Mizutani, Katsuhiro



School of Medicine, Department of Neurosurgery (Shinanomachi)



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  • Molecular investigation of brain tumors progressing during pregnancy or postpartum period: the association between tumor type, their receptors, and the timing of presentation

    Ichimura S., Ohara K., Kono M., Mizutani K., Kitamura Y., Saga I., Kanai R., Akiyama T., Toda M., Kohno M., Yoshida K., Sasaki H.

    Clinical Neurology and Neurosurgery (Clinical Neurology and Neurosurgery)  207 2021.08

    ISSN  03038467

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    Objective: Brain tumors often become clinically evident during pregnancy; however, the mechanism has not been well elucidated. Purpose of this study is to investigate the influence of molecular genetic factors on the progression of brain tumors during pregnancy or the postpartum period. Methods: Twelve cases of brain tumors that presented during pregnancy or postpartum period were included: five gliomas, three meningiomas, two vestibular schwannomas, and two chordomas. Tumor samples were investigated by metaphase comparative genomic hybridization and immunohistochemistry, for chromosomal copy number aberration (CNA) and receptor expression of sex hormones and growth factors. Results: The results were correlated with the timing of tumor presentation in relation to the stage of pregnancy. EGFR, VEGFR-1/2, AR, and c-Myc were expressed in gliomas, PgR, ER, HER-2, VEGFR-1, EGF and VEGFR2 in meningiomas, VEGFR-1 in vestibular schwannomas, and EGFR, VEGFR-1/2, and c-Myc in chordomas. The CNAs of the tumors varied. Four of the five gliomas presented in the 2nd trimester, all three meningiomas in the 3rd trimester or postpartum period, and both of the two schwannomas in the late 2nd trimester. Expression of VEGFR-1/2 and EGFR was observed regardless of the timing of tumor presentation, whereas female hormone receptors and HER-2 were exclusively found in meningiomas. Interestingly, one anaplastic astrocytoma (IDH mut, non-codeleted) that progressed from precedent grade 2 tumor harbored amplification of the MYC locus. Conclusion: Progression of brain tumors during pregnancy is associated with various growth factors as well as sex hormones. The timing of presentation is likely dependent on molecular receptors specific to each tumor type.

  • Mechanical Thrombectomy in Distal Residual Occlusions of the Middle Cerebral Artery after Large Vessel Recanalization in Acute Stroke: 2b or not 2b? A Pragmatic Approach in Real-Life Scenarios

    Russo R., Del Sette B., Mizutani K., Coskun O., Di Maria F., Lapergue B., Wang A., Bergui M., Rodesch G., Consoli A.

    World Neurosurgery (World Neurosurgery)  151   e793 - e802 2021.07

    ISSN  18788750

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    Background /Objective: Recent studies have suggested that a recanalization grade of modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2c is strongly related with good clinical outcome rather than the current therapeutic angiography target ≥2b. To achieve better recanalization, additional further maneuvers on distal residual vessel occlusion (RVO) may be required. The aim of this study was to evaluate the safety and efficacy of rescue treatment in RVOs after recanalization of large vessel occlusions in the anterior circulation. Methods: A single-center retrospective review of a prospectively maintained stroke databank was performed. Patients presenting with RVOs after mechanical thrombectomy on the M1/internal carotid artery terminus were included and further divided into treated and untreated groups: the former underwent additional maneuvers on RVOs, whereas the latter did not. Baseline and posttreatment clinical, radiologic, and angiographic data were compared between the 2 groups. End points included good functional outcome (modified Rankin Scale [mRS] score ≤2) rates of hemorrhagic transformations, neurologic deterioration and mortality. Results: RVOs were observed in 183/488 patients (37.5%). 74/183 (40.4%) underwent rescue treatment, showing a better outcome in terms of median 24 hours National Institutes of Health Stroke Scale score (13 vs. 18; P < 0001), 24 hours Alberta Stroke Programme Early CT Score (6 vs. 5; P < 0.001) and 3 months mRS score 0–2 (47.3% vs. 33.1%; P = 0.06). Recanalization of the superior (frontal) branch of the middle cerebral artery was particularly critical in terms of outcome. Hemorrhagic transformation was higher in the untreated group (53.6% vs. 66.6%; P = 0.1) as well as symptomatic intracranial hemorrhage (13.1% vs. 29.4%; P = 0.01). Neurologic deterioration occurred more often among untreated patients (16.2% vs. 25.7%; P = 0.1). Three complications (1.3%) occurred during rescue treatment. Conclusions: When feasible, improving mTICI score 2a-2b recanalization to mTICI 2c/3 is safe and associated with a better clinical outcome, particularly for residual occlusions involving the superior branch of bifurcation.

  • Intradural spinal cord arteriovenous shunts in a personal series of 210 patients: novel classification with emphasis on anatomical disposition and angioarchitectonic distribution, related to spinal cord histogenetic units

    Mizutani K., Consoli A., Di Maria F., Auliac S.C., Boulin A., Coskun O., Gratieux J., Rodesch G.

