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Dive into the research topics where Yasutaka Hayama is active.

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Featured researches published by Yasutaka Hayama.


Digestive Endoscopy | 2010

CLINICAL EVALUATION OF EMERGENCY ENDOSCOPIC HEMOSTASIS WITH BIPOLAR FORCEPS IN NON‐VARICEAL UPPER GASTROINTESTINAL BLEEDING

Mikinori Kataoka; Takashi Kawai; Kenji Yagi; Chizuko Tachibana; Hiroyuki Tachibana; Hiroko Sugimoto; Yasutaka Hayama; Kei Yamamoto; Masaya Nonaka; Takaya Aoki; Toshihiro Oshima; Mari Fujiwara; Mari Fukuzawa; Masakatsu Fukuzawa; Kouhei Kawakami; Yoshihiro Sakai; Fuminori Moriyasu

The present study was designed to evaluate the usefulness and safety of bipolar hemostatic forceps, known as a less invasive and highly safe means of thermal coagulation used for hemostasis in cases of non‐variceal upper gastrointestinal bleeding. This technique of bipolar forceps is simple, safe and unlikely to induce complications, and is therefore promising as a new technique of endoscopic hemostasis. The study involved 39 cases where hemostasis was attempted with bipolar forceps to deal with non‐variceal upper gastrointestinal bleeding, including 28 cases of gastric ulcer, six cases of duodenal ulcer, three cases of bleeding after endoscopic submucosal dissection (ESD), one case of Mallory‐Weiss syndrome and one case of postoperative bleeding from the anastomosed area. There were 34 males and five females, with a mean age of 63.6 years. Bipolar forceps were the first‐line means of hemostasis in cases of oozing bleeding (venous bleeding), pulsatile or spurting bleeding (arterial bleeding) and exposed vessels without active bleeding. The primary hemostasis success rate was 92.3%, and the re‐bleeding rate was 0%. In cases where the bleeding site was located along the tangential line or in cases where large respiration‐caused motions hampered identification of the bleeding site, hemostasis by means of coagulation was easily effected by application of electricity while the forceps were kept open and compressed the bleeding area. In addition, there were no complications. This technique of bipolar forceps is simple, safe and unlikely to induce complications, and is therefore promising as a new technique of endoscopic hemostasis.


Journal of Gastroenterology and Hepatology | 2012

Narrow‐band imaging on screening of esophageal lesions using an ultrathin transnasal endoscopy

Takashi Kawai; Yu Takagi; Kei Yamamoto; Yasutaka Hayama; Mari Fukuzawa; Kenji Yagi; Masakatsu Fukuzawa; Mikinori Kataoka; Kohei Kawakami; Takao Itoi; Fuminori Moriyasu; Jun Matsubayashi; Toshitaka Nagao

Background and Aim:  Ultrathin transnasal endoscopy, used extensively in Japan, is considered to have inferior image quality and suction performance, and questionable diagnostic performance. So the aim of the present study was to compare the diagnostic performance of white light (WL) examination and non‐magnified narrow‐band imaging (NBI) examination in screening for esophageal disorders with ultrathin transnasal endoscopy.


Digestive Endoscopy | 2013

Mucosal cutting biopsy technique for histological diagnosis of suspected gastrointestinal stromal tumors of the stomach

Mikinori Kataoka; Takashi Kawai; Kenji Yagi; Hiroko Sugimoto; Kei Yamamoto; Yasutaka Hayama; Masaya Nonaka; Takaya Aoki; Masakatsu Fukuzawa; Mari Fukuzawa; Takao Itoi; Fuminori Moriyasu

The Japanese Gastrointestinal Stromal Tumor (GIST) therapeutic guidelines recommend endoscopic ultrasound‐guided fine‐needle aspiration biopsy for histological diagnosis. However, before 2010, this technique was only carried out at a minority of medical institutions in Japan. In the present study, we investigated the usefulness of mucosal cutting biopsy.


