A novel fully covered metal stent for unresectable malignant distal biliary obstruction: results of a multicenter prospective study

Arata Sakai,Atsuhiro Masuda,Takaaki Eguchi,Keisuke Furumatsu,Takao Iemoto,Shiei Yoshida,Yoshihiro Okabe,Kodai Yamanaka,Ikuya Miki,Saori Kakuyama,Yosuke Yagi,Daisuke Shirasaka,Shinya Kohashi,Takashi Ko 대한소화기내시경학회 2024 Clinical Endoscopy Vol.57 No.3

Background/Aims: Endoscopic self-expandable metal stent (SEMS) placement is currently the standard technique for treating unresectable malignant distal biliary obstructions (MDBO). Therefore, covered SEMS with longer stent patency and fewer migrations are required. This study aimed to assess the clinical performance of a novel, fully covered SEMS for unresectable MDBO. Methods: This was a multicenter single-arm prospective study. The primary outcome was a non-obstruction rate at 6 months. The secondary outcomes were overall survival (OS), recurrent biliary obstruction (RBO), time to RBO (TRBO), technical and clinical success, and adverse events. Results: A total of 73 patients were enrolled in this study. The non-obstruction rate at 6 months was 61%. The median OS and TRBO were 233 and 216 days, respectively. The technical and clinical success rates were 100% and 97%, respectively. Furthermore, the rate of occurrence of RBO and adverse events was 49% and 21%, respectively. The length of bile duct stenosis (<2.2 cm) was the only significant risk factor for stent migration. Conclusions: The non-obstruction rate of a novel fully covered SEMS for MDBO is comparable to that reported earlier but shorter than expected. Short bile duct stenosis is a significant risk factor for stent migration.

Experimental Verification of Weighted Moving Average 1MHz Multisampling Deadbeat Control for PMSM

Arata Takahash,Tomoki Yokoyama 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

A new digital control method for permanent magnet synchronous motor based on deadbeat control with multisampling method using FPGA based hardware controller is proposed. Adopting FPGA based hardware controller, all the control calculation can be finished within around 800 nano second, which result in the realization of the ideal digital control feedback without any sampling compensation method, and superior transient characteristics can be obtained. In this paper, weighted moving average 1MHz multisampling deadbeat control was proposed and compared with the conventional deadbeat control method through simulations and experiments. The advantages of the proposed method was verified.

Noise Lowering for a Large Variable Speed Range Use Permanent Magnet Motor by Frequence Shift and Structural Response Evaluation of Electromagnetic Forces

Arata, Masanori,Takahashi, Norio,Fujita, Masafumi,Mochizuki, Motoyasu,Araki, Takashi,Hanai, Takashi The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.1

According to electrical output up rating of a permanent magnet motor and request to operate for a large variable speed range, resonance between structural natural vibration and electromagnetic force inside the motor can take place and make noise. This paper describes the mechanism of a resonance between them and noise lowering procedure by frequency shift when they are applied to the reluctance torque largely employed new motor named Permanent magnet Reluctance Motor (PRM).

The Order of Differentiation Capacity in Rabbit Pluripotent Stem Cell is maintained even after Naïve-like Conversion

Arata Honda 한국동물생명공학회(구 한국동물번식학회) 2014 한국동물번식학회 한중일 심포지엄 Vol.2014 No.1

New Era of Management Concept on Pulmonary Fibrosis with Revisiting Framework of Interstitial Lung Diseases

( Arata Azuma ),( Luca Richeldi ) 대한결핵 및 호흡기학회 2020 Tuberculosis and Respiratory Diseases Vol.83 No.3

The disease concept of interstitial lung disease with idiopathic pulmonary fibrosis at its core has been relied on for many years depending on morphological classification. The separation of non-specific interstitial pneumonia with a relatively good prognosis from usual interstitial pneumonia is also based on the perception that morphology enables predict the prognosis. Beginning with dust-exposed lungs, initially, interstitial pneumonia is classified by anatomical pathology. Diagnostic imaging has dramatically improved the diagnostic technology for surviving patients through the introduction of high-resolution computed tomography scan. And now, with the introduction of therapeutics, the direction of diagnosis is turning. It can be broadly classified into to make known the importance of early diagnosis, and to understand the importance of predicting the speed of progression/deterioration of pathological conditions. For this reason, the insight of “early lesions” has been discussed. There are reports that the presence or absence of interstitial lung abnormalities affects the prognosis. Searching for a biomarker is another prognostic indicator search. However, as is the case with many chronic diseases, pathological conditions that progress linearly are extremely rare. Rather, it progresses while changing in response to environmental factors. In interstitial lung disease, deterioration of respiratory functions most closely reflect prognosis. Treatment is determined by combining dynamic indicators as faithful indicators of restrictive impairments. Reconsidering the history being classified under the disease concept, the need to reorganize treatment targets based on common pathological phenotype is under discussed. What is the disease concept? That aspect changes with the discussion of improving prognosis.

Clinical benefit of pirfenidone in IPF in Japanese experiences 90min

( Arata Azuma ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

IPF is an irreversible devastating pulmonary disease of unknown cause. Pirfenidone is a disease modulator with inhibition of decline in pulmonary functions, that was firstly available in Japan. Pirfenidone showed proof in attenuation in decline of FVC(VC) of patients with IPF in a clinical trial, that has led subsequently approval over the world. Real life practice makes multivariate analysis leading to other parameters including DLco, 6mw distance, symptoms, quality of life, radiological findings, acute exacerbation, and comorbidities such as lung cancer, risk of surgical procedure, and lastly overall survival. How much dosage is beneficial to IPF patients? Discussion will be continued in balance on risk and benefit. As drug development is globalized, the effectiveness of pirfenidone may depend on ethnic differences. We, all Asian need to share information about clinical practice across countries and times.

