Updated on 2025/04/07

写真a

 
NISHIHORI Masahiro
 
Organization
Nagoya University Hospital Neurosurgery Assistant Professor of Hospital
Title
Assistant Professor of Hospital
Contact information
メールアドレス
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Degree 1

  1. Ph.D. ( 2021.9   Nagoya University ) 

Research Interests 12

  1. 脳動脈瘤

  2. 硬膜動静脈瘻

  3. 医用画像処理

  4. 脳血管内治療

  5. carotid stenosis

  6. 脳血管内治療

  7. 脳卒中の外科

  8. stroke

  9. brain AVM

  10. brain aneurysm

  11. dural AVF

  12. mechanical thrombectomy

Research Areas 2

  1. Life Science / Neurosurgery

  2. Life Science / Neurosurgery

Research History 2

  1. Nagoya University   Nagoya University Hospital Neurosurgery   Assistant Professor of Hospital

    2016.3

  2. Nagoya University   Nagoya University Hospital Neurosurgery   Assistant Professor of Hospital

    2016.3

Education 2

  1. Nagoya University

    2013.4 - 2016.2

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    Country: Japan

  2. Nagoya University   Faculty of Medicine

    2002.4 - 2008.3

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    Country: Japan

Professional Memberships 12

  1. 日本脳神経外科学会

  2. 日本脳神経血管内治療学会

  3. 日本脳卒中学会

  4. 日本脳卒中の外科学会

  5. 日本脳神経CI学会

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Committee Memberships 9

  1. 第49回日本脳卒中学会学術集会   プログラム委員  

    2023.4 - 2024.3   

  2. 第39回NPO法人日本脳神経血管内治療学会学術集会   プログラム委員  

    2023.1 - 2023.11   

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    Committee type:Academic society

  3. Stroke2023   program member  

    2022.4 - 2023.3   

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    Committee type:Academic society

  4. 第38回NPO法人日本脳神経血管内治療学会学術集会   プログラム委員  

    2022.1 - 2022.11   

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    Committee type:Academic society

  5. CSNET   secretary-general  

    2021.12   

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    Committee type:Academic society

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Papers 101

  1. Superselective Angiography of Vasa Vasorum Within Partially Thrombosed Vertebral Aneurysm: A Case Report

    Kawasaki, Y; Izumi, T; Nishihori, M; Goto, S; Araki, Y; Yokoyama, K; Saito, R

    NEUROSURGERY   Vol. 96 ( 3 ) page: e52 - e57   2025.3

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    Language:English   Publisher:Neurosurgery  

    BACKGROUND AND IMPORTANCE:Partially thrombosed vertebral artery aneurysms (PTVAs) are rare, most of which are not easy to treat. Furthermore, endovascular treatment of PTVAs may not have favorable outcomes. The relationship between PTVAs and well-developed vasa vasorum (VV), including the mechanism of aneurysm growth, has been reported, but there are no reports of imaging findings by digital subtraction angiography (DSA). In this case, we successfully performed superselective angiography of well-developed VV and evaluated its imaging characteristics. We present the first DSA report of a well-developed VV of PTVA.CLINICAL PRESENTATION:A 54-year-old patient presented with a PTVA that exerted a mass effect on the medulla oblongata. The aneurysm had no cavity due to thrombosis. The 3-dimensional DSA images indicated VV. Superselective angiography of the VV indicated staining of the thrombosed aneurysm and draining into the suboccipital cavernous sinus through the venous VV. Thus, VV embolization with n-butyl cyanoacrylate was performed. After 3 months, the contrast effect of the aneurysm on contrast-enhanced magnetic resonance imaging disappeared and aneurysm shrinkage was observed.CONCLUSION:We successfully identified a VV within PTVA. Superselective VV angiography showed staining of the thrombosed component and venous return draining into the suboccipital cavernous sinus. In this case, the embolization of the VV proved to be an effective endovascular treatment of PTVA, but the safety of this method is a challenge. Further case studies are required to validate this method, and we hope it will evolve into a new treatment of PTVA.

