabilised to exponentially large values via using only perturbative corrections. In this article, using an orientifold of a K3-fibred CY threefold, we present the global embedding of an inflationary model proposed in the framework of perturbative LVS, in which the overall volume modulus acts as the inflaton field rolling on a nearly flat potential induced by a combination of the α
'3-corrections and the so-called log-loop effects. Given that having a concrete global construction facilitates explicit expressions for a set of sub-leading corrections, as a next step, we present a detailed analysis investigating the robustness of the single-field inflationary model against such corrections, in particular those arising from the winding-type string loop corrections and the higher derivative F4-corrections.
In-silico study on cumulative effects of degeneration and anterior circumferential annular tear on the L5-S1 spinal unit
Authors: Vinyas  , Bhat Subraya Krishna , Yamada Hiroshi , Shyamasunder Bhat N
Published: September 2024

Low back pain is a serious health concern prevalent in majority of the people around the world, especially in case of the elderly. The root cause for this is mostly observed to be the development of lesions/ tears complemented by degenerative effects in the intervertebral disc of L4-L5 and L5-S1 segments. This study aims to analyse the effects of disc degeneration and tears on the mechanical responses of the L5-S1 spinal unit, which has not been investigated. The annulus is represented by an anisotropic hyperelastic Gasser-Ogden-Holzapfel (GOH) model wherein the effect of degeneration is defined by varying the constants responsible for the behaviour of the material in different strain-ranges. A systematic approach is proposed for modelling the effects of disc degeneration in the annulus. Further, the commonly found anterior circumferential tear is modelled to understand its combined effects with degeneration of the annulus. The damaging effect of the tear was limited only to extension movement, causing critical stress variations in its vicinity. However, degeneration had a significant influence on both stress and range of motion of the spinal unit across all types of movements. This study highlights the complex relationship of the physiological movements with pathogenesis of tear and degeneration leading to discogenic pain thus enabling clinicians to develop conservative treatment strategies for specific age groups.
Comparative Effectiveness of the Revised American Joint Committee on Cancer Staging System
Authors: Kao Chia-Wen , Chiang Chun-Ju , Lee Wen-Chung
Published: September 2024

The American Joint Committee on Cancer (AJCC) staging manual is periodically updated. This study aims to examine the staging performances in delineating stage-specific survival curves and to evaluate the reclassification of cases based on the 7th and 8th AJCC editions in Taiwan. Data were sourced from the Taiwan Cancer Registry for cases diagnosed in 2017 (7th edition) and 2018 (8th edition), each with a 2-year follow-up period. Performance was assessed using the area under the receiver operating characteristic curve and the Lorenz curve-derived Gini index, along with 2-year survival rates for evaluating patient prognoses. The 8th edition showed superior staging in four specific cancer types. Oropharyngeal cancer exhibited more variable 2-year survival rates across stages, and liver cancer showed a clearer decline in survival rates with advancing stages. The 8th edition also improved prognostic staging for non-small cell lung cancer and reclassified 26.4% of stage 4 prostate cancer patients under the 7th edition into stages 3 or 4A, showing 2-year survival rates above 90%. Our study highlights the 8th edition’s refined capacity for stage-specific survival distinctions and reclassification of cases to enhance prognostication in certain cancers within Taiwan. We recommend a comprehensive evaluation when adopting a new edition or version.
A normal paradox
Authors: Rosenblatt Lucas
Published: September 2024

For the past 40 years, Neil Tennant has defended a proof-theoretic criterion of self-referential paradoxicality. According to this criterion, the defining characteristic of paradoxes is that, when formulated within a natural deduction system, they produce derivations that cannot be normalized. This paper raises doubts about Tennant’s approach. Recently, Tennant has suggested that Russell’s paradox might not truly fit his criterion. I will argue that the reasoning that rules out Russell’s paradox can similarly be applied to some semantic paradoxes. Therefore, if Tennant’s assessment of Russell’s paradox holds, few cases may genuinely qualify as paradoxes by his standards.
‘I do not know if I will have the energy to come to placement tomorrow’: Fast-Tracking Racially Minoritised Students to Failure in Social Work Education
Authors: Tedam Prospera , Finch Jo
Published: September 2024

