研究者業績

nishiyama yuya

  (西山 悠也)

Profile Information

Affiliation
School of Medicine Faculty of Medicine, Fujita Health University
Degree
医学博士(藤田保健衛生大学)

J-GLOBAL ID
201601014567541368
researchmap Member ID
7000015628

専門分野
脳腫瘍(良性、悪性)手術
神経内視鏡手術
片側顔面けいれん、三叉神経痛
眼窩内腫瘍


Education

 1

Committee Memberships

 2

Papers

 39
  • Yuya Nishiyama, Mitsuhiro Hasegawa, Yuichi Hirose
    Neurosurgical Review, 49(1), Apr 28, 2026  Peer-reviewedLead author
  • Mitsuhiro Hasegawa, Yuya Nishiyama, Takuro Hayashi, Yuichi Hirose
    Neurologia medico-chirurgica, 66(3) 135-144, Mar 15, 2026  
    This study aimed to develop a new, refined, and easy-to-use microvascular decompression surgical prosthesis and report its processability, uniformity, stability, and clinical safety.In an experimental study, the processing time required to create five slings and five balls from a prototype clump (0.010 ± 0.001 grams) was measured. Similarly, the processing time to form a clump (0.01 ± 0.001 grams) by plucking an equivalent amount of fibers from commercial polytetrafluoroethylene felt was measured. After approval from the Pharmaceuticals and Medical Devices Agency, the new prosthesis was used in 39 consecutive microvascular decompression surgeries.The handling time to make slings and balls from the refined polytetrafluoroethylene material was shorter than that from polytetrafluoroethylene felt (60.5 ± 4.81 versus 155 ± 6.59 seconds, p-value < 0.001 and 84.0 ± 8.51 versus 141.1 ± 7.02 seconds, p-value < 0.001). The tensile study showed that the prototype was significantly stronger than the slings conventionally made from polytetrafluoroethylene felt (6.2 ± 2.12 Newtons versus 1.56 ± 0.647 Newtons, p-value = 0.012). The adhesion study showed an equivalent adhesive strength to the conventional one (0.137 ± 0.05 Newtons versus 0.108 ± 0.05 Newtons, p-value = 0.40). The 39 microvascular decompression surgeries (trigeminal neuralgia, 13 cases; hemifacial spasm, 26 cases) showed no adverse events related to the materials (follow-up period: 9 months-3 years 9 months, mean: 2 years 9 months).The new Pharmaceuticals and Medical Devices Agency-approved, refined polytetrafluoroethylene material, which is easier to handle and less time-consuming, exhibited uniform characteristics, excellent manipulability, sufficient strength, and clinical reliability for prostheses. It may serve as a valuable additional option for prostheses in microvascular decompression surgery.
  • Daijiro Kojima, Shigeo Ohba, Yuya Nishiyama, Kazuhide Adachi, Madoka Isomura, Yuka Kondo, Mayu Takeda, Seiji Yamada, Jun Muto, Eiji Sugihra, Sachiko Minamiguchi, Kenji Kawada, Hideyuki Saya, Yuichi Hirose
    Clinical neurology and neurosurgery, 265 109371-109371, Mar 2, 2026  
    OBJECTIVE: Central nervous system (CNS) solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms with a high propensity for local recurrence and extracranial metastasis. Although surgery and radiotherapy are the mainstays of treatment, systemic therapeutic options for recurrent disease remain limited. Pazopanib, a multitargeted tyrosine kinase inhibitor, has demonstrated clinical activity in extracranial SFTs; however, evidence in CNS SFTs is scarce. METHODS: We conducted a retrospective, single-institution study of patients with recurrent CNS SFTs treated with pazopanib. Clinical data, including prior treatments, imaging responses, treatment duration, and adverse events, were collected from medical records. Exploratory next-generation sequencing-based cancer panel testing was performed in two patients. RESULTS: Four patients with recurrent CNS SFTs were included. All had undergone prior surgical resection and radiotherapy. Pazopanib achieved partial response in one patient and stable disease in three patients, with treatment durations ranging from 7 months to over 2 years. One patient experienced disease progression after an initial period of response. Adverse events, including fatigue, gastrointestinal symptoms, and hypertension, were observed in all patients but were generally manageable with supportive care or dose adjustment. Exploratory molecular profiling identified various genomic alterations in two patients. CONCLUSIONS: In this single-institution retrospective series, pazopanib provided durable disease control with acceptable tolerability in selected patients with recurrent CNS SFTs. These findings support considering pazopanib as a systemic treatment option when further local therapies are not feasible, while highlighting the need for larger multicenter studies.
  • Shigeo Ohba, Takao Teranishi, Kazuyasu Matsumura, Masanobu Kumon, Daijiro Kojima, Eiji Fujiwara, Kazutaka Nakao, Kiyonori Kuwahara, Kazuhiro Murayama, Eriel Sandika Pareira, Seiji Yamada, Masahiro Joko, Shunsuke Nakae, Jun Muto, Yuya Nishiyama, Kazuhide Adachi, Hikaru Sasaki, Masato Abe, Mitsuhiro Hasegawa, Yuichi Hirose
    Scientific Reports, 15(1), Jan 11, 2025  
  • 大場 茂生, 須藤 保, 杉原 英志, 山田 勢至, 西山 悠也, 安達 一英, 河田 健司, 安部 雅人, 佐谷 秀行, 廣瀬 雄一
    Brain Tumor Pathology, 41(Suppl.) 100-100, May, 2024  

Misc.

 128

Presentations

 50