    DOI: 10.1227/neu.0000000000003115

    Web of Science

    Scopus

    PubMed

  2. Postoperative fragmentation and distal migration of Carotid Stent in vascular Eagle Syndrome Open Access

    Masahiro Nishihori, Takashi Izumi, Shunsaku Goto, Shinsuke Muraoka, Hirotaka Kogame, Ryuta Saito

    Journal of Stroke and Cerebrovascular Diseases   Vol. 34 ( 2 ) page: 108202   2025.2

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jstrokecerebrovasdis.2024.108202

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  3. Regression of bilateral persistent primitive ophthalmic artery: a case report Open Access

    Takeuchi, I; Izumi, T; Nishihori, M; Goto, S; Hanyu, T; Suzuki, K; Takayanagi, K; Kawasaki, Y; Saito, R

    SURGICAL AND RADIOLOGIC ANATOMY   Vol. 47 ( 1 ) page: 42   2024.12

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    Language:English   Publisher:Surgical and Radiologic Anatomy  

    Purpose: We report a case of regression of a 2-year-old girl with bilateral primitive ophthalmic arteries (POAs). Case report: The patient presented with a headache and had no visual impairment or visual field abnormalities. Magnetic resonance angiography (MRA) revealed arteries originating bilaterally from the cavernous internal carotid artery segments, diagnosed as persistent POAs. Conclusion: Six months later, MRA revealed decreased origin delineation and five years later, MRA revealed bilateral origin disappearance from the orbit to the periphery.

    DOI: 10.1007/s00276-024-03522-7

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    Web of Science

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  4. Three-dimensional spiral-shaping method of microcatheter for paraclinoid aneurysms: assessment using silicone models Open Access

    Imaoka, E; Nishihori, M; Izumi, T; Goto, S; Araki, Y; Yokoyama, K; Uda, K; Kanamori, F; Saito, R

    NAGOYA JOURNAL OF MEDICAL SCIENCE   Vol. 86 ( 4 ) page: 655 - 664   2024.11

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    Language:English   Publisher:Nagoya Journal of Medical Science  

    Selecting an appropriate microcatheter tip shape for paraclinoid aneurysms is difficult. Therefore, we devised an original simple and uniform three-dimensional (3D) spiral-shaping method of microcatheter and validated the characteristics and usefulness of this method for coil embolization of paraclinoid aneurysms using patient-specific silicone models. These silicone models were produced based on clinical data from four patients with four paraclinoid aneurysms that underwent endovascular treatment using the 3D spiral-shaping method. These models were classified into four types: superior, medial, inferior, and lateral corresponding to the aneurysm protrusion and locations (C3 or C2 segments by Fisher’s classification). Employing a pulsatile pump setup, two operators assessed the following items: navigation methods (pull and wire guiding), catheterization times, microcatheter tip position in the aneurysm, and the feasibility of inserting a framing coil by simple technique compared with three other shapes (straight, 90, pigtail). Three-dimensional spiral-shaped microcatheter could be placed in the medial and inferior type models of C3 segments and superior type model of C2 segment by the pullback method. Catheterization times using a 3D spiral-shaped catheter were significantly shorter than other shaped ones in the superior type models. No significant difference was found in another silicone model. Three-dimensional spiral- and pigtail-shaped catheters tended to position the tip at the center of the aneurysm. In conclusion, 3D spiral-shaped microcatheter was especially effective for the superior projected aneurysm at the C2 segment. The 3D spiral-shaping method can provide easy and secure navigation of the microcatheter into the paraclinoid aneurysms, ensuring optimal positioning for coil insertion.

    DOI: 10.18999/nagjms.86.4.655

    Open Access

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  5. Efficacy and safety of endovascular coil embolization for unruptured middle cerebral artery aneurysms: middle-term clinical and imaging outcomes with 3 years mean follow-up periods, a 16-year experience Open Access

    Hanyu, T; Izumi, T; Tanei, T; Nishihori, M; Goto, S; Araki, Y; Yokoyama, K; Miyachi, S; Saito, R

    NAGOYA JOURNAL OF MEDICAL SCIENCE   Vol. 86 ( 4 ) page: 596 - 607   2024.11

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    Language:English   Publisher:Nagoya Journal of Medical Science  

    The anatomical characteristics of middle cerebral artery aneurysms make endovascular treatment difficult. This study evaluated the efficacy and safety of endovascular treatment of unruptured middle cerebral artery aneurysm in preventing rupture. A retrospective review of patients who underwent coil embolization for unruptured middle cerebral artery aneurysm between 2006 and 2022 at Nagoya University Hospital with at least 12 months followed up was conducted. Imaging and clinical outcomes were described using the Raymond classification and the modified Rankin Scale, respectively. Good imaging outcome was defined as complete occlusion or neck remnant and clinical outcome as modified Rankin Scale score of 0–2. Patients were divided into initial and recurrent group based on the number of treatments, pre- and post-stent groups based on when stents became available in Japan. A total of 77 patients (80 with aneurysms) were included in the final analysis. Their average age was 60.3 years, and their average follow-up period was 38 months. Favorable clinical outcomes were achieved for 96.2% among 66 (97.0%) initial and 11 (91.7%) recurrent aneurysms. Furthermore, good imaging outcomes were obtained in 90.0 %, and 5% had permanent symptomatic ischemic complications. The pre-stent group had a significantly higher proportion of patients with narrow-neck aneurysms than the post-stent group. There were no significant differences in terms of imaging and clinical outcomes or complication rates. The present study demonstrated that endovascular treatment of unruptured middle cerebral artery aneurysm was safe and effective in preventing rupture. The wide-neck aneurysm was also well embolized by using adjunctive technique.

