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Dive into the research topics where Keisuke Yamashita is active.

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Featured researches published by Keisuke Yamashita.


Hpb | 2010

Resection of hilar cholangiocarcinoma with left hepatectomy after pre-operative embolization of the proper hepatic artery

Yoshikazu Yasuda; Peter Nørgaard Larsen; Toshimitsu Ishibashi; Keisuke Yamashita; Hisao Toei

BACKGROUND Right or right-extended hepatectomy including the caudate lobe is the most common treatment for hilar cholangiocarcinoma (HC). A 5-year survival of up to 60% can be achieved using this procedure if R0-resection is obtained. However, for some patients a left-sided liver resection is necessary to obtain radical resection. The close relationship between the right hepatic artery and the HC in these patients frequently limits the ability to achieve a radial R0-resection without difficult vascular reconstruction. The aim of the present study was to describe the outcome of patients who underwent pre-operative embolization of the proper hepatic artery in an effort to induce development of arterial collaterals thus allowing the resection of the proper and right hepatic artery without vascular reconstruction. METHODS In patients presenting with HC who were considered to require a left hepatic lobectomy and in whom pre-operative work up revealed possible tumour invasion of the right hepatic artery, transcatheter arterial embolization (TAE) of the proper hepatic artery or the left and right hepatic arteries was performed. Three weeks later, a left-sided hepatectomy with resection of all portal structures except the portal vein was performed. RESULTS In six patients, pre-operative embolization of the proper hepatic artery was performed. Almost instantaneously in all six patients arterial flow signals could be detected in the liver using Doppler ultrasonography. No patient died peri-operatively. In all six patients an R0 radial resection was achieved and in three an R0 proximal transection margin was obtained. All post-operative complications were managed successfully using percutaneous drainage procedures. No patient developed local recurrence and two patients remain disease free more than 7 years after surgery. SUMMARY After pre-operative embolization of the proper hepatic artery, resection of the HC with left hepatectomy is a promising new approach for these technically demanding patients, giving them the chance of a cure.


Case Reports in Medicine | 2012

Takotsubo Cardiomyopathy as a Delayed Complication with a Herbicide Containing Glufosinate Ammonium in a Suicide Attempt: A Case Report

Keiichiro Tominaga; Manabu Izumi; Masayuki Suzukawa; Takafumi Shinjo; Yoshimitsu Izawa; Chikara Yonekawa; Masaki Ano; Keisuke Yamashita; Tomohiro Muronoi; Reiko Mochiduki

Background. Glufosinate ammonium has a famous delayed complication as respiratory failure, however, delayed cardiogenic complication is not well known. Objectives. The aim of this study is to report a takotsubo cardiomyopathy as a delayed complication of glufosinate ammonium for suicide attempt. Case Report. A 75-year-old woman ingested about 90 mL of Basta, herbicide for suicide attempt at arousal during sleep. She came to our hospital at twelve hours after ingesting. She was admitted to our hospital for fear of delayed respiratory failure. Actually, she felt down to respiratory failure, needing a ventilator with intubation at 20 hours after ingesting. Procedure around respiratory management had smoothly done with no delay. Her vital status had been stable, however, she felt down to circulatory failure and diagnosed as Takotsubo cardiomyopathy at about 41 hours after ingestion. There was no trigger activities or events to evoke mental and physical stresses. Conclusion. We could successfully manage takotsubo cardiomyopathy resulted in circulatory failure in a patient with glufosinate poisoning for suicide attempt. Takotsubo cardiomyopathy should be taken into consideration if circulatory failure is observed for unexplained reasons.