We build upon previous work that explored the evidence base of ‘failure to fail’ on practice placements across professions. We found a lack of convincing evidence of ‘fail to fail’ within assessed practice learning placements and could not ascertain the extent of this issue. The literature was stronger about why it ‘might’ or ‘could’ be difficult to fail students on placement. We concluded that if there was a reluctance to fail students, that hesitancy was not shown when failing racially minoritised students. Using critical race theory, we noted instead, fast tacking to failure. Data were re-examined from two previous studies that focused on the experiences of Black African social work students in England. We identified two ways in which practice educators operationalised fast tracking to failure. Firstly, the speed at which negative judgments were made about students’ abilities, and related to this, asking personal and insensitive questions, and secondly, the speed of decision about placement failure. We argue that the debate needs to move away from fail to fail and instead, focus on who is being fast tracked to failure, and how racism and other discrimination is addressed forcefully in social work policy, practice and education.
226. PHILOSOPHICAL CONSIDERATIONS IN SURGICAL INNOVATION
Authors: Khoma Oleksandr , Laurence Jerome , Sandroussi Charbel , Wijnhoven Bas
Published: September 2024

Background

Innovation in surgery has been viewed as synonymous with progress. This is not always the case as many new innovative processes, devices and techniques do not yield same results in "real world" as they do in the experimental stage. The purpose of this presentation is to discuss the role of philosophical experiment in the process of appraisal of surgical innovation.

Methods

A thought experiment was conducted analysing past surgical innovations. Introduction of electrosurgery, laparoscopic cholecystectomy, surgical safety checklist and laparoscopic aortic aneurysm repair were tested. All consequences (known and hypothetical) of these innovations were considered in attempt to establish a more holistic metric of success.

Results

Significant limitations exist in the current assessment methods of innovation "success" which is commonly defined based on the results of a study of chosen pre-set metrics (main outcome). The utility of key metric used to assess innovation (e.g. lengths of hospital stay or visual pain scores) is limited by the choice of these outcomes. This reduces the changes of detecting rate, but possibly, much more significant unintended effects both advantageous and harmful (e.g. discovery of insulin vs thalidomide). The magnitude of detectable change is dictated by practicality of powering controlled studies and exposes results to the sensitivity bias. Unanticipated effects of the innovation are frequently not discovered until it is adopted on a large scale. Various outcomes of innovation are non-commensurable and further complicate the definition of "success".

A novel innovation outcome assessment process is proposed: net global utility, a composite outcome measure which considers all potential effects of innovation (clinical, social, economic, ethical and other). Net global utility is a subjective measure that allows observer to compare non-commensurable values by not using them in isolation. One of the main advantages of net global utility is that it only requires knowledge of available metrics and principles of logical argument, providing an easy assessment tool to boost local oversight of introduction of innovation and policy-making. It includes calculation of risk (probability x consequence) which allows to account for improbable but highly consequential outcomes. Net global utility is compared to the best available alternative and derives internal face validity from this. Net global utility encompasses potential incidental future benefits as well as assessment of innovation against the test of justice.

Conclusion

Defining success in surgical innovation can be challenging. The use of thought experiment and logical argument is described to introduce a novel metric "net global utility" allowing for composite assessment of innovation success. Various previous surgical innovations used to demonstrate the application of the net global utility.
231. DESCRIBING THE LANDSCAPE OF ESOPHAGECTOMY BETWEEN EASTERN AND WESTERN ESOPHAGEAL SOCIETIES: COMPARATIVE STUDIES FROM THE JAPANESE NCD AND DUTCH DUCA
Authors: Matsuda Satoru , van der Sluis Pieter , Kumamaru Hiraku , Kingma Eeike , Kawakubo Hirofumi , Ruurda Jelle , Watanabe Masayuki , Miyata Hiroaki , Lagarde Sjoerd , Takeuchi Hiroya , van Hillegersberg Richard , Shirabe Ken , Wijnhoven Bas PL , Kitagawa Yuko
Published: September 2024

Objective

Differences in clinicopathological characteristics of patients with esophageal cancer between countries may exist and impact on perioperative and surgical treatment as well as outcomes. Identification of these discrepancies may help the interpretation of present and future studies.

Methods

Data on patient demographics, comorbidity, pathology, surgical procedure, and short-term outcomes were retrieved, and compared between countries. Furthermore, we conducted a risk factor analysis focused on the major postoperative complications after esophagectomy to reveal the similarities and differences in risk factors.

Results

The mean annual number of resections for oesophageal cancer was 6673 in NCD (5.3 cases per 100,000 population) and 551 (3.1 cases per 100,000 population) in DUCA. Patients from the NCD were older and had a lower BMI. Complete minimally invasive esophagectomy was performed in 52.7% in NCD and 85% in DUCA. A cervical anastomosis was performed in 83.5% of patients in the NCD and in 33.8% in the DUCA likely reflecting differences in the location of primary tumors. Mortality within 30 days after surgery in the NCD and DUCA was 0.8% and 2.7%, respectively. Risk factors for postoperative major complications were similar between countries.

