Soki Nishiyama
Hiroshima University
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Publication
Featured researches published by Soki Nishiyama.
Inflammatory Bowel Diseases | 2014
Soki Nishiyama; Shiro Oka; Shinji Tanaka; Nana Hayashi; Ryohei Hayashi; Kenta Nagai; Yoshitaka Ueno; Fumio Shimamoto; Koji Arihiro; Kazuaki Chayama
Background:Colitis-associated cancer/dysplasia is an intestinal tract condition that can affect the life expectancy of patients with ulcerative colitis. It is often difficult to detect neoplastic lesions. This study evaluated whether any endoscopic features are effective for distinguishing colitis-associated cancer/dysplasia from nonneoplastic lesions in patients with ulcerative colitis. Methods:The study involved 52 patients with 61 lesions treated at Hiroshima University Hospital between September 1999 and May 2012: 10 patients with 11 dysplastic lesions, 5 patients with 5 intramucosal carcinomas, 3 patients with 3 submucosal carcinomas, and 34 patients with 42 nonneoplastic lesions. All patients had undergone targeted biopsy. Endoscopic findings were compared between patients with biopsy-determined neoplasia and those with biopsy-determined nonneoplasia. Multivariate regression analysis was performed to identify magnifying chromocolonoscopy features predictive of neoplasia. Results:No significant difference was found in conventional endoscopy features between the neoplastic and nonneoplastic lesions. Under magnifying chromocolonoscopy, the pit density of the neoplastic lesions was found to be significantly greater than that of the nonneoplastic lesions (89% [17/19] versus 60% [25/42], respectively). Pit margins were more frequently irregular in the neoplastic lesions than in the nonneoplastic lesions (63% [12/19] versus 33% [14/42], respectively). Conclusions:In differentiating between colitis-associated neoplastic and nonneoplastic lesions, focus should be on the high residual density of pits and irregular pit margins observed under magnifying chromocolonoscopy.
Endoscopy International Open | 2016
Naoki Asayama; Shiro Oka; Shinji Tanaka; Kyoku Sumimoto; Daiki Hirano; Yuzuru Tamaru; Yuki Ninomiya; Kenjiro Shigita; Nana Hayashi; Soki Nishiyama; Kazuaki Chayama
Background and study aims: Poor endoscope operability remains a significant challenge during colorectal endoscopic submucosal dissection (ESD). We retrospectively evaluated the experience and clinical usefulness of a new single-use splinting tube in deep colonic ESD in the setting of poor scope operability. Patients and methods: Among 691 patients with colorectal tumors treated with ESD at Hiroshima University Hospital between November 2009 and July 2015, we analyzed 20 consecutive patients who underwent deep colonic ESD using a single-use splinting tube because of poor scope operability. Poor operability was defined as paradoxical movement of the endoscope, poor control with adhesions, and lesion motion with heartbeat or breathing. Technical and clinical success rates and adverse events were assessed. Results: Paradoxical movement and poor control with adhesions were improved in all cases using the single-use splinting tube. The en bloc resection rate was 95 % (19/20) and histological en bloc resection rate was 100 % (20/20). There were no complications related to use of the splinting tube. Conclusions: Use of a single-use splinting tube helped to overcome poor scope operability in deep colonic ESD.
Case Reports in Gastroenterology | 2015
Yuzuru Tamaru; Shiro Oka; Shinji Tanaka; Yuki Ninomiya; Naoki Asayama; Kenjiro Shigita; Soki Nishiyama; Nana Hayashi; Koji Arihiro; Kazuaki Chayama
The standard treatment approach for squamous cell carcinoma (SCC) of the anal canal includes abdominoperineal resection and chemoradiotherapy. However, there are currently very few reports of early SCC of the anal canal resected by endoscopic submucosal dissection (ESD). We report 2 rare cases of SCC of the anal canal resected by ESD. In case 1, a 66-year-old woman underwent a colonoscopy due to blood in her stool, and an elevated lesion, 15 mm in size, was identified from the rectum to the dentate line of the anal canal on internal hemorrhoids. The lesion was diagnosed as an early SCC of the anal canal, and ESD was successfully performed. The histopathological diagnosis was SCC in situ. In case 2, a 71-year-old woman underwent a colonoscopy due to constipation, and an elevated lesion, 25 mm in size, was identified from the dentate line to the anal canal. The lesion was diagnosed as early-stage SCC of the anal canal, and ESD was successfully performed. The histopathological diagnosis was SCC in situ. No complications or recurrence after ESD occurred in either case.
