Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Gentaro Ishiyama is active.

Publication


Featured researches published by Gentaro Ishiyama.


Digestive Surgery | 2005

A Novel, Easy, and Safe Technique to Repair a Stoma Prolapse Using a Surgical Stapling Device

Fumitake Hata; Shingo Kitagawa; Hidefumi Nishimori; Tomohisa Furuhata; Tetsuhiro Tsuruma; Eiri Ezoe; Gentaro Ishiyama; Keisuke Ohno; Rika Fukui; Yoshiyuki Yanai; Takahiro Yasoshima; Hirata Koichi

A stoma prolapse is one of the late complications and often occurs when the stoma is made in an emergency situation. This complication is not lethal, but causes irritable stoma, skin trouble, and difficulty in stoma care. We herein report the case of a 48-year-old female with an end colostomy that was created as an emergency operation 4 months before. On admission, her colostomy protruded approximately 20 cm from the skin with marked redness, swelling, and erosion; it was impossible to treat manually. We repaired the prolapse successfully in a simple procedure with a Proximate Linear Cutter 100. Briefly, under mild sedation, the instrument was diagonally inserted into the prolapsed stoma and applied twice on both sides. Then, the base of each divided tissue was stapled and cut with the same device. Finally, the prolapse was completely repaired without major bleeding and severe pain. We have applied this novel technique successfully in 5 further cases, and there have been no complications or recurrences. This technique can be performed without spinal or general anesthesia and seems to be a very useful procedure for patients with prolapse of a stoma.


Surgical and Radiologic Anatomy | 2014

Nerves supplying the internal anal sphincter: an immunohistochemical study using donated elderly cadavers

Gentaro Ishiyama; Nobuyuki Hinata; Yusuke Kinugasa; Gen Murakami; Mineko Fujimiya

PurposeNerves serving the internal anal sphincter (NIAS) have been described as the lower rectal branches of the pelvic autonomic nerve plexus. However, their topographical anatomy and fiber components have remained unclear.MethodsUsing histological sections from ten elderly donated cadavers, we investigated the topographical anatomy and composite fibers of the NIAS using immunohistochemistry for S100 protein, neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP) and tyrosine hydroxylase (TH).ResultsAt the 2–3 o’clock position in the lower rectum, the NIAS originated from nerves at the posterolateral corner of the prostate in males or in the lower paracolpium in females. The nerves ran inferiorly along the internal aspect of the levator ani muscle, and joined branches of the myenteric plexus at a level slightly above the epithelial junction. The NIAS contained both nNOS-positive parasympathetic nerve fibers and TH-positive sympathetic fibers, but VIP-positive fibers were few in number.ConclusionsThe origin of the NIAS at the posterolateral corner of the prostate as well as in the lower paracolpium might be sacrificed or damaged during radical prostatectomy or tension-free vaginal tape insertion. Low anterior resection of rectal cancer will most likely render damage to the NIAS because of its intersphincteric course. Although the nerve composition of the NIAS is characterized by a higher proportion of sympathetic nerve fibers than the myenteric plexus in the large intestine, their role is unclear. However, evaluation of sphincteric function after surgery would appear to be difficult because of the complex control mechanism independent of nerve supply.


International Journal of Clinical Oncology | 2009

Clinical compliance with an oral uracil/tegafur (UFT) plus leucovorin (LV) regimen as adjuvant chemotherapy in Japanese colorectal cancer patients

Makoto Meguro; Tomohisa Furuhata; Kenji Okita; Toshihiko Nishidate; Gentaro Ishiyama; Yuji Iwayama; Yasutoshi Kimura; Toru Mizuguchi; Koichi Hirata

BackgroundThe combination of oral uracil/tegafur (UFT) plus leucovorin (LV) is widely accepted as adjuvant chemotherapy for stages II and III of colorectal cancer. However, the clinical compliance of Japanese patients with this regimen has not been clearly elucidated to date.MethodsA total of 40 Japanese outpatients were treated with oral UFT plus LV as adjuvant chemotherapy following colorectal cancer surgery between January 2005 and June 2007. UFT capsules (300–500 mg/body per day) and LV tablets (75 mg/body per day, administered with each dose of UFT) were to be taken for 28 days, followed by 7 days of rest, with this cycle repeated every 35 days for 6 months or until recurrence. The patients were classified into the following three groups based on compliance: the completed group (n = 21), the modified group (n = 12), and the discontinued group (n = 7).ResultsThe UFT doses (mean ± SD) were 267 ± 35 mg/m2 in the completed group, 276 ± 50 mg/m2 in the modified group, and 288 ± 22 mg/m2 in the discontinued group. The UFT dose in the discontinued group tended to be higher than that in the completed group (P = 0.12). The most frequent symptoms of nonhematologic toxicity were appetite loss (45%) and fatigue (45%). There were no hematologic or nonhematologic toxicities of grade 3 or 4.ConclusionThe regimen of oral UFT plus LV produced only low-grade toxicity and was convenient for outpatients. It appears that the initial UFT dose might be associated with the development of toxicity in the oral UFT plus LV regimen.