Conclusions

Although there were differences in patient variables, no significant differences were observed in short-term outcomes and risk factors of postoperative complications. The current results provide insight into contemporary demographics and outcomes of esophageal cancer resections from two an Asian and Western perspective.
232. EPIDEMIOLOGY OF EOSINOPHILIC ESOPHAGITIS IN JAPAN: A POPULATION-BASED STUDY
Authors: Fujiwara Yauhiro
Published: September 2024

Backgrounds

Eosinophilic esophagitis (EoE) has been increasingly diagnosed in Western countries whilst there have been few general population-based studies in Asia. In addition, risk factors for EoE have not been examined completely. The aim of the study was to investigate the epidemiology and risk factors of EoE in Japanese general population.

Methods

We analyzed an employer-based health insurance claim database from January 2005 to September 2022. EoE cases were identified based on the International Classification of Diseases-tenth Revision code, K20.0. We calculated the incidence and prevalence of EoE using Poisson regression and binomial distribution with exact methods respectively. Using 10 times more matched controls for EoE cases, a nested case-control study identified potential risk factors for adult EoE.

Results

Of 15,200,895 individuals, 1,010 EoE cases were identified. The incidence and prevalence of EoE were 2.82 (95% CI 2.44–3.26) per 100,000 person-years and 10.68 (95% CI 10.01–11.37) per 100,000 people in 2022. Both rates had dramatically increased since 2017. smoking was associated with a 59% risk reduction of EoE whereas constant alcohol consumption was associated with a 63% increase in the risk of EoE. EoE was not associated with either body mass index or health-related diseases such as hypertension, diabetes mellitus, hyperuricemia, and dyslipidemia.

Conclusion

The incidence and prevalence of EoE in Japan has steadily increased over the past two decades. Nevertheless, EoE remains less common in Japan compared to Western countries. Factors contributing to the epidemiology of EoE on a global basis may improve our understanding of the contribution of genetic and environmental risk factors. In light of potential risk factors, further study is warranted to investigate whether lifestyle intervention can improve the management of EoE.
233. UTILITY OF SINGLE TRANSHIATAL CHEST DRAINAGE AFTER MINIMALLY INVASIVE OESOPHAGECTOMY: A PROPENSITY-SCORE MATCHED STUDY OF FEASIBILITY
Authors: Thong Da Wei , Gunawardene Ashok , Islam Shabnam Rabia , Kariyawasam Sanjeeva
Published: September 2024

Background

The routine placement of intercostal chest drains remains common practice following minimally invasive oesophagectomy (MIO). Chest drains may contribute to increased post-operative pain and morbidity. The aim of this study was to compare the outcomes of transhiatal chest drain with intercostal chest drain. We analysed use of analgesia, length of hospital stay, and postoperative pulmonary morbidity following MIO.

Methods

This was a retrospective case-control study of patients undergoing elective MIO at a quaternary centre in Western Australia between September 2016 and September 2023. To reduce confounding, propensity score matching was performed. All patients were identified from a prospectively maintained database. In patients undergoing MIO with exclusive transhiatal drainage, a 19 French Blake’s drain was advanced through the hiatus into the right pleural cavity and positioned adjacent to the anastomosis.

Results

Thirty patients were included in the study, fifteen of whom had exclusively transhiatal drain placement. Mean total daily oral morphine dose equivalent was significantly lower in the transhiatal drain group (58mg+/-35.8) compared with intercostal drain group (100.8mg+/-64.0) on day 1 (p=0.04). There is no statistically significant difference between the total oral morphine use on days 3 (p=0.44) and 6 (p=0.97). No significant difference was observed in reintervention rate (p=1.00), length of stay (p=0.78) or postoperative pulmonary complications (p=1.00).

Conclusion

The results of this study suggest that transhiatal drain placement following MIO is associated with a reduction in post-operative pain and no increase in pulmonary complications or length of stay. Larger, prospective studies are needed to further evaluate the safety of single transhiatal chest drain placement following MIO.
237. THE PROGNOSTIC VALUE OF NODAL SKIP METASTASIS IN PATIENTS WITH ESOPHAGEAL CANCER
Authors: Li Xiaokun , Yuan Yong
Published: September 2024

Background

Nodal skip metastasis (NSM), a common form of lymphatic spread in esophageal cancer (EC), refers to metastatic involvement of distant lymph nodes (LNs) without prior engagement of adjacent LNs. Previous studies examining the association between NSM and survival outcomes in EC patients have yielded inconsistent and even contradictory results. This systematic review and meta-analysis aim to assess the prognostic value of NSM and summarize NSM definitions used in prior studies.