Therapeutic Advances in Gastroenterology | 2016
Yuki Ninomiya; Shiro Oka; Shinji Tanaka; Daiki Hirano; Kyoku Sumimoto; Yuzuru Tamaru; Naoki Asayama; Kenjiro Shigita; Soki Nishiyama; Nana Hayashi; Kazuaki Chayama
Background: Dual red imaging (DRI), a novel image-enhanced endoscopic technique, is expected to improve visibility of thin vessels, but no reports of the clinical use of DRI in colorectal endoscopic submucosal dissection (ESD) have been published. We aimed to compare the visibility of vessels, demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine, and fibrosis on DRI with that on white light imaging (WLI). We applied the principle of DRI to the image of the submucosal layer during colorectal ESD as a pilot study. Methods: A total of seven physicians compared 17 DRI images to the corresponding WLI images in colorectal ESD. The physicians compared the number of arteries identified on DRI with the actual number of arteries. The physicians rated the visibility of vessels, the demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine, and fibrosis. Inter-observer agreement was also examined using the kappa statistic. Results: Visibility of vessels and the demarcation line between the submucosal and muscle layers after injection of hyaluronate sodium with minute indigo carmine improved with the use of DRI compared with that using WLI. DRI can discriminate between arteries and veins clearly through the color of the vessels. Conclusions: DRI improves the visibility of vessels, especially that of arteries, as they appear orange, and the demarcation line of the muscle layer. DRI may help to make colorectal ESD safer and faster.
Endoscopy International Open | 2016
Soki Nishiyama; Shiro Oka; Shinji Tanaka; Shintaro Sagami; Ryohei Hayashi; Yoshitaka Ueno; Koji Arihiro; Kazuaki Chayama
Background and study aims: Colitis-associated cancer/dysplasia (CC/D) can affect the life expectancy of patients with ulcerative colitis (UC). Although the utility of magnifying chromocolonoscopy has been shown, the use of optical magnification with narrow band imaging (NBI) for distinguishing CC/D from non-neoplastic lesions in patients with UC has not been reported. We evaluated whether endoscopic findings are distinguishing and thus assessed the clinical usefulness of NBI magnification for differentiating UC-associated lesions. Patients and methods: The study involved 27 patients diagnosed and treated at Hiroshima University Hospital between September 2005 and March 2015: a neoplasia group (16 lesions) and a non-neoplasia group (17 lesions). The neoplasias comprised 9 dysplastic lesions, 5 intramucosal carcinomas, and 2 submucosal carcinomas, and 17 non-neoplastic lesions. Targeted biopsy samples of suspicious lesions detected by conventional colonoscopy were classified pathologically as neoplastic or non-neoplastic, and NBI magnifying colonoscopy findings (i. e., the surface [unclear/regular/irregular/amorphous] and vascular [same as the background mucosa/regular/irregular/avascular] patterns) of the 2 lesion types were compared. Results: Irregular/amorphous surface patterns were significantly more common in neoplastic lesions than in non-neoplastic lesions (81 % [13/16] vs. 18 % [3/17], respectively, P < 0.001). Irregular/avascular vessel pattern tended to be more common in neoplastic lesions (75 % [12/16] vs. 41 % [7/17], respectively). The surface pattern correctly predicted 82 % of neoplastic lesions, and the vessel pattern correctly predicted 67 % of non-neoplastic lesions. The 2 endoscopic findings together correctly predicted 91 % of neoplastic lesions. Conclusion: Surface pattern, determined by magnifying colonoscopy with NBI, is useful for differenting between UC-associated neoplastic and non-neoplastic lesions.
Gastrointestinal Endoscopy | 2013
Nana Hayashi; Shinji Tanaka; Soki Nishiyama; Motomi Terasaki; Koichi Nakadoi; Shiro Oka; Masaharu Yoshihara; Kazuaki Chayama
International Journal of Colorectal Disease | 2014
Motomi Terasaki; Shinji Tanaka; Kenjiro Shigita; Naoki Asayama; Soki Nishiyama; Nana Hayashi; Koichi Nakadoi; Shiro Oka; Kazuaki Chayama
Journal of Gastroenterology | 2015
Yuki Ninomiya; Shiro Oka; Shinji Tanaka; Soki Nishiyama; Yuzuru Tamaru; Naoki Asayama; Kenjiro Shigita; Nana Hayashi; Kazuaki Chayama
International Journal of Colorectal Disease | 2013
Shun-ichiro Ozawa; Shinji Tanaka; Nana Hayashi; Soki Nishiyama; Motomi Terasaki; Koichi Nakadoi; Hiroyuki Kanao; Shiro Oka; Shigeto Yoshida; Kazuaki Chayama
Journal of Gastroenterology | 2015
Soki Nishiyama; Shiro Oka; Shinji Tanaka; Shintaro Sagami; Kenta Nagai; Yoshitaka Ueno; Koji Arihiro; Kazuaki Chayama