Elsevier BV Acta Medica Okayama 2590-1397 28 2025 Flow diverter treatment for internal carotid artery aneurysm following management of distal cerebral aneurysms: Technical note 100540 EN Yuichi Hirata Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Fukiko Baba Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Juntaro Fujita Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuta Sotome Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masato Kawakami Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ryu Kimura Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki Ebisudani Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jun Haruma Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hishikawa Department of Neurosurgery, Kawasaki Medical School Shota Tanaka Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background: In recent years, the effectiveness of flow diverters (FDs) for the treatment of intracranial aneurysms has been reported. While FDs are effective, their deployment involves advancing a delivery wire distally, which may pose a risk if a distal aneurysm exists within the same artery. In such cases, the delivery wire could potentially perforate the distal aneurysm. Here, we present two cases of tandem aneurysms in which an internal carotid artery (ICA) aneurysm was treated with an FD following the treatment of a distal cerebral aneurysm. Case description: A 44-year-old woman and a 67-year-old woman underwent magnetic resonance imaging for headache or abducens nerve palsy. In both cases, two aneurysms were revealed: one at the ICA and the other either at the middle cerebral artery or the top of the ICA. Due to the risk of perforation by the delivery wire during FD deployment, the distal aneurysms were treated first—either with surgical neck clipping or stent-assisted coil embolization. One month after the initial treatment, FD placement for the ICA aneurysm was performed as planned without complications in either case. Discussion: This is the first report where tandem aneurysms were successfully treated with treatment for distal cerebral aneurysms, followed by FDs for proximal ICA aneurysms. We emphasize the potential risk of perforation of the distal aneurysm by the delivery wire during FD placement. Conclusion: Treatment of distal cerebral aneurysms beforehand can help ensure the safe and effective use of FDs in patients with tandem aneurysms. No potential conflict of interest relevant to this article was reported.

Japan Neurosurgical Society Acta Medica Okayama 0470-8105 65 9 2025 Real-world Experience of Embolization for Intracranial Tumors in Japan: Analysis of 2,756 Cases from Japanese Registry of NeuroEndovascular Therapy 4 396 406 EN Jun HARUMA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji SUGIU Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito HISHIKAWA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuta SOUTOME Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki EBISUDANI Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ryu KIMURA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hisanori EDAKI Department of Neurosurgery, Kawasaki Medical School Masato KAWAKAMI Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi MURAI Department of Neurosurgery, Kawasaki Medical School Masafumi HIRAMATSU Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shota TANAKA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsu SATOW Department of Neurosurgery, Kindai University Koji IIHARA Department of Neurosurgery, National Cerebral and Cardiovascular Center Hirotoshi IMAMURA Department of Neurosurgery, National Cerebral and Cardiovascular Center Akira ISHII Department of Neurosurgery, Juntendo University Graduate School of Medicine Yuji MATSUMARU Department of Neurosurgery, Institute of Medicine, University of Tsukuba Chiaki SAKAI Department of Neurosurgery, Kyoto University Shinichi YOSHIMURA Department of Neurosurgery, Hyogo Medical University Nobuyuki SAKAI Department of Neurological Surgery, Shimizu Hospital Japanese Registry of Neuroendovascular Therapy (JR-NET) Investigators Embolization of intracranial tumors is predominantly performed in Japan, primarily before neurosurgical resection. The Japanese Registry of NeuroEndovascular Therapy (JR-NET) Study Group, established in 2005, aims to clarify the factors influencing the outcomes of neuroendovascular treatment. Japanese Registry of NeuroEndovascular Therapy 4 is a nationwide, multicenter retrospective observational study that evaluates real-world data on intracranial tumor embolization in Japan. Japanese Registry of NeuroEndovascular Therapy 4 is based on data collected from 166 neurosurgical centers in Japan between January 2015 and December 2019. Of 63,230 patients, 2,664 (4.2%) with intracranial tumors underwent embolization. The primary endpoint was the proportion of patients with a modified Rankin scale (mRS) score of 0-2 at 30 days post-procedure. Secondary endpoints included procedure-related complications. Among the 2,664 patients, 61 records lacked sufficient data, leaving 2,603 patients (1,612 females, median age: 61 years [interquartile range 51-71]). The proportion of patients with mRS scores ≤2 at 30 days after the procedure was 86.9%. The overall incidence of procedure-related complications was 4.8%, with 1.8% hemorrhagic, 2.0% ischemic, and 1.0% classified as other complications. In the multivariate analysis, general anesthesia and embolization of vessels other than the external carotid artery were identified as risk factors for the development of complications. Meningioma cases had a complication rate of 4.3%, with major complications occurring in 3.5%. Hemangioblastoma cases had a 14.9% complication rate, with major complications at 9.9%. Japanese Registry of NeuroEndovascular Therapy 4 provides comprehensive real-world data on intracranial tumor embolization in Japan, identifying risk factors to inform and improve the safe practice of intracranial tumor embolization in neuroendovascular therapy. No potential conflict of interest relevant to this article was reported.