    Journal of Neurosurgery: Spine (Journal of Neurosurgery: Spine)  34 ( 6 ) 920 - 930 2021.06

    ISSN  15475654

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    OBJECTIVE Few classifications of intradural spinal arteriovenous shunts (ID-SAVSs) have considered their anatomical localization in relation to their phenotype and angioarchitectonics. The authors propose another vision of ID-SAVSs allowing a reappraised classification based on analysis of the anatomical disposition, angioarchitecture, and histogenetic location of these vascular malformations. METHODS The radiological and clinical records of 210 patients with ID-SAVSs were retrospectively reviewed, considering their localization, vascular architectonics, and correlation with the 5 histogenetic units of the spinal cord. Among these, 183 files with complete data allowed precise analysis of the ID-SAVSs. RESULTS Among these 183 files (162 and 21 cases with single and multiple lesions, respectively), different entities were identified: 13 pial macro arteriovenous fistulas (MAVFs), 92 pial micro arteriovenous fistulas (mAVFs), 33 superficial pial niduses, and 69 intramedullary niduses. Thirteen sulcal shunts (either fistulas or niduses) were considered subtypes of pial lesions. Among the 21 multiple cases, 11 were monomyelomeric while 10 were multimyelomeric. Pial lesions, either fistulas or niduses, were dominantly vascularized by pial arteries (anterior or posterior depending on the localization of the shunt) and occasionally (except for MAVFs) by transmedullary arteries. Pial niduses occasionally extended into the funiculus by recruiting intrinsic veins or by extension of the nidus itself inside the white matter. Intramedullary niduses were always vascularized by both centrifugal and centripetal feeders, respectively, from sulcal arteries (SAs) and pial arteries. Sulcal lesions are pial lesions located within the ventral median sulcus and vascularized by SAs and veins. Single or multiple ID-SAVSs can be part of various syndromes such as hereditary hemorrhagic telangiectasia, Parkes-Weber, RASA1, CLOVES, and spinal arteriovenous metameric syndromes. Histogenetic analyses revealed a specific distribution of each ID-SAVS in the 5 histogenetic units of the spinal cord: Intramedullary niduses were found almost equally from cervical to thoracic units, while MAVFs and mAVFs were mostly found from thoracic to postcrural ones. Pial niduses showed intermediate features between intramedullary and fistulous lesions and were mostly distributed from brachial to crural segments. CONCLUSIONS Precise analysis of the anatomical disposition of ID-SAVSs in relation to functional histogenetic units allows a better understanding of these lesions and improved therapeutic management.

  • De novo arteriovenous shunts after endovascular cure of cerebrospinal macro arteriovenous fistulas. A role for the vasa vasorum?

    Tsang C.P., Mizutani K., Trenkler J., Holmin S., Rodesch G.

    Journal of Neuroradiology (Journal of Neuroradiology)  48 ( 2 ) 127 - 131 2021.03

    ISSN  01509861

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    Background and purpose: Macro-arteriovenous fistulas (MAVFs) are arteriovenous shunts draining into a giant venous ectasia. They can be treated by surgery or embolisation. Angiographic controls are usually performed rapidly after treatment in order to prove the cure of the lesion but no long term angiographies are generally scheduled. We wanted to control the stabilities of such lesions at follow-up. Method: Clinical history and imaging of ninety-five patients with high flow shunts draining into venous ectasias (MAVFs, Vein of Galen malformations and dilatations) were reviewed. Results: De novo arteriovenous shunts related to angiogenesis involving vasa vasorum developed in three patients with MAVFs at various intervals. Genetic underlying conditions as HHT or RASA 1 mutations were suspected in each patient. Conclusions: Neo-angiogenesis can occur after cure of MAVFs. Long term imaging follow-ups should be considered as the natural history of such recurrent shunts is currently unknown.

  • Benefits and Safety of Periprocedural Heparin During Thrombectomy in Patients Contra-Indicated for Alteplase

    Hebert S., Clavel P., Maier B., Mizutani K., Delvoye F., Lapergue B., Maacha M.B., Fahed R., Escalard S., Desilles J.P., Redjem H., Ciccio G., Smajda S., Blanc R., Piotin M., Mazighi M.

    Journal of Stroke and Cerebrovascular Diseases (Journal of Stroke and Cerebrovascular Diseases)  29 ( 10 )  2020.10

    ISSN  10523057

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    Backround and Purpose: Role of peri-procedural heparin as an adjuvant treatment during mechanical thrombectomy (MT) for patients contra-indicated for alteplase remains a source of debate. Methods: We included patients from the multicenter French register ETIS that underwent MT without administration of alteplase, and compared patients who received heparin during MT with patients who did not. Heparin impact on outcome were analyzed regarding final TICI score, NIHSS at day one, modified rankin scale (mRS) and intracranial hemorrhagic transformation on imaging at day one. Results: Over 1031 patients, 751 were included between January 2015 and June 2018 in 6 different centers, and 223 (26.69%) received heparin. Heparin administration was associated with a significant deleterious effect on NIHSS at 24h [adjusted OR = 1.2; p = 0.02], mRS at 3 months [adjusted OR 1.58; p = 0.03], and on complete reperfusion [TICI 3 adjusted OR 0.68; p = 0.02]. Heparin administration was associated with a significant reduction of hemorrhagic transformation [adjusted OR 0.48; p = 0.00005]. Conclusions: Heparin administration during MT seems deleterious for reperfusion and functional outcome. Randomized trials are needed to identify the role of antithrombotic treatments, such as heparin, in the setting of acute ischemic stroke management.

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  • 日本頭蓋底外科学会優秀論文賞

    2016, 日本頭蓋底外科学会

    Type of Award: Award from Japanese society, conference, symposium, etc.


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