Nishimoto, Masaaki

写真a

Affiliation

School of Medicine, Department of Neurosurgery (Shinanomachi)

Position

Instructor
Page Top ▲
 

Papers 【 Display / hide 】

  • A Case of Aggressive Recurrent Intracranial Subdural Hematoma Associated with Angiosarcoma Originating from the Skull

    Kanazawa T., Miwa T., Akiyama T., Ohara K., Kosugi K., Nishimoto M., Yoshida K.

    World Neurosurgery (World Neurosurgery)  126   120 - 123 2019.06

    ISSN  18788750

    　View Summary

    © 2019 Elsevier Inc. Background: Angiosarcoma often arises as a cutaneous disease in the scalp and the face; however, subdural hematoma (SDH) associated with angiosarcoma is extremely rare. Case Description: A 72-year-old woman visited our hospital with gait disorder and progressive consciousness disturbance approximately 3 months after a minor head injury. Initially, on reviewing the results of imaging studies, she was diagnosed with traumatic chronic SDH. Despite repeated operations thereafter, including the embolization of the middle meningeal artery, her general condition progressively worsened, and computed tomography of head repeatedly showed the recurrence of SDH. Based on histopathologic and intraoperative findings, she was finally diagnosed with angiosarcoma originating from the skull. She died shortly thereafter because of aggressive recurrent intracranial SDH caused by leptomeningeal dissemination. Conclusions: In addition to cancers metastatic to the skull or dura mater, angiosarcoma should be included in the differential diagnosis for patients with repeated SDH and bone defect. An effective treatment for angiosarcoma with SDH that shows an unfavorable prognosis has not been established; however, an early diagnosis might be useful for a novel treatment.

  • Usefulness of Intraoperative Imaging in a Patient with a Ruptured Aneurysm of the M4 Segment of the Middle Cerebral Artery

    Sasao R., Takahashi S., Nishimoto M., Yoshida K.

    World Neurosurgery (World Neurosurgery)  120   90 - 95 2018.12

    ISSN  18788750

    　View Summary

    © 2018 Elsevier Inc. Background: Treating cerebral aneurysms in the M4 segment of the middle cerebral artery (MCA) is challenging because they are small and are buried in the brain parenchyma. Case Description: A right-handed Asian woman in her 80s was referred to our hospital with a chief complaint of altered level of consciousness. On admission, her consciousness level on the Glasgow Coma Scale was 7 (E1V1M5), and a computed tomography (CT) scan showed subarachnoid hemorrhage with intracerebral hematoma in the left temporal lobe. Subsequent 3-dimensional CT angiography showed an aneurysm in the M4 segment of the left MCA. The aneurysm of the patient was clipped safely and effectively because of the navigation system in combination with intraoperative angiography. The navigation system was especially useful for estimating the proximal part of the parent artery at the brain surface, whereas intraoperative angiography was especially useful for confirming that the proximal portion of the parent artery identified by the navigation system was correct. Conclusions: We emphasize the importance of choosing the modality of intraoperative imaging according to each characteristic when treating M4 segment aneurysms.

  • Combined Endoscopic Endonasal and Video-microscopic Transcranial Approach with Preoperative Embolization for a Posterior Pituitary Tumor

    Yoshida K., Toda M., Akiyama T., Takahashi S., Nishimoto M., Ozawa H., Ikari Y., Yoshida K.