Japan Neurosurgical Society Acta Medica Okayama 0470-8105 65 7 2025 Nationwide Survey of Middle Meningeal Artery Embolization for Chronic Subdural Hematoma in Japan 319 325 EN Satoshi MURAI Department of Neurosurgery, Kawasaki Medical School Yuki EBISUDANI Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jun HARUMA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi HIRAMATSU Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito HISHIKAWA Department of Neurosurgery, Kawasaki Medical School Tetsu SATOW Department of Neurosurgery/Stroke Center, Kindai University Hospital Kenji SUGIU Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Middle meningeal artery embolization has increasingly been used to treat chronic subdural hematoma. However, the current state of its application and outcomes in Japan remains unclear. We conducted a multicenter observational study involving facilities affiliated with the Japanese Society for Neuroendovascular Therapy to assess current practices and clarify the usefulness and safety of middle meningeal artery embolization for chronic subdural hematoma. A total of 466 patients from 40 facilities were included. The mean age of the patients was 78.0 ± 10.5 years, and bleeding risks, including antithrombotic therapy or bleeding predisposition, were present in 36.1% of patients. The most common timing for middle meningeal artery embolization was after the second burr hole surgery, accounting for 34.8% of cases. N-butyl-2-cyanoacrylate was used as the embolic material in 67% of cases. The complication rate was 5.2%, with complication-related morbidity at 0.9%. Hematomas were stable in 91.5% of cases at 30 days post-middle meningeal artery embolization. The symptomatic recurrence rate was 8.9%. Cases that underwent middle meningeal artery embolization after the second or subsequent burr hole surgeries were significantly associated with symptomatic recurrence. This study is the first nationwide survey investigating the real-world clinical practice of middle meningeal artery embolization for chronic subdural hematoma in Japan. While it included many elderly patients, recurrent cases, and those with bleeding risks, the safety and usefulness of middle meningeal artery embolization were deemed acceptable. However, symptomatic recurrence was common even in cases with middle meningeal artery embolization when performed after the second or subsequent burr hole surgeries. A further prospective study will be warranted to clarify treatment indications, optimal timing, and treatment techniques of middle meningeal artery embolization. No potential conflict of interest relevant to this article was reported.