    DOI: 10.18999/nagjms.86.4.596

    Open Access

    Web of Science

    Scopus

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Books 1

  1. Use of embolization for the treatment of dural arteriovenous fistula

    Izumi T., Nishihori M., Tsukada T., Araki Y., Uda K., Yokoyama K.

    Arteriovenous Malformations of the Brain  2020.5  ( ISBN:9781536178920

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    Dural arteriovenous fistula (DAVF) is a relatively rare disease, and often develops pulsatile tinnitus. When accompanied by cerebral cortical venous reflux, patients may present with local neurological symptoms. Recently, transarterial embolization using Onyx is often the first-choice treatment for the patients with DAVF. Transvenous embolization for the affected sinus using platinum coils or liquid embolic material, is applied for cavernous sinus DAVF or transverse sinus/sigmoid sinus dural arteriovenous fistula (Borden type II). Since anatomical knowledge required for embolization is not required in the general practice of treating endovascular diseases, physicians treating dAVF must learn the anatomy of the arteries and veins of the head to increase the safety of embolization.

    Scopus

MISC 11

  1. Rare Dilated Collateral Circulation from Accessory Meningeal Artery to Inferolateral Trunk: A Case Report

    IKEZAWA Mizuka, MAEDA Kenko, TAKASU Syuntaro, TAKEMOTO Masaya, NISHIHORI Masahiro, CHOO Jungsu, SAGO Fumihiro, SOMIYA Daiki, DOBA Kohei, IKEDA Akira

    NMC Case Report Journal   Vol. 10 ( 0 ) page: 47 - 50   2023

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    Language:English   Publisher:The Japan Neurosurgical Society  

    <p>The accessory meningeal artery (AMA) demonstrates various potential anastomoses with the external (ECA) and internal (ICA) carotid arteries. However, rarely does the AMA markedly dilate and compensate for ICA blood flow. A 52-year-old woman with nonspecific symptoms was diagnosed with multiple cerebral aneurysms and abnormal blood vessels observed on magnetic resonance angiography. Digital subtraction angiography revealed four aneurysms and anastomoses between the left AMA and inferolateral trunk (ILT). In addition, two sequential severe flexions were observed in the cervical portion of the left ICA. No ischemic lesions were detected on magnetic resonance imaging. In conclusion, we experienced a rare case in which the AMA-ILT anastomosis was highly developed. This case also presented with the unusual characteristics of an anomaly in the extracranial ICA and multiple aneurysms.</p>

    DOI: 10.2176/jns-nmc.2022-0308

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  2. Sacral arteriovenous fistula with lower thoracic cord edema without perimedullary vein enlargement.

    Ishii M, Nishimura Y, Nagashima Y, Tanei T, Nishihori M, Izumi T, Saito R

    Surgical neurology international   Vol. 14   page: 295   2023

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    Language:English   Publisher:Surgical Neurology International  

    Background: Sacral dural arteriovenous fistulas (AVFs) are often undiagnosed at the initial presentation due to their rarity. Case Description: For 1 year, a 71-year-old man developed progressive motor and sensory disturbances in both legs. Magnetic resonance imaging showed spinal cord edema with mild contrast enhancement at the T9–10 and T12 levels. Although mild venous dilatation was observed only at the cauda equina level, it was not initially recognized as abnormal. Blood and cerebrospinal fluid tests and spinal angiography of the lower thoracic to upper lumbar levels were nonspecific. The patient was unsuccessfully treated with three courses of high-dose intravenous methylprednisolone. Ultimately, following repeat spinal angiography (i.e., including the bilateral internal iliac arteries) that revealed a low-flow sacral dural AVF supplied by the right lateral sacral artery, the patient underwent successful surgical venous AVF occlusion/transection. Conclusion: In cases of spinal cord edema without perimedullary abnormal flow voids, careful spinal angiography including the sacral spine is necessary even if only minimal venous dilation is initially observed at the cauda equina level.