Endoscopic Self-Expandable Metal Stent Placement for Malignant Afferent Loop Obstruction After Pancreaticoduodenectomy: A Case Series and Review

Arata Sakai,Hideyuki Shiomi,Takao Iemoto,Ryota Nakano,Takuya Ikegawa,Takashi Kobayashi,Atsuhiro Masuda,Yuzo Kodama 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.4

In this study, we assessed a series of our cases in which endoscopic self-expandable metal stents (SEMSs) were used to treat malignantafferent loop obstruction (ALO) that arose after pancreaticoduodenectomy (PD). We retrospectively examined the records of 7 patientswho underwent endoscopic SEMS placement for malignant ALO following PD. Clinical success was achieved in all cases. The medianprocedure time was 30 min (range, 15–50 min). There were no cases of stent occlusion, and no procedure-related adverse events wereencountered. All patients died of their primary disease, and the median overall survival period was 155 days (range, 96–374 days). Are-intervention involving endoscopic ultrasound-guided hepaticogastrostomy combined with antegrade stenting was performed forobstructive jaundice and acute cholangitis in 1 case. In conclusion, endoscopic SEMS placement may be an effective and safe treatmentfor malignant ALO that arises after PD.

Non-IPF fibrosing ILD

( Arata Azuma ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

IPF is an exclusively progressive fibrosing pulmonary disease of unknown cause. Other disease concepts have been excluded for enrichment of accurate diagnosis of IPF. Non-IPF fibrosing ILD is a disease phenotype of poor prognosis despite of widely distributed disease concepts. In recent years, since the introduction of therapeutic drugs, the discussion of the pathological conditions to be treated has been activated like IPF. Pirfenidone’s unclassifiable ILD clinical trial, Nintedanib’s SSc-ILD trial (SENSCIS trial) and PF-ILD (INBUILD) trial were challenging trials, but it has attracted a great deal of attention because it is a ‘positive trial results’. However, although the FVC, which is regarded as a surrogate marker for survival by IPF, has been adopted to determine the therapeutic effect at the primary endpoint, the validity of the discussion by FVC has not been verified for other disease units. In particular, CTD-ILD as a systemic disease needs to be evaluated for prognosis by multiple organ pathologies in addition to immunosuppressive treatment. Under anti-fibrotic management, CTD pathology is very complex. In the future, it will be necessary to discuss the pros and cons of therapeutic intervention while carefully observing the pathological condition.

The National Clinical Database as an Initiative for Quality Improvement in Japan

Arata Murakami,Yasutaka Hirata,Noboru Motomura,Hiroaki Miyata,Tadashi Iwanaka,Shinichi Takamoto 대한흉부외과학회 2014 Journal of Chest Surgery (J Chest Surg) Vol.47 No.5

The JCVSD (Japan Cardiovascular Surgery Database) was organized in 2000 to improve the quality of cardiovascular surgery in Japan. Web-based data harvesting on adult cardiac surgery was started (Japan Adult Cardiovascular Surgery Database, JACVSD) in 2001, and on congenital heart surgery (Japan Congenital Cardiovascular Surgery Database, JCCVSD) in 2008. Both databases grew to become national databases by the end of 2013. This was influenced by the success of the Society for Thoracic Surgeons’ National Database, which contains comparable input items. In 2011, the Japanese Board of Cardiovascular Surgery announced that the JACVSD and JCCVSD data are to be used for board certification, which improved the quality of the first paperless and web-based board certification review undertaken in 2013. These changes led to a further step. In 2011, the National Clinical Database (NCD) was organized to investigate the feasibility of clinical databases in other medical fields, especially surgery. In the NCD, the board certification system of the Japan Surgical Society, the basic association of surgery was set as the first level in the hierarchy of specialties, and nine associations and six board certification systems were set at the second level as subspecialties. The NCD grew rapidly, and now covers 95% of total surgical procedures. The participating associations will release or have released risk models, and studies that use ‘big data’ from these databases have been published. The national databases have contributed to evidence- based medicine, to the accountability of medical professionals, and to quality assessment and quality improvement of surgery in Japan.

Novel Unidirectional Porous Hydroxyapatite used as a Bone Substitute for Tibial Wedge Osteotomy in Canines

Arata Watanabe,Masataka Sakane,Toru Funayama,Masashi Iwasashi,Akihiro Kanamori,Naoyuki Ochiai 한국생체재료학회 2010 생체재료학회지 Vol.14 No.1

A microstructure of unidirectional porous hydroxyapatite (UDPHAp) has a diameter of 100-300 μm, which pene-trates through the material. In addition, it has a porosity of 75% and initial compression strength of approximately 14 MPa. The objective of the present study was to investigate the feasibility of UDPHAp for the tibial wedge osteot-omy in canines. We performed the operation on the right tibia of the dogs, and a wedge-shaped UDPHAp was implanted in the gap after the osteotomy. At 6 and 12 weeks after the operation, the specimens were solid and bony union could be macroscopically observed. Radiological examination revealed that complete consolidation between the osteotomy site and the UDPHAp was established at 12 weeks. Histological evaluation revealed fibrous tissues between the host bone and the UDPHAp at 6 weeks, although new bone formation was observed at the edges of the material. At 12 weeks, direct bonding and bone ingrowth was observed. This study indicates that UDPHAp has great potential for use as a bone substitute for open-wedge high tibail osteotomy in clinical condition.