Japan Neurosurgical Society Acta Medica Okayama 2188-4226 12 2025 Safety of Adenosine-assisted Clipping Surgery for Unruptured Cerebral Aneurysms: Interim Results of a Single-center, Single-arm Study 115 119 EN Tomohito HISHIKAWA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi MURAI Department of Neurosurgery, Kawasaki Medical School Masafumi HIRAMATSU Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jun HARUMA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki EBISUDANI Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takao YASUHARA Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji SUGIU Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazuyoshi SHIMIZU Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Koji NAKAGAWA Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Aya KIMURA-ONO Center for Innovative Clinical Medicine, Okayama University Hospital Katsuyuki HOTTA Center for Innovative Clinical Medicine, Okayama University Hospital Hiroshi MORIMATSU Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao DATE Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences The aim of this single-center, single-arm study was to evaluate the safety of adenosine-assisted clipping surgery for unruptured cerebral aneurysms. Five patients underwent aneurysmal clipping during adenosine-induced hypotension at ≤60 mmHg. The mean age of patients was 63.4±8.5 years, and the mean aneurysm size was 5.3±1.1 mm. The prevalence of patients with modified Rankin Scale scores of zero 30 days after surgery was 100%. The degree of aneurysm obliteration was complete in 4 patients and residual dome in 1 patient. The mean total dosage of adenosine was 37.4±18.8 mg. The mean duration of systolic blood pressure at ≤60 mmHg was 64.2±28.3 secs. No patients exhibited paroxysmal atrial fibrillation within 24 hours after adenosine administration or elevation of high-sensitivity cardiac troponin T on postoperative day 1. There was no reduction in either motor-evoked or somatosensory-evoked potential amplitude during surgery. Adenosine-induced hypotension is a safe procedure in clipping surgery for unruptured cerebral aneurysms. No potential conflict of interest relevant to this article was reported.

The Japanese Society for Neuroendovascular Therapy Acta Medica Okayama 1882-4072 19 1 2025 Non-Sinus-Type Dural Arteriovenous Fistula at the Foramen Magnum: A Review of the Literature ra.2023-0019 EN Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Tomohiko Ozaki Department of Neurosurgery, National Hospital Organization Osaka National Hospital Rie Aoki Department of Neurosurgery, Tokai University Hachioji Hospital Shinri Oda Department of Neurosurgery, Tokai University Hachioji Hospital Jun Haruma Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hishikawa Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Dural arteriovenous fistula (dAVF) of the foramen magnum (FM) region is rare. Moreover, the terminology of dAVF is very confusing in this region. In the narrow sense, the FM dAVF is the non-sinus-type dAVF with direct venous reflux to the medulla oblongata or spinal cord via the bridging veins (BVs) of the FM. Previous literature was systematically reviewed to investigate the clinical characteristics, angioarchitecture, and effective treatment of the FM dAVF. From the literature review, almost all the feeders of FM dAVF were dural branches. Spinal pial arteries were rarely involved as the feeder. All lesions had venous reflux to the medulla oblongata via medullary BVs. The FM dAVF is characterized by a significant male predominance and a high incidence of aggressive symptoms. The most common symptom is congestive myelopathy, followed by hemorrhage. The FM dAVF differs from the craniocervical junction (CCJ) arteriovenous fistula (AVF) and is similar to the thoracolumbar spinal dAVF. Direct surgery for the FM dAVF is effective and safe. Endovascular treatment for the FM dAVF may be more effective and has lower complication rates than that for the CCJ AVF. No potential conflict of interest relevant to this article was reported.

The Japanese Society for Neuroendovascular Therapy Acta Medica Okayama 1882-4072 17 9 2023 Questionnaire Survey of Neurointerventional Simulation Training in the Japanese Society for Neuroendovascular Therapy 181 187 EN Yuki Ebisudani Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Murai Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Jun Haruma Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hishikawa Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Faculty of Medicine, Dentistry and Pharmaceutical Sciences Objective: Simulation training has focused on education and practical training. However, the adoption rate of neurointerventional simulation training in Japan is unknown. Therefore, we sent a questionnaire survey form to consulting specialists from the Japanese Society for Neuroendovascular Therapy (JSNET) to clarify the actual simulation training situation and compare the differences between university hospitals and general hospitals in Japan. Methods: The questionnaire survey was conducted in 243 neurosurgical training facilities that had JSNET consulting specialists between May 31, 2021 and July 31, 2021. The questionnaire survey forms were distributed by Google Forms. Results: A total of 162 facilities responded to the survey (response rate: 66.7%; 35.2% from university hospitals and 64.8% from general hospitals). The adoption rate for simulation training was 53.7%, and it was significantly higher in the university hospitals than in the general hospitals (64.9% vs. 47.6%, p = 0.035). On the simulation effectiveness survey, more than 80% of respondents answered that the simulation training was a useful tool for upskill training. The open-ended question on interventional simulation training showed that there are limiting factors such as financial constraints. Additionally, respondents expressed a desire for a standard neurointerventional simulation training and education program. Conclusion: The adoption rate for simulation training was 53.7% in the training facilities of JSNET, and it was higher in the university hospitals than in the general hospitals. Most of the respondents answered that simulation training is an effective tool to improve neurointerventional skills. They also requested the establishment of simulation training programs and simulation tools. No potential conflict of interest relevant to this article was reported.