    DOI: 10.25259/SNI_606_2023

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  3. Dural Arteriovenous Fistula Mimicking a Brain Tumor on Methionine-positron Emission Tomography: A Case Report

    HANYU Taketo, NISHIHORI Masahiro, IZUMI Takashi, MOTOMURA Kazuya, OHKA Fumiharu, GOTO Shunsaku, ARAKI Yoshio, YOKOYAMA Kinya, UDA Kenji, SAITO Ryuta

    NMC Case Report Journal   Vol. 9 ( 0 ) page: 289 - 294   2022

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    Language:English   Publisher:The Japan Neurosurgical Society  

    <p>In this article, we report a case wherein a brain tumor was suspected based on computed tomography and magnetic resonance imaging findings. We made an initial diagnosis of malignant brain tumor based on methionine-positron emission tomography (PET) findings, but the correct diagnosis was dural arteriovenous fistula (DAVF). The patient was a 45-year-old man with DAVF who developed headache. Methionine-PET imaging showed high methionine uptake in the lesion. Although the tumor was strongly suspected from the findings of methionine-PET, the diagnosis of DAVF could be made correctly only by interpreting digital subtraction angiography and computed tomographic angiography. The findings of methionine-PET, which is considered useful in the diagnosis and denial of brain tumors, made the diagnosis of DAVF more difficult. The increased uptake of methionine-PET in DAVF is an important finding because, to our knowledge, this study is the first to report such finding. The results of this study might be useful for differential diagnoses when the diagnosis is uncertain.</p>

    DOI: 10.2176/jns-nmc.2022-0055

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  4. Anterior Communicating Artery Aneurysm with a Peculiar Angiographic Appearance: A Case Study

    OTAWA Masato, IZUMI Takashi, NISHIHORI Masahiro, TSUKADA Tetsuya, OSHIMA Ryosuke, KAWAGUCHI Tomomi, GOTO Shunsaku, IKEZAWA Mizuka, KROPP Asuka Elisabeth, WAKABAYASHI Toshihiko

    NMC Case Report Journal   Vol. 8 ( 1 ) page: 57 - 61   2021.4

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    Language:English   Publisher:The Japan Neurosurgical Society  

    <p>We describe a case of pulsatile anterior communicating artery aneurysm (A-com AN) with a peculiar angiographic appearance. An 81-year-old man was referred to the department of neurosurgery for a large A-com AN artery aneurysm, which was detected incidentally. The patient hoped not to be treated but to be followed up. After 4 months, magnetic resonance imaging (MRI) revealed the presence of a cerebral edema and hematoma around the aneurysm, and partial thrombus in the upper wall of the aneurysm was suspected. Based on these findings, the patient underwent an immediate coil embolization a day after admission. However, the portion of the neck remnant increased in size after the first procedure. Therefore, 8 months after the initial procedure, he was treated with stent coil embolization. Contrary to the first procedure, angiographic evaluation revealed an active pulsating aneurysm. Moreover, MRI revealed the presence of a partial thrombus in the upper neck segment of the aneurysm, with an intensity that changed over time. The patient underwent cautious treatment and was discharged without any symptoms. This is the first case study to reveal an A-com AN with active pulsation and the relationship between the pulsatile portion of the aneurysm and thrombosed portion by MRI.</p>

    DOI: 10.2176/nmccrj.cr.2020-0036

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  5. Management of Asymptomatic Vertebral Artery Injury Caused by a Cervical Pedicle Screw Malposition: Two Case Reports

    OTSUKA Takafumi, IZUMI Takashi, NISHIHORI Masahiro, TSUKADA Tetsuya, ARAKI Yoshio, YOKOYAMA Kinya, UDA Kenji, GOTO Shunsaku, IKEZAWA Mizuka, KATO Naoki, NAKANO Mizuki, SAITO Ryuta

    NMC Case Report Journal   Vol. 8 ( 1 ) page: 713 - 717   2021

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    Language:English   Publisher:The Japan Neurosurgical Society  

    <p>Iatrogenic vertebral artery (VA) injury in cervical fusion is an extremely rare complication but can lead to serious sequelae. We present two successful cases of internal trapping for preventing delayed-onset ischemic stroke after iatrogenic VA stenosis caused by a cervical pedicle screw. A 34-year-old female underwent posterior cervical fusion for C4/C5 dislocation fracture. No neurological deficits were observed after the operation. However, the postoperative images revealed that the left C5 pedicle screw perforated the transverse foramen, and the left VA was suspected to be occluded at the screw insertion site. Before revision surgery, we tried to embolize the injured VA with coils. A microcatheter could be navigated from the ipsilateral VA to the distal of the screw, and internal trapping was performed with coils. Another case is that of a 50-year-old male with cervical spondylosis, who underwent posterior decompression and cervical fusion. The neurological symptoms did not deteriorate after the operation. However, the postoperative computed tomography images revealed the perforation of the right C3 transverse foramen by the pedicle screw. In right vertebral angiography, about 70% stenosis was observed at the screw insertion site. Although revision surgery was not planned due to good stability, we embolized the right VA after balloon occlusion test, to prevent the delayed-onset thromboembolic complications. Both the patients recovered without any neurological deficits. Iatrogenic VA injuries, even if asymptomatic immediately after surgery, can lead to serious sequelae in case of delayed-onset ischemic stroke. Therefore, careful attention should be paid when the screw perforates the transverse foramen.</p>