Methods

Four databases were employed for this meta-analysis. The relationship between NSM and overall survival (OS) was assessed using pooled hazard ratios (HRs) and their 95% confidence intervals (CIs). Sensitivity analysis and funnel plots were utilized to evaluate publication bias.

Results

This meta-analysis incorporated nine studies, and the pooled results revealed no significant association between NSM and OS (HR = 0.99, 95% CI: 0.75–1.31; P = 0.951). Sub-group analyses based on histological features, method of lymphadenectomy, node staging system, and NSM definitions also failed to identify a significant association between NSM and OS.

Conclusions

Based on the available evidence, NSM cannot be considered a prognostic factor for EC patients. Future studies examining the prognostic value of NSM should focus on employing three-field lymphadenectomy with an adequate number of harvested LNs. NSM definitions based on lymph node station and anatomical compartment could both serve as feasible classifications for EC.
245. ESOPHAGECTOMY AFTER NEOADJUVANT CHEMOTHERAPY WITH AN INDICATION FOR CONVERSION SURGERY FOR HIGHLY ADVANCED ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMA
Authors: Okamoto Hiroshi , Taniyama Yusuke , Sato Chiaki , Ozawa Yohei , Ishida Hirotaka , Ando Ryohei , Shinozaki Yasuharu , Kamei Takashi
Published: September 2024

Background

There is currently no strong evidence for preoperative chemotherapy for advanced esophagogastric junction adenocarcinoma. Furthermore, no curative treatment strategy has been established for advanced junction adenocarcinoma, including Stage IV disease, with no indication for conversion surgery.

Subjects and Methods

In this study, we retrospectively reviewed nine patients with highly advanced esophagogastric junctional adenocarcinoma, including Stage IV adenocarcinoma, who underwent systemic chemotherapy followed by planned resection at our hospital.

Results

The participants included 6 males and 3 females, with median age of 64 (range: 45–72) years. Pretreatment stages III, IVA, and IVB, categorized based on UICC TNM classification (esophageal adenocarcinoma), were observed in 1, 4, and 4 cases, respectively, with 1 case of (#104) subclavian lymph node metastases, 1 case of (#16) abdominal para-aortic lymph node metastases, and 2 cases of liver metastases, including multiple lesions. All patients received S-1 plus oxaliplatin (SOX) therapy as preoperative chemotherapy (2–40 courses). Although we observed one patient with unresectable abdomen malingnancies, the others underwent R0 resection, six underwent esophagectomy (with three total gastrectomy and one liver resection), and two open (+ continuous right thoracotomy) lower esophagectomy + total gastrectomy. Pathological stages I, II, III, and IV were observed in two, one, four, and one patients, respectively. Postoperatively, stereotactic irradiation, chemotherapy, and immune checkpoint inhibitors were administered to the patients to treat recurrent brain and liver metastases, and the 1-year survival rate was found to be 71.4% with a median observation period of 17 (range: 0–61) months. Among them, downstage and pN0 cases were relatively promising.

Conclusion

Even in highly advanced cases, cases with promising prognoses with multidisciplinary treatment, including surgery, were observed. We hope that large-scale clinical trials, such as JCOG2203, will help clarifying the significance of this approach, and advancements in chemotherapy regimens are expected.
263. LEARNING CURVE ANALYSIS USING CUMULATIVE SUM TECHNIQUES FOR ROBOT-ASSISTED MINIMALLY INVASIVE ESOPHAGECTOMY
Authors: Mukoyama Tomosuke , Goto Hironobu , Koterazawa Yasufumi , Sawada Ryuichiro , Harada Hitoshi , Urakawa Naoki , Hasegawa Hiroshi , Kanaji Shingo , Yamashita Kimihiro , Matsuda Takeru , Oshikiri Taro , Kakeji Yoshihiro
Published: September 2024

Introduction

Robot-assisted minimally invasive esophagectomy (RAMIE) has improved the technical difficulty of the conventional minimally invasive esophagectomy, by more precisely operated forceps and stability of the surgical fields. Although it is widely accepted that RAMIE demands excellence in robotic surgery, it is unclear how many cases were needed to reach the proficiency. This study aimed to investigate the learnings curve of two surgeons, with respect to perioperative findings.

Methods

Patients who underwent RAMIE using a Da Vinci Xi Surgical System between November 2018 and February 2024 were included. Surgeon A introduced RAMIE and Surgeon B started the training of RAMIE after standardization. Both surgeons were certified by the Japan Society for Endoscopic Surgery and qualified surgeon by the Japan Esophageal Society. A cumulative sum (CUSUM) analyses were performed for console time for thoracic procedure to generate the learning curves of each surgeon. The cases before the changepoint of the CUSUM curve was defined as phase I (learning phase), and after the changepoint as phase II (proficiency phase). The perioperative outcomes were compared between the phases.