    World Neurosurgery (World Neurosurgery)  119   201 - 208 2018.11

    ISSN  18788750

    　View Summary

    © 2018 Elsevier Inc. Background: Posterior pituitary tumor is rare, and its optimal surgical strategy is undetermined. Surgical removal of posterior pituitary tumors is often complicated by their hypervascularity. Prevention and preparation for excessive hemorrhage is crucial for safe resection. Case Description: A 69-year-old woman presented with bitemporal hemianopsia and was found to have a sellar tumor with suprasellar extension, resembling a pituitary adenoma. Microscopic transsphenoidal resection was attempted but was interrupted by a massive intraoperative hemorrhage. Pathologic diagnosis was a spindle cell oncocytoma, and she was referred to our institution. She underwent preoperative embolization to decrease tumor vascularity, and resection was performed using a combined endoscopic endonasal and video-microscopic transcranial approach, using a 4K three-dimensional (3D) video microscope. The final diagnosis was a posterior pituitary tumor with immunopositivity for thyroid transcription factor-1, with preferred interpretation as a pituicytoma. Conclusions: A combined endonasal and transcranial approach with preoperative embolization is a useful strategy for hypervascular posterior pituitary tumors. A 4K 3D video microscope is compact, and it provides high-resolution images, contributing larger surgical space and facilitating a multi-team surgery.

  • Pros and cons of using ORBEYE™ for microneurosurgery

    Takahashi S., Toda M., Nishimoto M., Ishihara E., Miwa T., Akiyama T., Horiguchi T., Sasaki H., Yoshida K.

    Clinical Neurology and Neurosurgery (Clinical Neurology and Neurosurgery)  174   57 - 62 2018.11

    ISSN  03038467

    　View Summary

    © 2018 Elsevier B.V. Objective: To evaluate the pros and cons of using a newly developed microscope, ORBEYE™, during microneurosurgery. Patients and methods: ORBEYE™ use in 14 microneurosurgical procedures was retrospectively assessed by nine neurosurgeons after the procedure. A questionnaire comprising 20 questions was designed and used for evaluation. Results: Compared with the current gold standard, the binocular microscope, ease of setting up the equipment was scored the highest, whereas ease of conducting surgery in a position of an assistant was scored the lowest. Among characteristics of ORBEYE™ itself, the space-saving feature was scored the highest and was followed by the ability to perform procedures in a comfortable position. The only characteristic that was rated below average was ease of operation in a position of an assistant. Neurosurgeons with greater experience (more than five procedures using ORBEYE™) provided significantly higher scores (p = 0.0196) for characteristics of ORBEYE™ itself compared with neurosurgeon with fewer ORBEYE™ experience. Conclusions: The main benefits of the ORBEYETM are its compact size and freedom from focusing through the eye lens of a conventional binocular microscope. However, it appears to be disadvantageous for operating in a position of an assistant because the surgical field has a rotated view on the monitor from a position of an assistant. Nonetheless, because of certain advantages, we believe the ORBEYE™ could be of additional help to use of conventional binocular microscope at the moment and will facilitate microneurosurgery in the future.

  • Primary Intracranial Rhabdomyosarcoma in the Cerebellopontine Angle Resected After Preoperative Embolization

    Yoshida K., Miwa T., Akiyama T., Nishimoto M., Kamamoto D., Yoshida K.

    World Neurosurgery (World Neurosurgery)  116   110 - 115 2018.08

    ISSN  18788750

    　View Summary

    © 2018 Elsevier Inc. Background: Primary intracranial rhabdomyosarcoma is a very rare malignant tumor. Owing to moderately vascular and firm characteristics of the tumor, complete removal without complications is often difficult. In pediatric patients, the volume of total blood is less than in adults, and minimal intraoperative hemorrhage is desirable. Case Description: A 6-year-old boy presented with ataxia and was found to have a large cerebellopontine angle tumor and hydrocephalus. The patient underwent preoperative coil embolization of the anterior inferior cerebellar artery to decrease tumor vascularity, and gross total removal was achieved on the same day via a suboccipital approach. Pathologic diagnosis was rhabdomyosarcoma. Conclusions: Successfully resection of primary intracranial rhabdomyosarcoma was achieved after preoperative embolization. Tumor vascularity was significantly reduced, and gross total removal was achieved safely with less hemorrhage.

display all >>

Page Top ▲

Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • 希少悪性脳腫瘍に対する免疫監視機構を標的とした新規治療法開発のための基礎的研究

    2018.04
    -
    2020.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists , Principal investigator

Page Top ▲