    DOI: 10.2176/nmccrj.cr.2021-0062

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Presentations 7

  1. コイル塞栓術の治療戦略とコイル選択

    西堀正洋、泉孝嗣、塚田哲也

    第36回日本脳神経血管内治療学会学術総会  2020.11.19 

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    Event date: 2020.11

    Language:Japanese   Presentation type:Public lecture, seminar, tutorial, course, or other speech  

    Venue:京都   Country:Japan  

  2. フローダイバーターステントの術後長期経過における動脈瘤収縮に関連する因子の解析  

    西堀正洋、泉孝嗣、塚田哲也、池澤瑞香、後藤峻作、大塚崇史、加藤直毅、中野瑞生、クロップ明日香、若林俊彦

    第36回日本脳神経血管内治療学会学術総会  2020.11.19 

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    Event date: 2020.11

    Language:Japanese   Presentation type:Symposium, workshop panel (public)  

    Venue:京都   Country:Japan  

  3. 不安定プラークはCASハイリスクか? Invited

    西堀正洋、泉孝嗣、塚田哲也、池澤瑞香、後藤峻作、大塚崇史、加藤直毅、中野瑞生、クロップ明日香、若林俊彦

    第36回日本脳神経血管内治療学会学術総会  2020.11.19 

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    Event date: 2020.11

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:京都  

  4. 頸動脈ステント留置術 (CAS) feel the difference Invited

    西堀正洋、泉孝嗣、塚田哲也

    第36回日本脳神経血管内治療学会学術総会  2020.11.19 

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    Event date: 2020.11

    Language:Japanese   Presentation type:Public lecture, seminar, tutorial, course, or other speech  

    Venue:京都   Country:Japan  

  5. フローダイバーターステントの術後長期経過における動脈瘤収縮に関連する因子の解析  

    西堀正洋、泉孝嗣、塚田哲也、池澤瑞香、後藤峻作、大塚崇史、加藤直毅、中野瑞生、クロップ明日香、若林俊彦

    第79回日本脳神経外科学会総会  2020.10.15 

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    Event date: 2020.10

    Language:Japanese   Presentation type:Symposium, workshop panel (public)  

    Venue:第79回日本脳神経外科学会総会   Country:Japan  

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KAKENHI (Grants-in-Aid for Scientific Research) 1

  1. Sexual hormone concentration measurement in intracranial dural arteriovenous fistulas

    Grant number:18K16580  2018.4 - 2022.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Early-Career Scientists

    Nishihori Masahiro

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    Authorship:Principal investigator  Grant type:Competitive

    Grant amount:\1950000 ( Direct Cost: \1500000 、 Indirect Cost:\450000 )

    Dural arteriovenous fistula is a rare intracranial shunt disease that occurs at various intracranial sites, with differences between men and women at each location. The cavernous sinus (CS) is more than twice as likely to be involved in women than in men. Although trauma, inflammation, and other factors are contributing factors, the cavernous sinus is in contact with the pituitary gland. It is thought to be affected by sex hormones. Blood samples were collected from 25 patients, and sex hormone levels were measured at each site. There were significant differences in E2 and LH between the internal jugular vein and peripheral areas. E2 was also significantly different between the CS and transverse sinus (TS) groups. The internal jugular vein area was significantly higher than the peripheral blood in the CS group. For LH, there was an overall significant increase in blood drawn in the internal jugular vein compared to peripheral in women.

 

Teaching Experience (On-campus) 3

  1. 血管吻合実習

    2020

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    クリニカルシュミレーションセンターにて血管吻合実習を行なう

  2. 脳新規外科 脳血管内治療・画像講義

    2020

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    血管撮影室において、脳血管内治療・脳卒中画像の講義を行なう

  3. PBLチュートリアル

    2020

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    症例ベースでの問題解決型チュートリアル授業

 

Academic Activities 1

  1. The 46th congress of japanese stroke society

    Role(s):Peer review

    2021.3

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    Type:Academic society, research group, etc.