Japan Neurosurgical Soc. Acta Medica Okayama 0470-8105 61 7 2021 An Evaluation of the Safety and Feasibility of Adenosine-assisted Clipping Surgery for Unruptured Cerebral Aneurysms: Study Protocol 393 396 EN Tomohito Hishikawa Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Murai Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jun Haruma Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazuhiko Nishi Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yuki Ebisudani Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yu Sato Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takao Yasuhara Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazuyoshi Shimizu Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Motomu Kobayashi Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Koji Nakagawa Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Aya Kimura-Ono Center for Innovative Clinical Medicine, Okayama University Hospital Katsuyuki Hotta Center for Innovative Clinical Medicine, Okayama University Hospital Hiroshi Morimatsu Department of Anesthesiology and Resuscitology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences The effectiveness of adenosine-induced flow arrest in surgical clipping for the cerebral aneurysms with difficulties in temporary clip placement to the proximal main trunk has been reported. This is the first clinical trial to evaluate the safety and feasibility of adenosine-assisted clipping surgery for unruptured cerebral aneurysms (UCAs) in Japan. The inclusion criteria are as follows: patients over 20 years old, patients who agree to be enrolled in this study after providing informed consent, patients who undergo clipping surgery for UCA in our institute, and patients in whom the surgeons (T.H. or I.D.) judge that decompression of the aneurysm is effective. The primary endpoint is a modified Rankin Scale (mRS) score 30 days after surgery. We plan to enroll 10 patients in this study. The original protocol of adenosine administration was established in this trial. Herein, we present the study protocol. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0001-6268 164 2 2021 Mobile endovascular therapy for acute treatment of ruptured vertebral artery dissecting aneurysm in multiple hospitals 517 523 EN Naoya Kidani Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kaoru Terasaka Department of Neurosurgery, Kure Kyosai Hospital Hiroyuki Nakashima Department of Neurosurgery, Okayama Kyokuto Hospital Koji Tokunaga Department of Neurosurgery, Okayama City Municipal Hospital Kazuki Kobayashi Department of Neurosurgery, Tsuyama Chuo Hospital Hirokazu Kambara Department of Neurosurgery, Japanese Red Cross Okayama Hospital Tomohito Hishikawa Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background The patients with ruptured vertebral artery dissecting aneurysm (rVADA) should be treated as early as possible because VADA carries extremely high risk of rebleeding in the acute phase. We have established a mobile endovascular strategy for the patients with rVADA between our flagship center and its affiliated local hospitals. We introduced and reviewed our mobile endovascular therapy in this study. Methods We retrospectively evaluated 98 consecutive patients who underwent endovascular surgery for rVADA from 2000 to 2018 at our institution or five affiliated hospitals. When each patient was initially transported to the local affiliated hospitals, neuroendovascular surgeons traveled directly to the affiliated hospital from the flagship center in order to treat the patient there. Clinical outcomes using modified Rankin Scale at 6 months after treatment, radiological results, and procedure-related complications were reviewed to justify our mobile endovascular strategy. Results All aneurysms were cured successfully by internal trapping. Favorable outcome was achieved in 61 patients (62.2%) even though 53 patients (54.1%) had presented with severe subarachnoid hemorrhage. Overall mortality rate, treatment-related mortality rate, and treatment related complication rate were 18.4% (18/98), 0%, and 16% (16/98), respectively. There were no differences in clinical and radiological outcomes between the patients treated in the flagship center and those who treated in the affiliated hospitals. Treatment in the affiliated hospital was not a predictive factor of unfavorable outcome in our multivariate analysis, and elderly age (>= 60) was negatively associated with favorable outcome. Conclusions Our results prove the efficacy and safety of mobile endovascular therapy for the treatment of rVADA in the ultra-acute stage. Mobile endovascular therapy may work well in the acute treatment of rVADAs in the certain circumstance. No potential conflict of interest relevant to this article was reported.