Results

Surgeon A and B performed 63 and 33 cases, respectively. Surgeon B started RAMIE under guidance of Surgeon A, who had already experienced 39 cases at that time. CUSUM curve showed that Surgeon B required fewer cases to reach the phase II (proficiency phase) than Surgeon A (16 cases for Surgeon B vs. 27 cases for Surgeon A). There was no significant difference between the phase I and II in patient characteristics including age, sex, tumor location, neoadjuvant chemotherapy, and clinical TNM stages and the extent of lymph node dissection. Total operation time significantly decreased from phase I to phase II: 796 min [730-824] vs. 708 min [627-764]; P<0.01 for Surgeon A, 806 min [751-853] vs. 686 min [635-707]; P<0.01 for Surgeon B. During Phase I, console time of Surgeon B was significantly longer than console time of Surgeon A (408 min [354-432] vs. 360 min [325-385], P<0.01). However, in Phase II, the difference in time attenuated (281 min [255-299] vs. 266 min [244-316], P=0.68). There was no significant difference in intraoperative blood loss or the incidence of postoperative complications including recurrent laryngeal nerve palsy, anastomotic leakage and pneumonia.

Conclusion

It is suggested that training in standardized surgical procedures for RAMIE under the guidance of an experienced surgeon could accelerate the pace of learning.
270. ANALYSIS OF THE RELATIONSHIP BETWEEN CARDIAC DIAMETER AND ANASTOMOTIC TROUBLE IN TRANS HIATAL ESOPHAGOGASTRIC JUNCTION CANCER SURGERY
Authors: Higuchi Yudai , Maruyama Suguru , Shoda Katsutoshi , Akaike Hidenori , Kawaguchi Yoshihiko , Saito Ryo , Takiguchi Koichi , Izumo Wataru , Nakata Yuki , Shiraishi Kensuke , Furuya Shinji , Amemiya Hidetake , Kawaida Hiromichi , Ichikawa Daisuke
Published: September 2024

Background

The number of esophagogastric junction (EGJ) cancers has been increasing in recent years, and the trans hiatal lower esophagectomy is widely used for cases with shorter esophageal invasion. However, the mediastinal surgical view through the hiatus is sometimes poor due to cardiac compression, and resection and reconstruction are often difficult in these cases. We therefore retrospectively examined the influence of cardiac diameter on short-term postoperative outcomes.

Methods

From June 2004 to December 2022, 97 patients underwent radical surgery for EGJ cancer at our hospital, of those 67 patients underwent trans-hiatal approach. We retrospectively analyzed the relationship between cardiothoracic ratio (CTR) on preoperative chest radiographs and left ventricular diastolic diameter (LVDd) on echocardiography and postoperative complications in patients underwent trans hiatal approach.

Results

Patients with preoperative CTR >50% had a significantly higher rate of anastomotic leakage (33% v.s. 7%, p<0.05), and similarly for LVDd, when divided into two groups using 43 mm as cut-off, patients with larger heart diameter had significantly more anastomotic leakage (69% v.s. 24%, p<0.05). We performed a multivariate analysis using CTR, ASA-PS, blood loss, operative time, BMI, and tumor diameter, and defined CTR as an independent risk factor for anastomotic leakage (OR: 7.76, 95%CI: 1.45-41.4, p<0.05).

Conclusion

Trans-hiatal approach can be used for resection of EGJ cancer. However, special attention should be paid to the prevention of anastomotic leakage in patients with cardiac comorbidities or a large preoperative CTR or LVDd.
271. EFFICACY OF NEOADJUVANT CF OR DCF, FLOT PLUS NIVOLUMAB FOR RESECTABLE LOCALLY ADVANCED ESOPHAGEAL SQUAMOUS CELL CARCINOMA (JCOG1804E: FRONTIER)
Authors: Tsushima Takahiro , Yamamoto Shun , Kato Ken , Daiko Hiroyuki , Hara Hiroki , Kojima Takashi , Abe Tetsuya , Tsubosa Yasuhiro , Kawakubo Hirofumi , Yoshii Takako , Fujita Takeo , Kadowaki Shigenori , Matsuda Satoru , Nagashima Kengo , Aoki Kazunori , Yachida Shinichi , Kitagawa Yuko
Published: September 2024

Background

The standard neoadjuvant therapy for resectable locally advanced esophageal squamous cell carcinoma (ESCC) in Japan is DCF (docetaxel [DTX] + cisplatin [CDDP] + 5-fluorouracil [5-FU]). In addition, neoadjuvant immune checkpoint inhibitors have shown a survival benefit for metastatic ESCC and several other cancers. We previously reported that neoadjuvant CF (CDDP + 5-FU) + nivolumab (Nivo), DCF + Nivo, and FLOT (5-FU + l-leucovorin [l-LV] + oxaliplatin [L-OHP] + DTX) + Nivo are tolerable and show promising short-term efficacy for resectable locally advanced ESCC. However, the long-term efficacy of these neoadjuvant treatments remains unclear.