Journal of Telemedicine and Telecare | 2014

Development of a first-responder dispatch system using a smartphone:

Chikara Yonekawa; Masayuki Suzukawa; Keisuke Yamashita; Katsuaki Kubota; Yasuharu Yasuda; Akihiro Kobayashi; Hiroki Matsubara; Yoshiki Toyokuni

We constructed a prototype community first responder (CFR) dispatch system. The system sends incident information, including a map, to the chosen CFRs mobile phone. We tested it in a simulation of 30 out-of-hospital cardiac arrest incidents which had occurred in the town of Motegi during the previous year. Thirty off-duty firefighters acted as CFRs and were sent to the same locations. The mean response time (from the CFR receiving dispatch information to arrival at the scene) was 3 min 37s faster than the actual response time in the corresponding historical control, i.e. the response time was reduced by 36% (P < 0.01). The median travel distance of the CFRs was 3.4 km and there was a positive correlation between response time and travel distance. The study showed that interactive communication between dispatcher and CFR was important for effective operation and that CFRs could reach an OHCA patient before the Emergency Medical Service arrives.


Prehospital and Disaster Medicine | 2014

Predictability of the Call Triage Protocol to Detect if Dispatchers Should Activate Community First Responders.

Kenji Narikawa; Tetsuya Sakamoto; Katsuaki Kubota; Masayuki Suzukawa; Chikara Yonekawa; Keisuke Yamashita; Yoshiki Toyokuni; Yasuharu Yasuda; Akihiro Kobayashi; Kazunori Iijima

INTRODUCTION Shortening response time to an emergency call leads to the success of resuscitation by chest compression and defibrillation. However, response by ambulance or fire truck is not fast enough for resuscitation in Japan. In rural areas, response times can be more than 10 minutes. One possible way to shorten the response time is to establish a system of first responders (eg, police officers or firefighters) who are trained appropriately to perform resuscitation. Another possible way is to use a system of Community First Responders (CFRs) who are trained neighbors. At present, there are no call triage protocols to decide if dispatchers should activate CFRs. OBJECTIVE The aim of this study was to determine the predictability to detect if dispatchers should activate CFRs. METHODS Two CFR call triage protocols (CFR protocol Ver.0 and Ver.1) were established. The predictability of CFR protocols was examined by comparing the paramedic field reports. From the results of sensitivity of CFR protocol, the numbers of annual CFR activations were calculated. All data were collected, prospectively, for four months from October 1, 2012 through January 31, 2013. RESULTS The ROC-AUC values appear slightly higher in CFR protocol Ver.1 (0.857; 95% CI, 79.8-91.7) than in CFR protocol Ver.0 (0.847; 95% CI, 79.0-90.3). The number of annual CFR activations is higher in CFR protocol Ver.0 (7.47) than in CFR protocol Ver.1 (5.45). CONCLUSION Two call triage protocols have almost the same predictability as the Medical Priority Dispatch System (MPDS). The study indicates that CFR protocol Ver.1 is better than CFR protocol Ver.0 because of the higher predictability and low number of activations. Also, it indicates that CFRs who are not medical professionals can respond to a patient with cardiac arrest.


World Journal of Emergency Surgery | 2012

Ex-vivo porcine organs with a circulation pump are effective for teaching hemostatic skills.

Yoshimitsu Izawa; Shuji Hishikawa; Tomohiro Muronoi; Keisuke Yamashita; Masayuki Suzukawa; Alan T. Lefor

Surgical residents have insufficient opportunites to learn basic hemostatic skills from clinical experience alone. We designed an ex-vivo training system using porcine organs and a circulation pump to teach hemostatic skills. Residents were surveyed before and after the training and showed significant improvement in their self-confidence (1.83 ± 1.05 vs 3.33 ± 0.87, P < 0.01) on a 5 point Likert scale. This training may be effective to educate residents in basic hemostatic skills.


International Journal of Emergency Medicine | 2013

Introduction of the community first responder system into Japan: is that possible?