Surgical Endoscopy and Other Interventional Techniques | 2013

Comparison of hemostasis using bipolar hemostatic forceps with hemostasis by endoscopic hemoclipping for nonvariceal upper gastrointestinal bleeding in a prospective non-randomized trial

Mikinori Kataoka; Takashi Kawai; Yasutaka Hayama; Kei Yamamoto; Masaya Nonaka; Takaya Aoki; Kenji Yagi; Mari Fukuzawa; Masakatsu Fukuzawa; Fuminori Moriyasu


Pediatric Dermatology | 2010

A Case of Ischemic Entelitis in Young Age

Junichi Uematsu; Takashi Kawai; Kei Yamamoto; Mari Fukuzawa; Tetsuya Yamagishi; Hiroyuki Tachibana; Yasutaka Hayama; Masaya Nonaka; Kenji Yagi; Masakatsu Fukuzawa; Mikinori Kataoka; Kouhei Kawakami; Yoshihiro Sakai; Fuminori Moriyasu


Pediatric Dermatology | 2012

A myelodysplastic syndrome with early gastric cancer and early colon cancer : case report

Chika Kusano; Takuji Gotoda; Syuntaro Mukai; Yasuo Yamanaka; Akio Sugita; Masakatsu Fukuzawa; Mari Fukuzawa; Kenji Yagi; Yasutaka Hayama; Masaya Nonaka; Ayako Sugimoto; Yuichiro Tsuji; Mami Takeuchi; Shin Kono; Takashi Kawai; Fuminori Moriyasu


Pediatric Dermatology | 2009

A case of small cell carcinoma of the stomach which was effected by chemotherapy

Hiroko Sugimoto; Mikinori Kataoka; Takashi Kawai; Masaya Nonaka; Asuka Harada; Sakiko Tsukamoto; Hiroyuki Tachibana; Kei Yamamoto; Yasutaka Hayama; Kenji Yagi; Mari Fukuzawa; Mari Fujiwara; Masakatsu Fukuzawa; Kouhei Kawakami; Yoshihiro Sakai; Fuminori Moriya


Pediatric Dermatology | 2008

Clinical outcome of endoscopic treatment of colorectal tumor larger than 20mm.─EMR/EPMR vs. ESD─

Masakatsu Fukuzawa; Satoru Taira; Mikinori Kataoka; Rie Takeshita; Chizuko Manabe; Tachibana Hiroyuki; Fumihiko Yanagisawa; Masaya Nonaka; Yasutaka Hayama; Kei Yamamoto; Takaya Aoki; Kenji Yagi; Toshihiro Oshima; Mari Fukuzawa; Kohei Kawakami; Takashi Kawai; Yoshihiro Sakai; Fuminori Moriyasu


Gastrointestinal Endoscopy | 2008

Can Magnification Narrow-Band Imaging (NBI) Colonoscopy Determine Invasion Depth of Early Colorectal Cancer? - A Prospective Study -

Masakatsu Fukuzawa; Satoru Taira; Yutaka Saito; Takahisa Matsuda; Hiroko Hara; Chizuko Manabe; Hiroyuki Tachibana; Fumihiko Yanagisawa; Masaya Nonaka; Yasutaka Hayama; Kenji Yagi; Toshihiro Oshima; Mari Ko; Mikinori Kataoka; Kohei Kawakami; Takao Itoi; Takashi Kawai; Yoshihiro Sakai; Fuminori Moriyasu


Gastrointestinal Endoscopy | 2008

Feasibility and Safety of Endoscopic Submucosal Dissection (ESD) for Treatment of Colorectal Tumors and Effectiveness of Measures to Prevent Complications. -Compared to Therapeutic Results from Gastric ESD-

Masakatsu Fukuzawa; Satoru Taira; Mikinori Kataoka; Hiroko Hara; Chizuko Manabe; Fumihiko Yanagisawa; Hiroyuki Tachibana; Masaya Nonaka; Yasutaka Hayama; Kenji Yagi; Toshihiro Oshima; Mari Ko; Kohei Kawakami; Takao Itoi; Takashi Kawai; Yoshihiro Sakai; Fuminori Moriyasu

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Kenji Yagi

Tokyo Medical University

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Takashi Kawai

Tokyo Medical University

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Masaya Nonaka

Tokyo Medical University

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Mari Fukuzawa

Tokyo Medical University

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Kei Yamamoto

Tokyo Medical University

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Kohei Kawakami

Tokyo Medical University

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