Methods

JCOG1804E (FRONTiER) is a multi-cohort phase I study designed to evaluate the safety and efficacy of Nivo combined with neoadjuvant CF (cohorts A and B [adding run-in Nivo]) or DCF (cohorts C and D [adding run-in Nivo]) or neoadjuvant FLOT (cohort E) for resectable locally advanced ESCC. The eligibility criteria were histologically proven ESCC staged as cT1N1-3M0 or cT2-3N0-3M0 (8th UICC TNM classification), age 20-75 years, performance status (PS) ≤1, and no prior cancer treatment. Secondary efficacy endpoints were pathological complete response (pCR), progression-free survival (PFS), and overall survival (OS) for each treatment.

Results

Thirty-seven patients were enrolled (median age [range]: 62 [31-75] years; PS 0/1: 32/5; clinical stage I/II/III/IVA: 7/9/20/1; PD-L1 TPS <1%/≥1%/unknown: 10/26/1). In CF-based treatment cohorts (n=13), median follow-up time (range), pCR, and 3-year PFS were 42.3 (20.9-50.1) months, 7.7%, and 66.6%, respectively. The respective values for the DCF-based treatment cohorts (n=12) were 32.2 (8.0-39.8) months, 33.3%, and 83.3% and for the FLOT-based treatment cohort (n=12) were 16.2 (5.3-20.6) months, 41.7%, and 91.7%. In the overall population (n=37), median follow-up time was 31.9 (5.3-50.1) months and 3-year OS was 82.4%.

Conclusion

Neoadjuvant CF or DCF or neoadjuvant FLOT + Nivo followed by surgery for resectable locally advanced ESCC showed promising short- and long-term efficacy. (NCT03914443)
275. SAFETY AND TREATMENT RESULTS OF SELF-EXPANDABLE METAL STENT (SEMS) PLACEMENT FOR ESOPHAGEAL DISEASE
Authors: Yamamoto Kei , Hirao Takafumi , Oka Yoshio
Published: September 2024

Background

Self-expandable metal stent (SEMS) placement for esophageal strictures and fistulas caused by malignant tumors has been reported from various institutions as a relatively minimally invasive and safe palliative treatment. SEMS placement is often selected for cancer-bearing patients whose general condition has already deteriorated, but there are many unknowns regarding the risks and benefits of placement.

Methods

We retrospectively examined swallowing scores, oral intake status, complications and prognosis for 41 cancer-bearing patients who underwent SEMS placement in our hospital from 2011 to 2023.

Results

There were 29 men and 12 women, with a median age of 77 years. The types of cancer were esophageal cancer / gastric cancer / lung cancer / others in 22/12/3/4 cases, respectively. The reason for stent placement was stricture / fistula in 39/2 cases. Stent placement was successful in 40 cases (97.6%), and complications were observed in 7 cases (17.1%), including bleeding, displacement, and aspiration pneumonia in 2, 3, and 2 cases, respectively. Three patients underwent second stent placement for restenosis, and the median time to restenosis was 57 days. After stent placement, dysphagia score improved in 30 cases (78.9%). After stent placement 35 patients (87.5%) chose palliative treatment and the median survival time (MST) was 1.7 months (0.2-10.8). Comparing patients with PS≦2 and PS≧3 using performance status (PS) at the time of stent placement, patients with PS≦2 significantly ate more after stent placement (median amount of oral intake; 80 % vs. 40%, p=0.037), and the survival period was longer (MST; 3.1 months vs. 1.3 months, p=0.0018). Univariate analysis on the risk of complications by stent placement showed that chemotherapy history, radiotherapy history, and pretreatment dysphagia score were not risk factors, but poor PS (≥3) was the only significant risk factor (Odds ratio: 12.5, 95% CI:1.3-117, p=0.027).