Yoshiki Toyokuni; Masayuki Suzukawa; Keisuke Yamashita; Chikara Yonekawa; Katsuaki Kubota; Yasuharu Yasuda; Akihiro Kobayashi; Hiroki Matsubara

BackgroundTo improve out-of-hospital cardiac arrest (OHCA) survival rates in Japan, implementation of a community first responder (CFR) system is considered one of the most effective emergency medical service options. We investigated the possibility of introducing a CFR system in Japan.MethodsCross-sectional surveys were given to 1,350 residents over the age of 18 who were selected from resident registration lists in Tochigi prefecture. Residents were questioned whether they would agree to have a CFR system in their community and whether they would participate as a responder. Positive attitudes about the cross-sectional study led us to conduct pilot CFR trials. Trials were conducted in rural areas of Tochigi prefecture by local EMS personnel. We were able to discuss and develop CFR introduction guidelines for Japanese communities using the results of the individual surveys, pilot trials, and other countries’ guidelines. Finally, our CFR system, which referred to developed CFR introduction guidelines, was introduced into Ishikawa prefecture’s Shioya town (population of 710).ResultsA total of 92.5% of Tochigi residents either strongly agreed or agreed to have a CFR system in their community, and 16.7% of Tochigi’s residents chose to participate. The two CFR introduction prerequisites were identified as: (1) an information delivery system for CFR and (2) budget preparation. CFR introduction guidelines were developed, and a CFR system was introduced in Shioya town on 4 November 2012 with 32 participants. On 1 January 2013, a CFR responded for the first time, and the CFR system worked efficiently.ConclusionsBy providing information about the CFR system to the community and preparing several infrastructural elements, it was possible to introduce and operate a successful CFR system in Japan.


International Medical Case Reports Journal | 2011

Successful management of aortic thrombi resulting in spinal cord infarction in a patient with antiphospholipid antibody syndrome and acute cholecystitis

Manabu Izumi; Shoko Teraoka; Keisuke Yamashita; Kenji Matsumoto; Tomohiro Muronoi; Yoshimitsu Izawa; Chikara Yonekawa; Masaki Ano; Masayuki Suzukawa

A 74-year-old man with coronary artery disease was suffering from acute nonobstructive cholecystitis and was admitted to a nearby hospital. Dual antiplatelet (aspirin and ticlopidine) therapy was discontinued before preparation for surgical resection of the gall bladder. During his time in hospital he was aware of lumbar pain and weakness in both legs. He was transferred to our hospital for further evaluation and therapy. Diffuse intra-aortic thrombi were revealed by computed tomography with contrast media, and magnetic resonance imaging showed spinal cord infarction. However, computed tomography scans of the descending aorta obtained 4 months before admission exhibited no signs of atherosclerotic plaques or intra-aortic thrombi. Laboratory data suggest that antiphospholipid antibody syndrome might have caused these acute multiple intra-arterial thrombi. By restarting dual antiplatelet therapy and increasing the dose of heparin (from 10,000 IU/day to 15,000 IU/day) we successfully managed the patient’s clinical condition and symptoms. It is important to understand that stopping antiplatelet therapy may rapidly grow thrombi in patients with a hypercoagulative state.


Japanese Journal of Clinical Oncology | 2004

The correlation of microsatellite instability and tumor-infiltrating lymphocytes in hereditary non-polyposis colorectal cancer (HNPCC) and sporadic colorectal cancers: the significance of different types of lymphocyte infiltration.

Nobuyuki Takemoto; Fumio Konishi; Keisuke Yamashita; Masayuki Kojima; Taiji Furukawa; Yasuyuki Miyakura; Kazuhisa Shitoh; Hideo Nagai


Hpb | 2010

Resection of hilar cholangiocarcinoma with left hepatectomy after pre-operative embolization of the proper hepatic artery: HPB

Yoshikazu Yasuda; Peter Nørgaard Larsen; Toshimitsu Ishibashi; Keisuke Yamashita; Hisao Toei


World Journal of Emergency Surgery | 2016

Ex-vivo and live animal models are equally effective training for the management of a penetrating cardiac injury

Yoshimitsu Izawa; Shuji Hishikawa; Tomohiro Muronoi; Keisuke Yamashita; Hiroyuki Maruyama; Masayuki Suzukawa; Alan Kawarai Lefor

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Akihiro Kobayashi

New York City Fire Department

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Yasuharu Yasuda

Kyoto Tachibana University

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