Wolters Kluwer Acta Medica Okayama 2394-8108 5 3 2019 Cerebral circulation improves with indirect bypass surgery combined with gene therapy 119 123 EN Alex Shear Department of Neurosurgery and Brain Repair, College of Medicine, University of South Florida Morsani Shingo Nishihiro Department of Neurological Surgery, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University Tomohito Hishikawa Department of Neurological Surgery, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University Masafumi Hiramatsu Department of Neurological Surgery, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University Kenji Sugiu Department of Neurological Surgery, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University Takao Yasuhara Department of Neurological Surgery, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University Isao Date Department of Neurological Surgery, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University Angiogenesis involves new blood vessels sprouting from preexisting blood vessels. This process may serve to improve brain circulation. Moyamoya disease (MMD) is a cerebrovascular disorder causing intracranial stenosis which significantly reduces the blood supply to the brain. Mainly stroke is the first symptom of the disorder, so treatments that reduce the risk of stroke are used for patients with MMD. To prevent stroke for those with chronic cerebral hypoperfusion, more blood needs to flow to the brain, which was thought to be achieved by enhancing angiogenesis. Indirect bypass surgery, such as encephalo-myo-synangiosis (EMS), is used for revascularization. However, EMS alone sometimes cannot provide enough circulation to avoid ischemic strokes. The current study examined if EMS combined with high-mobility group box-1 (HMGB1) and vascular endothelial growth factor (VEGF) enhanced angiogenesis and increased cerebral circulation. The results indicated that HMGB1 administered with EMS increased angiogenesis through a VEGF-dependent mechanism. In addition, exercising and stem cell transplantation possess possible means to increase angiogenesis. Overall, EMS with gene therapy, maintaining fitness, and stem cell utilization may prevent or help one recover from stroke by enhancing brain angiogenesis. Thus, these treatments may be applicable for patients with MMD. This paper is a review article. Referred literature in this paper has been listed in the references section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. No potential conflict of interest relevant to this article was reported.

Nature Acta Medica Okayama 2045-2322 10 1 2020 Precise MEP monitoring with a reduced interval is safe and useful for detecting permissive duration for temporary clipping 3507 EN Masahiro Kameda Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hishikawa epartment of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takao Yasuhara Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kazuhiko Kurozumi Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Although temporary clipping of the parent artery is an indispensable technique in clipping surgery for intracranial aneurysms, the permissive duration of temporary clipping is still not well known. The aim of this study is to confirm the safety of precise motor evoked potential (MEP) monitoring and to estimate the permissive duration of temporary clipping for middle cerebral artery (MCA) aneurysm based on precise MEP monitoring results. Under precise MEP monitoring via direct cortical stimulation every 30 seconds to 1 minute, surgeons released a temporary clip and waited for MEP amplitude to recover following severe (>50%) reduction of MEP amplitude during temporary clipping. Precise MEP monitoring was safely performed. Twenty-eight instances of temporary clipping were performed in 42 MCA aneurysm clipping surgeries. Because precise MEP monitoring could be used to determine when to release a temporary clip even with a severe reduction in MEP amplitude due to lengthy temporary clipping, no patients experienced permanent postoperative hemiparesis. Based on logistic regression analysis, if a temporary clip is applied for 312 seconds or more, there is a higher probability of a severe reduction in MEP amplitude. We should therefore release temporary clips after 5 minutes in order to avoid permanent postoperative hemiparesis. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 21 11 2020 Cerebellar Blood Flow and Gene Expression in Crossed Cerebellar Diaschisis after Transient Middle Cerebral Artery Occlusion in Rats 4137 EN Naoya Kidani Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hishikawa Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shingo Nishihiro Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kyohei Kin Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yu Takahashi Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Murai Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takao Yasuhara Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ikuko Miyazaki Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masato Asanuma Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Crossed cerebellar diaschisis (CCD) is a state of hypoperfusion and hypometabolism in the contralesional cerebellar hemisphere caused by a supratentorial lesion, but its pathophysiology is not fully understood. We evaluated chronological changes in cerebellar blood flow (CbBF) and gene expressions in the cerebellum using a rat model of transient middle cerebral artery occlusion (MCAO). CbBF was analyzed at two and seven days after MCAO using single photon emission computed tomography (SPECT). DNA microarray analysis and western blotting of the cerebellar cortex were performed and apoptotic cells in the cerebellar cortex were stained. CbBF in the contralesional hemisphere was significantly decreased and this lateral imbalance recovered over one week. Gene set enrichment analysis revealed that a gene set for "oxidative phosphorylation" was significantly upregulated while fourteen other gene sets including "apoptosis", "hypoxia" and "reactive oxygen species" showed a tendency toward upregulation in the contralesional cerebellum. MCAO upregulated the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the contralesional cerebellar cortex. The number of apoptotic cells increased in the molecular layer of the contralesional cerebellum. Focal cerebral ischemia in our rat MCAO model caused CCD along with enhanced expression of genes related to oxidative stress and apoptosis. No potential conflict of interest relevant to this article was reported.

Springer Nature Acta Medica Okayama 00016268 161 8 2019 A comparison of the prevalence and risk factors of complications in intracranial tumor embolization between the Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and JR-NET3 1675 1682 EN Tomohito Hishikawa Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Murai Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yu Takahashi Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Naoya Kidani Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shingo Nishihiro Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological SurgeryOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsu Satow Department of NeurosurgeryNational Cerebral and Cardiovascular Center Koji Iihara Department of Neurosurgery Graduated School of Medical SciencesKyusyu University Nobuyuki Sakai Department of NeurosurgeryKobe City Medical Center General Hospital JR-NET2 and JR-NET3 study groups. BACKGROUND: The Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and 3 (JR-NET3) were nationwide surveys that evaluated clinical outcomes after neuroendovascular therapy in Japan. The aim of this study was to compare the prevalence and risk factors of complications of intracranial tumor embolization between JR-NET2 and JR-NET3. METHODS: A total of 1018 and 1545 consecutive patients with intracranial tumors treated with embolization were enrolled in JR-NET2 and JR-NET3, respectively. The prevalence of complications in intracranial tumor embolization and related risk factors were compared between JR-NET2 and JR-NET3. RESULTS: The prevalence of complications in JR-NET3 (3.69%) was significantly higher than that in JR-NET2 (1.48%) (p = 0.002). The multivariate analysis in JR-NET2 showed that embolization for tumors other than meningioma was the only significant risk factor for complication (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.13-12.10; p = 0.032), and that in JR-NET3 revealed that embolization for feeders other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; p < 0.001) and use of liquid materials (OR, 2.65; 95% CI, 1.50-4.68; p < 0.001) were significant risks for complications. The frequency of embolization for feeders other than ECA in JR-NET3 (15.3%) was significantly higher than that in JR-NET2 (9.2%) (p < 0.001). Also, there was a significant difference in the frequency of use of liquid materials between JR-NET2 (21.2%) and JR-NET3 (41.2%) (p < 0.001). CONCLUSIONS: Embolization for feeders other than ECA and use of liquid materials could increase the complication rate in intracranial tumor embolization. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 00016268 159 7 2017 De novo vertebral artery dissecting aneurysm after internal trapping of the contralateral vertebral artery 1329 1333 EN Naoya Kidani Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tomohito Hishikawa Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masafumi Hiramatsu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Jun Haruma Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shingo Nishihiro Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yu Takahashi Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences We present the case of a de novo vertebral artery dissecting aneurysm (VADA) after endovascular trapping of a ruptured VADA on the contralateral side. The first ruptured VADA involved the posterior inferior cerebellar artery, which was successfully treated by endovascular internal trapping using a stent. A follow-up study at 3 months revealed a de novo VADA on the contralateral side. The second VADA was successfully embolized using coils while normal arterial flow in the vertebral artery was preserved using a stent. Increased hemodynamic stress may cause the development of a de novo VADA on the contralateral side. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 4 2016 Moyamoya Disease: A Review of Clinical Research 229 236 EN Tomohito Hishikawa Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenji Sugiu Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Isao Date Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Review 10.18926/AMO/54497 About 5 decades have passed since the concept of moyamoya disease (MMD) was established in Japan. In that time, many clinical MMD studies have been performed from several different points of view, such as epidemiology, pathophysiology, surgical procedures, and prognosis. In addition, rapid developments in MMD genetic analysis have occurred. In light of all this activity, clinicians must continually update their knowledge of MMD in order to improve the prognosis of MMD patients. In this review article, we summarize the clinical MMD studies and introduce cutting-edge findings regarding MMD. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 128 1 2016 平成26年度岡山医学会賞胸部・循環研究奨励賞（砂田賞） 5 7 EN Tomohito Hishikawa No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 0028-3940 55 9 2013 Novel 3D-CT evaluation of carotid stent volume: greater chronological expansion of stents in patients with vulnerable plaques 1153 1160 EN Hisakazu Itami Koji Tokunaga Yu Okuma Tomohito Hishikawa Kenji Sugiu Kentaro Ida Isao Date Although self-expanding carotid stents may dilate gradually, the degrees of residual stenosis have been quantified by the NASCET criteria, which is too simple to reflect the configuration of the stented artery. We measured the volumes of the stent lumens chronologically by 3D-CT in patients after carotid artery stenting (CAS), and analyzed the correlations between the volume change and medical factors. Fourteen patients with carotid artery stenosis were treated using self-expanding, open-cell stents. All patients underwent preoperative plaque MRI (magnetization-prepared rapid acquisition gradient-echo, MPRAGE) and chronological 3D-CT examinations of their stents immediately after their placement and 1 day, 1 week, and 1 month after the procedure. The volume of the stent lumen was measured using a 3D workstation. The correlations between stent volume and various factors including the presence of underlying diseases, plaque characteristics, and the results of the CAS procedure were analyzed. Stent volume gradually increased in each case and had increased by 1.04-1.55 (mean, 1.25)-fold at 1 postoperative month. The presence of underlying medical diseases, plaque length, the degree of residual stenosis immediately after CAS, and plaque calcification did not have an impact on the change in stent volume. On the other hand, the stent volume increase was significantly larger in the patients with vulnerable plaques that demonstrated high MPRAGE signal intensity (P < 0.05). A 3D-CT examination is useful for precisely measuring stent volume. Self-expanding stents in carotid arteries containing vulnerable plaques expand significantly more than those without such plaques in a follow-up period. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 125 1 2013 頚動脈内膜剥離術あるいは頚動脈ステント留置術施行後の患者固有データに基づく頚動脈血流の流体力学的シミュレーション 5 7 EN Hitoshi Hayase Koji Tokunaga Toshio Nakayama Kenji Sugiu Ayumi Nishida Seiji Arimitsu Tomohito Hishikawa Shigeki Ono Makoto Ohta Isao Date No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2008 Effects of deferoxamine-activated hypoxia-inducible factor-1 on the brainstem after subarachnoid hemorrhage in rats EN Tomohito Hishikawa No potential conflict of interest relevant to this article was reported.