Conclusion

Esophageal stents are less invasive treatment than any other palliative methods, like esophageal bypass or radiation therapy for patients who strongly desire oral intake. However in patients with poor general condition the risk of complications is high and the survival period is not long, so it should be performed after fully explaining the risks and benefits.
279. NOVEL REFLUX MICROASPIRATION SCINTIGRAPHY ALLOWS EFFECTIVE PATIENT SELECTION FOR ANTIREFLUX SURGERY IN PROXIMAL REFLUX EVENTS
Authors: Khoma Oleksandr , Van der Wall Hans , Burton Leticia , Cooke Michelle , Falk Gregory
Published: September 2024

Background and Aims

There is currently no reference standard test for the detection of the extra-esophageal manifestations of gastroesophageal reflux disease (GORD). The current suite of diagnostic tests principally assess reflux events in the oesophagus have problematic accuracy issues in the pharynx. A new scintigraphic technique has been developed and validated against 24-hour oesophageal monitoring with pH, impedance. It allows direct visualization of refluxate in the laryngopharynx and lungs. This was utilised to evaluate patients having laparoscopic fundoplication for severe proximal reflux resistant to maximal medical therapy. Scanning may allow succesful patient selection for antireflux surgery.

Methodology

Following Institutional Ethics approval, 50 patients were assessed by scintigraphy before and after laparoscopic fundoplication (LF) at a single nuclear medicine facility. Standardised Reflux Symptom Indices (RSI) were obtained from each patient before and after surgery. Patients were scanned after oral 99m technetium Fyton administration with early dynamic images and delayed SPECT/CT images of the head, neck and lungs. Background corrected time-activity curves were generated for the pharynx and upper oesophagus from which frequency of reflux was estimated by counting events with activities greater than 2 standard deviations above fitted values. Frequencies, Spearman correlation and the student’s t test were utilised for analysis.

Results

The study population (35F, 15M) had a mean age of 63.9 years (Range 21-86). All patients underwent LF. Mean BMI was 26.8 with 67% being over-weight or obese. All patients had proximal reflux events in the early dynamic study. SPECT/ CT showed LPR events in 45/50 and pulmonary micro-aspiration (PMA) in 45/50 pre-operatively and in 36/50 and 20/50 post-operatively. The RSI, cough and throat clearing indices showed a significant fall post-operatively (p< 0.001). The frequency of scintigraphic pharyngeal reflux events was reduced from a mean of 4.5 in 30 minutes to 2.9 (t=9.1, p=0.004).

Conclusion

The novel scintigraphic test detects oesophageal and extra-oesophageal reflux events and permits direct visualization of refluxate in the head and neck structures and lungs. Scintigraphy correlates well with symptoms of reflux in the oesophagus and extra-esophageal structures such as the laryngopharynx (chronic cough and throat clearing) and the response to LF albeit partial. PMA was significantly reduced.
283. MODIFIED FRAILTY INDEX AND CLINICAL FRAILTY SCALE TOOLS ARE NOT GOOD PREDICTORS OF SURVIVAL AFTER MINIMALLY INVASIVE ESOPHAGECTOMY
Authors: Ari Kaso , Sivarajan Sri , Shenoy Sachin , Patel Martyn , Kumar Bhaskar
Published: September 2024

Background

Assessing frailty in elderly patients is pivotal for preoperative risk stratification. Whilst the modified Frailty-Index (m-FI) and Clinical Frailty Scale (CFS) have been used to predict postoperative mortality and morbidity in various surgical contexts, their prognostic value for complications and overall survival following esophagectomy remains uncertain. Several studies have assessed pre-operative application of frailty indices and whether they have prognostic value for long-term postoperative outcomes, however, none have compared m-FI and CFS in patients undergoing esophagectomy. This study examines and compares m-FI and CFS with overall survival and post-operative complications in patients undergoing Minimally Invasive Esophagectomy (MIO).

Methods

We retrospectively analysed data from a prospectively maintained database, including patients aged ≥65 years undergoing MIO for esophageal cancer from January 2014 to December 2023, at a high-volume esophago-gastric tertiary centre. We compared the m-FI 11 and m-FI 5, CFS, all measuring frailty parameters in surgical patients. Frailty was defined as m-FI 11 ≥3, m-FI 5 ≥2, or CFS ≥4, based on the current literature evidence for application of these frailty assessment tools. Primary outcomes were 2- and 5-year all-cause mortality, with anastomotic leak, serious complications (Clavien-Dindo grade ≥IIIa) and average length of stay (LOS) as secondary outcomes.