Nippon Daicho Komonbyo Gakkai Zasshi | 2002

A Resected Case of Pancreatic and Splenic Metastases from Cecal Carcinoma

K. Okada; Y. Kondoh; H. Isizu; S. Osawa; Hiroyuki Masuko; Gentaro Ishiyama


Nippon Daicho Komonbyo Gakkai Zasshi | 2004

Significance of Surgical Treatment for Pulmonary Metastases in Patients who Underwent Resection of Liver Metastases from Colorectal Cancer

Hiroyuki Ishizu; Yukifumi Kondo; Hiroyuki Masuko; Kuniaki Okada; S. Osawa; K. Uemura; R. Yokota; Gentaro Ishiyama


Digestive Surgery | 2010

EDS Society News

Peter Kornprat; Hans-Jörg Mischinger; Kenneth Fearon; Jens Andersen; Seyfettin Köklü; Mehmet Ibis; Herwig Cerwenka; Heinz Bacher; Mehmet Arhan; Kristoffer Lassen; Cornelis H.C. Dejong; Olle Ljungqvist; S.R. Bramhall; Yasemin Özin; Erkan Oymaci; Hans G. Smeenk; Luca Incrocci; Geert Kazemier; Per Hellman; Lucas W. M. Janssen; R. K. J. Simmermacher; Ivo A.M.J. Broeders; Wolfgang Schlosser; Marco Siech; Hans G. Beger; Takatsugu Yamamoto; Takahiro Uenishi; Masao Ogawa; Tsuyoshi Ichikawa; Seikan Hai


World Journal of Gastrointestinal Surgery | 2015

Anal cushion lifting method is a novel radical management strategy for hemorrhoids that does not involve excision or cause postoperative anal complications

Gentaro Ishiyama; Toshihiko Nishidate; Yuji Ishiyama; Akihiko Nishio; Ken Tarumi; Maiko Kawamura; Kenji Okita; Toru Mizuguchi; Mineko Fujimiya; Koichi Hirata


Nippon Daicho Komonbyo Gakkai Zasshi | 2014

Topohistology of the Paravaginal Nerves and Fasciae with Special Reference to Nerves to the Internal Anal Sphincter

Fumitake Hata; Takashi Arakawa; Kuniaki Okada; Hidefumi Nishimori; Shinichiro Ikeda; Manami Yamada; Tomomi Hirama; Tomomi Yajima; Gentaro Ishiyama; Shiniti Abe


Nippon Daicho Komonbyo Gakkai Zasshi | 2011

Treatment of Chronic Anal Fissure -Anal Dilatation-

Ken Tarumi; Yuji Ishiyama; Maiko Kawamura; Gentaro Ishiyama; Akihiko Nishio


Wound Repair and Regeneration | 2005

NonInvasive Approach for Refractory Enterovaginal Fistula

Nishimori Hidefumi; Fumitake Hata; Tomohisa Furuhata; Gentaro Ishiyama; Koichi Hirata

Collaboration


Dive into the Gentaro Ishiyama's collaboration.

Top Co-Authors

Avatar

Fumitake Hata

Sapporo Medical University

View shared research outputs
Top Co-Authors

Avatar

Koichi Hirata

Sapporo Medical University

View shared research outputs
Top Co-Authors

Avatar

Tomohisa Furuhata

Sapporo Medical University

View shared research outputs
Top Co-Authors

Avatar

Hiroyuki Masuko

Memorial Hospital of South Bend

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Heinz Bacher

Medical University of Graz

View shared research outputs
Top Co-Authors

Avatar

Herwig Cerwenka

Medical University of Graz

View shared research outputs
Top Co-Authors

Avatar

Peter Kornprat

Medical University of Graz

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jens Andersen

Karolinska University Hospital

View shared research outputs
Researchain Logo
Decentralizing Knowledge