Results

Among 174 patients (median age 72 years, range 65-85, male-to-female ratio 4:1), no significant associations were found between age, sex, TNM stage, and pre/post-op chemoradiotherapy within each scoring category. Neither tool showed significant associations for 2-, 5-year, and overall mortality (Table 1), nor for average length of stay. However, an m-FI 5 score ≥2 exhibited an odds ratio (OR) of 2.41 (95% CI 1.00–5.78, p = 0.049) for anastomotic leak, and a CFS score ≥4 had an OR of 2.46 (95% CI 1.02–5.90, p = 0.044) for serious complications.

Conclusion

In frail patients undergoing MIO, both the m-FI and CFS tools demonstrated no significant prognostic value for predicting overall survival. However, m-FI 5 ≥2 correlated significantly with anastomotic leaks, while CFS ≥4 correlated with serious complications. Relying on scoring tools for frailty assessment may inadvertently trivialise what is intended to be a multidimensional evaluation of health domains. Nevertheless, their utility in predicting complications should not be overlooked. We propose a more strategic use of frailty assessment tools to triage patients for comprehensive geriatric evaluation. This approach identifies patients at highest risk of complications and facilitates targeted prehabilitation for optimising outcomes.
289. OUTCOME OF CONVERSION SURGERY FOR ESOPHAGEAL CANCER WITH SYNCHRONOUS ABDOMINAL PARAAORTIC LYMPH NODE METASTASIS
Authors: Tanaka Koji , Sugimura Keijiro , Sugase Takahito , Momose Kota , Yamashita Kotaro , Kanemura Takeshi , Makino Tomoki , Shiraishi Osamu , Miyata Hiroshi , Yasuda Takushi , Yano Masahiko , Doki Yuichiro
Published: September 2024

Background and Purpose

Stage IVb esophageal cancer with distant metastasis has a poor prognosis with a 5-year survival rate of approximately 10%. Among distant metastases, the treatment strategy for esophageal cancer with metastasis to the #16 para-aortic lymph node has not been defined, and the significance of surgical resection is not clear.

Methods

Using the database of Osaka University and related institutions, we selected 41 cases of thoracic esophageal cancer with simultaneous #16 metastasis that underwent surgical resection between 2005 and 2021, and examined treatment outcomes.

Results

Patient background was median age 64 (43-76) years, gender M/F = 32/9, and primary site of occupancy Ut/Mt/Lt = 1/17/23. Tumor progression was cT factor T1/T2/T3/T4 =0/6/25/10, cN factor N0/N1/N2/N3 =0/13/19/9. Chemotherapy was administered as initial therapy in 38 patients, and CRT was administered in 3. Primary esophageal resection was performed in all 41 patients, and metastases were resected in 36 patients (88%). 38 patients (93%) were eligible for R0 resection. Pathologically, pT0-2/T3-4=22(54%)/19(46%), pN0/1/2-3 8(20%)/6(15%)/27(66%), and pN2 or higher were common. The 3-/5-year survival rate for all patients was 22.8%/19.0%. In all cases, pN0-1 had significantly better survival than pN2-3 (p=0.0252).

Conclusion

Conversion surgery for esophageal cancer with simultaneous #16 metastasis had a relatively good outcome, suggesting that the pN factor may be a prognostic factor.
290. EVALUATION OF THE POST-OPERATIVE GERD AND RESIDUAL CHEST PAIN AFTER POEM
Authors: Muranami Yuto , Sato Chiaki , Taniyama Yusuke , Okamoto Hiroshi , Ozawa Yohei , Ishida Hirotaka , Koseki Ken , Kamei Takashi
Published: September 2024

Background

Per-oral endoscopic myotomy (POEM) for esophageal achalasia has increasingly become a mainstream procedure worldwide, and its short and middle term efficacy and safety are more and more recognized. However, the long-term outcomes are still unclear and we sometimes experience the cases with severe post-operative GERD and residual chest pain.

Methods

We retrospectively reviewed 241 cases who were performed POEM in our center from Apr 2015 to Feb 2022 and evaluate their post-operative GERD and residual chest pain.

Results

Before POEM, 126 cases (54.8%) had chest pain. Residual chest pain 2 months after POEM was observed in 28 patients (23.1%). 78.2% had complete remission of chest pain after 1 year. Severe GERD (LA Grade C or D) 2 months and 1 year after POEM was observed in 5.1%, 8.2%, respectively. All of them except one patient were improved by PPIs. On univariable analysis, younger patients and pre-treatment were at risk for residual chest pain (p=0.02, p=0.04, respectively). Higher BMI was risk for severe GERD after 2 months (p=0.02), however it was not associate with that after 1 year (p=0.04).

Conclusion

Younger age and pre-treatment were at risk for residual chest pain after POEM and post-operative severe GERD was related to higher BMI, however almost all of them was controlled by PPIs. The number of cases was small, so it is necessary to accumulate more cases.